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Major breakthrough on nuclear fusion energy (bbc.co.uk)
1128 points by playpause on Feb 9, 2022 | hide | past | favorite | 792 comments



In extension to this news and the press conference, one thing I am super excited about, is the private SPARC project and the MIT-spinoff Commonwealth Fusion Systems (CFS). If you don't know about it already, I would highly recommend checking it out (e.g. by searching YouTube for "MIT Sparc Fusion Reactor" for some fairly accessible videos on the theory behind why they should achieve fusion way faster than the current roadmap with ITER and DEMO).

In the press conference just ended, they repeated how exactly the JET reactor worked as predicted by theory. In my layman's understanding, for the exact same reason (seemingly very sound theoretical groundwork), the SPARC reactor should exceed breakeven within the next few years.

From Wiki on CFS:

* Back in September 2021, they built the strongest high-room-temperature superconducting magnet (20 Tesla) suitable for a fusion reactor

* Theory dictates that with stronger magnets, the reactor can be scaled down (with the square/cube, can't remember exactly), and thus cost and time to develop

* Back in November 2021, they raised $1.8 billion from the likes of Bill Gates

https://en.wikipedia.org/wiki/Commonwealth_Fusion_Systems

Boy, do I think it would be crazy cool if they succeed, even taking twice as long as they've planned! :)


The insane thing that people should realize about the 20T CFS test back in September was that it was them completing the first of 18 coils, and it performed incredibly well.

The secret sauce is better high temperature superconductors, and the ridiculous magnets you can build with them. They're pretty much putting these coils together as quickly as they can accumulate the HTSC wiring, and once they have all 18, they basically just need to put them all in a ring and light it up, and in theory they'll be generating over 10x the amount of power that they're putting into it.

This is the kind of tangible progress that gets me really excited. I wish there was a tracker on the CFS site to see how many coils they've completed so far, similar to tracking the progress of the JWST. Last I checked they were estimating completion around 2025, and at this pace that actually seems reasonable.


ReBCO tape is the specific high-temperature superconducting material they're using.

Another important material is FLiBe, which is a liquid that I think absorbs the energy from the fusion reactor. I don't really understand the properties that make it particularly well suited to the task, but I gather it's important.

https://en.wikipedia.org/wiki/Rare-earth_barium_copper_oxide

https://en.wikipedia.org/wiki/FLiBe


According to the article, FLiBe has the same heat capacity of water, but a boiling point over 14x higher (1430 °C according to the article). Melting point is 359 °C, 3.5x higher. I will speculate that its basically used as a water coolant with the phase shifts shifted up and out. I bet the heat exchangers are exotic, too, having to operate at such high temps! In fact I'd expect to see a pretty sophisticated cascade of exchangers.


Nitpick, ratios of °C do not make physical sense. For ratios of temperatures you should first convert them to Kelvin, Rankine, or something similar.

Accordingly, the ratio of 1430°C to 100°C is roughly 1703/373=4.6.


The ratio between waters melting and boiling point is amazingly high at 100°C/0°C!


Higher temperatures in the coolant loop are normally desirable for efficiency. In a heat engine, the hotter the hot side, and cooler the cold side, the more energy you can extract after all.

I don't really see why it's important for a fusion reactor though, where efficiency isn't really a concern at this point.


Efficiency is the main concern for a fusion reactor!

We've known how to produce fusion reactions for a long time, the difficult part is to generate net energy.


Well, the energy output of the reactor is limited by the amount of energy you can get out, which is limited by how much coolant you can move through it and how much energy the coolant can absorb without boiling/exploding. The MIT SPARC/ARC reactor designs are physically rather small, so it's possible that heat exchange could be the limiting factor in power output of an individual reactor.


typo, I guess: the melting point is 459 °C, 359 degrees higher than water but 4.5x higher.


It captures neutrons and breeds tritium, which will be separated out and used to fuel the fusion reaction.

https://www.sciencedirect.com/topics/engineering/breeding-bl...


The relevant breeder equations, since I was wondering how to create tritium by neutron capture without deuterium:

n + ⁷Li → T + ⁴He + n′

n′ + ⁶Li → T + ⁴He

(and ⁴He + n → D + T)

It didn't help that I was scanning the equations for ²H and ³H, not D or T.


> they basically just need to put them all in a ring and light it up

Well, if that's not under understatement... There are surely many more challenges in the high-field line of research, probably more than we know of, since they're kind of pioneering this field. Large size tokamaks, depsite their huge costs, have some considerable benefits like longer timescales for MHD instabilities and smaller stresses (both thermal and mechanical).


> in theory they'll be generating over 10x the amount of power that they're putting into it

Does this mean 9/10ths of the power can be sold and the other 1/10th can be re-used to power the reactor endlessly?

How much power does this produce compared to a nuclear reactor?


> Does this mean 9/10ths of the power can be sold and the other 1/10th can be re-used to power the reactor endlessly?

In theory, yes, but in practice it doesn't. But it does mean that they'll've proven the concept sound, and we can start making real fusion reactors.


> Does this mean 9/10ths of the power can be sold and the other 1/10th can be re-used to power the reactor endlessly?

No: https://youtu.be/LJ4W1g-6JiY


That video's a bit confusing because it purely talks about watts and not everything is continuous.

Anyway, the important part: In addition to the output being thermal, with losses from conversion, only the energy going into the plasma is being counted. So measuring the entire system, this reactor might still be a little short of break-even.


So they arent counting magnets/magnetism as a source of energy like a battery then? However I'm sure these newer stronger possibly more directional/controllable batteries will have an effect in electric motors in the future.

I think the newer higher temperature super conductors helps, but then I wonder if the cooling facilities of the older generation of super conductors might have been a potential future safety feature on earth but not in space.


Shows how much progress begets progress.

There was alot of debate about spending so much money on the large hydron collider when there was other social programs the money could be spent on instead of probing the fundamental nature of the universe.

LHC actually paved the way for commercial production of novel superconductors and magnets, leading in some way to helping fusion become a reality. In my opinion, Fusion and solving death should be my generations guiding star. (i'm 26)


yea, just "draw the rest of the owl" :-D


> Theory dictates that with stronger magnets, the reactor can be scaled down (with the square/cube, can't remember exactly), and thus cost and time to develop

OTOH, in a tokamak, the plasma volume (and potential energy output) scales quadratically with the torus' aspect ratio (ratio of major to minus radius), so I'm not sure that tokamak-based fusion really is particularly suitable to miniaturization.


Tokamak output scales with the square of reactor volume but the fourth power of magnetic field strength, so with sufficiently powerful magnets, scaling down the size can be an option.


However, you as you scale down, all the radiation damage effects per unit volume or unit surface area increase rapidly causing higher material activation and maintenance cost.


This technical deep-dive by Dr. Dennis Whyte goes into the scaling considerations: https://www.youtube.com/watch?v=rY6U4wB-oYM

TLDR: Tokamak economics scale in size with 1/B^5 -- so doubling the magnet field strength reduces the physical size substantially. This factor dominates other scaling parameters by a substantial margin, and is entirely enabled by high-temperature superconductors. A host of other key fusion parameters also scale beneficially with B^x (for some value of x) -- most of which are discussed in first half the video.


I had no idea, thanks for sharing.

Again, I'm very much a layman to this subject, but how does miniaturization necessarily affect that particular aspect ratio? Since it's literally a ratio of two dimensions of the torus, shouldn't this be invariant to the overall size? (Assuming all things being equal, which I have no idea whether holds.)


Miniaturization has never been realistic with tritium fusion anyway due to neutron production - you need several metres of material to stop them, otherwise your reactor is just kicking off radioactive oxygen into the atmosphere.


Wouldn't the aspect ratio remain constant as you scale down?


Unless you forget to hold the shift key as you drag.


This guy clearly does nuclear fusion.


You win HN for today...


> Theory dictates that with stronger magnets, the reactor can be scaled down (with the square/cube, can't remember exactly), and thus cost and time to develop

Here's the quick summary:

B: magnetic field strength

R: length scale

Fusion rate ∝ (plasma pressure)^2 ∝ B^4

Energy gain (Q) ∝ R^1.3 B^3

Power density ∝ R B^4

Cost ∝ R^3

So, say for example you're targeting a fixed Q. Doubling the magnetic field strength results in R1 = R0 / 2^(3/1.3) = 0.2 R0. And 0.2 R0 translates to 1/(0.2)^3 = 0.008 = 0.8% the cost.

The scaling is absolutely insane, and a stronger magnetic field has other advantages (such as making plasma instability far less of a concern), though structural loads can be an issue (that, at least is a relatively straightforward engineering problem).

If you take 12T for ITER and 20T for SPARC, that's not actually 2x, it's 1.67, which translates to 30% the size and 3% the cost (and time). It should also be noted that this is just rough, order-of magnitude estimation, but it should be broadly accurate.

For a more detailed explanation: https://youtu.be/KkpqA8yG9T4


To be fair, the main reason instabilities are less of a concern is wrapped up in that B^4 scaling.


I understand there's a bit more to it than that.

Here's the section in Professor Whyte's talk: https://youtu.be/KkpqA8yG9T4?t=2215

> It's even more subtle than that, in fact this is really one of the things we've studies at MIT, is that there's other things that come in terms of benefits, particularly when you make the magnetic field very high, it basically starts to tame, just all of the whole suite of plasma instabilities that exist.


There's no such thing as a room temperature super-conducting magnet. You are talking about "high temperature" magnets, which are YBCO tape magnets. High temperature, in this case, means about -290 degrees F.

The next breakthrough that will come will be YBCO powder-in-tube wires, that will allow much stronger fields than currently. They'll be here within a decade, probably much less, as working prototypes exist now.


Anything that is warmer than liquid nitrogen is room temp for scientists.

It's easy to produce, handling is well understood and cheap.


Yeah, you're right. That was a typo and now I can't correct it.

I'm not sure what "high room temperature" would even entail :)


> -290 degrees F

-273.15°C == −459.67°F


I think they were referring to the boiling point of liquid nitrogen, at around -196°C, not being cooled by nitrogen being what makes them "high temperature".


I'd love to work at CFS. Cambridge, MA is right down the road from me and there is no greater cause right now than fusion energy in my opinion.


Why though, we already have Nuclear energy, we could easily build enough that it could power the world's energy needs. The issue is storage, until we have a revolutionary storage solution very little will change with fossil fuel usage.


Storage is an issue for the other renewables due to intermittent peak power. Fusion should be able to operate like a traditional power station.


However! fusion plants are much larger than fission cores, and the neutrons are an order of magnitude more energetic, so you wind up with both way more mass and way higher activation.


Did you mean power storage or waste storage?


At this point, I think fusion has the best chance of saving us from ourselves wrt to climate change, so long as the unforeseen consequences aren’t too bad.


It doesn't seem like it's quick enough. We're, at minimum, decades away from it even being built out commonly, and to _really_ save ourselves we should have already replaced a substantial portion of the world's energy generation decades ago.


Sure, it may be too little, too late.

You don't know that until the failure is complete, though, and "it may fail" is a terrible reason to not try the best shots we have.


I mean, it _will_ fail at stopping global warming, there's no "may" about it. It will probably have other positive effects though.

I'm very onboard for any potential fusion power generation, I just don't think it has any hope of saving us from global warming.


Can we use it to put the CO2 back in the ground?

I guess there are some irreversible effects once warming reaches a certain threshold however.


Yes, this is part of what would need to happen: using a super abundance of essentially carbon-free energy to do geo-engineering on a massive scale (including artificial carbon sequestration).


It might in the future turn out to be more efficient with a "few" reactors than, say, lots of batteries and wind turbines and solar panels, from a resource perspective. But I think not even that will come true, if we optimize stuff enough, which we will have a long time to do before fusion is here.


Fusion would "solve" the climate change issue, but do nothing in regard to all other crises affecting our environment right now (biodiversity collapse, various sources of chemical and particulate pollution, fertilizer runoff...).

On the contrary, unlimited energy would exacerbate the man-made crises we are having today by further pushing the potential impact of man on its environment.


I remember being nervous about CFS not being able to raise its 100 MUSD target a few years ago. I'm very excited for their results.


There are certainly some exciting projects happening in the fusion world coming up. It seems likely we will start seeing much higher energy outputs, I think for SPARC they are predicting >10x the energy produced as what it will consume (Q > 10).

My biggest question is with the crazy temperatures involved will we ever see one of these things able to run for hours at a time? With SPARC they are shooting for 10 second bursts, so that would double this breakthrough for the JET reactor. Even with the magnetic containment there are components in there exposed to millions of degrees Celsius right? That leaves us with some significant material science problems to solve.


Temperature is high but total heat isn't remarkable. The atoms are moving very fast but there aren't many of them.


Private companies have a big incentive to share the good news and hide the bad news.

What are the chances these guys have a pile of problems they can't solve with their approach, but rather than trying to approach it from another direction like an engineer would, instead they continue development because collecting more investor cash while the investors are unaware of the showstoppers is good employment.


I think at this point it's very likely that CFS will succeed. But economics could be a problem, which is why I'm more excited about Helion or ZAP.


>> Back in November 2021, they raised $1.8 billion from the likes of Bill Gates

<joke> I guess windows will be resetting the house energy provider on each update soon

</Joke>


I am a strong proponent of Fusion energy and did some work on the subject in undergrad.

This is not a major breakthrough, it's a benchmark.

A major breakthrough would be materials that could withstand the neutron bombardment longer, the ultimate limiting factor for fusion energy plants after we achieve positive net energy.


I used to like the idea of fusion energy, but practical application has always seemed to be 40 years in the future, and it's starting to sound more like 60 years now.

I hope it will be possible some day, but it's not going to help with out energy needs in our lifetime. (Unless that longevity research is going to pay off, I guess.)


It took more than 300 years to build the cathedral [1] in my home town (albeit with a 60-year pause in the middle). So indeed it might take another 4 or 5 generations to master nuclear fusion, but I see no issue with that. We should not shy away from starting projects that we won't see any benefit in our lifetime.

But of course, it also means that we should not rely on nuclear fusion being available in the short term...

[1] https://en.wikipedia.org/wiki/Metz_Cathedral


The linear model of time estimates here work well for cathedrals but not necessarily for scientific and engineering advancements.

For a Cathedral, you have a general idea of how long it's going to take (at least finite) and know that every piece of material added onto the structure is going to move it closer to the end goal.

For things like fusion, anything beyond say 20 years is basically a bullsh_t speculative guess that sounds better than "we don't really know whether this will even work out in the end". It doesn't really matter whether it's 30 or 60. The real question is whether the number is finite or infinite.


I suspect there was a lot of inceramental value to be had while the construction was ongoing. A cathedral doesn't need to be 100% complete to use as a house of worship, an inspiration for the community, a display of wealth and soft power, and so on.

Fusion hasn't really produced much utility at all so far, aside from some interesting discussions.


I imagine there have been some practical and theoretical gains from efforts to make fusion work already:

https://www.energy.gov/science/articles/fusion-research-igni...


Are you trying to argue therefore we should stop or something? There are countless areas of research and activities we do as humans that offer virtually no tangible benefit to society.

It seems to me that fusion is unfairly criticized because there is an obvious end-goal.


If you never stop working on some creative art project it's never finished, your endless cathedral build has nearly zero relevance to nuclear fusion producing electricity for consumers which would be a definitive "delivered" goalpost, after which any further developments/improvements would just be optimization iterations.

I'm reminded of the Crazy Horse Memorial... https://en.wikipedia.org/wiki/Crazy_Horse_Memorial


There is a class of problems that I've become accustomed to being forever in the future.

- Nuclear Fusion - AGI - Driverless cars - Quantum Gravity - Carbon Nanotubes

There appears to either be a problem where these are either convenient money sinks, problems that are missing key break-throughs or missing critical technologies. Nuclear Fusion would be easy if we had 400T magnetic fields and the structures to support them.

We seem to be missing a critical cultural element required to drive these types of innovations - or we are missing the slow tooling, process, and incremental innovations required to support these technologies.


Used to be on the list: reusable rockets, reasonably priced electric cars with charging infrastructure, rapid development of new vaccines with direct genetic engineering mechanisms.


Pocket supercomputers, meat-like fake meat, addictive virtual dystopias, two-way wrist radios…


What's the addictive virtual dystopia? Qanon, Facebook?


Flying cars


You can add graphene based technologies to that list.


I've heard of horses taking their blackout/drunken owners home before. CHECKMATE DRIVERLESS VEHICLES


Driverless cars really aren't that useful.


Driverless cars would be very useful; it would mean I can use my time in the car in a more useful way, like reading. Now I have to use the train for that.

But maybe that's also the risk of driverless cars: it would make them more attractive than they should be, because they're really too inefficient to be able to afford them as society's main form of transportation.


> I used to like the idea of fusion energy, but practical application has always seemed to be 40 years in the future, and it's starting to sound more like 60 years now.

You have to understand that fusion has been funded at "fusion never" levels for 5 decades now.

The amount of money that we poured at the mining engineering that later became "fracking" was larger.

Had we funded fusion at the amount we have funded petroleum extraction, we'd have free energy by now. :(


Who is "we"? Fracking was funded with private money. It was "conventional" technology, no edge-of-science stuff, so private entrepreneurs could afford it, and the rewards were quick to materialize.

Nuclear fusion? There's this urban myth that fusion could have been achieved if only we'd have poured more money into it, but where's the evidence? Plasma modeling requires a lot of computational power. What you have now in your iPhone in your pocket you could not have had for 10 billion dollars back in 1970. How much money were we supposed to put into fusion research? Do you think with lots of money and just a slide rule, you can solve the fusion problem?


I think you're mistaken about the government involvement in fracking. Sure, the basic technique may have been developed by private companies, but government supported research expanded it to oil and gas applications.

https://thebreakthrough.org/issues/energy/us-government-role...


> government supported research expanded it to oil and gas applications.

The Government gets involved in a lot of things, but it doesn't mean its contribution is essential. For a recent example, the NIH is claiming the Moderna vaccine is due to their contribution, and sure, you'll be able to find one or a few grants here or there of a few hundred thousand dollars, but the massive investments of tens of millions of dollars were done by Moderna itself.

As for fracking, the father of fracking is considered to be George P. Mitchell [1].

[1] https://en.wikipedia.org/wiki/George_P._Mitchell


You're right, but I think it was essential in this case: " His comment that “the DOE started it” refers to the Eastern Gas Shales Project, a research effort in the Appalachia Basin from 1979 that proved shale rock was rich in natural gas. The DOE-supported project tested the use of nitrogen foam to fracture shale formations, and its analysis led to a deeper understanding of natural shale fractures.

George Mitchell’s team studied those results while developing the Barnett Shale near Fort Worth, the first modern fracking play. The company relied on research from the Sandia National Laboratory to use micro-seismic technology to map the shale fractures in wells, and Mitchell also benefited from federal tax credits for unconventional drilling, which helped underwrite the cost of developing hydraulic fracturing. " https://www.forbes.com/sites/lorensteffy/2013/10/31/how-much...


From your link:

“The government’s role in fracking’s development was important, but not so important that it eclipses the effort and investment of private industry”


I interpreted that as meaning "don't forget private industry had an important role". This doesn't mean that the private sector could have done it alone (my interpretation of government investment being essential).

But at that stage it's semantics really.

Maybe we could ask the question: "would private industry have funded all the basic research to get to the same starting point?" I doubt it since it would not have been shown returns for many decades and had a high risk of showing no returns. But maybe they would have, who knows?

A parallel question: "would private industry have developed semiconductor transistors without WW2 research into radar systems?


At the very least I would have expected money to help with superconductor research.


I love the idea of fusion and certainly hope people make progress, but given advances in solar and wind, I’m starting to think the best location for a fusion reactor is 93M miles away.


Have you heard of General Fusion? They're using liquid metal as both containment and energy extraction. Really cool, they're building a demo plant in the UK.


https://en.wikipedia.org/wiki/Neutron_reflector Doesn't reflectors help a lot here or am I missing something?


Probably, but I'd guess that the reflector still absorbs a small percentage of the beam it's reflecting. And at the GW scale I'm sure even a small percentage is enough to absorb a great deal of energy.


What I'd like to know is what design or material changes were required to reach this benchmark? The picture of the fusion chamber is still the same torus donut shape as the ones from the 90s.


I believe the issue is that the surrounding materials of the torus in the TOKAMAK become highly radioactive due to neutron bombardment and decay accordingly.

IIRC, there is some sort of Silicon Carbon based material that need to be economically feasible to manufacture (that can withstand a fair amount of neutron bombardment without crumbling like other materials) before a plant will ever make sense. There may be alternative materials but none of them are cheap enough to build a long-term TOKAMAK even if we could achieve the incremental net power necessary for a power plant.


You will find, especially after reading the comments, that fusion is not about creating electricity (it never will), it is about sparking people's imagination. Many people grew up reading science fiction and there is seriously nothing it the last 50 years that comes close to the amazing breakthroughs in the physical world that happened in the 50 years before that. The idea of fusion is the best thing going right now.

You won't be able to have a serious conversation about the pros and cons of fusion power because any serious conversation will always be trampling on people's dreams.


If fusion is the best thing right now, that would be incredibly sad, because it barely seems to be making any progress at all.

Fortunately we've seen tons of progress in other fields: computing, quantum computing, solar energy, medical, gene therapy. Even superconductors are slowly getting better.


I don't get comments like this. Is there a measure of progress we should be using for this? Not only does this resemble the "where's the flying car I was promised?" complaint but it ignores the very real realities that a lot of progress is measured in increments that have a way of sneaking up on you exponential-style. Solar energy, for instance, was not a huge announcement, but it was a steady trickle of learning curve improvements (https://news.ycombinator.com/item?id=25265819)

Do you remember ten years ago when nobody had heard of mRNA or CRISPR? Or fifteen years ago when neural networks were a dead end and SVM were all the rage?

I'm not saying fusion is the "best thing" or have any insight as to where it might be in the curve of adoption, but it feels weird to be making a race out of fusion with these other technologies.


The comment I responded to held fusion up as an example of something that sparked the imagination. I'm just pointing out that it's a sad example and we have far better and more inspirational examples. mRNA and CRISPR are great examples of that; those are real breakthroughs.


Yeah but that stuff just doesn't really tickle the imagination. You won't see that stuff on the cover of an 80's scifi book.


That first sentence is an entirely subjective take, and one that I disagree with entirely.


Lol I wonder if anyone ever said this about flying.


> It's not a massive energy output - only enough to boil about 60 kettles' worth of water.

This made me laugh. How much more British can you get?


It's also quite a helpful metric.

Most British people are aware that the national grid used to spend a lot of time making sure they had the power available to draw during the commercial breaks of mass-media TV events (series finales, half time in a cup match etc) purely for the nation boiling water with electric kettles en masse.

Great intersection of hard science (energy necessary to boil water + extremely efficient energy transfer) and everyperson knowledge. Good journalism!


Makes you wonder if the US idea of using just 110 volts isn't better... not from an individual viewpoint (slower to boil water) but from the grid perspective.


The US grid (the last-mile bits anyway) isn't 110 volts, it's 220. It's just our houses that are wired for (mostly) 110 V.

Edit: I would love to see some sort of hybrid 110/220 V residential wiring/plug standard take hold in the US. It would require more expensive cable in the walls (since you need one additional conductor) and plugs, but it's totally doable. Most electrical products and appliances made these days are easily converted between 110/220, or run just fine on either.


There is NEMA 14, which has hot,hot,neutral,ground, but I don't think anything lower than 20amps is available, and that's a locking one, 30 amps is available without locks, but 30 amps at 220v is a lot of power for household outlets. You'd need larger wire in the walls, not just more of them.

Any sort of outlet upgrade would need a really good plan for how to make it viable, because even if 100% of new construction used the new outlet, it would be decades before you could sell devices that relied on it.


I have a 20A 220 circuit for an electric kettle with multiple 6-15Rs. It has a 20A gfci breaker.


You could include a second cable with the teapot, and wire it to work with 110 or 220 depending on which cable is used. This is already reasonably common. I have plenty of useless European cables laying around to prove it.


> The US grid (the last-mile bits anyway) isn't 110 volts, it's 220. It's just our houses that are wired for (mostly) 110 V.

Similarly, in most of continental Europe phase-to-phase is 400V but most outlets are 230V. E.g. in my apartment only the stove has a 400V three-phase (4-wire) connection.


but 3phase (120degrees) is a lot better for powering motors than the 2 phase one in the US


3-phase is available in USA, but it's typically not provided to residences.


of course, the heavy motors/industrial equipment loves 3 phase AC. Higher voltages allow lower losses in the conductors, hence less copper needed everywhere incl. small motors as the current us lower through and through.


I kinda like that all but a couple outlets in my house can't kill me.

Also, I boil my water on an induction stove plugged into 50 amps at 220 volts. I'm not waiting around, to put it mildly.


110v can easily kill you. It's a little harder to get a good solid connection through your body and into the ground than 220v. But it certainly can and does happen.


Amps kill, not volts. Hence high voltage low amp Tesla coil spark shows.


Thats not quite accurate- it is true that high amp current is deadly in many scenarios, but it takes both amps and volts to kill. High amp, high voltage current is a killer for sure, but high current at sufficiently tiny voltages is not necessarily deadly. Similarly, high voltage at low currents is usually not deadly (but can be very painful).


You need to be introduced to a classic: https://www.youtube.com/watch?v=XDf2nhfxVzg


Your comment is completely irrelevant to wall sockets because they can all supply more than a tenth of an amp.


High voltage from a Tesla coil not only has low average current, but is subject to the skin effect. So while it can still cause a painful shock to your superficial sensory nerves, not much of that energy ends up in contact with the motor nerves.

TL,DR: you probably don't want to be shocked by a big Tesla coil, even though it won't kill you.


Never heard of anyone getting killed by the 230V power in Europe. A few people I know touched it and it does hurt.

Perhaps it's because all houses have residual current devices which trigger much faster than fuses if current leaks to earth (eg through a person).


30A at 400V is how we roll in the EU.


Wow. A typical induction hob in the UK is 32A at 230V. 230V is of course the nominal voltage of a single phase, although in practice in the UK the voltage is closer to 240V.

That's only 7.35kW of power. Do you have significantly more powerful cookers?


400V is only used for stoves or instant water heaters, but e.g. our stove uses 11kW actually.

If you don’t have these amounts of energy available, the temperature your instant water heater can reach or the speed with which you can cook obviously suffers (which I suspect is one of the reasons why americans prefer gas stoves so much).


the 3phase is used for motors - a lot more efficient (and the better power factor) than the single phase ones.


For industrial applications definitely, but at home there's few people who power motors with triphase or five phase power.


these are 3-phase stoves, they require a certified electrician to install, because they don't have plugs and there's no wall socket - just a place into which you can easily connect cables.


That makes sense. In the UK you can buy induction hobs that plug into sockets, but they are limited to a measly 3.7kW or there abouts. A nicer 32A induction hob needs hardwired (single phase).

You can have upgrade your domestic supply to three phrase, but AFAICT it's uncommon. Perhaps with electric cars and induction hobs replacing natural gas and petrol, it will become more common.


You could just run US-style appliance circuits to your kitchen, etc. Those are sometimes three conductor and other times four conductor.

However, I doubt it'd pass inspection if they were easily accessible from the counter-top.

If you're going to flout building codes anyway, it'd probably be easier/more practical to just run circuits with foreign outlets instead. Also, it might be easier to find appropriate GFCI breakers.


Use 6-15R or 6-20R. I think it would pass inspection because most safety requirements around gfci and afci don’t apply to 240V circuits


They do now, but only when accessible by a person. Even car charging station outlets do (even though every car charging station has gfci built in...)


Ah looks like this was a change in 2017. With any outlet there’s no guarantee what will end up plugged in so it’s logical to require it even if the purpose is an EV charger.

Thanks!


EU is on 50hz AC, where as the US is on 60hz. It would work fine for purely resistive appliances, and possibly devices with switching mode power supplies, but some devices would be unhappy plugging in to the wrong frequency at 220V.

I'm not sure about the phase alignment but that may be an issue as well. US is split phase, but Europe has 220 on a single conductor?


it's 230 (+-10%) nominal not 220. At my house it's around 235. It's 230v phase/live to neutral and 400V between live wires in 3phase. Nowadays 3-phase (120degree between each) is a commodity.


In my part of USA the typical voltage between the two sides of a breaker box is 240V. It actually moves around a bit below that value, but doesn't seem to ever exceed 240V. I think most consumer devices have the circuitry necessary to survive such variation, but I have seen some (expensive) professional equipment fried in an instant...


Thanks for that. Sounds wonderful compared to the typical 200 amp, split phase service we commonly have in the US.


How many non-switching power supplies will care either?


110v does nearly halve your peak power draw... But the transformers have a bit of added complexity and in homes and businesses you need thicker wire to move the same amount of power.


Power is power. To the extent 110V is slower to boil water, it's a reflection of either inadequate power delivery capacity due to the higher currents required, or wasted heat in places other than the kettle. Either way, heat gets lost over time.

You're almost always better off with higher voltage and less current, when given a choice. An obvious exception being when you get shocked. :-P Or when corona losses come into the picture.


No, it’s absolutely not. They consume a lot of power on average as far as I remember. They have just more transmissions loss at a lower voltage and I guess that it would be a pain to use a normal induction cooktop with 9-10KW at 110V.


Yes, and some places world cup viewership can take down the grid!


Whilst kettles are used as the unit of measurement the main driver of power consumption spikes during those breaks was electric pump for toilet cisterns.


Wasn't there a relevant Tom Scott video on the subject?


https://www.youtube.com/watch?v=6Jx_bJgIFhI about pumped hydro at Dinorwig Power Station


That's enough energy to boil those kettles dry, if my calculations are correct. To bring them to the boil, 59MJ would run about 600 kettles.


Water has a specific heat capacity of 4184J/kg/C. Lets say to get to the boil you need to go from 20C to 100C and that a kettle holds 1.75L.

59MJ / (80C * 4184J/kg/C) = 176kg ~= 176L ~= 100 kettles.

Water has a latent heat of vaporization of 2260 kJ/kg. So to boil it dry:

59MJ / (80C * 4184J/kg/C + 2260 kJ/kg) = 22kg ~= 22L ~= 12 kettles.

I have no idea what the journalist calculated.


I suppose it's possible that the "standard" kettle size is ~3L. They don't seem too uncommon on Amazon.


I think the journalist is calculating load capacity. A 1500A @120V kettle requires 0.18 MW. Rounding up, 60 kettles requires 12 MW. It's not how much water you can boil, it's how many kettles you can run at the same time.


59MJ over 5 seconds would be 11GW, so if it was load, that would be 6000 2kw kettles!

Although obviously those kettles wouldn't achieve much in those 5 seconds!


I'm way off. I meant 15A. Now I've no clue what the journalist is calculating.


They should start selling 1500A kettles though. Bring a pot of water to the boil instantly.


But they’re UK, so it wouldn’t be 110V. Nice try, though!


A 180kW kettle ?! Great Scott !


Did you factor in the inefficiencies of the power distribution grid and the heating element of the kettle? I'd say the journalists are just repeating what they've been told by the scientists, and the scientists factored inefficiency in on a calculation similar to your first.


There may exist inefficiencies in the transfer of heat from the element to the water, but there is no such thing as an inefficient heating element. All of the power it uses will be converted to heat. Take a light bulb for example. When used to light a space, the inefficient part would be the energy that is lost to heat. The rest is converted to light, but as soon as that light hits an object, it's converted to heat. So even a light bulb is a perfectly efficient heating element.

With this in mind, you aren't saving any money on your electric bill by turning off lights when your furnace is on.


The internal heating element isn’t strictly speaking 100% efficient on AC as it’s producing a changing electric field etc. It’s just generally ignorable in practical terms.


Presumably heat dispersing into the air rather than into the water would be an example of an inefficient heating element.


The kettle is also losing a lot of heat to the air in the room.


Nope, I didn't factor in anything like that. Also kettle's don't actually heat every ml to 100C so there's some fudge in the other direction. I mostly was just getting nerdsniped.


Thermodynamics is very good at sniping nerds. The first law is basically a universe builder. The second law is maybe a universe destroyer? :)


Maybe they meant from a frozen solid state?


Are you referring to a morning kettle of tea or an afternoon kettle of tea?


an african or european kettle?


Maybe two kettles could boil the water together?


I thought they were these Kettles: https://youtu.be/ieKTU94-BgI

Good at math, but I'm not sure they could boil any water.


Yes but how many football fields can that throw a beer can?!


African or European beer cans?


Most importantly, US or rest of the world football?


You'd probably be surprised to learn that the UK is not at the top of the list of countries with the highest tea consumption.

https://en.wikipedia.org/wiki/List_of_countries_by_tea_consu...


Not even remotely surprised. I'm decently surprised they made it to number 4; I thought some southeast asian countries might have a higher per-capita tea consumption. Come to think of it, I think the list is probably highly skewed towards countries that import their tea and countries with local tea production will be a lot harder to pin down more accurately. Many countries missing from the list as well!

There are other "oddities" that make me suspicious. e.g. Saudi Arabia and UAE have extremely similar native population (bedouin Arab origins) and neither culturally drink black tea, but KSA ranks much higher than UAE. My immediate guess is the massive (underpaid) southeast asian labor force in KSA¹, which I know firsthand consume tea ceaselessly - but India supposedly has a lower per-capita consumption rate than the UAE. In fact, I'm sure both KSA and UAE are up there because of their foreign laborers, lending credence to my suspicion that countries with local tea production (such as India) are massively under-represented in that list.

¹: KSA does admittedly have a higher percentage of Levantine and North African permanent residents.


It's strange to me how low India is on the list. As an Indian all the Indians I know drink huge amounts of tea. Might just be an economics thing-- they can't afford to buy as much tea as they'd like to. That or it's something to do with the way the stats are collected


Actually, tea is about as cheap as clean water there. I commented separately, but tl;dr I think local tea consumption in countries that produce tea is being massively undercounted.


As an Indian living in the Netherlands, I suspect you're correct. Coffee is drunk here similar to how tea is drunk in India, and the Netherlands is the top #1/2 in per Capita coffee consumption. However, tea in India is often tied to a routine (eg time of day) while here it's more of an opportunistic thing (after a big meeting in the break).


Ireland is #2? As a culturally ignorant American, that _does_ surprise me.


I much prefer an Irish breakfast to an English breakfast tea. It’s stronger and has a distinct taste (although I didn’t like it as much initially.)


We are absolute fiends for tea.


Just learned new slang for "whiskey". Thank you.


The box of Barry’s in my drawer (I’m in America) agrees with you


Ah go on, go on, go on.


The source at the origin of the data is paywalled but there’s no way this is representative. Japan and Taiwan surely must have higher consumption than that. As someone else noted, wouldn’t be surprised if this is purely based on import statistics and therefore ignores domestic consumption.


...for five seconds, no less. Just now beating a record set back in 1997.

That sentence really hit me. Is that really only how far we've come? If so, the pace is so glacial that...I don't know, maybe this isn't worth it?


was it British Teapot Units all along?


> The fusion announcement is great news but sadly it won't help in our battle to lessen the effects of climate change.

> There's huge uncertainty about when fusion power will be ready for commercialisation. One estimate suggests maybe 20 years. Then fusion would need to scale up, which would mean a delay of perhaps another few decades.

> And here's the problem: the need for carbon-free energy is urgent - and the government has pledged that all electricity in the UK must be zero emissions by 2035. That means nuclear, renewables and energy storage.

> In the words of my colleague Jon Amos: "Fusion is not a solution to get us to 2050 net zero. This is a solution to power society in the second half of this century."

Between promising results like this, the Wendelstein-7X (which sadly seems to have been delayed by COVID), and then the exceptionally exciting CFS in Massachusetts, I have a sense that we're making real progress toward fusion for the first time in a few decades. Doom and gloom won't do anything to increase investment in fusion that is beginning to look like a reasonable bet.


Can anyone explain these timelines better? Can we throw more money at this and scale much faster? Are safety/regulation considerations the main bottleneck?

This has gotta be one of the most important investments for humanity and our planet. Hard to fathom these timeline predictions in the same world where mRNA vaccines and various spacecraft have scaled in <1 year.


This has gotta be one of the most important investments for humanity and our planet.

If you think climate change is an existential threat, we should divert fusion research money into immediate construction of traditional nuclear power plants.


Divert a puff of dust? Why not divert the deluge that is fossil fuel subsidies or defense budget?


sure! There was $6.82 trillion in government spending in the US last year(defense was just over 10%). You could just redirect 1% and fully finance 10 new nuclear plants a year. But it is easier than that, the government could simply guarantee loans for any state or power company that wants to build. Make a model plant design that can be reproduced to reduce costs.

The main point is, if you aren't taking nuclear power seriously, you really aren't taking climate change seriously. Subsidizing Teslas for rich Californians is metaphorically rearranging deck chairs on the Titanic.


I don't argue against any of that. Fusion does not have a path to "stop climate change". We have much faster acting options we can and should pursue.

The point I take exception with is diverting funding away from fusion. Fusion has a great many benefits. I argue these benefits are existential to our society in the 100-200 year timeframe.


Fusion is still at the phase of fundamental research in some areas, while others are in a sort of "engineering research".

Either way, it's actually hard to imagine fusion will ever be a promising power source, at least with any tech resembling what we know today. It is extremely complex technology living in proximity to extreme radiation bombardment and extreme temperature differences. A fusion reactor will need basically complete replacing every 20 years in the best possible conditions, assuming nothing goes wrong. Re-building the most expensive power plant in the world every decade or two is not likely to be a great way of powering your country.

Also, despite the common narrative, it requires an extremely rare fuel: tritium. Basically the only way to create tritium is to run a fission reactor, which negates the safety promises of fusion.

I think overall wind+solar+fission are a much better and safer investment in the future. Fusion is fine as an experiment progressing along in the background, but nowhere near as promising as it's made out to be.


Not an expert at all in this area, but my understanding was that CFS' design addresses the neutron bombardment problems and the tritium breeding problems by making the reactor smaller and enveloping it in some sort of molten salt. Because the wall is smaller, they plan on being able to replace the inner wall yearly via 3D printing.

Wind & solar are fine where they make sense (i.e. windy or particularly sunny places), though solar panel production depends on rare earth metals, and wind + solar at scale require huge land areas covered with panels or turbines. Fission is fine, but is expensive and has a serious regulatory hurdle to getting safer, modern designs up and running, and produces long-lived radioactive isotopes.

Anyway, I'm interested in all of the above. Any of them are better than fossil fuels, and some scale better than others.


> CFS' design addresses the neutron bombardment problems and the tritium breeding problems by making the reactor smaller and enveloping it in some sort of molten salt. Because the wall is smaller, they plan on being able to replace the inner wall yearly via 3D printing.

My understanding is that even these molten salt or molten lithium blankets can only catch some of the neutrons - so the magnets and other outer structures will still get neutron bombardment, and the tritium you can produce will not fully replace the tritium you put in. The once a decade or two replacement of the entire reactor number I heard was predicated on a shield like this - without a shield IT would probably be once every few years.

Note that I am not claiming wind, solar and fission don't have problems. It's just that they all seem to be much simpler problems than fusion has, fundamentally, even in the long run.

I'm not suggesting we shouldn't keep researching fusion technology, but I also don't think it can or should he treated as a priority, or as if once it's done it will solve all of our energy woes. It will take a huge amount of time even after the first actual plant is operational until fusion becomes in any way economical and widespread, with initial fixed costs that will make fission seem like chump change.


The LCOE of wind/solar is under natural gas, and sodium ion batteries will hit the market this year or next according to CATL press releases (always a grain of salt until you see the product on the market).

They are supposed to be half the cost of LFP.

And let's face it, nat gas / coal are effectively subsidized by ingrained government policy while they SHOULD be subject to a ten year escalating carbon tax.

Nuclear is still ... ok, it's on the high end of solar/wind deployments.

Perovskites may solve even more problems, but that hasn't really panned out like hoped, probably a ten year project.

Wind and solar don't require "huge areas of land". Well, not new land or land we need. There's a LOT of roofs everywhere. Residential power can be almost completely addressed with rooftop solar + storage, I haven't seen single family homes that need "more than the roof", and the excess can go to multifamily buildings.

Windmills can be offshore, or sticking out of farmland or nature preserves.

Utility solar can use deserts, there's plenty of that. I hate the hype about "green hydrogen" since it is a shadow play by oil companies to keep other "color" hydrogen sources which are invariably oil/gas.

Fusion should continue to get research dollars. We should be pursuing LFTR and other new gen fission.

But let's be real, no fission or fusion project initiated now will be ready in ten years, and no one can predict the price of solar/wind/storage in ten years. It won't drop like the previous ten years, but there is enough in the works that it will likely drop ... 50%?

I don't think new fission/fusion can be commercially planned until wind/solar/storage prices stabilize. It doesn't matter how cool a fusion reactor is if the energy it produces is 3x the cost of wind/solar.

I think the hardest thing to say about fusion is that the "it's always 20/30/40 years in the future" was always a technological commentary.

But now the new challenge even if they get a working plant in 20/30/40 years is "is it cheaper?"

Constant 3D printing reactor walls sounds like an expensive proposition. Granted I think the same strategies are in LFTR designs since the materials is hard there too. Liquid metal fusion and molten salts has all the materials engineering and endurance issues LFTR had. I guess fusion fuel is effectively liquid though, so they could just move the liquid to another generator while they "overhaul" the one that has neutron degradation. I figured if LFTR hit mainstream they would do the same: mass produce the reactors and then just move the fuel between them as they wear out, and then recondition the "spent reactor".

Can a LFTR expert comment on whether it can "burn"/breed/transmute/process most nuclear waste as usable fuel, or at least move the isotopes to other better isotope decay paths? LFTR is supposed to be able to use 99% of its thorium fuel without nuclear waste.


I think you're a bit too optimistic on solar deployment for residential areas. Sure, you're probably right in California, but Norway won't be powering their homes through roof-top panels.

Also, most people don't live in single family homes, they live in 30-100 family apartment blocs, where even at the equator there won't be enough roof space to power the whole building through solar.

Wind does have a massive land use problem as well (as does hydro). In most of the world outside the USA, there aren't huge swaths of unused land anywhere near residential or industrial areas.

Which is why for example France has green-lit 6 new fission reactors, and the EU in general is looking at declaring fission green energy to get the required subsidies. This is also why Germany, that went all in on wind and solar and even has a few days each year where the entire grid is running on wind+solar+hydro, still produces about twice the GHG as France (both total and per capita).


> This is more than double what was achieved in similar tests back in 1997.

The experiment produced

> 11 megawatts of power

and at Jet

> two 500 megawatt flywheels are used to run the experiments

log_2(2*500/11)*(2022-1997) + 2022 = 2185

At this rate we will have fusion by 2185 I guess?


Even if it takes 200 years it is likely still worthwhile. Unfortunately we, as a culture, have a problem seeing and planning across generations. https://longnow.org/


I'm happy to hear someone make this point. Rather than sneering "vaporware" when decades fail to crack a problem, I would prefer us to keep in mind that if we never try multi-generational projects, we will never taste the fruit of multi-generational projects, and those are some sweet fruit indeed.


It's also good to have a number of these things in the oven, because it's hard to predict when a sudden discontinuous leap might make practical in the short term something that previously seemed like a multi-generational project.

I presume almost no one in 1920 could have imagined that anything approaching the output of fission energy would become common in their lifetime.


It runs into the spaceship problem where later iterations of a spaceship reach the destination first because new technology allows them to fly faster. At some point (maybe) materials and other technology will develop enough so that fusion becomes feasible on a decades or so timeline. Or solar & battery technology will develop to the point where fusion isn't really needed.


But if the first spaceship was never developed, would the second spaceship have been?


Sure because you develop technology while working on achievable goals. As an example, what could someone in 1920 do to help develop fusion power? Pretty much nothing that would be practically useful today. But they had stuff they could achieve which laid the groundwork to what we're doing today.


But then you run into things that you only discover while trying to do something practical. Like the space shuttle having to land--NASA developed grooved runways specifically for this purpose and now they're on our highways. https://www.nasa.gov/centers/langley/news/factsheets/Groove....

There are technologies, materials, and methods we've developed, tested, and perfected because of some specific need. I mean, how much of the internet do we have today as a result of CERN having to store and share vast amounts of data and information?

Sure, you can say /eventually/ we would've come up with alternatives. But a lot of the internet and technology in the 90s came as a direct result of CERN doing practical things. How would we know we'd need solid state drives today if we didn't develop a need for hard drives? The same can be said of NASA, the space shuttle, the Hubble telescope, etc.

Going back to CERN, maybe it would've been better to wait for the Superconducting Super Collider because it was going to be more powerful than the Large Hadron Collider. But so far only one of these particle accelerators has detected the Higgs boson.


Your examples agree with what I am saying. Target things you can build today.


I was just talking about this the other day, its formal name is called the Wait Calculation https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calcu...


How does it make any sense for science? If noone builds version 1, there will be no version 2.

You can't skip inventing ironworks because eventually titanium will be invented.


It's an interesting sci-fi thought, but why wouldn't the second spaceship just catch up with the first one and pick up the passengers to avoid their unnecessary travel time?


Why pick up the passengers only? Plan ahead and build it to pick up the entire ship, including not just the passengers but all the materials and supplies they had packed as well.


Incompatible docking apparatus, not backwards compatible. Engineers invented these doors, after all.


So? If you know there's another spaceship that you're going to pass and you need to pick people up, you make your docking apparatus backwards compatible.

This isn't rocket science :-)


Yes but this spaceship was made by Apple. It's a feature.


Because you'd have to leave the 2nd one nearly empty to fit the extra passengers in?

Might be a good idea if nobody wants to go on the 2nd ship though.


I am not sure if we have a project that spans multiple generations?

It would be easier to do a project that provide some kind of immediate benefit while having long term multigenerational long term effect.

Science is kinda that way. We get immediate knowledge with long term unknown payoff.


Not a scientific achievement, but doesn't the Sagrada Família count?

"On 19 March 1882, construction of the Sagrada Família began ... It was anticipated that the building would be completed by 2026, the centenary of Gaudí's death, but this has now been delayed due to the COVID-19 pandemic."

Continuing construction (admittedly not continuosly) for roughly 150 years is pretty impressive in my opinion.

https://en.wikipedia.org/wiki/Sagrada_Fam%C3%ADlia


The Netherlands would like a word. Holding back the sea was a monumental project that will definitely last generations to come. Maybe not as exiting as high temp superconductors and fusion but still a nationwide unique product.


It may last for generations to come, but did the original development take generations?


Old-school land reclamation worked by putting woven fences in the water where waves would deposit sand over decades and centuries, slowly growing the land bit by bit. Those versions were already multi-generational projects.

(I'm citing the techniques used in the north frisian wadden sea, I'm unsure if the same techniques were used in west frisia as well)


Oh, that's very interesting. So I'm guessing that technique was used to make areas that were put of the water during low tide, and then eventually dikes were added to make them dry land?


Exactly. But this technique only allows you to get land that's exactly at sea level, so dikes are absolutely necessary.

This also means you need drainage systems to remove the water from already reclaimed land, as it's still exactly at sea level and will be relatively wet marshland otherwise.


Thats why the netherlands built those old school windmills. thats how land was reclaimed below sea level. They no longer serve the same function but are used instead for small shops and for tourists.


Many churches built before the industrial age took multiple generations to build.


Modern civilisation may not have multiple generations left.

And it might not even take an all out nuclear war, social media may turn out to have been even more destructive than nukes.


Also in the era of family businesses, businesses were much more sustainable, sometimes competitive over hundreds of years. The useful lifespan of a modern public company is much smaller.


Decommissioning a fission power plant and storing nuclear waste in a safe way? That's probably a multi civilization project. The easy part first.


that's perfect analogy, since most fruit & nuts are multi-generational projects.


> we, as a culture, have a problem seeing and planning across generations

From a political perspective, there is little incentive to plan further ahead than the current administration.


Yup, that's exactly the problem. We need to find an incentive for the ones in power to invest in things that would be good for the future.

Maybe I'm going too far but in the future cryonics and being frozen and be brought back when the promise of these investments be resolved in the future might create some incentives.

Even though this seems super-scifi for now, it probably won't be in about 100 years.


Yes! As a concrete example, people spent all of the C19 trying to fly, learning lots about aerodynamics along the way (https://en.wikipedia.org/wiki/History_of_aviation#19th_centu...). This culminated in the Wright Brothers making the final improvements that made it work. A century or two to get fusion would be quite efficient.


We're currently on course for having trouble existing across generations. The path we're on now I don't think meeting fusion goals will be big concern if there's anyone around to even be concerned.


True, but if we can crack fusion energy, we can stop burning fossil fuels and we might even have ample energy to extract CO2 from the atmosphere.


We already have the capability to economically capture atmospheric carbon with existing nuclear power generation systems


<poignant joke about being able to capture atmospheric carbon since the dawn of time>


Fusion produces a lot more radiation than fission, AIUI.

What makes you think it will be any more politically viable to scale out than fission reactors?


> What makes you think it will be any more politically viable to scale out than fission reactors?

IIRC a major difference would be the danger potential in case of a "meltdown", since a fusion reactor wouldn't have kilograms or even tons of uranium etc. laying around to form another elephant's foot but "just" the irradiated reactor vessel which AIUI is both not as dangerous or as long-lived as fission fuel, a fission reactor itself and fission waste products.

Also IIRC the actual "meltdown" of a fusion reactor would involve the reaction environment (extremely high temperatures and pressures) breaking down at which point the reaction stops almost immediately no longer producing any additional radiation or waste products, leaving only the already irradiated reactor vessel to deal with since the comparatively tiny volume of reactant(s) (probably one or more different Hydrogen isotopes) and reaction product(s) (probably Helium) will escape quickly and with pretty much no harm done.


That is a sane, logical argument.

I'm just worried. If sane, logical arguments worked, then there'd be a lot more fission reactors in the world and a lot fewer coal plants.


Yeah; meltdown-proof clean fission reactors have been a solved problem for what, fifty years now?


There is no nuclear waste, what radiation are you measuring to come to this conclusion? neutrons that dissapear the moment the reactor switches off?


Activation of the reactor walls. The neutrons don't disappear; they're absorbed, and some fraction of the atoms that absorb them become radioactive themselves. I've seen lifetime estimates ranging from five to ten years for the walls, after which they'll be high-level waste.


Isn't the breeding blanket suppose to prevent that?


The breeding blanket does slow the neutrons, but there needs to be a first wall material that does not ablate into the plasma. You need very little of non-hydrogen material in the vacuum to cause a density collapse. If you made the wall out of liquid lithium then there would be a lot of lithium in the plasma.

Tungsten is a good choice for a first wall material because of its uniquely high melting point, low rate of embrittlement in high neutron flux, and short-lived radioisotopes.


Would it? We could have hundreds of runaway-meltdown proof nuclear fission reactors now if we wanted.


This is a disingenuous argument. JET was not designed as a power plant. Those flywheels are used exclusively to transiently power the copper confinement coils. Since superconduction was discovered, no reactor study has had non-superconducting confinement coils because they are (very obviously) impractical.


Remember, the easiest way for uninformed people to appear scientific is to lob high-level criticisms about the topic. In this case, it's "But it only doubled the output!" or something similar.

We see this pattern on every single piece of science news that comes across the front page of HN.


The only purpose of my comment was to provide context for the numbers in the article via a thought experiment involving doubling.

Since the calculation involves taking log_2, even if the estimate for the "used power" is off by a factor of 4 the result will only change by 50 years.

Can you make your qualitative comment quantitative and update the numbers in my doubling thought experiment?

I would be curious about what you think is more realistic.


A quantitative approach is no virtue here, just a more convincing way to lie.

ITER will use roughly the same amount of power as JET, produce 10x the power 40 years later. Even using poor metrics such as Q you have enough data points to p-hack whatever incorrect timeframe model you want.

ITER isn't even using HTS coils.

If you really want a quantitative projection of MCF performance over time, here you go. Don't lie with numbers if you don't know what you're talking about.

https://en.wikipedia.org/wiki/File:Fustion_triple-product_di...


That's a co-insidence, 2185 is also the year of Linux on the desktop.


Or it could be like Zeno's Dichotomy Paradox.


It's 30 years time. It's always 30 years time.

https://www.discovermagazine.com/technology/why-nuclear-fusi...


This is a very dumb meme that people use to avoid learning anything about the actual hurdles that are currently being faced by fusion researchers. At some point, fusion will be much less than 30 years away, and at that point, I guarantee you that lazy people will still be repeating this joke, because it is literaly the only thing they know about the subject.


"Fusion is always 30 years away" is a heuristic that almost always works. https://astralcodexten.substack.com/p/heuristics-that-almost...


We haven't even been splitting atoms for a full century yet. Give science some goddamn time to work.


20 century progress was so crazy that people got all the kinds of unrealistic expectations.


Not to mention we haven't invested a fiftieth of what we should have into fusion research.


More money goes to subsidizing almonds.


Not reading the article in the link you're replying to is a heuristic that almost always works ;)


We did nuclear fusion in 1952. Controlled nuclear fusion--and producing more power out than goes in--that's another matter.


This is an excellent read, thanks for sharing


"Assuming anything Scott Alexander Siskin says is wrong" is also a heuristic that almost always works.


If only I didn’t do my phd in a department with plasma guys 30 years ago back in the 90s eh?


It was 30 years away at current levels of funding. Funding dipped considerably. This is as dumb as when they ask you for an estimate at work, then change the scope of the project and then retort with "well it was your estimate".



Inflation.


They're still a very long way from getting a net gain in energy: https://youtu.be/LJ4W1g-6JiY


For those wondering, the Q for this particular result was 0.33. https://www.youtube.com/watch?v=H99hvPlC4is&t=48m


He says this is also a world record, but JET got 0.67 in 1997 (according to Wikipedia). The missing asterisk may be that this Q was the average for the whole shot, whereas the 1997 result may have been measured over a short time. Just my speculation, based on slide 21 here: https://fire.pppl.gov/iea_bp_w60_stork.pdf

Edit: Confirmed by this comment https://www.reddit.com/r/fusion/comments/soc5xo/oxfords_jet_...


We can make it up in volume.


Sadge. But I think this is the best bet for sustainable and clean energy, so why not put all the enthusiasm we can into it?

A breakthrough is a breakthrough, and that's good news.


> bet for sustainable and clean energy

The best bet for sustainable and clean energy is to stop using fossil fuels and figure out how to deal with the economic consequences.

I feel this optimism around this far off solutions for decades has been just a detrimental to climate action as out right climate denialism.

Growing up in the 90s I was always told "everything will be fine, since we'll figure it all out with technology". It wasn't until decades later, when I kept hearing this promising but seeing CO2 emissions rise that I looked into the details and realized how incredibly in danger our society is, as well as how nearly impossible to solve this problem is at this point.

The reason we shouldn't put our enthusiasm into it is because it's a distraction from the fact that we may already be past essential limits in our climate system and if we want any chance of survival as a civilization and potentially species we need drastic action now.


> the economic consequences.

you mean the death of billions of people ?


Describe to me the scenario where billions don't die?

I think you're pointing to the very likely reality which is that there is no way out. More often than not I agree with you. It's just a shame that, as a society, we've chosen not to even publicly allow conversations about what's really happening and the choices we have to make.


> Describe to me the scenario where billions don't die?

There is not one.

I was merely pointing what I think is an euphemism.

> we've chosen not to even publicly allow conversations about what's really happening and the choices we have to make.

Because we are ashamed. We all know that the price of our current comfort is blood. Now and in the future. And our human nature seem to be unable to abandon comfort once we have it.


No


What? We have the best bet for sustainable and clean energy.

Wind and Solar. They soon will beat natural gas for cheapest unsubsidized LCOE, and considering all fossil fuels are shadow-subsidized, that's huge.

Fusion needs to prove is can be cheaper than old-crappy-pressurized solid rod fission first, which is right now getting killed by alternative energy.

I was a big LFTR stan for a while. But wind/solar has won. Keep investing in fusion and fission, but they are subsidy and research projects right now only.


Wind and solar are great but they use up a lot of space and ideally we'd have more electric power than can be provided with just those two.


Wind + Solar are near useless without storage, and we do not have anything close to the storage necessary.


Storage likely will be a non-issue once sodium ion batteries scale up, even cheaper and safer than LFP. A couple more years of scale efficiencies and alt+storage will be cheaper without subsidies. Consumer solar+storage will be cheaper than nat gas in a couple years with any rational subsidy.

Land issues? Seriously?

The land issue for solar is a non-issue, it's like fake hand-wringing by the oil astroturfers over birds and windmills when skyscrapers kill 100xs more birds. There's this type of land called desert. Also, there is this thing called roofs where modern solar panels only need a small part of the roof to do a suburban house or apartment building including recharging your EV.

The land issue for wind is even less on an issue:

As for wind, I don't know if you've seen windmills on farms but... yeah, the pole doesn't take up much space. Then there is offshore wind. Windmills can integrate with existing use land (why not nature preserves?), you don't need to dedicate acreage to windmill farms.

Meanwhile, fusion reactors have a wee bit of problems with neutrons flying everywhere and turning the reactor vessels slightly radioactive from neutron capture. Maybe they'll fix that with good absorption spectrum elements, but let's not pretend fusion is 100% clean.

https://thebulletin.org/2017/04/fusion-reactors-not-what-the...

But again, the promise is there for fusion and LFTR/"new" fission. Keep the research, maybe the economics will turn around. Industry sure would need it to fully decarbonize, or, heck, space colonies. Or flying cars! Or any of the other sci-fi stuff we have given up on.

Right now we have an existential threat from GW, and an actual industrialized / productized and economic path is right there: wind and solar. That's what we need money printing for.


The land requirement for solar should not be so casually dismissed.

To power the US energy needs, you need an area about the size of New Jersey. Also roughly equivalent to the area taken up by roads. The interstate highway system alone has been cited as the largest public works project in history, and that's "just" asphalt.


The LCOE of solar and wind is cheaper than all fossil fuel plants and nuclear plants. Existing generation will peak load.

Look, any new nuclear or fusion project won't turn on for a decade. Given that even with inflation wind/solar STILL dropped in LCOE cost last year, and still likely has technological and economies of scale, you REALLY think a 10 year out fusion or nuclear project will launch at a price competitive with what even solar/wind + storage will be?

Solar/wind likely will be half the inflation adjusted cost it currently is now even with storage in 10 years.

LFP batteries are coming on the market now for storage that are half what lithium ion cost. Sodium will be release by CATL later this year or next. I'm not handwaving anything.

There is a LOT of roof real estate. A fair amount more than the interstate system. The costs are already pushing wind/solar to deploy as fast as it can be made, it basically is a production scaling problem.

New Jersey is not a large state, given we have west texas, Arizona, New Mexico, and lots of other desert. Which we don't need, because of rooftops and wind.


You can't say fusion is impractical while saying solar and wind is better by hand waving all the current concerns and technological walls we still haven't solved. Plans on an whiteboard do not count, sorry.

Storage isn't solved, land space isn't solved, efficiency isn't solved, just like fusion isn't a solved problem.


> Storage likely will be a non-issue once sodium ion batteries scale up, even cheaper and safer than LFP.

Sure, once storage is solved it will be a non-issue. But it is not currently solved, and you will forgive my skepticism.

I also never brought up land issues; I agree that it's not a real problem.

TL;DR we need to be realistic about the capabilities of solar + wind. You argue that storage will solve itself. Your sibling argues that we don't need storage at all.

The reality is that storage is a huge issue right now. It's the #1 technical issue stopping us from shutting down coal and natural gas plants.


Not nessesarily, alternative approach is to overbuild them 10x so thay we always generate more wnergy than we need and have continent spanning super-grid because it's always windy and sunny somewhere.


Today Boston has a sunrise at 11:47 am utc and Los Angeles has a sunset 1:30am utc. That is 10+ hours where the USA gets zero sunlight. Inconveniently, we also hit peak energy usage during those 10 dark hours.

So if you want to ignore the storage problem, you need to rely on wind only. And if you have to dramatically over provision production to be able to meet demand, the cost benefits disappear.

Storage is a must for renewables to really take off.


> And if you have to dramatically over provision production to be able to meet demand, the cost benefits disappear.

"Not cost-effective to be the majority of power production while CO2 pollution is free." is very different from "near useless".


> the cost benefits disappear

But I am not claiming there is any cost benefit at all - alI am claiming it's doable, and we will have zero or negative electricity price on windy days, that coupd be put to good use for electrolysis, hydrogen production, etc.


Going in the wrong direction with development that can never work as intended is always a waste no matter how good the goal. Incorrectly reporting this modest incremental change is the kind of thing that allows doomed projects like this to consume vast resources of money, material and skilled labor that could be used to explore other alternatives.


In what sense do you think this is good for sustainable energy? Do you think it will cost less, or have less environmental impact than, say, newer deep well geothermal? I'm not so optimistic that costs could ever be competitive with geothermal.


Doesn't deep geothermal generally require fracking? At least the geothermal plants that I've seen being implemented right now do. Is there any fancy new tech breaking through there currently?

I think both fusion and geothermal are very exciting, crazy thing is although geothermal sounds simpler, I have no idea what's holding it back technology-wise, yet I have a pretty good understanding of the state of fusion research right now.

Why couldn't we get geothermal without fracking? Is it so hard to establish a more controlled heat exchange channel down there? Harder than developing nuclear fusion?


Geothermal is very location sensitive and requires huge outlays upfront. Maybe it’d be a clearer choice if energy storage were better solved. It also requires political support to cross NIMBYism.


Aren't we at the point where most large scale infrastructure projects require huge outlays? Unless geothermal is an order of magnitude more expensive per MW or GWH than say nuclear, is it a point against it?


I think people both aren’t making the logical connection for why they need more power for their current way of life. Also, the NIMBYism against geothermal may be even stronger than that against nuclear because of the governments involved.

Consider how much commerce is done in the US via truck. Those trucks average 6 miles per gallon diesel. That represents a huge amount of energy. But it currently relies on fossil fuels so people don’t think of it as being potentially served by renewable energy sources.


The idea is that it would cost less and make energy so cheap and abundant that it would completely change society. Fusion would allow you to get 30x energy out vs energy in and has 10,000x the energy density of coal. If you want to explore space, it’s a good option.


I guess, why is it thought that it could be cheaper than geothermal, for example? Geothermal doesn't have fuel at all. I don't see how fusion produces energy cheap enough for it to be super abundant. And maybe that's just a failure of my imagination, but there seem to be massive gaps in others' reasoning that nobody has been able to fill me in on.

Space travel is an entirely separate type of energy use, and I could see it being the only option for lots of applications. But that would be much further away, and the significant hurdles there can also be solved by other future tech advances like direct conversion for fusion to electricity.


Even without fuel, geothermal still has constraints. Where can we build it? What are the build costs and costs to run (maintenance, staffing, etc)?

I doubt we can scale geothermal indefinitely. Fusion might suffer from similar constraints, but afaik, doesn't need "much" space or specific geographic structures.


FWIW, drilling tech is advancing at an incredible rate, making geothermal possible in all sorts of new places all the time.

But my primary concern with fusion is cost. I don't see the path to being cheaper than geothermal, nor fission, and new fission is already some of our most expensive energy. The goal may be eventual space travel, which seems like a more plausible goal to talk about than sustainable energy.


There’s nothing fundamentally expensive about a Tokamak. We’re in the phase of fusion of “computers have 1 Kb of memory and take up a whole basement.”


What does 'fundamentally expensive' mean?

If it does not incluse precision engineering to build largest vacuum vessel, supercomputers, superconductors, generation and containment of hottest substance on the planet, and largest magnetic fields we can produce. If that's not 'fundamentally expensive', then what is?

Especially when your interlocutor is asking for geothermal, a.k.a. a hole in the ground?


You mean fundamentally expensive like building billions of nano meter scale devices, aligning and wiring 24 million of them to be individually addressable on a 6 inch plane? Oh and we build those by the thousands on factory lines.

That's a whole lot more of precision engineering than is needed to build a nuclear fusion reactor, and you can buy it on the order of a hundred bucks.

And it's not just a hole in the ground, last time I checked the thermal conductivity of rocks isn't exactly stellar.


I think this is a great example of why fusion will probably not drop in price.

With semiconductors, prices fall continuously because there is continuous iteration, and starting from the very very first lithographic circuits there was a market. There's an entire industry, competitors, and it's a factory system.

Fusion is not like that, it will be like building monuments, there's not thousands or millions of the same thing getting churned out, it will be all specialized construction for each piece.

You may say that a chip did specialized in that each of the transistors re wired together in very specific ways, but the semiconductor industry is a factory factory in some sense, you build a set of masks and that's your factory for your chip.

Let's say you design a fusion reactor, and then 12 months later you see how to shave off 1% of the costs somewhere. That iterative gain is lost, because the fusion reactors will be built very rarely, and building each one in a new custom way poses lots more risk than doing the same design for 10 years. They are just too big and expensive to show the same sort of mass manufacturing gains that can be seen with technologies that have learning curves.

I could be wrong, and I certainly hope I am, but I would bet a hell of a lot more money on a new battery chemistry than I would on fusion as being a terrestrial power device.


I think you're underestimating how small fusion reactors are. We're going to be needing not just fusion reactors per city, but per city block. If we manage to get them to break-even, they're going to be super plentiful.

At least, that's what the promise is, we'll have to see of course.


I've never heard anyone suggest that fusion could scale to be really tiny like that. Do you have any pointers on where I could look to learn about something like that? Because every existing thermal electricity generator scales to be really big for the efficiency gains, and fusion is a thermal electricity generator as planned so far. Tiny steam turbines in each block does not sound cost effective, even if the heat is free.


I'm basing this basically on the size of the experimental reactors currently being developed like sparc and the ST40. No doubt building larger plants is going to be more efficient, but if the fusion reactors themselves are going to be that small a single plant will probably have multiple ones.

I think fission reactors and ITER have shown the downside of building really large one off reactors, I don't think they're gonna make that mistake again.


There’s no piece of the Tomamak individually that can’t be miniaturized or benefit from economies of scale. It doesn’t require exotic fuel like nuclear fission reactors do. It doesn’t need gigantic quantities of space and material like wind and solar. It doesn’t have high up front engineering costs like geothermal. One day a tokamak might be an off the shelf industrial purchase, maybe akin to an MRI machine.


"It doesn’t have high up front engineering costs like geothermal."

You are commenting on an article about how scientists had to build a reactor out of berillium and tungsten.

Have you ever touched those materials? Is there any berillium in your car, or your washing machine? If you go around your neighbourhood looking for someone who can weld or work tungsten, will you find anyone? Can you buy a tool on amazon that will cut tungsten?

The number of facilities that can produce precision-enginered thousand-ton vacuum vessel with exotic materials, are counted with fingers on one hand.

> Tritium is very exotic, and fuel cost is a small and irrelevant cost to fission powerplant

This is downright delusional, solar is the only technology that you can go and buy off the shelf and it is much cheaper than an MRI machine, any joe with basic electrical education can put together a solar power system and poor people in developing nations do it. Anyone who thinks that fusion will be easier than slapping solar panels together is smoking some serious dope


You’re missing the point a little bit. No one is arguing that solar is going to be more expensive than fusion. The point is that fusion is about as far fetched as a lot of technology seem at first. Like microprocessors (billions of transistors?) or medical imaging (put a human into a giant magnetic field to see inside them) or internal combustion engines.


I'm not quite sure why but I have this flashback-like feeling from blockchain with this Q_total < Q_plasma confusion.


Pardon the analogy, but bringing up Q_engineering in this context is like someone shopping for a car running into Ford's engine design department and complaining that the engineers are not using the car's fuel economy to increase the engine's performance.

How much power the subsystems takes has no influence on the plasma's performance. How much power goes into the plasma (and what type of power and where and when, etc.) do influence the plasma's performance.


We (now) know but most people don't, when somebody says it'll "produce X amount of power than you put in" any normal human being would think "it's done" but then they'll wonder for next X decades why there are no power plants yet? Because nobody told them that you need more power than it produces at the end and positive net was just for final reaction and without heat to electricity conversion.


You should watch the hour long press release and see just how clearly they explain what has been done.


What's nice is that even for Q_plasma this only gets 0.33. So it's a net loss no matter how you measure it.


I'm confused. What do you think the goal of the campaign was?


It's tough to say because the campaign is a signpost on the way to an eventual end goal. But the end goal is easy to describe: "a working fusion power plant."

The end goal is so far away at this point, not a single player in this space is even trying to do it, even on their farthest-out roadmaps...


No, the campaign's goals were to push higher plasma energy out of a JET pulse. This required upgrades to many subsystems and to dust off everything necessary for nuclear operations.

They did this in support of ITER, but there are also likely other political motivations. There has been no nuclear MCF operation on Earth in decades and now the UK has invested in resuming theirs rather than mothballing it.

You can't make claims about the motivations of the campaign (such as it being a signpost?) if you don't know what was even done.

And again, you shouldn't talk about the roadmaps if you haven't looked at them. Look at PPPL FIRE and power plant studies.


Clearly the end goal is to beat the First Law of Thermodynamics and its pesky "conservation of energy." We already know how to print money, now it's time to print energy! /s


When you are comparing across different fusion techniques, which we implicitly are in our brains (because we are not sophisticated plasma physicists and not every strategy right now is magnetic confinement), Q_engineering is important to think about: different strategies will have different capabilities of harvesting the energy and turning it into power, and maybe some of the strategies (laser inertial confinement cough cough) are super-unlikely to ever have reasonable and efficient capture strategies. It would be nice to have an "estimated Q_engineering" come out of these experiments, even if they are wildly overinflated and crap estimates (as long as the assumptions that go into that are recorded). For that matter, it's not entirely clear to me how one harvests energy from magnetically confined fusion plasmas. Can someone give me a soundbyte on that?


You're asking for a simplification when there is no way to do it without lying. The fact is you do need to know more than a layman to appreciate how impractical ICF really is or how useless looking at Q is in nearly every context that matters. No MCF machine has even attempted to get a higher Q in the past 25 years. Look at lawson criterion and scaling laws for progress.


But at the end of the day, if this is to be useful, we need the plant to produce more than it uses, right?


Then read the power plant studies published every few years by numerous institutions.

There are no showstoppers.

Here is a good (stellarator-focused) resource made by PPPL:

http://firefusionpower.org/


This wasn't a high-Q campaign.


Haven’t we already had fusion experiments with net positive energy?


No, unless you count thermonuclear explosives. This experiment didn't demonstrate it either. The fusion only yielded 1/3 the energy used to heat the plasma.[1] That doesn't include the energy needed to run the rest of the machine (magnetic containment etc) and it doesn't include any losses converting the fusion energy to electricity (which was not attempted).

[1] https://www.nature.com/articles/d41586-022-00391-1


I think this explanation is more comprehensive: https://youtu.be/JurplDfPi3U


I really appreciate the note of the environmental analyst which helps readers who don't have deep knowledge of the field understand the meaning of this breakthrough in context. I wish more news agencies adopted the same practice.


The Financial Times, though pricey as a financial newspaper, is a good source for this. It regularly publishes in-depth articles with a wide range of interviews with experts for readers to learn the context of current issues (via their "News in-depth" series, and also their series called "The Big Read").


Thanks for the tip!


A shot of the pulse from within the reactor: https://www.youtube.com/watch?v=IMuOaTqdp4c


Isn't the stream supposed to be in the middle, away from the melty bits?


Yes, but the really hot part is not emitting visible light. ;)

If you're curious about why the bottom glows: ExB drift pushes electrons to the bottom. I'm sure that doesn't make sense, but unfortunately there isn't really a shortcut to understanding here. Some books are pretty accessible though (I'm a fan of The Future of Fusion Energy).

https://ebrary.net/174598/mathematics/drift_motion_energetic...

And, of course, there is always the freely available IAEA textbook:

https://www.iaea.org/publications/8879/fusion-physics


What would happen if you stood in that


You contacting the plasma would cause it to collapse, but you would already by cooked. It's a chicken and egg question, because a plasma is never going to get started with a person inside; it needs a near perfect vacuum.


Not the same thing, but Russian scientist tested a proton beam with his head and lived to tell the tale. https://en.wikipedia.org/wiki/Anatoli_Bugorski


You would die


You can tell when someone didn't read the article, because the video is at the very top of it :)


I read through the whole article and didn't realize the video was there until I read this comment chain. I had just glanced past the video assuming it was an ad.


> This is more than double [the energy] what was achieved in similar tests back in 1997.

I was excited for a little bit there.


I wonder, in the future when everyone's attention has been burned by turning up the volume on all headings to 11... will everyone ignore and miss a truly "major" breakthrough.


Using the same machine. That's a pretty impressive jump.


Yep - we're still nowhere near break-even.


We're not that far off. JET previously achieved Q=0.67, ie. two-thirds as much energy output as input. (The new result has higher output but lower Q.)

For a practical reactor we need Q around 30, which might seem far away but tokamak output scales with the square of reactor volume and the fourth power of magnetic field strength. Double the field, 16X the output, and we can generate much more powerful magnetic fields with modern superconductors than we can with JET's copper coils.


> For a practical reactor we need Q around 30

Did we figure out how we could harness the energy released? It appears to me that all current research are about maximizing Q without really looking at how the energy will be converted into usable form.


For D-T fusion, the output is 80% neutrons, so the only option is to let them heat something to run a turbine. You also need the neutrons for breeding the tritium, so you let your breeding blanket heat up and run coolant pipes through that. Commonwealth plans to use molten FLiBe salt as the breeding blanket and first loop of coolant.

Aneutronic fusion produces fast-moving charged particles instead of neutrons, so if anyone gets that working, we could extract electricity without a thermal cycle.


So they just need to build the same thing, but make it gigantic in size?

Why is it not yet done?


It is very expensive to do.

HTS was known but not practical when ITER was planned, but it's almost done. ITER is almost large enough to be an LTS-based power plant.

ITER will still produce a lot of useful science, but there is a now a potential class of mid-scale HTS machines that would help develop plasma models.

These iterations seem frustrating and time consuming, but their results are lowering the cost of a hypothetical power plant until one day maybe society will decide they're worth making for power generation.


Any source on that Q=30 requirement for practical reactors?

I’d assume that anything >1 is theoretically “profitable” and something like 2~5 might already be economically viable.


Q=1 just means that the plasma is putting out more energy then is put in. However, that doesn't mean you can recover all of that energy; you can't run a heat engine at millions of degrees, so energy generation has to be fairly indirect, which means you need about Q=30 to handle all the various conversion inefficiencies and still come out net positive enough to be practical.


Yup, a major breakthrough in this glacial field is doubling the energy output in 25 yeas.

So by the time captain Picard is born, we might have a very expensive and massive fusion reactor that will generate the same kind of energy we can generate today with very expensive and massive fission reactors.

Really now, this is pure garbage and does not solve the major problems in the field nor do most of the myriad startups trying to cash in on speculative seed funds.


"with very expensive and massive fission reactors"

The laws if physics don't owe us a free lunch. Light, safe and cheap powersource does not exist

Fossil fuels aren't a power source, they wre a power store - that power was collected and millions of years ago.

Also 100% productivity on 25 years is quite good - what did combustion engines improve in that time, 5%?


The 1997 F-150 made 220bhp and got 18mpg [0], while the 2022 F-150 makes 400bhp and 19mpg [1], so fusion is doing way better than that!

(...i think i chose comparable trim levels to do that comparison, there are a stunning number of choices there!)

[0] https://www.cars.com/research/ford-f_150-1997/specs/103719/ [1] https://www.edmunds.com/ford/f-150/2022/features-specs/


Mileage figures have little to do w/ max power. That mileage figure is roughly using the same actual power, which is a relative sip of fuel.

The main difference would be in testing EPA methodology which which would be a bit more stringent/realistic to world use. On top of that, there likely is more rolling resistance at lower speed due to larger tires and heavier weight, offset somewhat by lower C/D at speed.

Basically it's hard to extrapolate ICE efficiency gains... they're there are sure, but probably in the single or low double digits.


The newer F150 also weighs more. Also, if it didn't have to make twice the power, it would probably get 40mpg today.

ICE engines have advanced a lot in 20 years, especially in terms of cost per HP/MPG.


I don't understand why they can't just build a basic pickup truck any more.

We had an old pre-fuel injected pickup. It had a bigger bed than the current truck, and seated six instead of five. It got 33% more miles to the gallon. The new one's transmission likes to overheat, even when not towing.

Seriously, wtf?


Safety, mostly.

I have a 2015 Colorado with a 6 speed manual, long bed, 4.10 read end, and the 2.5L 200Hp four cylinder. Probably as basic as you can get, and nobody buys them, because for like 2k more you can get a v6 and fancy electronics.

Tows 4k lb trailer fairly fine...


The real question would be, what's the fuel consumption for a given, sustained, bhp, for both? The mpg numbers are often pretty unrealistic. [-1]

[-1] https://www.edmunds.com/fuel-economy/heres-why-real-world-mp...


I mean, if you don't invest in the speculative, how do you expect things to advance? Failure at any particular venture isn't a bad outcome.


Sometimes I wonder what would happen if we put the massive amounts of money we have put into nuclear fusion and fission into bone simple solar panel purchases. I wonder if anyone has done the math.

There’s a fully functioning fusion reactor 91 million miles from us that sends a lot of energy our way.


The levelized cost of large scale solar power is about 7 cents per kilowatt-hour.

ITER alone will cost $21B minimum and won’t make power. DEMO will conservatively cost about the same, but let’s be generous and round up the total “fusion research cost” to just $30B.

That would buy about 1.5e18 joules, or around the same amount of energy as the electrical generation of the United States… for a month.

So, a drop in the bucket compared to what we use globally…

Even if you use much bigger numbers for fusion research and assume further solar power cost improvements, fusion might still be worth it.

However, it’ll only be worthwhile if the total cost the production fusion plants is not too high. If they end up costing $10B each then the whole thing will be a dead end economically.


Nothing about the current tokamak based designs suggests they will be any cheaper to build for a given power rating than existing fission designs:

- They need large, highly advanced cryocooled superconducting magnets in very close proximity to a hundred million degree plasma. This only makes economic sense in massive, and expensive plants.

- They are a very strong source of fast neutrons useful to transmute cheap depleted uranium into plutonium, so carry massive proliferation risks, need close regulatory scrutiny and will require mounts of paperwork to operate, thus exceptionally inflexible to improvements and rapid iteration. Just like the current fission crop.

- Aneutronic fusion is a currently a purely theoretical concept, in the last 70 years nobody has been able to contain even the much cooler D-T plasma for economically viable durations and temperatures.

- The structure of the reactor becomes radiologically active and cleanup operations must be considered. Highly penetrating neutron radiation means some radiation will escape regardless of containment, requiring a radiological exclusion zone. No Mr. Fusion in your car, sorry.

- They operate and must breed sensitive nuclear materials - Tritium, a well known component of boosted thermonuclear weapons. The limited efficiency of tritium production from lithium-6 might require obtaining some from fission reactors to top up the fuel cycle and keep fusion reactors operating.

So when you draw the line, a life time of magnetic containment research has produced a speculative design that even if it were to work, which it doesn't, would be, in the best case scenario, comparable to existing fission designs that are being phased out for cost and risk issues.

A PhD money pit with zero chance of ever building anything useful.


Thank you!


When Fusion is on the front page, I like to take the opportunity to mention the Fusion reactor I have designed.

The device will cycle between a hot dense implosion (similar to NIF) and a cold, rotating cloud, at a very high frequency in a large Penning trap.

I have more information at my website, http://www.DDproFusion.com

If things go well, I should begin building the first prototype in a few months. I just acquired the main magnet, an old permanent magnet MRI machine, that will provide the field for the giant Penning trap.


Edit: it's finished

--The live announcement is going on now: https://www.youtube.com/watch?v=H99hvPlC4is (from 12:00 until 13:00 GMT)--


Not a breakthrough, just a milestone. Yet again they cite the "20 years out" which has become a joke among anyone that follows fusion research.

There is really nothing to see in this article, move along.


when i was a boy it 40 years out, seems good that even the hyper cynical snarky comments are twice as optimistic now.


LMAO.

I really think these fusion people just need more money. MIT wants to build their SPARC reactor prototype, which will make ITER look stupidly large and expensive, but they need $40 Billion.

I dream of the future of SpaceX fusion powered star-ships with quantum computers and Alcubier warp drives are thing.


What is stopping one of the major western governments from printing $50B of their own currency and investing it all in an intensive fusion programme?

There doesn’t seem to be much to lose (these economies are already unreasonably inflated) but so much to gain from viable fusion.


In the current economy the funding of these types of projects is usually not the bottleneck. It's finding the people and achieving the actual scientific / engineering breakthroughs. The marginal return on more money is pretty insignificant for that. If you just threw a ton of money at it much of it would probably be splurged or straight away misappropriated. Then you'll get a whole lot of terrible press, undermining other scientific funding and putting the politicians reelection at risk.


I don't believe that is true. This famous chart shows funding levels versus requested since the 1970s:

https://images.app.goo.gl/58YdLFt7R9uY8dyR6

The much maligned prediction that fusion is 30 years away was always anticipating stronger financial support.


Thanks for that chart. Maybe famous, but first time I've seen it. It's a bit pathetic. And explains a lot about progress.


As others have pointed out, ITER has this kind of funding, and it is not the only nuclear fusion research program. It is unclear whether more money will accelerate.

As for green R&D in general, the EU is massively investing in hydrogen research, as something that can be made with excess variable solar and wind power, and be used as a green alternative to natural gas in many situations.

https://www.forbes.com/sites/mariannelehnis/2021/12/31/the-e...


Well, they do:

https://physicstoday.scitation.org/do/10.1063/PT.6.2.2018041...

The latest ITER budget update puts the cost at $65 billion dollar.

And, yes, there's 1 million, 10 million, 100 million and so on grants for smaller scale efforts too, JET being one example.


ITER is doing that, no? Large scale test of fusion energy output.


Problem with ITER is it's not 1 country, it's lots, and they all want their piece of the pie instead of doing it efficiently


Does one country have all the smart people needed to go it alone?

(This is not a further joke about Brexit I pinky promise)


If you're willing to print enough cash to pay for the smart people to come to you, you can probably import them. It seems to be more the exception than the rule that people dislike a country so much that no amount of money could get them to go there to do research on the topic they're interested in.


A $50b program from 1 country would likely have the same problem (as indeed would a large private program). Injecting a large amount of capital all at once into a project just isn't efficient.


If so then it's impossible to advance, which would be annoying.

What's needed is people who know the subject matter and are experts at running large companies.

SpaceX turned rockets into a production line, experimented, blew a load up, and then fixed the problems with landing. But that's productising last year's thing, not inventing a new possibly impossible thing. Interesting to see how Starship goes.

Need a leader to stay: you do x, you do y, not a committee where every country gets to make one of the 12 magnets because they're a primary school and everything has to be "fair"


Questions about how effective this would be aside. What is there to really lose? If we inflate the economy via current means or inflate the economy via employing scientists and engineers ineffectively, it’s inflation nonetheless.


> Injecting a large amount of capital all at once into a project just isn't efficient.

SpaceX would beg to disagree here. The reason why they are so cheap, agile and sustainable (=reusable rockets) is precisely because SpaceX got a load of money without the "pork" requirements that were commonplace with ULA & friends. That enabled SpaceX to embrace vertical, on-site integration and go for what was technically the best option instead of what was required by some buffoons in Congress.

Although a point may be made that a "hand out cash" program needs a competent, strong and undisputed leader at the top. There's a lot of issues with Elon Musk, but it is undeniable that he is a very effective and inspiring leader.


ITER vs SpaceX is a really poor comparison.

ITER is a high risk foray into still-experimental technology with no hope of direct return on investment (it can not function as a commercial power plant). It had to be built at this scale because they had reached the limits of smaller-scale prototypes (tho I think there was not unanimity about this). Pooling resources makes sense here.

SpaceX is a more efficient take on technologies and processes that have been battle tested over many decades. This gives them a clear path to profitability, with some risk, but low enough to get investors on board, which ITER would have no hope of doing. Granted they are innovating, but incrementally, not from scratch. Very different.


> Pooling resources makes sense here.

Yes, but still - instead of all the components needed being manufactured on or near site, they are shipped from across the world... so parts end up damaged [1], not made according to spec or the spec having errors introduced somewhere among dozens of companies and institutions. With sometimes weeks or months of shipping round-trip times, that is causing a fucking lot of delays. Not to mention that shipping all the stuff around itself is also causing issues given the current COVID-caused shipping delays.

The problem is that ITER, ULA, EADS, Airbus, the ISS and a bunch of other international cooperative projects all are considered by politicians primarily as a way to distribute pork, secondarily as a way to show off on the international stage and only then as a way to actually advance scientific knowledge.

[1]: https://news.newenergytimes.net/2021/09/26/component-issues-...


Airbus is an inefficient port project? They build almosy half the world's aircraft.

Boeing has 1 boss and what are they better at, defrauding regulators to sell dangerous aircraft? And all other private manufacturers combined are a rounding error?


They could be a lot more efficient if they were not forced to ship parts and airframes around Europe multiple times.


SpaceX is so much more than just the capital. It's the capital plus the unwavering vision of the leadership. The latter is much harder to find.


It helps that SpaceX is just iterating on 1960s technology.


SpaceX didn't get anything near $50B in investment though. And certainly not committed all at once.


Darn, I found the article quite underwhelming. It may be a major breakthrough relative to past accomplishments in the field but it’s far from commercial viability.


Yes, but every step forward on this path is thrilling. If we crack carbon capture at scale, and unleash fusion, it would change the game for the survival of our species.


To change the game for the survival of our species (if protecting a species that destroyed 75% of ecosystems as of today is really sth wanted anyway) we might want to protect the other species as well since we rely on them almost entirely for anything relevant to survival. Also I am not sure having ten times more energy would do any good.

IPBES reports as well as the literature in relevant conservation journals are recommended readings.


Yes fully agree but step one on that path is to stop dumping carbon into the air and oceans.


Agreed, but thinking that a new energy source will solve that is completely incorrect. It can help, yes, but it's not a given fact that it will.


Negative. If we want to "change the game for the survival of our species" that would be fission, a super-mature and proven technology that is already widely deployed.

As far as "carbon sequestration" - that is just a tree. No R&D required.


I think fission has very good technical merits but the unfortunate reality is it's politically untenable.


It would benefit the discourse on this subject a great deal if these stories were subject to having their headlines edited, or if there were a sticky comment summarizing the actual substance of the “breakthrough.”

A great deal of VC money is going into nuclear fusion at the moment, and there is obvious interest in creating the impression that economically viable fusion reactors are just around the corner. It would be prudent to guard against the efforts of publicists and PR professionals by providing context.


The timing is impeccable (making me suspicious), I was just at a UKAEA public meeting yesterday -- they're choosing a site for a new fusion project, a small "demo" reactor.

https://step.ukaea.uk/

You couldn't have better timing to encourage the public that this is a positive thing for us to develop.

FWIW I'm a big fan of JET, Wendelstein, and fusion research in general. And, I think this STEP project is very positive.


I noticed the waste output is helium. Does this fix the worldwide helium scarcity issue?


Let's make some back of the envelope calculation:

* World electricity production: 25000TWh/year https://en.wikipedia.org/wiki/Electricity_generation

* Energy per Helium atom: 17.6MeV https://en.wikipedia.org/wiki/Deuterium%E2%80%93tritium_fusi...

So per year (with a 100% efficiency [1]) you would produce as a side effect 25000TWh/17.6MeV ~= 3E31 Helium atoms.

The Avogadro constant is 6,022E23 and that produces 22.4 liters of gas, so you get 1.2E9 liters, that is 1.2E6 cubic meters. Let's round that to 1 million cubic meters per year.

The worldwide production of Helium is 140 million cubic meter per year https://www.statista.com/statistics/925214/helium-production...

[1] A 100% efficiency is too optimistic. The second law and the nasty details of the real world reduce the efficiency a lot. Let me guess 50% from https://en.wikipedia.org/wiki/Energy_conversion_efficiency#E... But this is good! If you waste half of the produced energy, you need the double of fusion plants, and that means the double of Helium balloons.


This calculation was done on an HN thread a few years ago. I have not reviewed it recently.

If all power generated right now was from D+T fusion, it would generate about 8.2% of the current helium consumption. We consume 153,596 TWh of thermal energy per year [1]. Each D+T reaction releases 17.59 MeV [2]. Multiply by the atomic mass of He4 and divide by Avogadro's number to get the mass of He4 produced per energy produced. Divide by the density of He4 at STP to get volume of He4 produced per second [3]. Divide by the consumption of He4 to get the ratio of He4 produced to He4 consumed [4].

(153596 TWh / year) / (17.59 MeV) / (avogadro's number 1/mol) * (4.002602 g/mol) / (0.1786 g / liter) / (88 million m^3 / year)

https://www.wolframalpha.com/input/?i=(153596+TWh+%2F+year)+...

1. https://ourworldindata.org/energy-production-and-changing-en...

2. http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/fusion.htm...

3. https://www.engineeringtoolbox.com/gas-density-d_158.html

4. https://link.springer.com/article/10.1007/s11053-017-9359-y


No, fusion power plants will likely need helium to run: it's necessary to cool the magnetic coils. Unless there will be a breakthrough in room-temperature superconductivity, helium will still be needed and consumed (through leakages) at a faster rate than the fusion reactions can provide.

source: https://doi.org/10.1016/j.fusengdes.2013.01.059


Even with hypothetical very high temperature superconductors we still want to run cryogenics to push the critical current higher. At some point mechanical stress would be the limiting factor but there is no path towards discovering such a miracle material. If one were to be discovered it would revolutionize our world.

For the foreseeable, we use HTS materials, that can superconduct at LN2 temperatures, with helium.


No, there's very little helium produced for the same reason that fusion generates massive amounts of energy from very tiny amounts of fuel. In fact there'd be more helium produced in the nuclear reactor generating the tritium than there would be in the fusion reactor burning it. Eventually commercial nuclear fusion reactors will generate their own tritium from a lithium blanket but for now that's all from fission reactors.


One thing's for sure - the scientists working there will all have really squeaky voices


No idea. But it would be absolutely awesome if we had another age of airships.


I thought they'd found masses of deposits recently?


As an uneducated observer to nuclear physics, I could not tell the significance of this achievement. Did we finally learn how to extract more energy from a fusion rector than we supplied to operate it? Could anyone more in the know here explain in simpler and more practical terms please?


The energy generated is a small red herring here.

For a long time one of the hardest problems in fusion reactor design is what the hell you make it out of. The big win here is that they replaced the walls of the reactor with a new alloy, and it worked according to what theory predicted, which gives them the green light for using that material in ITER.

To simplify a little (ok, a lot) there are two big materials problems inside the reactor. The first is the walls: you need something that's going to survive the temperatures, not disturb the reaction, and not get too radioactive in the process. They previously used carbon, which isn't great: it gets radioactive because it absorbs tritium, which is in the fuel. This experiment used a beryllium alloy, which doesn't absorb nearly as much, and worked, validating the material choice for ITER.

The second problem is to do with the exhaust. You need to get hot plasma out of the chamber without disturbing the ongoing reaction, and with a tokamak that means ridiculously energetic particles hitting a solid divertor. Again, the problem here is what materials you might come up with that stand a chance of surviving useful operational periods. ITER is currently planned to use beryllium walls and a tungsten divertor, but I don't know what JET's divertor is made of at the moment to know whether this experiment will have informed whether tungsten is a good enough choice.

What all this means is that there's one less thing on the "ITER might fail because of..." list.


> Did we finally learn how to extract more energy from a fusion rector than we supplied to operate it?

No.

> Could anyone more in the know here explain in simpler and more practical terms please?

It's impossible to tell because the story is incoherent. The central claim is that they "release[d] a record 59 megajoules of sustained fusion energy" but this makes no sense. One can talk about sustained power (over a period of time) but "sustained energy" is a category error because energy is just power integrated over time. You can get 59 megajoules out of your wall socket if you wait long enough.

They apparently did something that had never been done before, but there's no way to tell exactly what that was from what is written in this story.

(This kind of obfuscation is not unusual in fusion research. A cynic might argue that this is because if they were clear about the actual state of things their funding would cease.)


They expand under the article (not the clearest visual design though, I thought it was an ad or some "related" section)

The record is for energy generated. They generated the most energy, however they did not generate the most power (unlike the previous record which generated both the most energy and most power) because they were focusing on sustained generation

The sentence "59 megajoules of sustained fusion-energy", where fusion is the source of the energy, doesn't make sense

I think they meant it as "59 megajoules of sustained-fusion energy" where sustained fusion is the focus of the experiment (not sure I managed to get through what I meant and it's worded awfully on the website)

I hope / expect the actual paper/technical reports which will come out will be worded more clearly


I don't believe that this is entirely mis-stated.

We already know that fusion power plants are going to operate by igniting plasma in short bursts -- a few seconds, maybe 10s at most -- and generating a huge amount of power during that single burst. You then ignite it again and again.

The question is how much total energy you can extract from each of those bursts. By that metric, the total energy is what's important, not the power. Producing 10 quadrillion watts of power isn't that useful if it's only for 100 trillionths of a second. (Both numbers pulled from an actual recent result last August. [1])

"59 megajoules of sustained fusion energy" means a single burst produced that much. That's significantly more than the paltry 1.3MJ from that other result I just linked to.

Yes, of course you could get that much from a wall socket over the course of hours, but we know we haven't been able to sustain a fusion reaction for a few seconds, so that's the timeframe we're talking about for a single burst.

1. https://www.livescience.com/fusion-experiment-record-breakin...

EDIT: And, at the bottom of the article it says that the reaction ran at 11MW, so plugging that in it sounds like, indeed, it ran for 5 seconds.


> "59 megajoules of sustained fusion energy" means a single burst produced that much.

In what sense is that "sustained"? A typical power plant produces that much energy in less than a second on a continuous (i.e. sustained) basis. Producing 59 megajoules once is basically a joke. It is analogous to detonating a pipe bomb (at a cost of several billion dollars) and claiming that as significant progress towards an internal combustion engine.


> A typical power plant

Fusion power plant aren't typical though


Yes, that is exactly the problem. If they are ever going to be commercially viable they need to become typical. 59MJ per cycle isn't going to do you a lot of good if a cycle time is measured in months as is currently the case. You have to get that cycle time down to fractions of a second at this energy level before you even have a chance at commercial viability. 59 MJ is a tiny amount of energy by the standards of commercial power generation.


I hope you realize that these are research reactors that are not designed to give you a low interval between cycles or produce power. They are meant so clarify some of the open research questions for the likes of ITER/DEMO that will integrate these findings into things that are actually designed to produce a lot more power quicker.


Yes, of course I realize that. I hope you realize that even if they get these research reactors to work (which is far from given) that there will still be a shit ton of work to be done before this technology can be used to produce commercially viable power.


internal combustion engines do this and are basically sustained. integrate over cylinders and time. Aka diesel or gas generators.


See this comment for my reply:

https://news.ycombinator.com/item?id=30274449


Your description made me wonder if it would be possible to make an ICE to extract the power. I then found a paper called Fusion Internal Combustion Engine from 2010 [0]. Does anyone know if there was any merit to this idea and if anything else has come of it since?

0: https://www.researchgate.net/publication/215544178_Fusion_In...


A few elementary calculations reveal how feasible this might be. A typical ICE produces a few hundred horsepower using 4-8 cylinders rotating at a few thousand RPM. 1 HP = 745 watts. Figure out how much energy is released per cylinder on each cycle, and compare that to the energy released in a typical fusion ignition. Also note the cycle time of an ICE rotating at a few thousand RPMs, and compare that to the cycle time of a current state-of-the-art fusion reactor. (Hint: the former is measured in milliseconds, the latter currently in months if not years.)


I'm a layman and so its possible I am missing some limiting factors but I do feel as though this rebuttal does not take into account the possible ranges of values that can be configured when tweaking things like scale and operating speed. For example the Wärtsilä-Sulzer RTA96-C operates at 15-102 RPM generating 100,000 HP (or 74.5 megawatts for your comparison) [0].

Nor does it take into account the difference between a prototype investigation being constantly modified for experimentation and analysis and a production system built to purpose.

0: https://en.wikipedia.org/wiki/W%C3%A4rtsil%C3%A4-Sulzer_RTA9...


Yes, I probably should have used numbers from a large diesel rather than an automobile engine. Wow, the Wärtsilä-Sulzer RTA96-C operates at speeds as low as 15 RPM! That is just mind-boggling. I found this video:

https://www.youtube.com/watch?v=jXHvY-zY9hA

Still, I think you will find that even this doesn't help all that much. A cycle time measured in seconds rather than milliseconds is still orders of magnitude away from what can presently be achieved.

> the difference between a prototype investigation being constantly modified for experimentation and analysis and a production system built to purpose.

AFAICT, no one has ever built an ICE that is within even an order of magnitude of realistic operating parameters of a fusion ICE. It's a whole 'nuther level of engineering challenge beyond just getting the fusion itself to work. I'm not saying it's impossible, but I'll give you long odds against seeing it happen in any of our lifetimes.


> You can get 59 megajoules out of your wall socket if you wait long enough.

Assuming a French wall socket, 240 V at 13 amps, and a pure resistive load, that will take

  $ units
  Currency exchange rates from FloatRates (USD base) on 2020-11-15
  3677 units, 109 prefixes, 114 nonlinear units
  
  You have: 59 MJ
  You want: (240 V * 13 A) * s
          * 18910.256
          / 5.2881356e-05
  You have: 18910.256 s
  You want: hms
          5 hr + 15 min + 10.256 sec
which helps put the figure in perspective.


> Results fully in line with predictions, strengthening the case for ITER

This is the main take away for me, JET is not a standalone project, it's part of the whole ITER project which is supposed to go like this:

+ JET as a scaled down model provides testing and data for + ITER which I believe is a full scale model and is supposed to generate net gain (heat in vs heat out, not net electricity) and provide information to + DEMO which is supposed to produce net electricity (though not at market rate costs)

So the fact that it worked as predicted is a good sign (or at least as good as we can get) that ITER will work which will be a good sign for DEMO etc

Also not an expert though


> Did we finally learn how to extract more energy from a fusion rector than we supplied to operate it?

No. The issue is that most people only report the gain over the plasma (i.e. how much energy was put into generating the plasma) rather than the full amount of energy put into the process (i.e. superconductors, magnets, generating the deuterium/tritium, maintaining the sun-like heat, etc). If you add this to the computation, you end up having to have a "fusion-gain" of around 50x to break even. The reason people report the plasma efficiency instead of the actual operating efficiency is to get funding and hype.

Don't get me wrong, this result is still impressive, but it's still orders of magnitude off of the required efficiency.


50x is not orders of magnitude off. It's one order of magnitude


According to Wikipedia (German) the Wendelstein 7-X already did 150 mega joules of "sustained fusion" [1]. So how is this record breaking?

[1]: https://de.wikipedia.org/wiki/Wendelstein_7-X


That's the energy into the plasma. W7-X plasma did not produce any energy because it was not using nuclear fuel. Don't despair! W7-X is an incredible machine and Germany and IPP should be proud of their achievement. The ECRH system is awe-inspiring and the sheer length and power of the pulses is unmatched by any MCF machine on the planet.

Until recently no MCF device on Earth was nuclear. Today's headline is the return of JET's nuclear operations.

There are dozens of MCF machines operating right now and only one is nuclear. That means Q as a metric is only useful for one machine. Something to think about when people toss around Q-related rhetoric around here.


Wendelstein 7-X is for plasma science, it is not intended to fuse anything.


> though this experimental reactor will not produce electricity, it is used to evaluate the main components of a future fusion power plant


And you can evaluate fusion reactor components without fusing anything. Or are you disagreeing because I summarized it with the term plasma science? In that case, I was not really happy with the term either but could not come up with anything better. My point however is that Wendelstein 7-X is not intended to fuse anything, not to precisely describe the nature and goals of the experiments.

Google translation of the beginning of the Strahlenschutzaspekte (radiation protection concerns) section from the German Wikipedia article [1]. There will only be a tiny bit of accidental fusion.

Wendelstein 7-X only examines plasmas made of hydrogen (H) or deuterium (D), so it does not use a mixture of deuterium and tritium, as is necessary for later fusion reactors. The omission of this reduces the release of neutrons and enables access to the facility and the surrounding instruments immediately after the end of each experiment. This facilitates modifications for subsequent experiments. During operation, however, access to the torus hall is generally not possible for safety reasons (danger of voltage flashovers, stored energy in the magnetic fields).

Hydrogen is provided as the working gas for normal operation. In addition, experiments with deuterium are to be carried out in order to extrapolate the properties of a plasma mixture of deuterium and tritium. Fusion reactions between deuterium nuclei, in which neutrons are released, can occur to a small extent. To shield them, the torus hall is surrounded by a 1.8 m thick wall made of borated concrete.

[1] https://de.wikipedia.org/wiki/Wendelstein_7-X#Strahlenschutz...


OK so with fusion everybody loves it because the fuel would be clean and nearly endless.

Isn't that what solar power offers?

Nobody wants to deploy solar due to high upfront cost. However, wouldn't the startup on a fusion reactor be much greater?


The thing is, a commercial-scale fusion reactor could produce the same energy as a truly vast solar array, and also produces power at night, does not need to be exposed to wind and rain to operate and can be scaled directly instead of with costly battery arrays.

Solar has the upside of actually producing a power surplus already, though.


How about putting panels in space?


Solar comes with a lot of challenges for large-scale usage as a replacement for coal, nuclear, etc. Really, the only thing better about solar at the moment is that it is available.

First off, the daylight cycle is an obvious concern and there still isn't a great way to store solar energy during the day for use by cities (or generally large consumers) at night. Not to say it's not possible, but people are largely still trying to figure out what the right solution for that is.

Second, the startup requires a significant amount of land in advantageous locations for sunlight. There's a lot of the planet that just won't see the same advantages as others, and transporting energy long distances to them is another unsolved problem.

Lastly, and this is more for fun, but solar won't be as useful when we as a species aren't exclusively on earth anymore. Fusion would be a pretty nice step forward for things like space travel.

Both have a really high startup, but achieving fusion would mean 24/7 clean energy that works regardless of environment.


An other large drawback with solar is the required latitude. The further north it gets the fewer hours of sun light, and the energy you get is lower from the lower angle of attack. At the same time the energy needed for heating goes up during winter.

Solar makes great sense for places where energy consumption is higher during the summer than during winter.


I know a guy who lives in Canada pretty far north of the US border. He heats entirely with PV solar. He claims it's also way less expensive than other fossil fuel heat. Basically PV solar cost has plummeted to the point that it is conceivable this sort of thing is possible. No need for a battery here as he pumps his electrons directly into concrete slabs which then radiate heat at night.


Storing solar power for the night isn't hard. It has been possible to do so for decades with concentrated solar power (CSP). You heath up salt directly with the sun. The hot salt can then drive steam turbines at night.

CSP has been dying for years however because Photovoltaics are cheaper. However, this is largely due to regulation. Solutions are picked based on price per kWh. CSP cannot compete on that with Solar cells. However today government have started modifying regulation so that a premium price is paid to those which can deliver power at night.

CSP projects then become competitive since unlike solar cells they can deliver power at night. In the past CSP projects delivered power the whole day. Now they are increasingly only delivering power at night, thus getting the premium price.

This goes to show that to get desired development in renewable energy it is crucial to get regulation right. Until now, regulation has not properly rewarded projects which can deliver power on demand.

However once that is in place, thermal and cryogenic storage of power will become competitive and be built.


Pedantically, both are fusion, one's just 1 AU away.


> First off, the daylight cycle is an obvious concern and there still isn't a great way to store solar energy during the day for use by cities (or generally large consumers) at night. Not to say it's not possible, but people are largely still trying to figure out what the right solution for that is.

Not a concern at all. Google renewable energy storage. It is there but there is profit merit, so it is not welcome


Could you just be more specific about the storage method you're hoping I'll find on google? I know that there are a number of "viable" options for massive population centers in theory (or even in limited use today), but to call it a solved problem is, to my knowledge, incorrect


We will need an infinite impossibility drive to break the light barrier. ;-)


A fusion reactor can conceivably provide a continuous, uninterrupted stream of energy, and from any location, while solar (and wind) energy can only be harvested intermittently, from certain specific locations.

The main issues with renewable energy sources today are electricity storage and transmission. If it weren't for these limitations, wind and solar would already be superior to other means of energy production.

Most likely problems with storage and transmission will be solved first, before fusion energy is proven to be commercially viable. However, there is no guarantee that they will be—especially in the case of transmission, which is primarily a political problem.


The problem with solar is unpredictability and A LOT of batteries needed to bridge the mismatch between production peaking at noon and consumption peaking at late evening.

Both of these are solved with fusion power.

Energy market operates on the assumption that whoever unbalances the network has to pay for balancing it. Providing too much and too little energy is both bad - you have to pay someone else to use more/less or to produce less/more to balance the mess you made. There are specialized powerplants for this, they are "on standby" and jump in when needed - and they charge much more than the normal powerplants. When there's a big shortage they can charge absurd prices for energy. And if you caused the shortage by mispredicting weather - you have to pay for it.

This makes the energy provided by solar panels much less valuable than the energy provided by a predictable, controllable source. Often by 1:10 factor.


But if we as a society decided to put a large investment into solar and had that augmenting the grid, you should be able to dramatically reduce the amount of fossil fuels used to produce our daily energy, thus slowing climate change. Imagine if we could cut fossil fuel energy by 40-50% and rely more heavily on solar/wind. Fusion may not be available for another 40 years and who knows what the environment situation will be then so we should probably be looking to leverage any clean sources that are available right now.


But nuclear power is also not predictable, as plants regularly experience unexpected downtime. No power source is fully predictable, which is why you need controllable power sources to make up the difference.

I would say solar’s problem is controllability. You can only turn it up to the limit of the amount of sun received, which is none at night, and sometimes very little in the day.

It remains to be seen how controllable fusion power will be. Will it be for base load only, or will it also be useful to flexibly dial up and down for variable load? Much of current nuclear power is base load only. Clean base load power is still super useful, but it is not a complete solution.


Yes, unexpected stuff happen to baseload powerplants too. Once every year on average maybe? Probably less. If that happens you may need to pay for balancing once a year.

Meanwhile solar is unexpected on the scale of minutes to hours, every day. It's not the same.



You don't need batteries for this. You could build concentrated solar power (CSP), instead. These have trailed PV development for years because they have not been paid a premium for being able to deliver power on demand. Thus PV has outcompeted them. But with better regulation giving them a premium for delivering power at night they are getting a comeback.

Also thermal storage and cryogenic storage can easily provide enough capacity. The problem is that they are not as efficient as batteries. If you buy electricity but only get 50% of that electricity back after storage, then you need to sell at 200% the price you paid.

Electricity prices don't swing enough today to make the feasible. But if far more wind and solar was built, then you would get much cheaper power at peak, which storage providers could buy and sell with a profit.


Imagine you live in a smallish, not-so-sunny country like the UK. How much of your land area do you have to cover with solar panels in order to completely rid the nation of fossil fuels?


Apparently, about 12% of the land or 29,690 sq km in order to meet current energy demands (electricity, petrol, oil and gas). Apparently, only 6% of the country is currently built on which suggests that for any country of a similar latitude, you can estimate a land total of double that currently used per person. This does not take into account energy storage and assumes no energy is generated at night.

https://www.finder.com/uk/solar-power-potential


Of course that 6% only counts land usage by humans. How many (additional) non-human habitats would you have to decimate to cover 12% of the land with (ugly) solar panels?

Maybe thats acceptable in some deserts, but pretty terrible in other places. 1 step forward, 1 step back.

Plus that figure is for our current energy usage, which is only going to increase over time.


Put the solar panels over parking lots.

Production is very near the usage sites (for BEVs, very near). It keeps the cars cooler in summer. And you can't make the parking lots any uglier.

(I am aware there aren't enough parking lots, but this deals with a fraction of the needed space.)


Curious, do you find server farms also ugly to look at? To me both server racks and solar panels look like modern technology.


1 sq km = 100 hectares = 100 GWh of energy produced per year in northern Europe.

29000 sq km = 2900 TWh

Which is 10x the current electricity use of UK.

I think they may be overestimating the numbers by taking the petrol, oil and gas verbatim - whereas they should consider that electric cars have way higher efficiency, and electric heating can be done also way more efficiently than gas heating (because heat pumps).


This guy electrodacus.com swears that panels are so cheap now that it really only makes sense to heat with PV directly. He stores extra into an array of concrete slabs which then radiate out over the night. He built a special type of MPPT to orchestrate this flow of energy from PV into thermal mass. He lives in deep freeze Canada.


Interesting. In Poland, where I live, I researched this recently, for my mother's house - and it won't work. The heat is needed from October until April, and most of that time solar panels generate close to zero electricity.

In the end, my mother will have a significant surplus of power during summer (even with storage), and will still need to heat up house in winter using gas, or grid electricity (coal :/).

I read about some Nordic researchers developing long-term heat storage, which would be way better.


Fun fact - solar energy production over a year only differs by a factor of 4 between worst and best reasonably inhabited places.


Another fun fact. When I installed my PV array, I got the alignment of one of them wrong by 1 degree (from due south). I looked up how much power I lost from this mistake ... not much, about 1%. Then I used the same tool to check what would have happened if I had installed them facing due north. To my surprise: only 15% less power!


> only differs by a factor of 4

how is a factor of 4 "only". It's absurdly high.


Is it? Oil/coal/gas reserves differ by factors of millions.

You only get 3 times less power/area of solar in Scotland than in California. That's pretty surprising (part of it is higher efficiency of photovoltaic cells in lower temperatures) and pretty great for our future.

For example it means once we switch from fossil fuels pumped out of the ground to fossil fuels generated with surplus renewable energy (and it's not that far - it will probably be profitable in most of the world in next decade) - there will be much less incentives for fossil fuel dictatorships.


I have a bunch of renewable energy calculations here:

https://nextjournal.com/erik-engheim/renewable-energy-calcul...

They show that you need roughly 25 m2 to cover energy use of a family. That easily fits on most roofs. A regular apartment is at least 80 m2, so you only use a fraction of the roof space. That means regular roof could in principle cover a 3 story apartment building with all the needed power.

Of course industry and business also use power. But if every house had 50 m2 solar panels on the roof on average you would cover that as well.

Thus roofs are in principle more than enough for most countries. Sure this will not always work, but it actually works quite well to combine solar power and agriculture: Agrovoltics. It can actually improve yields and give extra income to farmer which can sell electricity.

These kinds of things is not taken into consideration when comparing land usage of nuclear power and solar power. Solar power can be mixed with residential areas and farms. Nuclear power can't. You are not going to place a fusion power plant on people's roofs.


Morocco or southern Spain isn't that far away.


Solar takes up quite a lot of space, but most importantly only works for a portion of a 24 hour cycle.


The Chinese & Japanese governments are investing in space based solar which solves the nighttime problem: https://wonderfulengineering.com/china-is-aiming-to-build-a-... https://nextrendsasia.org/japan-pioneer-of-transferring-sola...

But we really need more energy storage, and there are plenty of good ideas in this area too: better batteries, gravity bases systems, crowd sourced storage, etc.


I don't know much about the physics, but it seems like you'd want square miles of solar panels, even in space, and then there's the problem of getting that energy back to earth. On the other hand, in space you'd get a lot of light frequencies that are rarer on Earth. It's not clear to me if those could be harnessed somehow. Regardless, it's a creative idea.


Ideas are great however even a small country like the Netherlands is looking at a trillion € bill to switch to 100% renewable by 2050.


I remember that early this autumn Sweden had to borrow energy from other countries because it relied too much on renewables which turned out to be unstable.


The electricity import and export of individual countries fluctuates constantly. A nice map with live data can be found here: https://app.electricitymap.org/map (in German).

Dealing with the instability of solar and wind energy is very complex and requires numerous measures, such as better integration of wide-area electricity grids, more electricity storage, more generation reserves, etc.

But even nuclear power generation is dependent on the weather. During heat waves, nuclear power plants located on rivers in Germany and France repeatedly had to shut down because there was not enough cooling water available or the water in the rivers would otherwise have become too warm.[1] During cold spells, nuclear power plants had sometimes to be shut down because the supply of cooling water was no longer guaranteed due to ice.[2]

[1] For example: https://www.reuters.com/article/us-france-electricity-heatwa...

[2] For example: https://fortune.com/2019/01/31/ice-shutdown-new-jersey-nucle...


The basic problem is energy storage. If your not talking gigawatt-days then it's not feasible and most storage currently is megawatt-hours... i.e. because you need to store energy made during the day to use at night, to make solar power realistic you need a way to store huge amounts energy. BTW: The England power grid is about 30 GW. So 1 GW-day is just shy of an hour of demand.


No. Fusion is completely different from solar. It can provide steady energy without going down for years. Solar goes down multiple times a day.


Name a single fusion plant that has been running uninterrupted for years.

Meanwhile Australia has retooled for 10% Solar and batteries in a matter of years, that number is rapidly increasing, and is turning off their coal plants.


It can do that if they manage to make it work as planned

Solar, even under ideal conditions, needs backup and much more manpower and management to make it work... and even then, it is not reliable.

So, solar is not a replacement for fusion, or nuclear or coal for that matter. It is great for supplementation though.



They are high maintainence and very expensive, but the thermal storage is very promising, in that it doesn't have the worst downside of solar. China has been experimenting with them, so I'm hopeful that they will come up with a cheap way to do that.


> Name a single fusion plant that has been running uninterrupted for years.

Minutes, even. Perhaps you meant fission?


No, I mean fusion. The parent comment claims "[Fusion can] provide steady energy without going down for years". I want a single example of this.

Meanwhile, we have massive grids of solar and battery being installed _today_, and existing installations replacing coal plants.

I'm tired of people talking about fusion (or even nuclear, as it's so mired in public FUD) as if it's some panacea. We have a solution right now: Solar and batteries. It works in places with cloudcover. It works in cold and hot climates. It works at night. It's getting cheaper every year.


We haven't invented commercial fusion power, so none; but theoretically that is how they would function.

Solar and batteries are nice but they're not yet cost effective. They're getting better. But you can't just handwave away real problems from your armchair viewpoint and assume thats all fine.


> We haven't invented commercial fusion power

We don't have working fusion power, at all.

> Solar and batteries are nice but they're not yet cost effective

"Cost effective" is a judgement call, not physics. If I told you that the cost of coal-generated electricity was that your great-grandchildren would live in an impoverished and difficult world, you might not view that a particular cost-effective either, yet somehow that's the "standard" against which things are judged.


> We don't have working fusion power, at all.

Sure we do. Look no further than this article. We can make it, but its not commercially viable.

> "Cost effective" is a judgement call, not physics. If I told you that the cost of coal-generated electricity was that your great-grandchildren would live in an impoverished and difficult world, you might not view that a particular cost-effective either, yet somehow that's the "standard" against which things are judged.

Ah yes, think of the children.

Yes, coal is problematic, but the reality is that energy is expensive and we need a lot of it. If we tried to go full solar right now it would cost trillions of dollars, and the grid would still fail in the winter when heating is most important, and the economy would enter a massive depression as the cost of doing things gets both more expensive on average and extremely volatile.

You say this is a judgement call, not physics, but then go on to just broadly make assumptions about all of the relevant facts. You're not the one being logical and fact based. You're the one observing, yes, we have a climate crisis, and thus assuming that a radical solution for which you have no particular understanding of the economic or infrastructure implications is the right one because it's at least different from what we have now.

Renewables are good. They are getting cheaper. They're growing in capacity. And yet, I guarantee you, we cannot go full solar now. And I also guarantee that you do not have nearly sufficient of a view of the system dynamics to be making statements as bold as you are. This is hard. It's not just evil greedy coal mine operators ruining everything.


> Sure we do. Look no further than this article. We can make it, but its not commercially viable.

Q total is way below 1 (translation: it took far more energy to make the energy that was produced, than was produced). We do not have working fusion power, if "working fusion power" means "you get more out than you put in".

As for the rest of this, I have no idea who you think you're replying to. Just one follow up, neverthless:

> And yet, I guarantee you, we cannot go full solar now.

The USA spent more than US$300M per day on the war in Afghanistan, for 20 years. I guarantee you that if "we wanted to go full solar" now, we could. US$2T buys you a lot of anything, including even today's vaguely clunky battery tech.


> Q total is way below 1 (translation: it took far more energy to make the energy that was produced, than was produced). We do not have working fusion power, if "working fusion power" means "you get more out than you put in".

That's not what it means. Working means it works. Can you produce fusion power? Yes. Can you do so in a commercially viable way? No. Q is obviously a part of this. Uninteresting semantics.

> The USA spent more than US$300M per day on the war in Afghanistan, for 20 years. I guarantee you that if "we wanted to go full solar" now, we could. US$2T buys you a lot of anything, including even today's vaguely clunky battery tech.

And I'm telling you, no, we could not, because that's not how the world works. From many perspectives, including economics of how to actually acquire all these solar assets many of which are already being consumed as fast as produced and dependent on limited metals supply chains; land availability with reasonable transmission setups; grid capacity to absorb these new generation facilities on the transmission lines; power availability during non peak times; and the preposterous externalities of trying to rapidly undermine the global energy market.


> Can you produce fusion power? Yes

If it takes more than 1W of input power to produce 1W of power from fusion, then I'd say the answer is no. The distinction is not "commercially viable", it's "net energy production". We're not there yet (and are actually quite a lot way from it).

> And I'm telling you,

... that US$2T is a lot of money, and that's just what we spent on 1 war. Yes, there would be complications and side effects and what have you. Money, in our system, combined with the other abilities of the federal government, can do a lot.


> They're getting better.

Solar is getting so much cheaper, at such a fast pace, that I really don't understand how one can disagree that it's the future of our energy grids. Installing solar is a no-brainer in some parts of the world now, and in the very near future (extrapolating from the last 10 years), it'll be every part of the world soon.

What problems am I hand waving away?

https://www.statista.com/chart/26085/price-per-megawatt-hour...


I don't get why you and many other commenters are so against the idea of fusion. Solar is decent, not perfect by any stretch, so we should just give up trying to solve the energy technology for the next 200 years? It's not even like it's one or the other. No one is abandoning solar to work on fusion. But fusion, if it works, is orders of magnitudes more efficient than solar is. It opens avenues that are considered impossible and science fiction today.

It's like being back in the 1700s and arguing that research into petrol is a waste of time. I absolutely do not understand this mindset.


I'm not against fusion, there just is simply no viable fusion power that can be built today. It's not going to get here fast enough. We need to adopt renewables yesterday. There is no time to be wasted pretending that fusion provides any value aside from starry eyed theoretical aspiration.

We will not be here in 200 years to enjoy fusion if we don't adopt solar and battery _right now_.


> We will not be here in 200 years to enjoy fusion if we don't adopt solar and battery _right now_.

Technically, none of us will be here in 200 years.

I very much doubt if climate change will lead to an end to the human species, so I think a better way talk about this stuff is to frame it in terms of our descendants living in an impoverished, less beautiful, more strife-filled world.

But yes, FFS, action yesterday or last week, and make it trillions of dollars worth of action, like an actual war, but for infinitely better reasons.


I'm 48.

When I was 16 I remember reading a Scientific American article that was describing how nuclear fusion was around the corner. Within the next 2 years!


I hear a lot of stuff like this and it just doesn't jive with my childhood experience. I have a suspicion that bullshit was, on some specific channels like pop sci, much easier to pass in the pre-internet days. Or at least the signal : noise ratio has gotten much better with a voice of reason saying "no" whenever these things pop up.

It's always been clearly communicated to me that fusion is extremely hard and we're not that close to getting it working.


Solar is, without a doubt, a major part of future energy grids.

But this chart is the levelized cost of energy. Its not the price at which you can get it. Energy demands are higher in winter. They are non trivial at night. The cost of energy might be low, but the price at which you can get it may be very high if not enough is available.


A lot of the "not available at night" argument can be solved with.... owning an EV.

I use 6kWh / day. (not sure how! but that's what the power company says)

A decent EV battery holds 20 kWh or more.

Boom. There is my night time storage buffer.


Average home uses 30kWh per day. And that's average. Winter is higher, and would be much much higher if we were trying to use electricity to heat homes instead natural gas. Where do you live? CA? You have a lot more sun and land than other areas. Building the generation capacity in your area might not help areas that actually need the power to the north and east. And what if you need your car to have full power? What if you're not a low needs residential unit but a hospital? Or a factory? What if you have a couple low sun days in a row? What if your city just does not have enough power in reserves and its very cold or very hot?

Battery tech and solar is great, but its not the perfect solution.


to be fair, you need more than the EV. Using your EV battery as a power source to feed into your main house/home wiring is not crazy complicated, but it's not just a plugin.


the sun


This is a great example, we should try to make use of all that sun (is there another word for that?) energy!


Obviously, it is a bit silly to point to the sun and say it's a successful fusion reactor in a discussion meant to refute solar's usefulness. Despite that, it is an example of the principles of fusion working quite reliably, and it should stand to reason that having smaller sun-like power sources would be preferable to relying on a single fusion reactor that's only available half of the time.


Fusion power could give you power when you need it unlike solar power which would need storage. Of course Fusion power is so complex and expensive that it is likely far cheaper to simply build solar panels and add storage.

While Fusion obviously has merits I think it is overhyped as a solution. Molten Salt Reactors are a much more sensible solution if nuclear power is the desired solution. Why? Because they actually generate LESS nuclear waste than Fusion power plants.

The big selling point of Fusion reactors is that they don't generate any nuclear waste. Except they kind of do. Molten Salt Reactors (MSR) in contrast actually "eat up" nuclear waste. You can power them on nuclear waste and get less waste out. Thus an MSR has negative radioactive waste production. Fusion has positive waste production.

Unlike Fusion reactors we have already proven that we can build MSR reactors. It doesn't mean I think we should give up Fusion research. I just think that if we want to get cheap, clean and reliable power today, then solar, wind and MSRs are probably the most sensible options, not fusion.

https://erik-engheim.medium.com/yes-clean-nuclear-power-exis...


Solar is using the fusion generator in the sky, which is out of view half the time and obscured by clouds some other times.

Fusion is having our own little portable sun that can be utilized more efficiently.


Solar panel manufacturing and disposal is far from clean though.


You can easily throw solar panels in a land fill. It isn't a big problem. Slag heaps from coal is already a much larger problem than a solar panel landfill would ever be. A single coal mine has a bigger slag problem than all the worlds solar panels combined.

Yes, we should take the problem serious, but it is also grossly overrated. It is certainly not a reason to avoid solar panels.

https://www.solarquotes.com.au/blog/recycling-solar-panel-wa...


What disposal? Less than 1% of the solar plants have been ever decommissioned. It's hard to set up recycling plants if you have nothing to recycle yet.


Lifespan is 25-30 years, they don't last infinitely. What's your point?


The point is that it's hard to expect industrial processes for recycling solar panels now, since there is no market for them yet, and won't really be any for the next decade.

Also, the lifespan is 25-30 years, but after that time the panels will still maintain 50-80% efficiency - so they can be reused for different purposes (or shipped to Africa, where there is a plenty of cheap space, sunlight, and they will work well).


And you think this is going to be any different for fusion plants?


You seem to think it's not going to be any different (or maybe even worse). Could you elaborate?


A fusion reactor works at night, and could produce considerably more energy per square foot of land area than photovoltaics.


This is super cool, but I didn't see how much energy was put into the system in order to generate the output 57 MW, and whether the output energy was all usable (e.g. could the team have actually boiled 60 kettles of water?). It'd also be useful to know how whatever energy is needed to run the machine would be expected to scale as the output is increased.

Don't get me wrong, fusion (IANANP) seems to be the best approach for long-term energy, and I'm strongly in favor of lots of research and experimentation in this area, and this seems like incremental progress. Kudos to the team!


>I didn't see how much energy was put into the system in order to generate the output 57 MW

It's in the article: 500 MW. Scientists hope further experiments move into breaking even and later having net gains.


It's great to have a nuclear magnetic confinement device anywhere on the planet again. It looks like things are running well: profiles of NBI, and density are all under control.


According to Sabine Hossenfelder, published numbers are frequently mis-stated on purpose. When you look at frequently reported Q Plasma (or plasma efficiency) we are not that far from it being > 1. However, we should look at Q Total (total efficiency), which is still way below < 1, even in the best plans.

https://www.youtube.com/watch?v=LJ4W1g-6JiY

For years, I was hoping fusion is close. After watching Sabine's video, I'm not so optimistic anymore.


She makes several significant mistakes in that video. One example is the energy used to heat the plasma is now heat in the plasma identical to the heat generated by fusion. This means you can recover a percentage of that with a steam turbine.

Second a great deal of ITER’s energy usage is as a science experiment not a fusion reactor. Most of their monitoring equipment for example is irrelevant to an operating power plant. Thus Qplasma is giving relevant information where Qtotal is largely meaningless at this stage.


But her point stands even if there were mistakes: the press and many scientists, even if unwillingly, have failed to communicate the real state of fusion as an energy source. And I can believe that maybe some representatives did not fully understand the difference between Qtotal and Qplasma and the amount of time a reaction can be sustained (all three things that they would understand if they were explained clearly).


Some context please. Where did they make this failure in the hour long press release?


The parent comment was talking about a video outside of the context of this entry in HN. My reply was in the context of parent comment referring to that video, the video in question provides excerpts of example of that failure of communication.


Sabine is overly critical IMO. The distinction she is making is known to anyone who has spent a little bit of time thinking about fusion (hopefully that includes the grant writers) and projects like ITER are explicitly aiming for Q=10, not just "breakeven"


That's kind of her thing. She is usually right, but also overly pessimistic in a way opposite from the popular press over-optimism.

I get frustrated because it paints science in an undeserved negative light. It is at least truthful, in a way that most anti science writing is not. Mostly I find it unhelpful in that it points out problems without either explaining why they were reasonable or giving a real alternative.


Indeed. Her arguments made in the aforementioned video are slanted. There are many lies by omission that paint an inaccurate worldview for laypeople.

It's incredible that the term "Lawson criterion" wasn't mentioned once.


Sabine is not as "right" as many of her pop-sci fans seem to want. Most of her opinions about the direction of theoretical physics are not really falsifiable or "right."


That's correct. That's sort of the point. Fundamental research is in kind of a slump right now, and it's hard to judge where (or whether) it should continue.

I don't think much of her "just do something different, don't ask me what" approach.


Popular 'i f#@cking love science's type science deserves to be painted in a negative light.

IFLS pushers are motivated by money, clicks, and clout and to a large extent misinform the public.


Agreed. But there is blowback on the actual scientists doing the real work.

I suppose you could say that they also get benefits from appealing to the IFLS crowd, so live and die by the same sword. I believe IFLS does more harm than good, but it's hard to be sure.


ITER is a bit too optimistic IMHO. For example I've always found the "UNLIMITED ENERGY" on their website a bit funny https://www.iter.org/


Which Q? Qtotal or Qplasma?


Qplasma. Supposedly, with Qplasma > 20 Qtotal should also be > 1 with current magnet tech.


Nothing concrete to add, just the anecdote that the plasma physics class I took in grad school hands down had some of the sketchiest looking physicist math I think I have ever seen. Felt like a SWAT team from the mathematics department might burst through the door at any time.


Just imagining the mathematics SWAT team coming through the door and swatting the marker out of one of my physics profs' hands when they went from ydy/dx=x -> ydy=xdx as if they were simply re-arranging a fraction, made me chuckle.


Like an ECON 101 course?

I felt like the Calculus SWAT Team was going to burst through the doors in that class, ha.


This was no regular spherical cow, I tell you it was assumed to be time-independent while at the same time having an oscillatory frequency.


Why would any experimenters optimize for Q total if Q plasma is a prerequisite to get anywhere?


The problem is press/marketing. When you read about this stuff 1.0 is claimed to be break-even, the threshold where fusion start to become practical. So in one piece of writing they will talk about this important number and (deliberately) conflate it with fusion being practical. Yes, getting Q plasma above 1 is necessary, but it's about an order of magnitude too low in reality. Sure everyone in the field know that. Her criticism is thats not how its presented to the outside world.


Well, because it makes no sense to try to increase Q plasma; to what end? As pointed by others, you can increase Q plasma at the expense of Q total, thus precisely optimizing for the wrong objective (fusion can be produced and studied without looking at Q plasma or Q total; although reporting Q plasma along with the time that the reaction was sustained is helpful). I give you an analogy: let's make the most power-efficient floating point unit; but let's focus on Q_float, instead of Q_total; at the end we would end with a simple very wide adder; if we want to multiply two numbers, the system will convert them to their logarithms, add them, and then use exponentiation. Yes, the floating point unit consumed very little power Q_float was great. Well, I guess you get the point.


The concern is that experimenters are wasting time on experiments with promising looking Q plasma but with orders of magnitude smaller Q total (eg pulsed laser systems)

It’s important not to forget the big picture. Otherwise you end up optimizing one piece of the system, and causing another piece of the system to work less well in a way the degrees overall system performance.


[flagged]


I don't see any criticism of her video in the link you provided.


I don’t see much criticism about that video in the linked submission.


I believe this is the original/primary source for this news. Can someone confirm?


Had to look up what JET stood for: Joint European Torus.


It's not a massive energy output - only enough to boil about 60 kettles' worth of water. ...

The British and their penchant for tea...


Tell someone how many watts/kWh/etc, and they'll maybe have an inclination of what that means to them. Tell them something in a way they can relate by referencing something they do multiple times in a day, then they can understand.

Doesn't seem like a mystery on why the reference was used.


It was a joke


Don't quit your day job


Did the British go with 240V because it makes tea faster? I don't know the history... but I want to believe.


They went with it because their Rock music sounds better:

"110v vs 220v amp tone" https://www.thegearpage.net/board/index.php?threads/110v-vs-...


I think you mean 230V, but it was picked because it's more efficient and cheaper (you can use smaller wires for the same output).


The UK used to be 240V and many countries in Europe were 220V. The compromise was for everybody to use 230V

But what I've heard is that the voltages staid the same, but 240V is still within spec of 230V with tolerances.


Well, yeah, but 300V allows smaller wires still, and 1000V even smaller, and so on. Hell, you could just wire distribution voltage straight to the socket, make the wires tiny, and eliminate the need for a zillion transformers! Of course, we don't do that for safety reasons, so the choice of socket voltage represents a compromise between safety and efficiency/power. The US and Britain made different tradeoffs, which probably means the constraints were slightly different. I could see "brews tea faster" as a significant factor in a country that once spent 10% of its GDP on tea. That would be a fun fact, if true. But maybe it isn't, and the whole thing is dumb luck and poor coordination around transformer tapping. Shrug.


I think it used to be 240V-ish (back then, IIRC they allowed larger fluctuations) but we slipped to 230V for compatibility with EU?

This corroborates that enough that I'm not checking their sources: https://www2.theiet.org/forums/forum/messageview.cfm?catid=2... moved from 240±6% to 230 +10%/-6%.


But the size of those wall plugs tho...


IMO they are not meaningfully larger than US plugs (I'm British, but have travelled to the US several times, as well as many other countries), but they are safer.


They're definitely much bigger. Look at a British power strip vs an American one. The same length but twice as many plugs on the American one.


They're definitely larger, but as I said in a sibling comment they're not directly a result of the higher voltage specifically.

German Schuko is also 230V and even safer (in countries that use it), yet still significantly smaller than British plugs.


Other European countries use ~230V as well and have smaller plugs than the UK.

The UK has fuses in their plugs, which if I recall correctly had something to do with copper shortage during the war constraining the electrical cabling for houses, but I don't want to accidentally put wrong information out, so better look it up yourself.


They are mostly that size for safety. You can't electrocute yourself nearly as easily in the UK.


Nice idea, but I believe it was due to lack of lawyers.



Here is the paper detailing the preparations, which were about mimicking an ITER-like wall:

https://iopscience.iop.org/article/10.1088/1741-4326/ab2276/...


So I read that this is good news for ITER.

Sorry for the noob question but there is something I do not understand. I thought ITER design was more or less decided now as they are building it. Should I understand that they started building ITER without really knowing where they were going to go and are using JET experiment as a way know how to build ITER?


ITER was planned in part through early results from JET in the 90s - but they more recently replaced the inner wall of JET to match what ITER will use, which was a good choice according to models but this gives empirical confirmation that it's possible to sustain the plasma using the new wall material.

All new fusion plants are a risk, that's why they're experimental. I suspect they were reasonably confident they could make ITER work and that's why they started building, but this will give them confirmation that the material choice was a good one and will also show them in advance some of the operational obstacles and possible solutions.

In other words, they knew "where they were going to go" but this gives them more confidence they were correct in deciding the direction, and will speed up their learning curve setting up the machine once built. Even if it is built and something fundamentally doesn't work about the concept, that will still be useful scientific knowledge, even if it is disappointing.


> The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power).

> This is more than double what was achieved in similar tests back in 1997.

> It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France.

I thought this was interesting as 59 megajoules of energy or 11 megawatts of power seems more than you would need to boil 60 kettles' of water. In fact, it takes 4,184 joules to raise the temperature of 1kg of water by 1 degree. Or 313800 joules to raise 1kg of water by 75 degrees. That means JET could have boiled about 188 kg of water.


That calculation is correct if you assume that by "boil water" they mean to bring the water to 100°C (which is what you'd use a kettle for usually).

However to go from liquid water to water vapor you need to add even more energy [0]. The enthalpy of vaporization for water is 2257 kJ/kg, it takes much more energy to boil water at 100°C than it takes to get there from room temperature.

Warming by 75 degrees + boiling = 2570 kJ/kg -> enough to boil 23 liters of water

I'm guessing in reality the energy needed to operate the kettles would lie somewhere in between, as a small part of the water will be boiled and most of it kept around 100°C. For 2L kettles the value seems in the right ballpark.

[0] https://en.wikipedia.org/wiki/Enthalpy_of_vaporization


>In fact, it takes 4,184 joules to raise the temperature of 1kg of water by 1 degree. Or 313800 joules to raise 1kg of water by 75 degrees. That means JET could have boiled about 188 kg of water.

This is missing the heat of vaporization[1] needed to actually boil the water though, i.e. to turn 100C liquid water to 100C steam. That's another 2250kJ/kg on top of the 313.8kJ/kg you've mentioned.

It's why steam is such a great carrier of energy for industrial applications.

I guess you could argue that you wouldn't evaporate all water in the kettle, but then you do want a rolling boil. It's probably a bit up for discussion at which point you'd stop heating the kettle.

[1] https://en.wikipedia.org/wiki/Enthalpy_of_vaporization


> I guess you could argue that you wouldn't evaporate all water in the kettle...

One does not have to argue for that interpretation - raising the temperature to boiling point, not boiling it dry, is indisputably the accepted and intended meaning of the phrase wherever English is spoken... though it would fit with a certain stereotype of scientists if a bunch of plasma physicists did not know how to make a pot of tea!


indisputably the accepted and intended meaning of the phrase wherever English is spoken

Not exactly. In American English "bring a pot to a boil" is much more common. When I read "enough energy to boil 60 kettles of water" I thought "vaporize".


Point taken - I can't dispute the fact that you read it this way!


> Not exactly. In American English "bring a pot to a boil" is much more common. When I read "enough energy to boil 60 kettles of water" I thought "vaporize".

Disagree that this is a) a much more common phrasing or b) that your interpretation would be the common one. I've yet to run into a situation where somebody asked me to "boil some water" and intended for me to vaporize all the water in some vessel.


Start by assuming a spherical teapot in a vacuum...


It's entirely disputable as evidenced by this conversation.

It's also an incredible waste of time to argue over definitions. They're always disputable because they always arise in response to two people using a word differently. Maybe they're wrong and you're right, or maybe others also use the word that way—it doesn't matter. Humility and aiming at mutual understanding is far more worthwhile.


This issue is indeed trivial, but I don't know how, in general, we are going to achieve mutual understanding without establishing an agreed-upon semantics.


It's not possible to fix a particular semantics outside a particular time and context, and certainly not possible to do so in general.

Here, as soon as someone recognizes that the amount of energy cited is way higher or lower than would be implied by their own definition, they should 1) identify the difference ("Boil here means 'boil n kettles dry' rather than 'bring n kettles to boil'") and 2) in most cases, avoid the wasted debate by adopting the other person's language if further conversation using the concept is needed.


Indeed - so it is clear what one should do here, which is to begin by assuming the author is adopting a well-established meaning within the relevant context. For this, we have a couple of clues: one is British English usage, given that this is a press release from a British laboratory, and the other is that there is a meaning in which the calculation works out correctly.

In the light of this, what is your objection to my comment? As far as I can tell, it is in conformance with your numbered principles.


Saying "X is indisputably the accepted and intended meaning of the phrase wherever English is spoken" is not in conformance with those principles at all.


There appears to be a certain irony in how, in your rather sanctimonious posts here, you seem to have generally failed to act in accordance with the very principles that you accuse me of violating.


Of course this is great news, however, it is worth taking into account it took them 25 years just to double the energy output. They are also nowhere near long sustained operation of such reactors. It really requires an order of magnitude increase before nuclear fusion becomes a realistic prospect in two decades.

I understand this just to validate design choices and it is a good step forward. However, it doesn't make nuclear fusion a reality in two decades unless further records are set using this design


JET ran its moonshot campaign 25 years ago. Moonshot as in "we don't care if the machine runs again", for whatever reason. It hasn't been funded for nuclear operations since then. It's not that it took 25 years to make progress. It took 25 years to find funding.


From the article I gathered that this run was mostly about validating some design choices for ITER, not about pushing output limits.


Yes in that sense it is a great achievement, however, it only put us a tiny baby step closer to fusion power.


> That means JET could have boiled about 188 kg of water.

> only enough to boil about 60 kettles' worth of water

Exactly, no one has 3l kettles, but it's the right ballpark. You could also run about 9k kettles for that 5 seconds but not boil them, and if you tried to run 60 kettles consuming all that power for 5 seconds you would have quite the fire...


> no one has 3l kettles

I have! Duckduckgo it.


Yep, just checked mine and its 3l, oops.


But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France.

They already started construction on a larger one? What if it had invalidated design choices?


Presumably they feel like the major design choices at ITER have already been validated and this experiment validates some more minor design choices.


> What if it had invalidated design choices?

The government money was already allocated and even the government can't unring that bell!


Is it possible they subtracted the energy required to facilitate the reaction in the first place? So net energy was enough to boil 60 kettles worth of water?


"At Jet, two 500 megawatt flywheels are used to run the experiments."

So net power is -989MW, assuming both flywheels are at full pelt the whole time and no power is required before fusion is acheived.


Those are used for the confinement coils. Incredibly, JET uses copper coils. You can't run those all day, so the flywheels are used. The last machine I worked at worked the same way. 16 train motors with 1 ton flywheels spinning at 1600 RPM to be an 11 MW power supply for 1 second every few minutes.

Plasma heating in JET is done via NBI+ICRH and is about 59 MW.


I've seen those copper busbars -- they drill holes for water throughout them. The whole design of high-B field environments is fascinating; you end up with things like Bitte designs with split rings and a whole lot of engineering to stop the copper vapourising. Highly recommended if you're ever in the area – they do two sorts of tours (or did, prior to covid), the "general public" tour and the "scientist" tour. I went on the latter. The sight of two giant robotic arms playing Jenga to train their operators is not one to forget.


I should visit JET sometime. Of all the systems on the machine I worked on (https://hsx.wisc.edu/), the coil current feeds were the most difficult. Trying to cram that much current through a small piece of copper with a discontinuity takes years of effort.


That would be a fusion breakthrough worth mentioning on its own.


Well my kettle is 3kw and takes about 2 minutes to boil so about 200 of my kettles... BUT they don't say how big the kettle is or how much water it contains so it could be 60 BBC kettles. I bet they drink a lot of tea...


When discussing nuclear power plants we can all debate aspects of the bikeshed.

When discussing fusion power, we can all debate how many kettles we can boil.

Kind of funny :)


3L kettles I guess


It's in French, but here is a fascinating documentary about ITER https://www.youtube.com/watch?v=36WpRwY2DYw


One thing that has been on my mind lately is wondering if having easy fusion would be bad.

I am 50. All my life, we have been told that workable fusion would end our energy problems. But now we have the climate crisis, which is a result of inhabitants of the planet not being responsible for externalities.

If we all had cheap fusion reactors, wouldn't humanity just use a lot more energy, creating waste heat and dumping it into the atmosphere?

I'm not convinced humans can be trusted with cheaper energy if it leads to more waste heat.


I feel that the issue at the moment is the more heat is being trapped due to a CO2-rich atmosphere rather than producing excessive heat. After all, the energy we produce is probably miniscule compared to the amount of energy Earth receives from the sun.


That’s a good point.

But I still wonder what happens when we can cheaply generate orders of magnitude more energy. I don’t see how we would be stopped from causing problems with it.


If fusion is achieved I guess we can at least start to remove carbon from the atmosphere by spending generous amount of energy.

Though I do agree with you that once human mastered nuclear fusion, it will only be a matter of time before we have to start worrying about overheating our planet. A potentially Sci-Fi solution would be to build planet-scale radiators to disseminate the waste heat.


I am unfortunately also pessimistic about carbon sequestration. There is a game theory problem in that it only works if we get everybody on the same page for carbon targets. If I start spending energy to sequester carbon, I remove some pressure for others to limit carbon output.


We did fix the hole in the ozone-layer once, so there is that. But I agree, it won't be easy because generating energy from carbon sources is still going to be cheaper than building fusion plants for quite a while.

That being said, with today's social climate, I won't be surprised if countries race to do it just to boost their PR image; that would require some serious carbon-shaming though.


"This is more than double what was achieved in similar tests back in 1997"

Hopefully the current crop of VC funded fusion projects can improve the tech a little faster than this.


Does deuterium-tritium ("D-T") fusion really have a future?

Net energy output is one thing but neutrons are the big problem. The two issues are energy loss and destruction of the container (aka neutron embrittlement). I see ITER plans to handle this with basically a large, thick absorption layer (steel and water). CFS OTOH is looking at molten salt solutions.

But these solutions seem to be aimed at the embrittlement issue and not really the energy loss issue.


I'm pretty sure I've seen "fusion breakthrough" articles every year on HN for at least 10 years now. So I'm waiting for a real plant.


Can someone ELI5 for people that don't follow fusion tech closely? In particular does this mean we're going to have fusion soon?


To respond to the second question, though I haven't followed fusion tech closely, from the environmental analyst featured in the article:

"The fusion announcement is great news but sadly it won't help in our battle to lessen the effects of climate change.

"There's huge uncertainty about when fusion power will be ready for commercialisation. One estimate suggests maybe 20 years. Then fusion would need to scale up, which would mean a delay of perhaps another few decades.

"And here's the problem: the need for carbon-free energy is urgent - and the government has pledged that all electricity in the UK must be zero emissions by 2035. That means nuclear, renewables and energy storage.

"In the words of my colleague Jon Amos: "Fusion is not a solution to get us to 2050 net zero. This is a solution to power society in the second half of this century.""


We have controlled fusion in labs, but it takes more energy to start up than what you get out of it. The longer you can sustain the fusion reaction, the more you can get out of it. They did it for 5 seconds, which is longer than anyone else, but still a net negative.

Predictions about the future of fusion are notoriously difficult to make.


How much energy was required to start the fusion ?


Probably a lot, and while that's generally a useful question to ask about fusion research, in this case the point is not to create a sustainable fusion process but to validate specific pieces of technology, so it doesn't really matter here.


For me, a working net positive fusion reactor means a ton. Here are some things you could do with free (or essentially free) clean energy:

1) desalinization to provide water to everyone. 2) massive carbon capture 3) convert the world away from liquid fuels - and for the cases we are unable to do that, make the fuels from captured atmospheric carbon.


> There's huge uncertainty about when fusion power will be ready for commercialisation. One estimate suggests maybe 20 years.

I bet whoever 'estimated' that said it as a joke. I'm no physicist, but that seems like reporting 'insiders suggested the toroid could be made about as long as a piece of string' to me.


This has been by far the most informative source on Fusion I've seen and gives a clear picture on how to evaluate claims like this.

MIT's Pathway to Fusion Energy (IAP 2017) - Zach Hartwig

https://youtu.be/L0KuAx1COEk


If humanity switches to fusion and as a result vastly increases our energy usage, how much waste heat can we emit before it starts to affect global temperatures? Will we need to use some of that energy on carbon dioxide removal from the atmosphere?


It's incredible how much innovation it's coming from EU recently instead of US.


We're always pretty good on fundamental science. It's the commercialization front that's letting us down.


These are international projects.


Sabine Hossenfelder did a sobering wrap-up about fusion power press announcements a few months ago

https://www.youtube.com/watch?v=LJ4W1g-6JiY


I don't understand a lot about these fusion plans, so this might be a dumb question, but if it were to be used at scale, aside from the energy stuff, would it be a viable source of substantial quantities of helium?


Not in significant quantities.

It also produces huge amounts of activating radiation. The reactor walls will be highly radioactive, as will everything from the fuel supply to the helium itself. In principle you can split that off, but I wouldn't want to try. Fission reactors are a lot more tractable.


This is a red flag:

"These experiments we've just completed had to work,"

Situations like this create a pressure cooker of bias. Maybe they got the result they wanted by force of will not because of the underlying science or engineering.


The stakes are high, but failure is always an option. I've seen machines take years to get density under control. What the JET team has achieved is exceptional.


I mean... they achieved the milestone. That seems like an objective fact that isn't really subject to bias.

It sounds like what you are talking about is "motivation" not "bias".


I just can't get over the fact even fusion reactors are basically just steam engines. We haven't figured out a better way to produce electricity than boiling water?


Just to be sure: what we are seeing in the video is plasma from the fusion of hydrogen atoms, right?

(And if I'm terribly wrong please don't flame, not a nuclear physics expert here)


Yes, two different isotopes. JET uses deuterium-tritium fuel.


I've always wondered, can fusion be weaponized like fission?

Because if so, that's the first thing governments are going to do with it, not free/cheap power for the masses.


Nuclear fusion bombs are old tech, fission research is about getting fusion without requiring detonating a fission bomb first.

Even if that wasn’t the case, why would they? Once you can kill the whole planet, there’s no extra points for killing it multiple times over.


It has been. "Hydrogen" bombs are fusion bombs, they were invented in the 50s.


This is the ONLY way we'll get out of our current situation. Unfortunately I think it might be a decade too late as we're still about 10 years from viability.


59 megajoules (MJ) = 16.4 kWh. For comparison: Tesla Model 3 (Standard Range) has 60 kWh battery. So they made about 1/4 of the full Tesla Model 3 battery.


> So they made about 1/4 of the full Tesla Model 3 battery.

Focusing on absolute numbers is pretty irrelevant, wouldn’t you say ?

We know once we get a working prototype it can be scaled up relatively easily.

Strange to see a storage mechanism (battery) compared to a generation mechanism (fusion plant)


So comparison is about the "amount of energy", not about mechanisms...


My point is the comparison is meaningless.

If they get this to work, they will just build something with 100x or 1000x the output.

The number isn’t really important here, some indication of how the development of the technology is coming along is what we care about. Compare this energy to the last best output.

If this works and we productionize it, we will suddenly go from 1/4 Tesla battery to 10,000 Tesla batteries.


Ok, sure -- but it's nuclear fusion. Gotta start somewhere, right?


Two times as much energy as 1997. That’s… dissapointing?


It’s not a linear process. It’s about solving specific problems before you scale up exponentially.


So are they still using a steam engine to generate the electricity? Will the design of the steam engine working with this reactor be revolutionary?


Probably not. Steam turbines are a pretty mature technology, though I suppose you'd want to use the most efficient kind of turbine available if energy output isn't overwhelmingly bigger than energy input.

edit: since JET is used for research rather than practical power generation, they might not have a steam turbine at all. I was thinking more of the scenario where they're past the research phase and actually doing power generation.


Dumb question from a non-nuclear expert: I more or less understand the science and the goal, but: is this safe? What are the dangers/risks?


As the article itself states: In the words of my colleague Jon Amos: "Fusion is not a solution to get us to 2050 net zero. This is a solution to power society in the second half of this century."


Sorry for being like this but what I like most about that remark is the joyful optimism that there will be a society to power in the first place, and secondly one that can (still) build and operate such technology.

Edit: maybe I’m needlessly pessimistic but I feel societies are much more fragile than they seem. We had it unreasonably good in ‘the west’ for the last 77 years but that time span is so short in the grander scheme of things, it gives a false sense of security.

In some part, due to societal changes, schisms, injustices, the increasing distrust that eats at the foundation of society,

At some point, there may be nothing worth left to power with nuclear fusion.

Although I start to wonder if we should keep powering a lot of things in today’s world. There is so much needless unnecessary madness going on.


Huh? It's only like 30 years off. They didn't say 2150 or something else further into the future. How bad do you think things are currently that 28 years from now, society will be totally shattered?


Are there any studies on what the world might look like in 50 years, based on a reasonable, realistic projection of climate change, human change in behaviour etc etc?

Just to be clear, I 100% believe in climate change, and do what I think is a fair amount to help (cycle as much as I can, don't take long haul flights, take train instead of short haul flights, drive EV, insulate house, don't eat much meat, Solar PV panels).

BUT!

I feel like humanity and the earth are way more fault-tolerant than the parent comment gives them credit for. I don't think we are going to see the total collapse of civilisation - far from it. But I would welcome any links on people/studies/groups who have theorised what might happen in a medium-case scenario?


Don’t worry, Earth is pretty fault tolerant. It will still be here long after we’re gone


Exactly this! I believe global warming can become an inconvenience but nothing totally off the scale compared to the problems we face today (and especially have faced in the past). If there is even a 1% chance of a nuclear war that would be much more devastating (even in expected value) than climate change. I actually have grown to fear the opposite: We come up with an efficient cycle to capture carbon (like the one to create starch that was all over the news some time ago) and suddenly it becomes a race to the bottom where we need international treaties so people are not sucking all the carbon from the atmosphere. I have no clue about chemistry whatsoever so I can hardly tell if this is plausible but if it is, it appears far more dangerous to me than a couple degrees in global warming.


It seems highly improbable we won't have society in 2050. We're currently in 2022, we've existed alongside nuclear weaponry for 75 years, I doubt the next 28 will see annihilation but I do dread the small chance (maybe 5-10%)?

So other than nuclear apocalypse, I fail to see what could remove society by 2050? Climate Change's worst effects will not be seen by 2050, they'll be very bad but they won't destroy society in all places, just hamper its economy and lower societal living standards.


Why bet against society existing in 30 years? If you're right then you make money and if you're wrong then money is worthless.

Replace money with "technology that sustains society".


You don’t give it 28 years? In the early 2000s I was in the “fast crash” camp, too. Not anymore.


Ok .. let's pack it in, and kiss our tails goodbye then .. lol


Even that is optimistic; they don't expect any net production of energy before 2055, and I doubt there's any guarantee that that will work, because if there was, they'd be trying that right now.


This was a test to validate what will happen with ITER. ITER will really only start, by their own planning, that has been consistently delayed, only in 2035.

They will start in 2025, then will stop for a few years then will really only start in 2035. ITER is a scientific experiment not the first commercial prototype.

Assuming it succeeds you are looking at a procurement and construction process of 20 years for the first commercial prototype by 2060!

At best, you will start constructing commercial power in 2060 and making in impact in 2080. If its even commercially feasible and not an incredibly expensive toy.

Fantastic achievements from the SPARC (MIT) project are not likely to impact this. Conclusion: Forget about Fusion as a solution to help with the current climate change emergency. The planet will be here, but Gaia will clean us up as parasitic extras, if we don't do something in the next 5 to 10 years.

And no, you wont be allowed in the Belt.


Maybe put more effort into using that big fusion reactor in the sky. That's a fusion reactor that already works, and solar panels have been making amazing advancements over the past two decades, so that's a much quicker solution at this point.

Fusion research is still very interesting, but honestly it's starting to feel more like an expensive hobby by now. It certainly shouldn't take precedence over more attainable and faster solutions.


2050 is coming sooner than any of us can imagine. I'm glad there are people looking out on that horizon!


Yeah!

But we need to go nuclear [fission] in the mean time... I can't imagine any other way that wouldn't devastate the environment excessively at the same time (e.g. river dams are bad IMHO).


Flamanville 3 in France was started in 2007 and is due to be launched in 2022. It's the first of its generation (in France at least) so the delays and cost overruns are not unexpected. Even so, if more are to be built they will not come into service until the mid 2030's at the earliest. I don't think we can wait that long.


Well yeah, I think we should industrialize it, make nuclear fission reactors serial. I don't think what we're doing is sufficient either.


As Tyler Cowen always responds to headlines like this: "If it’s true, why isn’t the price of oil down?"


Sidenotes from the Blockchain Twitter-sphere, Fusion = Proof of Work that Doesn't Destroy the Planet.


Can someone explain something about fusion for me? To make a fusion reactor that's useful you have to solve two problems: First you have to build a working fusion reactor. Second, you have to capture that energy to do useful work.

Given that, wouldn't it make more sense to focus on technology to capture energy from the giant, already working fusion reactor in the sky?


Thirty years ago it would have been true to say "Solar is decades away from being viable as our primary energy source, whereas fission has been ready and able for decades."

I really wish we'd gone with Nixon's 1970s proposal to make our entire grid carbon-neutral using fission, but given how the politics of that worked out, I'm also incredibly grateful that people kept working on photovoltaic technology anyway.

We're building out solar pretty rapidly, and the technology has been advancing at an incredible rate, but we can work on multiple solutions simultaneously, and solar is a clear case study in why working on not-yet-viable technology is incredibly worthwhile pursuit.


In addition to what others have said, the sun isn't always in the sky.


I'd like to see a side-by-side... The sun is always in the sky, just not where power is needed. If you look at the global investment into fusion, I wonder by what order of magnitude that compares to scrapping that work and building HVDC lines East-West to major population centers and North-South to places with super-high availability wind resources. We could basically build those "tomorrow" as compared to spending billions/year in research and then tens of billions/year in actual construction cost when we figure out the technology. Not a 'fair' comparison by any stretch but I think it'd be interesting.


We generate electricity with fusion the same way we do with many other technologies.

We heat up water until it turns to steam which moves a turbine to spin some magnets to generate electricity.

Fusion’s advantage over solar is it can theoretically generate unlimited energy in a relatively small footprint. It also doesn’t go out 8-12 hours per day.

But I think the reality is that we need to pursue many options for clean energy.