
Nuclear fusion 'will work' (auto-starting audio) - ColinWright
http://news.bbc.co.uk/today/hi/today/newsid_9585000/9585189.stm
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tsotha
Maybe. Probably, though people asking for billions of dollars can hardly be
considered disinterested observers.

The question really isn't "will it work?", but rather "when, how much will it
cost to develop, and (most importantly) will commercial power production via
fusion ever be cheaper than the alternatives?"

I see no indication tokomaks will ever be commercially viable, even if they
can be made to work. The up-front cost to construct a plant will be ruinous
under the rosiest of scenarios. It would probably be cheaper to fake base load
power with solar cells backed by lead-acid batteries.

And laser ignition? Who knows? I would like to see someone ask these guys
"Okay, assume all the technical problem are resolved the way you expect, how
much is it going to cost to build a commercial power production plant?"

~~~
jeffreymcmanus
The billions of dollars of investment is nothing compared to the positive
effect that this will have on our society.

The fact that this looks difficult from where we sit is not a good reason to
not do the research. Many of the biggest discoveries in history looked
impossible before they became ubiquitous.

~~~
tsotha
_The billions of dollars of investment is nothing compared to the positive
effect that this will have on our society._

You missed the point entirely. Billions of dollars in research, even if
successful, will have _no positive effect whatsoever_ if they don't lead to a
commercially viable means of generating power. It's not enough to get to break
even. The end result has to be cheaper than the alternatives.

I'm not a big solar power fan, in general, because I think it's too expensive.
But if we're going to pretend cost doesn't mean anything, we'd be far better
off taking those billions and building out a solar infrastructure with
technology we have today rather than taking a dodgy gamble on something that
a) may never work at all and b) probably won't be cheaper than solar if it
does work.

~~~
Yaggo
> I'm not a big solar power fan, in general, because I think it's too
> expensive.

Solar energy has already reached grid parity¹ in Australia².

[1] <http://en.wikipedia.org/wiki/Grid_parity> [2]
[http://www.abc.net.au/news/2011-09-07/solar-industry-
celebra...](http://www.abc.net.au/news/2011-09-07/solar-industry-celebrates-
grid-parity/2875592/?site=sydney)

~~~
tsotha
Sure... with feed-in tariffs and as long as you don't account for the idle
capacity that needs to be there in case the sun isn't shining. If you ignore
all that... grid parity!

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ams6110
The short version: talking about laser inertial fusion energy, estimating 18
months away from POC in the lab, a decade away from utility scale usage if all
goes well.

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cletus
I used to have high hopes for fusion power until I came to learn two things:

1\. Neutrons rapidly destroy any kind of containment. He-3 is seen as some
kind of holy grail here. Unfortunately it's _incredibly_ rare. The best source
is probably the Moon (which, with no atmosphere, has had billions of years of
solar winds to collect non-trivial amounts of He-3); and

2\. To sustain a fission reaction any current research reactor I can recall
reading about uses probably radioactive isotopes (most likely tritium ie H-3)
or at least somewhat uncommon isotopes (ie deuterium, H-2).

Fun fact: per cubic foot compost generates more power than an equivalent
volume of material from the Sun's core [1]. What makes stars such great energy
producers isn't fusion per se, it's their sheer size and fuel supply.

Fusion goes hand-in-hand with the Utopian concept of "free energy" because
obviously water (and thus hydrogen) is abundant. But no energy will truly be
"free" although it may be cheap enough to have the almost the same impact as
being free.

There are four component costs in energy:

1\. The cost of building a device that produces energy;

2\. The cost of maintaining that device;

3\. The R&D required to bringing that device to market. Obviously, over time,
this cost diminishes to zero; and

4\. The cost of extracting, storing and transporting whatever fuel is
required.

So for hydrogen, assuming a fusion reactor doesn't use sea water, you must
first extract hydrogen. This is actually relatively expensive. Hydrogen
extract is seen as a way of smoothing out power generation from renewable
sources (most often wind power) [2].

Sure a fusion power installation could produce the energy for this but
remember that any power system needs to produce more power than it uses or its
largely worthless (barring corner cases like producing energy in portable
form, which is the entire model for batteries). With hydrogen extraction,
you've just raised the bar on how much power than reactor needs to produce.

Likewise, hydrogen storage is non-trivial. It's flammable and hard and
expensive to store in liquid form (compared to, say, liquid nitrogen [3].

Energy needs to be produced in many forms. Fusion is on the scale required for
power stations but that's only one of our needs. What about vehicles? It's
really hard to beat the amount of energy stored in oil (by mass or by volume)
and the ease with which it is extracted.

I see a long term solution to this in genetically engineering microbes to
produce readily consumable compounds for abundant and sustainable inputs.
Another fun fact: if you've read Neal Stephenson's _Anathem_ you'll probably
recall his mention of "fuel trees" that suggest this kind of approach.

In the far distant future I see the only viable power source that would allow
us to live in space, let alone cross interstellar space, to be black holes
[4].

[1]: <http://en.wikipedia.org/wiki/Solar_core>

[2]: <http://en.wikipedia.org/wiki/Wind_hybrid_power_systems>

[3]: <http://hypertextbook.com/facts/2007/KarenFan.shtml>

[4]: [http://io9.com/5391989/a-black-hole-engine-that-could-
power-...](http://io9.com/5391989/a-black-hole-engine-that-could-power-
spaceships)

------
tingletech
some related links

<https://lasers.llnl.gov/>

<https://life.llnl.gov/>

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pointyhat
It'll work when someone shows it working. Until then it's just conjecture.

~~~
pcottle
It's tempting to say this to avoid getting your hopes up, but there has been
solid concrete progress in fusion technology over the last decade. Getting net
positive fusion to occur on Earth is an _incredibly_ difficult technical
challenge. It's like climbing a scientific mountain, and right now we are a
few hundred meters from the top with a few more obstacles to go. So saying you
won't believe it until we reach the summit discredits all the progress we have
made to date.

This technology is not a matter of 'is it possible?' but 'is it technically
feasible?' And the scientific community has been chipping away at the latter
for a long time.

~~~
jcrites
One thing which surprised me to learn was the fact that the Sun, per cubic
meter, generates about as much power as an active compost heap.

<http://en.wikipedia.org/wiki/Sun#Core>

The Sun is not like a nuclear bomb going off. It's just a big radiating
compost heap. Its huge energy output is due to its large size, and not the
intensity of its reaction. (If the Sun's reaction were like a nuclear bomb,
the solar system would be destroyed in a supernova-like explosion.)

In other words, nuclear fusion at the Sun's scale isn't very intense a
reaction. Why do we expect it's a good idea for a power plant? Do we expect to
get significantly _hotter_ than a star? Significantly more dense? It makes
sense how nuclear power works. Fusion power, it's not so clear.

Of course, there are fusion bombs as well, but aren't those set off by nuclear
bombs?

~~~
neutronicus
The bulk of the energy release from hydrogen bombs is not generated by fusion.
The general design of a hydrogen bomb is that a hydrogen "blanket" surrounds a
fission "core". When the fission "core" goes supercritical, it releases enough
energy to initiate fusion in the "blanket".

What the "blanket" does at this point is exert pressure on the "core", which
would be beginning to blow apart in a conventional nuclear device. Keeping the
"core" together for just that small bit of time longer allows it to remain
supercritical for just that small bit of time longer, with the energy release
growing exponentially with a time constant of 10^-7 seconds.

~~~
queensnake
How about that - I thought it was all about the _binding energy curve_ :
[http://ec.europa.eu/research/energy/fi/fi_bs/images/fig2_147...](http://ec.europa.eu/research/energy/fi/fi_bs/images/fig2_1473.gif)

where, as the diagram shows, fission comes up from the heavier elements (less
energy difference) and fusion from the lighter (greatly more).

~~~
neutronicus
Per fusion event, you get about 14 MeV to the about 200 MeV you get per
fission event. It's true that the binding energy per nucleon is higher, but
there are many fewer nucleons.

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wavephorm
There is a big difference between "I think it will work" and "it works!".

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donnaware
Fusion has always been and always will be 30 years aways...

~~~
hartror
The saying is 20 years not 30 and they're saying it without tongue in cheek
now.

