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How Windmills as Wide as Jumbo Jets Are Making Clean Energy Mainstream (nytimes.com)
242 points by dankohn1 9 months ago | hide | past | web | favorite | 279 comments

Selling solar back to the grid has one major problem that, fortunately, doesn't plague windmill installations: The Duck Curve [1].

The problem is that peak energy usage now occurs after sunset. So no matter how many solar panels you stack on your home, around 6-7 PM the coal, oil, and gas power plants all have to spin up to their max capacity. Your solar panels are new less likely to _replace_ a coal power plant, although they do change how many hours a day it runs.

Unfortunately for the power companies, running a coal power plant for 3 hours a day costs just about as much as running it for 8 hours a day. This leads to the power companies naturally feeling rather sour about being forced to credit residents for the power they supply to the grid during low-demand hours. Their costs are staying about the same, but now their revenue stream goes down.

In some regions (Utah/Idaho/Colorado is the one I'm aware of) these power companies are now negotiating with governments for lower and lower solar credits for these kinds of residents and they're winning because the abundance of solar power at mid-day is legitimately creating an oversupply, thus making that energy worth less and less.

I see this causing problems for many of my neighbors, who had solar sales reps factoring in energy buy-back rates from 2016 into 10-year loans models to pay for the solar panels. Soon the energy the power companies pay my neighbors is going to offset their panel loans less and less, which may result in a reversal of the economics that led to them buying the panels in the first place.

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

You need a surprisingly small battery to shift use a mere 4 hours.

This is why we need market rates for power, for everyone. If I have a bunch of panels and my power is worthless at 2pm, that's fine. A small battery system will pay for itself quickly if that power is worth peak at 6pm. Or maybe I set my car to charge in the early afternoon? Maybe when I install my system, I put my panels facing West instead of south?

Can you quote costs here? How much will it cost me to install a battery that lets me come home from work, turn on the air conditioner for 3-4 hours, run 2 loads through my washer and dryer (cause I have 3 kids), do a load of dishes, all while running the water heater, lights, etc?

Does a single $4,000 power-wall do that? And if it is merely saving me the cost differential from electricity at noon and electricity at 6pm, is it going to pay itself off in less than 15 years?

You're going to be closer to $10,000 for that kind of storage. Probably not economical for your use case unless you get good rebates and electricity is expensive where you live.

Source: I build home battery backup systems for a living.

The types of people buying batteries today live in places where arbitrage is an option (california, hawaii), or where the grid is frequently or always down (puerto rico)... or rich people who want to be energy independent. They generally haven't made it to the general public yet, but cost is coming down every year and utilities/incentive programs are spreading.

My parents live in a well-to-do suburb of Chicago. After the frequent, repeated power outages in recent years, a battery pack would be considered as an alternative to a generator.

They don't have a generator -- their property does not make one convenient, and they don't currently have medical needs that require constant power.

But when the power goes out in their neighborhood, just walk outside after a few minutes and listen to all the generators.

A lot of U.S. infrastructure is no longer really being adequately maintained. I expect quite a few battery packs will be sold to scenarios like theirs. As long as the power failures don't come to exceed the batteries' power delivery capabilities.

$10,000 is ~ 50kwh of battery power, that's vastly more than most people are using over a few hours.

I was speccing to the 10-15 kwh range. Maybe you can get it for cheaper, but with the use case he described you're talking about a substantial continuous rated power and surge power. How many amps can your $10,000 50 kwh battery push? Also I'm including installation, warranty, etc. It would honestly probably be more than that because he'd likely need a more expensive inverter or 2 inverters to deal with that kind of load (I doubt his AC unit and dryer are DC).

His AC unit and dryer may actually be DC, just internally. Modern AC compressor motors are now moving to inverter drive, so incoming alternating current gets turned into DC for the inverter, washers/driers do something similar for the motor. Heating elements are just a resistor, so could run from DC. If I were putting together a system for myself those are the things I would consider, and find ways not to duplicate power inverters throughout the system.

As of yet there is nowhere in the world where the installed cost of a 50 kWh hour battery system is only $10,000. I don't think you can even get that much storage for that little money even if you're qualified to install it yourself and are just paying for the hardware. Are you perhaps just looking at wholesale cell costs?

I don't think there is any reason for a home use to install a battery pack without solar power, and with solar power they already need an inverter.


Now this is Alibaba so we are talking about dubious quality still it's showing 2,000$ for 25kwh battery pack when buying 2 or more. 50kwh is 2 so that's 4,000$. That's for Lithium iron phosphate battery which should give ~2,000 cycles though they say 3,500.

PS: Grid scale you would want to install the batteries at the solar power plant so again no need for an extra inverter.

If that's not a scam or something that fails in 2 years, it's pretty amazing. At a lifetime of 3500 full-depth cycles it works out to a lifetime capital cost of only 2.2 cents per kWh. In sunny regions, with instantaneous solar generating costs already below 2.5 cents/kWh, it means that you can supply power around the clock at costs lower than fossil combustion.

In a March 2018 report, BNEF put 2017 utility-scale battery costs at $209/kWh:


And that report was already taking into account global supply chains. That's why I am skeptical about the low Alibaba price. If EPCs can get reliable battery packs at $78/kWh (sans inverter) just by ordering from China, I would expect utility scale battery installation rates to soon go from "brisk" to "breakneck."

<$100/kwh for LiFePo4? That seems really hard to believe.

Perhaps that includes labor and permits, not insignificant costs

Do you believe the batteries should be subsidized instead of the power going back into the grid?

Not sure why that's an either or?

Do you believe the batteries should be subsidized - Yes, I think that they should be subsidized now. I normally don't like government involvement in markets other than protecting against externalities, but in this case I believe that subsidies can expedite innovation in the area. Once the market exists and the technology moves far enough along, I think that we will be able to slowly remove the subsidies and battery systems will be cheap enough to warrant their place in the market without. Also I strongly believe that the faster we move away from fossil fuels, the less lives will be lost to climate change.

instead of the power going back into the grid - Not sure what you mean here. People sell back to the grid all the time. A battery backup system in sell mode is essentially another power plant. Great!

It would be more efficient to cool the home while you're not there than to turn on AC immediately after you come home from work in a hot home.

> run 2 loads through my washer and dryer (cause I have 3 kids)

Surely you don't run 2 loads through your washer and dryer _EVERY_ day, do you? Do your children change clothes every 2 hours? Do you change bedding and towels every day?

Point being, I can come up with incredibly inefficient and wasteful scenarios too and then say "well, it doesn't serve my needs either, see!"

Shifting energy usage patterns is just as much part of being green as is generating energy in a renewable way. Just because you can come up with a scenario that isn't 100% addressed by that, doesn't mean it's not worth doing in aggregate.

> Surely you don't run 2 loads through your washer and dryer _EVERY_ day, do you?

No, but I need to be able to _any_ day, and honestly for us doing 2 loads a day happens very often - it's not an edge case for us. If you're befuddled as to how that is possible, join the club.

As for shifting our day's schedule around electricity rates, good luck bringing that idea up with my wife.

Yeah, but the once a week cases are handled by a connection to the grid, just as at present. The bulk of the necessary time shift is handled by the battery and some other techniques to shift demand, and the rest is balancing contention between households in aggregate, and nudging storage and peaker plants, that is, exactly what currently occurs on the grid.

> As for shifting our day's schedule around electricity rates, good luck bringing that idea up with my wife.

The electricity costs of washing and drying are significant, could easily be hundreds of dollars a year. If you could save half of that by generally running a programme overnight, lots of people would do it . Not everyone would be able to because of noise, with that number increased by technological developments in software and hardware specialized for that use-case, but a lot of people would. And you wouldn't do it for every wash, only when it was convenient. This already happens over here, I often run my dishwasher overnight when the tariffs are lower, it's good for the environment and saves me money, or when I need it sooner I run it straight away.

Nothing to do with solar (yet), but I have time-of-use charges here in Australia, where it was 11¢/kwh 10pm-7am, 30¢ shoulder and 45¢ 2-8pm. So you bet I only started the dryer and dishwasher after 10pm (or when I get up at 6am).

We often had 2 loads of washing a day too; when you're night-time toilet training the kids it's a killer. Fortunately we're past that; now it's just loads of school and sports clothes, still not as much.

>Not everyone would be able to because of noise

Then they should get newer appliances. Modern dishwashers are whisper-quiet, and modern front-loading washers are barely audible for most of the cycle. The energy savings on these newer appliances should more than pay for the initial costs pretty quickly.

> Modern dishwashers are whisper-quiet

No kidding. Our 2006 dishwasher wasn't too bad, but we just got a 2nd-hand 2016 Bosch and you can watch a movie while it's running.

As I said, for us it's not an edge case, but the norm. May not be 2 loads every day, but if I had to guess I'd say that happens about every other day.

It's not an edge case for you.

I assure you, the vast, overwhelming majority of households can go a workweek without using washer/dryer.

You live in Texas and you dry your clothes using an electric dryer? Use a clothes line - they're solar powered.

Is it that hot in your area that you have to run air conditioner for 3-4 hours after sunset? Typically solar output correlates really nicely with the need for air conditioning. Washing and drying could be done say on a weekend ( during daylight hours ).

Many water heaters come with an integrated storage tank for hot water so they can actually be used as a form of energy storage. That leaves lights in your example and yes battery like powerwall will be more than enough to power modern energy efficient lighting and electronics overnight.

It's not uncommon for outside temperatures in Texas to stay above 80F (27C) until midnight during the summer months. The modern homes there are designed to stay sealed, rather than open windows for ventilation at night. Running AC every ~45 minutes until morning is considered the norm.

Hmm, here in Europe were I live 27C would be considered a rather pleasant temperature. Anyway, sealed houses are not only good for keeping the heat in but also to keep the heat out. If you cool your house sufficiently during the daylight hours that should prevent it from heating up too much even after you stop cooling it (after sunset).

But if you absolutely must use active cooling after sunset you might want to get something like Ice bear 20 ( https://www.ice-energy.com/technology/ - i'm not affiliated with them just an example) hopefully it should solve it once and for all.

Bear in mind that 80F is a typical overnight low in most parts of TX during the summer, particularly in most of the heavily populated areas. Typical high temps during the summer months are mid to upper 90's or higher. Most of these same areas also have relatively high humidity, so it feels even hotter and can take quite a while for the temperature to drop even after the sun sets.

I've never been to Texas but a Wikipedia article ( https://en.wikipedia.org/wiki/Climate_of_Texas ) suggests that 80F low occurs only in Galveston in July and it's more like 60s and 70s elsewhere. If a humidity is such a problem then you could run dehumidifier during the day and that would lower humidity ( in a sealed house ) overnight.

I mean these temperatures don't strike me as particularly intolerable. I wonder if it's the case of keeping up with Joneses as in "my house is cooler than yours". There are some reports ( https://www.theatlantic.com/magazine/archive/2015/07/saudis-... ) that rich Arabs in Saudi Arabia are running air conditioners at temperatures that require sweaters — even when they go on vacation. Which is really amusing for these of us who come from colder climates.

Dallas native here... and a runner and weather nerd constantly monitoring for the best running conditions...

In July and August it will often stay above 90F until midnight. There’s usually a few evenings in August where it will still be 100F at 2200.

The overnight lows in the upper 70s won’t be reached until dawn, and it will be back into the upper 80s before 10.

And the breeze is a hot wind, that feels like it makes it worse rather than helping.

Interesting, I wonder how people survived before the advent of modern air conditioning. 35C/95F should be fatal at 100% humidity (as your body can no longer shed heat).

Well, something like IceBear20 ( https://www.ice-energy.com/wp-content/uploads/2016/03/ICE-BE... ) seems to be the way to go. It can run for up to 4 hours off the stored ice so it should be able to cover you from sunset to midnight.

> Interesting, I wonder how people survived before the advent of modern air conditioning.

I believe that there used to be many fewer people (absolutely and relatively) living in the southern US. Then air conditioning was invented and people realized they could get away from the sometimes brutal winters in the north without having to be miserable in the summers.

> Hmm, here in Europe were I live 27C would be considered a rather pleasant temperature.

There are many factors that influence how tolerable the heat is - low humidity and the presence of a breeze can make a huge difference on how tolerable 27C is.

Without solar gain you still need less solar power even if the temperature is 80+. Further, you use exponentially more energy to cool as the temperature rises. So, 80f is significantly cheaper than 90f.

Probably quadratically, or even linear, but to the difference.

Heat gain is linear, but efficiency drops with larger temperate differences. Further, you have to worry about lower relative humidity percentage as you increase temperate differences.

The hottest time of day is 3:00 PM and, due to heat-lag, the hottest time of day _inside_ a house is a little bit after that. Since I set the thermostat higher while I'm gone during the day, this means the house can be roasting by the time I return and require 3-4 hours of AC for it to get more manageable.

And no, our washing and drying can not be done on a weekend. We have 3 kids and if we waited for a weekend to do our laundry then that is the only thing we'd be doing all Saturday long.

In such case you might want to use this thermal lag to your advantage. Set AC to cool your house as much as possible during the midday and you'll come back to hopefully much cooler house in the evening ( so no need to run air conditioner ). Here essentially you would be using the thermal mass of your entire house as an energy storage medium.

With washing, if you have to do it every day you might want to start it right after the sunrise when you're likely to to leave for work. If your kids are old enough you can instruct them to take the washing out and put into a dryer as soon as they get home.

The point is you'll need to make some changes to your lifestyle and habits but these changes are not as severe and problematic as some people claim.

"Since I set the thermostat higher while I'm gone during the day"

Aren't you looking for a way to store excess solar power generated during the day? Use it to cool your house! If your house is at 68 when the sun goes down and power generation stops, you may very well be fine without AC until the morning.

Use the power when its generated and you don't need as big of a battery to store it for later use.

The point is to shift how much power you generated for several off-peak hours to the on-peak hours, not to be totally energy independent for some allotted time.

For example, say you can store up 10 kWh of excess energy during the noon sun when it's worthless. If peak is from 5 to 9, you only need a 10 kWh pack that can discharge in 4 hours.

Let's say you spend 10c/kwh and your electric bill is 100$/month. That's 33kwh / day. Let's assume you need 1/3 of that to cover the evening, and batteries cost 200$/kwh and last 10 years that's 2,200$ / 120month ~= 18$/month.

That's about the ballpark we are talking about though actual numbers will be different.

Not so small when you're shifting power for your entire customer base. Even a small metro area power company is going to be over a million customer hours there.

>The problem is that peak energy usage now occurs after sunset. So no matter how many solar panels you stack on your home, around 6-7 PM the coal, oil, and gas power plants all have to spin up to their max capacity.

Where are you getting this assumption from?

In hot climates like Arizona, peak energy usage during the summer months is in the afternoon, not the evening. When it's 115 degrees outside, that's when everyone's A/C is running at full capacity. It gets cooler in the evening and A/C usage goes down then.

The claim that energy usage peaks after sunset comes from the diagram[0] in the OP's link[1].

In the diagram, you can see that solar power peaked at around 3pm on the graphed day, then declined to near-zero by 6pm. Meanwhile, the total load rose steadily throughout the day, peaking at about 9pm before declining.

[0] - https://en.wikipedia.org/wiki/File:Duck_Curve_CA-ISO_2016-10...

[1] - https://en.wikipedia.org/wiki/Duck_curve

I'd like to see what the curve looks like for southern Arizona and also southern Nevada. California (at least in the populated parts) isn't remotely as hot as either of those places.

I think the duck curve is more about residential usage rather than overall grid usage. And this conversation is about home solar installations rather than commercial ones in offices and places of work.

California and Hawaii have already implemented price curves that make purchasing solar + storage viable for homeowners. As more states adopt these policies and more homeowners adopt batteries the duck curve can be solved. Also battery storage gives the added benefit of not needing a gas generator when the grid goes down if you have an islanding system!

How does one implement a price curve? By supply & demand, it is just the result of energy production + energy usage. Are you saying that California has somehow made energy scarce during the day or are you talking about price manipulation?

The price of buying/selling to/from the grid is different at different times of the day. Artificially set by the utility. Different utilities have different rules. In some you can take advantage of the arbitrage if you have a battery; buying during the day and selling in the evenings.

Exe here is San Diego's pricing from the perspective of consumption only: https://www.sdge.com/residential/pricing-plans/about-our-pri...

You could skip the price models/curves, and just go with a real-time exchange. Something like NordPool (https://www.nordpoolspot.com/), which trades electricity between UK, Germany, Nordics and Baltics.

Electricity price on the market changes every hour depending on production and consumption. You can trade on it like on any futures market, or as an active participant if you had a large battery or transmission cables. Local utilities here offer "market price + 5% margin" plans to home consumers if you want to take advantage of the lows to adjust your usage.

When power gets more expensive in the evenings, a lot of heating/cooling/charging loads may shift in time. Also, hvdc grids let you transmit over a couple of timezones.

(And wind does not have the problem the first place, obviously)

Heating and cooling needs are fairly inelastic temporally. Your house is going to get cold in winter and hot in summer. You'll need to consume energy for this which is largely during the evening when everyone returns from work as you have fewer and fewer single income families. The refrigerator runs through the day.

Sure you can set the dryer and dishwasher if you have one to run at a time when the power rates are lower but you can't really shift most loads. Not even electric cars because you'll use the car to go to work.

If something doesn't need heating or cooling, in the bigger scheme of energy consumption, it barely moves the needle.

You can add components with high, desirable thermal mass to your heating/cooling system to time-shift that as well. You heat and cool your thermal mass when energy is cheap and then use your thermal mass to heat and cool your house much more efficiently during expensive energy periods.

Indeed! In Florida, I use my 10k gallon pool to dump heat from the house into until its thermal capacity has been reached, at which point the heat exchanger switches back to using the condensor unit. Along with my solar panels, my only grid use is for charging an EV at night if it’s not home during the day.

> I use my 10k gallon pool to dump heat from the house into until its thermal capacity has been reached

That sounds amazing. I can't seem to find any commercial solutions for that, only a DIY-ish toggle between a heat exchanger cooled by the pool pump and the usual condensor. Is that what you've done? Guessing this would also work for heating during winter; use the pool water when it's above ambient?

While looking, I did come across a tangentially related problem I thought was interesting too: cooling your pool in summer. [1]

[0]: https://www.thisoldhouse.com/how-to/how-to-heat-swimming-poo... [1]: http://www.abc.net.au/news/2018-02-28/cold-pool-in-hot-heat-...

I bought the below heat exchanger system, which dropped right in to my pool equipment and condenser redridgeant lines. It would work in the winter if the pool was above ambient temp, but that rarely happens so I primarily use the condenser unit in heat pump mode to heat the house on cold days.

There is a controller that takes the pool temp as input, and switches the valves between the heat exchanger or the air condenser, while ensuring the pool pump is running.


Every time I think I grasp the expansiveness and wealth of the US, something comes along and whacks my concepts. In the Asian cities where I live, the well off live in condos where a 100 houses share a pool and the area occupied by a 10k gallon pool would be as big as a third of the house.

I'm not sure these solutions work for even the well off in most parts of the world, let alone common people.

In most cases adding a swimming-pool sized tank of water to your house complete with a heat-exchange system to save $40 a month on your electric bill isn't going to be very economical, let alone practical.

While correct, if you already have a pool, the heat exchanger equipment to use the pool as a thermal sink is eligible for a 30% federal tax credit (as long as you’re installing to heat/cool your house with it, not heat/cool your pool).

The tank need not be that big. Water has a very high heat capacity compared to air.

You can cool or warm your house preemptively during the day/early evening (if you have reasonable insulation). Or heat/cool a tank of water.

If possible, but it may only get worse. If EVs become more prevalent, it will only increase the evening demand as most people will charge when they get home from work. Sure, maybe with timers you can shift that to midnight or something, but it's still happening at a time when Solar adds nothing.

You can't just toss out something like HVDC grids as a quick solution. That kind of infrastructure takes decades to build out.

I'm not sure why you discount charging during the day. Most EVs don't empty their battery by 6pm and require a full charge at 8am.

I'm guessing because there is less availability for charging during the day when you are at work, rather than at night when you are home.

How long to EVs take to charge? Should be pretty simple to put a time delay into the charger to _begin_ charging around 2 AM when energy usage has gone back down again.

This is already happening, in a more sophisticated way:


Consumers are offered reduced cost tariffs to simply request a charging level by a certain time tomorrow morning, and in the meantime let the grid take or receive electricity as it wishes.

EVs can also be part of the solution with demand-based pricing. Instead of charging when they got home from work, people could start dumping excess energy from the battery into the grid during the peak and charge overnight at lower-demand times.

Shifting heating & cooling demand sounds difficult. Without a lot of distributed energy storage

I would think this could be fixed simply by cooling the home lower than optimal at peak solar, plus some thermal storage.

You just have to reduce the cost of electricity in the middle of the day and the market will find 1000 ways to make use of it. Another example is that large scale electric car charging stations already use batteries to trickle charge through the day, and then dump electricity when a car needs it. If there are big cost differences in electricity through the day, it strengthens their business model to do arbitrage, charging more at cheap times.

As another comment pointed out in the thread, Germany's aluminum manufacturers are already taking advantage of negative energy prices and scaling production up and down at least 25% during peak energy producing hours.

Residential users and smaller companies will eventually find ways to make use of such energy in a similar way.

It only takes a little bit of battery capacity to shift the duck curve, and is a nice lead into the market ramping up volume to cover more and more capacity and time. It's also an power time-cost arbitration model which is very comprehensible to financial backers.

There was a very interesting article about hydrogen fuel cell cars posted on HN the other day, one of the things they mention is that excess energy could readily be diverted to hydrogen manufacture.


* This leads to the power companies naturally feeling rather sour about being forced to credit residents for the power they supply to the grid during low-demand hours. Their costs are staying about the same, but now their revenue stream goes down.*

Time to get rid of coal? What the Duck Curve indicates to me, is that California's grad-scale solar really should be located about 6 hours time difference to the west. How about ocean solar farms located in the plastic laden mid-Pacific gyre? They could be equipped with plastic harvesting equipment.

Operating a power plant in the middle of the World's largest ocean, then transmitting the power 4500+ miles (7000+ km) across that ocean would be one of the World's major engineering undertakings, and vastly more expensive than any current method of generating electricity.

Agreed. The ocean is just too deep there. I have a better idea for a megaproject: build a dam across the Strait of Gibraltar, and lower the water level of the Mediterranean. You could get an enormous amount of power from a hydroelectric dam in this location (and later another one near Sicily, after the Mediterranean's level is lowered), plus you'd have a huge amount of new land in the area.

> build a dam across the Strait of Gibraltar, and lower the water level of the Mediterranean.

You mean like this? https://www.atlasobscura.com/articles/the-bonkers-reallife-p...

Yep, I was wondering if anyone would get the reference. I don't know why they call it "bonkers", though: it seems perfectly feasible from an engineering perspective, although it's obviously a serious megaproject, and would be extremely costly. But the cost could very well be worth it, for both electricity generation and land creation. The main problem I see is political: who would own and control it, and who would get to take ownership of the new land, and also a lot of people would probably fight it because it'd be changing the geography so significantly (lots of wealthy people with waterfront property wouldn't after the sea level fell).

Queue the next crypto fancy: Gibraltarcoin! Decentralized electricity monetization transfer something something profit.

Would you want to live below sea level and trust the dam? Not me.

Why not? Countless people worldwide live in places that would be flooded if a dam broke. We saw this last year in California. And how many more people live at sea level in coastal areas that are prone to flooding?

Maybe you refuse to live in such areas, but there's probably several billion people who do.

If the Gibraltar dam broke, you'd have nowhere to run to.

You'd run for higher ground, just like if any dam broke. There's plenty of places where people are going to be in big trouble if some big dam suddenly bursts. How often does that actually happen though? Never. That one in California didn't suddenly burst, it broke down and caused flooding, but not in one giant cataclysm; people were able to evacuate just fine. We have many dams out there, many quite old, that work just fine. Look at the Hoover Dam for instance; it's over 80 years old now I think.

By your logic, no one should go into a skyscraper: what would happen if it suddenly collapsed? But that never happens.

> You'd run for higher ground, just like if any dam broke.

Good luck with that when you're in the middle of Mediterranean basin.

The solution is straightforward - lower consumer electricity rates when power is cheap, and raise them when it is expensive. Consumers will naturally shift the elastic part of their electric demand to when power is cheap.

For example, charging the car when power is cheap.

Yep. Here in Texas we have an open energy market and in most areas you get to choose your energy provider and an array of plans.

One of my co-works with a Tesla got a plan where electricity is free at night. He cranks the AC during the night and charges the car and ends up paying around $40 a month. Not bad.

If only consumers were so rational.

Laziness and complacency is the main hurdle you need to overcome. It needs to be automated.

Hey, this AC will cool your house and save you $$$. Hey, turn on this automatic switch and your car will save you $$$.

The market should be able to handle this. Thus, the government should create the curcumstances this can occur, which means in practice that timeslot-based tarifs should be enabled.

The interesting question is what effect clean energy has to the usage of hydrocarbons. Will it bring reduce global demand or just reduce the price of energy.

The good news is: CO2 emission intensity is going down globally and emissions per capita in US, China and EU28 are going down.

The bad news are: Emissions per capita are still going up globally, and hydrocarbon usage and CO2 emissions are breaking records year after year. http://folk.uio.no/roberan/img/GCP2017/PNG/s09_FossilFuel_an... Economic downturn was the only thing causing temporary decline.

It looks like clean energy reduces the demand in developed countries, thus reducing the prices of hydrocarbons. It will not reduce the CO2 emissions globally, it just moves them from the developed world to the developing world. Maybe it slows down CO2 emission growth rate?



EDIT: Just to point out how complex the dynamics between clean energy, hydrocarbons and policy are, here is nice recent research paper from Acemoglu and Rafey:

Mirage on the Horizon: Geoengineering and Carbon Taxation Without Commitment https://economics.mit.edu/files/14855

>Abstract: We show that, in a model without commitment to future policies, geoengineering breakthroughs can have adverse environmental and welfare effects because they change the (equilibrium) carbon taxes. In our model, energy producers emit carbon, which creates a negative environmental externality, and may decide to switch to cleaner technology. A benevolent social planner sets carbon taxes without commitment. Higher future carbon taxes both reduce emissions given technology and encourage energy producers to switch to cleaner technology. Geoengineering advances, which reduce the negative environmental effects of the existing stock of carbon, decrease future carbon taxes and thus discourage private investments in conventional clean technology. We characterize the conditions under which these advances diminish—rather than improve—environmental quality and welfare.

This is why the only way to deal with climate change is countries with carbon reserves deciding to leave it in the ground.

If they don't, there is so much demand for the stuff (burning it is so incredibly useful) that it'll all be burned.

Or for those with wealth to buy those reserves and put mechanisms in place to inhibit the extraction of those petroleum resources.

Judging from all of human history.. 'those with wealth' tend to not be the conscientious type.

edit: Because, they are insulated from the bad repercussions of their harmful policies. Eg. Trafigura polluting the shit out of Ivory coast and poisoning people there. The CEO doesnt live there, he drinks bottled water and lives somewhere else in a gated compound.

Making those destructive choices makes things better for them so they keep making them over and over. If a CEO made a conscientious choice then it would most likely be at the expense of short term profit, which would diminish the extent of his power, sort of self-selecting himself out of the decision making pool.

I agree, but I find it hard to beleive that isolation alone is enough to make them so unempathetic. I can only assume it has something to do with the human capacity to lie to one self, otherwise even acknowledging the truth would just be too uncomfortable.

Makes me imagine some weird distopian future where all people with power and wealth are forced to take some anti-self-deciet drug to prevent crimes against humanity :P

> all people with power and wealth are forced to take some anti-self-deciet drug

But who would force them?

Well it's a sci-fi distopian future so there would be some twisted pseudo dictatorship of course ... except for the one guy at the top who exempts himself from the drug. Ok this is basically "equilibrium" with a different brain mod isn't it :P

Our future AI overlords, I imagine.

Equador tried an interesting approach: "pays us and we won't extract oil".


"tried" indeed - because according to the wikipedia lemma covering the topic: However, in July 2013, Ecuador's president Rafael Correa's commission on the Yasuni-ITT Initiative's progress, the commission concluded that economic results were insufficient, leading Correa to scrap the plan on August 15, 2013. As of early 2014, campaign groups are still attempting to save Yasuní-ITT from oil activities.

Unfort, those in the position of power throughout the modern history has done the exact opposite.

If clean energy manages to get cheap enough eventually it will be easier to synthesize simple hydrocarbons out of atmospheric and water than to drill them out of the group and we can end up carbon neutral as a whole. We'll see how cheap midday solar ends up when the price finishes dropping.

The cost of solar stabilizes when the cost is determined by the cost of land, energy storage, electric grid and transfer cost and installation and maintenance.

If you get the conversion efficiency to the same level as photosynthesis (30% nominally) the cost of energy could approach the cost of producing biofuels.

Except - lots of current biofuels are thought to be "fossil fuel subsidized" and not that energy positive.

Solar panels also don't wear out soil nutrients, don't need crop rotation, and are probably much less likely to be completely destroyed by weather patterns than the average corn crop grown for biofuels.

The efficiency of photosynthesis is nowhere near 30%. It’s 3% if so.


You’re both right - there’s lots of room for practical improvement.

Even if that number is correct for photosynthesis, there are lots of inefficiencies when it comes to converting the products of photosynthesis (biomass) into usable energy (electricity). Wood pellets burn well, but people forget that wood pellets use energy in their creation (drying) and transport (trucks). There are also a host of evils in terms of habitat destruction and emission of pollutants other than CO2. Solar panels can live quietly and locally, producing electricity directly rather than trying to convert it too and from biomass.

Compared to the rest, which are much more static in terms of cost, energy storage will continue to drop in cost almost as much as solar panels will over the next 10-15 years.

>> CO2 emission intensity

Avoid this phrase at all costs. It is a buzzword used by the likes of the clean coal lobby. Global warming isn't tied to emission intensity, but net emissions. The fact that CO2 emissions are down relative to economic growth, but are still climbing, is not useful. It is PR turd-shining.

> it just moves them from the developed world to the developing world

This is a really good point, clean energy seems to be a luxury at the moment.

No one can blame poorer countries, they aren't all in a position to invest in renewables, for many of them it would be crippling, the argument that renewables is sometimes cheaper only works long term, and long term takes significan't up front investment, burning coal etc takes significantly less.

Most of the developing world doesn't have a grid today. Building microgrids powered by small clean energy resources is much cheaper than building a grid. Now this is only true at modest per-capita electricity consumption amounts, but that matches the wealth available in a lot of places.

On a very small scale, that's why you see solar-powered flashlights being so popular in rural areas of the developing world. And my favorite charity (kickstart.org) is currently designing a solar-powered water pump, as a step up from their current human-powered water pumps.

I am hopeful the cost of entry will be greatly reduced in the near term with so many developed nations turning to renewables.

By helping ourselves, we are lowering the barrier for less developed nations.

Emissions continue to go up because relatively speaking renewables are still a small portion of the global energy use and the need for more energy is still rising fast (renewables or not).

I assume just the fact that companies (and consumers to a smaller degree) can install solar power and then generate "free" electricity plays a non-insignificant role in getting them to use even more electricity.

However, I don't think that's what causes most of the rise. It's all the planned obsolescence electronics we use and throw into the garbage every 2-3 years and other stuff like that. We simply need more energy to build more stuff. At least if we go 100% renewable power and electric vehicles, that will minimize the impact on the planet, even if we double our energy use over the next 50 years.

There will also be new energy efficiency technologies that will at least slow down our increase in energy use.

Are there known fundamental obstructions to developing a leap frog effect in energy tech?

I don't think it's the question of technology, it's the question of economy, incentives and investment costs.

Even if the clean energy becomes cheaper hydrocarbons can have comparative advantages and when their price goes down it's creating new uses and new demand.

Even if EROI (energy return of investment) of hydrocarbons turns negative, it may be cheaper to use clean energy to extract hydrocarbons from existing sources than transfer CO2 to back to hydrocarbons.

No. Searching "solar in developing countries" suggests it is an ongoing process.

As a new farmer, this is good news. My target range for CO2 is 1200ppm. This means our future will be greener! https://www.youtube.com/watch?v=XkDgYLxp8Sg

You posted a link to a rabbithole of fascist-cheering, bone-stupid argumentation, and conspiracy theory. Setting aside their fairly obvious attempts at political astroturfing, the depths to which those people are lying with regards to AGW to people who lack the scientific literacy to evaluate the arguments being made is appalling. So are their race-baiting shithead politics, but this more bluntly--I mean, this is math.

I make this post assuming you're not in on it.

Plants are often limited by resources other than CO2. Also, high temperatures reduce crop yields in most places.

Wait, you think that we should triple the CO2 levels? Humanity's well-being on this earth is not exactly bottle-necked by our current ability to produce plant matter, and at 1200ppm I'm pretty sure we'll discover lots of new and exciting (not-good exciting) ways that our survival is bottle-necked.

As the production costs with windpower decrease due to the technological progress, the question of grid storage and grid interconnection becomes more pressing.

E.g. in Germany, they frequently have days of negative energy prices, where producers need to pay to feed energy into the greed because of overproduction of energy on windy/sunny days [0](in German). Without storage and grid interconnection, there is only so much renewable energy from intermittent sources like wind and solar you can handle.

[0]: https://blog.energybrainpool.com/bereits-103-mal-in-2017-neg...

Germany has at least one example of an aluminium producer testing dialing the power use of their melter up/down by 25% in response to input from the grid [1]:

> Trimet says that implementing its technology across Germany’s four aluminum smelters, three of which it owns, could provide a demand response capacity equal to a third of Germany’s 40 gigawatt-hours of pumped hydro storage.

There was a lot of confusion about this one when it was published, but as the article points out, they're not using their molten aluminium pools as a liquid battery - they're merely dynamically adjusting the electricity usage of their hydrolysis cells, which also requires some other adjustments to keep the process going, but it's still a lot of power and more responsive than what they do today (which involves taking the smelters entirely offline for short periods).

It helps that their test plant is near Hamburg in the North, "close" to most of Germany's wind turbine capacity which helps alleviate transmission/interconnection problems to the South.

[1] https://www.greentechmedia.com/articles/read/german-firm-tur...

As turbines get larger, not only do the costs go down, but the reliability of supply goes up. It becomes more economical to place them out at sea, where winds are more reliable, and the size allows them to run more effectively off low speed winds. These turbines are claiming 60%+ capacity factor, compared to 20-30% for smaller, onshore turbines.

The UK is already up to about 15% of its electricity from wind right now, these developments will open that up significantly more. Obviously at high levels of penetration there are going to be issues, we'll just have to see how far we can go, but even 25-40% of electricity would be a huge contribution.

Combine that with the new and existing nuclear, another 15%, some biomass and tidal lagoons, with the rest from gas (which produces half as much CO2 as coal) and it will go a long way towards meeting the UK's 80% CO2 reduction target from 1990 to 2050.

Isn't this where pumped storage and other forms of storage come into play? Here in Scotland we routinely pump water back up into our lochs in order to store it for future use.

There's also various news articles reporting on German mines beginning to be used as pumped storage sites, with a reservoir on the surface, and water dropping into the mines below when there's sudden demand.

This is a good problem to have, though.

In Ireland there have been studies using sea-facing valleys to store pumped sea-water. There are an order of magnitude more of these (left-over from the last ice-age) than river valleys for pumped hydro storage. The spirit of ireland group looked at them. When we really need the stored energy, this plan will get dug up again. Reference: http://www.sciencemag.org/news/2012/02/massive-energy-storag...

A lot of the best sites for pumped storage are already developed as pumped storage. It's kind of the opposite of other storage technologies. As sites get developed the economics of future sites get worse.

According to Wikipedia we have 15 GWh of pumped storage capacity in Scotland. Per annum we use 27,000 GWh. So by my calculations we have a pumped storage battery that lasts about 5 hours.

(NB: I didn't check whether the power output of this battery is enough to actually meet demand, but wikipedia says it can run at full capacity for 22 hours, so no)

It can be reused more than once a year. You could use it every day, charge at night when there's no demand, discharge it during the peak. Really depends on how fast it can charge and discharge.

Depends more on how variable your supply is. If you have to meet a two week window with below average wind it isn't enough. If you have to just meet day to day variation in wind it is probably enough.

Unfortunately two weeks without much wind are common in general weather patterns. Thus my gut reaction is it isn't enough. However we are now talking weather where local patterns are the important thing which means each situation needs to be considered separately.

Sounds about right. It's used for demand-smoothing over fairly short periods.

(I've been to Cruachan, well worth the visit even though you can't walk around the turbine hall any more)

It is important to note, that here in Germany, wind and solar does not quite reach 100% of our energy consumption yet - I think it has done so only once on a public holiday. The more frequent overproduction comes from high wind/solar output combined with the output of power plants which can't be shout down quickly enough, that is coal/nuclear. If those would be replaced by gas plants with faster reaction times, a much higher amount of reneweable energy could be used without requiring storage.

But indeed, as the amount of renewal energy production increases, more storage is needed. Perhaps less so for wind which has a more smooth output over days, but for solar, which has a strong peak over noon and of course shuts down alltogether in the evening. Distributing the solar curve over more time of the day would be very useful.

Coal power plants can ramp up and down pretty quickly in response to demand. Not quite as quickly as gas, but generally quick enough to respond to changes in renewables supply when operated as "spinning reserve". Nuclear plants, of course, can not.

There are plenty of coal plants that absolutely can not ramp up and down in less than many hours, and will lose money as they do so.

There are also many nuclear plants perfectly capable of "load following", responding in the time frame of minutes to 10's of minutes to load changes.

My understanding is that while load following is possible in nuclear plants, there are significant design, efficiency, and cost compromises involved. For these reasons, load-following nuclear is fairly rare.

In the UK, all of our nuclear power plants operate at their design capacity all the time. Their output only changes during scheduled periods when they are shut down for maintenance, refuelling, etc.

In contrast, all of the remaining coal-fired power plants in the UK effectively operate as load-following reserve. They ramp up only on cold winter days when demand is high and when wind generation is low. There are now many "coal free" days in the warmer months where there is no coal-fired power generation in the UK at all (it looks like today will be one of them!)

> frequently have days of negative energy prices, where producers need to pay to feed energy into the greed because of overproduction of energy on windy/sunny days

This is one reason why I'm skeptical for home production of solar and wind for the ability to "feed back" into the grid while getting a credit on your account.

If the power company is also doing this, at scale, I find it really hard to believe that there's no reason the power company won't discredit/discount my rates being returned to the grid.

In which case, I'd rather have a battery installation and not rely on the power company at all.

Most service reps for solar disagree with me. Maybe because battery storage isn't super common/in their inventory?

I think is a totally reasonable point of view and comes down to a classic cost-benefit analysis.

Are you OK with using the grid as a highly-reliable, ~infinite capacity power source to smooth over your uneven solar generation at a cost of selling your excess back at a discounted rate,


do you want to try and capture that discount yourself at the cost of having to buy, install and maintain your own integrated battery backup system?

Maybe the calculus works out in your favor for you, specifically. Maybe not. But it's good to have options.

It's more that batteries are expensive. Especially in places where there is a law saying that the power company has to pay a nice rate for power fed back to the grid.

Understandable, the legislation isn't brought up (but maybe this concern isn't, either) that often. It could certain be a non-issue.

Though I rarely experience power outages, knowing almost all instances would be non-existent is really nice (for a battery backup program), especially as more and more heating solutions are using electricity as the main component (heat pumps; winter power failures are most of the power failures for me).

Can you explain why you think these negative prices are a bad thing?

I think they're an efficient use of market based tools to ensure that the group who can reduce the input to the grid does so, and to incentivize electricity production that can meet the flexible demands of the grid (e.g. slow ramping coal would be penalised over fast ramping gas without any regulation needing to specifically target the coal and the coal plant can do anything it wants to improve this, e.g. fit batteries, since no technology is mandated.

Negative price signals that cause solar or wind production curtailment is essentially throwing clean energy away.

Negative prices are a helpful market signal, but must be combined with battery storage requirements.

Negative price signals encourage people to use that excess energy as they are paid to do so at exactly the times that solar or wind are overproducing.

They are the solution to that problem, not part of the problem.

As for batteries, there needs to be an economic incentive for people to invest in deploying batteries (or any other type of storage). Negative prices are that incentive. Negative prices don't need batteries, batteries need negative pricing.

I think the dream is just to make wind power so ludicrously plentiful that the fact that it's kind of mediocre during daytime is overwhelmed by sheer quantity of generators.

As for storage, shouldn't there be plenty of hydroelectric dams that could run "backwards"? Or is there an interconnection issue you mention?

For a hydroelectric dam to be able to "run backwards", it needs a lower reservoir. Many dams have only an upper reservoir.

Simply turning them off would be running backwards since water would build up behind them.

It’s not about building up capacity alone: you want to take power off the grid at negative energy price times.

You are taking power off the grid: The power otherwise produced by the hydro plant.

Of course with a lower reservoir, you can go into negative territory instead of "just" taking the plant down to 0.

No, you need to consume what other methods, e.g. wind, are producing when there isn't the demand to use it.

There is always demand. The issue is that sometimes demand exceeds supply. Taking away supply has the same net effect as increasing demand.

EDIT: with the one caveat of transmission capacity, which certainly can be an issue.

I don't think you're quite getting this. There are times where there is excess demand, even when removing these stores. What's so hard to understand?

Prices go negative in the US at times and in Germany more often. That is exactly when something like this would be used: to store that capacity.

The point is that you have a given supply and demand. As long as they are in the right positions in the grid that transmission capacity is not the limiting factor, then you can fix that by reducing supply, or by increasing demand - apart from the issue of transmission those options are equivalent from the point of view of bringing the supply under control. They may not be equivalent in terms of cost, but that is a separate issue.

The original point was that you do not need to have a reservoir to pump from to take advantage of the fast start/stop capability of a hydro plant: Closing the sluice gates and/or bypassing the turbines is sufficient to reduce supply by the generating capacity of the plant.

Having a reservoir as the potential to significantly increase the reduction in excess supply you can handle, that is true, but the lack of that option does not change the benefit of shutting off generating capacity.

Hydro plants have been used to adjust grid supply for as long as they have existed in this way. Not least because with grid prices adjusting dynamically, as long as the reservoir is not full, most hydro plants yield better economic result if they respond to falling prices by letting the reservoir water levels build back up.

> Having a reservoir as the potential to significantly increase the reduction in excess supply you can handle, that is true, but the lack of that option does not change the benefit of shutting off generating capacity.

The point is to not turn off generation capacity that we don't control the start of, like wind. Why should we not generate if the wind is blowing at night?

What I commented on, and what you quoted above, was about hydro plants, not wind. With hydro plants, as long as the reservoir has capacity the reservoir acts like a battery, as hydro plants tend to be built with turbine capacity sufficient for a flow large enough to drain the reservoir. As such, unlike with wind, nothing is lost if you close the sluice gates or a while - the reservoir just builds up and you can generate more when needed.

That's the entire point: That hydro plants can act as storage even if there's no lower reservoir to pump from. Which means they're good fast response plants exactly so that types of plants where turning them off wastes potential energy, like wind farms, can keep running.

The original claim I took issue with, was that a hydro plant can't serve this purpose without a second reservoir, which is not true - a second reservoir can be used to increase total effective storage capacity, and to make the plant increase demand rather than just decrease supply, but a hydro plant on itself can improve grid responsiveness, given enough transmission capacity.

This whole discussion has been around the use of pumped hydro plants to store the output of other sources during times of low demand.

Yes and no. The two comments leading up to my first comment was one suggesting that you could achieve a similar effect by simply closing a damn, followed by one implying that did not take power out of the grid. My first comment then stated:

> You are taking power off the grid: The power otherwise produced by the hydro plant. > > Of course with a lower reservoir, you can go into negative territory instead of "just" taking the plant down to 0.

In other words, my point from the beginning was that there is - absent transmissions limitations - no conceptual difference in the outcome of stopping a damn and pumping into a reservoir, as I've gone into at great length in the subsequent comments.

Nope. Adding power to the grid is +X MW. Removing power to the grid is -X MW. Not producing any power is 0 MW.

That's true when looking at an individual plant, but is not directly relevant when you're looking at the grid as a whole (though it may be an issue when you have transmission limitations), where the problem is that at some point you have a supply of +2X MW, and demand is only X MW, and you need to deal with the X MW of oversupply. If one of the suppliers can then turn off X MW of supply rapidly, that has the same effect as if you add X MW of demand.

At a hydro plant you have multiple options: You can bypass the turbines; you can close the dam, as long as it's not near capacity; if you have a lower reservoir you can close the dam and pump water up to the upper reservoir. All of these help reduce the excess supply, but pumping up does so by increasing demand and reducing supply, and the other two options reduce supply.

You can of course do pumped storage without normally producing electricity too - in places where the only convenient location for a reservoir is not "in line" with a water source with sufficient fall height, you can still pump up to a convenient location, in which case the plant is basically "only" storage.

Unfortunately the capacity of these dams in most areas is far from enough to compensate all fluctuation in renewable energy production.

You not only need variable volume reservoirs on both ends, but you also want to have very high drop, because liars from seepage and evaporation scale with volume but not with height. Low-drop pumped storage might be useful for very short term storage, but usually you'd want something that is efficient over a wider range of usages.

This sounds like an opportunity for collaboration between crypto miners and the wind people.

And maybe it can be mediated by fungible electricity transmitted over a grid of conductive wires. Or an electricity market.

What I've meant was mining on the wind mills themselves. So there would be no need of passing through the grid.

I heard that crypto mining hardware has to have decent-ish (80-90%) uptime to be profitable. That would make it infeasible to have it on standby waiting for excess energy on the grid.

After the windmill is paid off, the mining is then practically ( some maintenance will be needed ) for free.

Isn't the number 80-90% based on electricity price?

Electricity prices matter but lower prices give diminishing returns.

Going from $0.20 per kWh $0.05 to per kWh only increases profits by 50%




and going from 0.05 to -0.05 only increases it by 20%


By the way, these mining calculators are very "optimistic" but for relative comparisons they are sufficient. In practice you will get significantly less because of increasing difficulty and hidden costs like motherboards, CPUs, etc.

I'm afraid I have no idea. I vaguely remember reading about it, do not remember where.

I know. And there's really no difference between colocating mining hardware on wind turbines and just mining using the lower cost electricity which will be on the grid thanks to the turbines. Except the inconvenience of the colocating.


(1) Cheap, large scale storage of electric energy might be a big game changer.

(2) Without such storage, basically a country has to notice what their peak load is and assume that they have installed capacity that is reliable, e.g., independent of the weather, and meets this peak load.

(3) So, net, intermittent sources such as wind and solar don't much lower the capital expense needed. That is, the country still needs the same capacity to meet peak loads without the intermittent sources. So for this capacity they can use nuclear fission, coal, oil, natural gas, hydro, geo-thermal, and that's about it.

So, net, when power from intermittent sources is available, then get to save on the fuel cost of fission, coal, oil, and natural gas and accumulate some water behind hydro. So, e.g., a big fission or coal plant is still there, still with its capital expense and operating expense but is running at reduced power and, thus, saving on direct fuel costs.

At that point, I'm wondering if, really, just for the money part, if the intermittent sources are wanted on the grid even for free.

There is an issue about the intermittent sources: They are not very predictable and, thus, can cause some grid stability problems. E.g., IIRC, can't just change the power level of a fission or coal plant minute by minute to match the minute by minute fluctuation in the intermittent sources; so, can get some grid instability, and that is bad stuff for the whole grid and country.

Worse, the big power plants get much less fuel efficient at lower loads. In some cases you will actually burn more fuel at 50% than 80%!

The title is wrong. One blade is the length of the wingspan of the A380, 80 meters. The rotor diameter is 154 meters.

I like this article. I like that is has nice big pictures and videos, but they dont do that stupid big 'screenspace' image thing that seems to be popular in these sorts of articles now.

Also their control centre looks horrible. Wheres all the crap on their desks? I hope they only just had to tidy it away for the sake of a press photo.

The guy on the left appears hard at work looking at an empty Windows desktop.

Well... at least on one of his 3 screens.

I'm sorry, stupid question, but exacly how much power do those big ones generate? 20 times more than what? This actually most crucial tidbit isn't even covered in that article, or am I blind?

The biggest ones produce over 5 megawatts at peak capacity, I think someone has built over 10 megawatts but I'm not sure.

5 megawatts is a pretty useless figure for most people to imagine, and I think imagining it in units of homes-powered isn't great either because we don't have a sense of the heat or kinetic energy equivalent because our homes are quiet machines. A 260 horsepower car (think new minivan) at full throttle is producing about .2 megawatts, so the worlds largest turbines are generating the same power as 10/.2=20 minivans at full power.

Another way to think of it is in terms of heat. A big stovetop burner will generate about 3000 watts of heat, so a minivan is like 65 burners at full blast, and a 10 megawatt turbine is like 3300 burners.

So, basically a single big offshore turbine 5-10MW can power a single electrical locomotive with power ranges 5000-10000 kW continuously. That's rather impressive considering how insanely powerful locomotives are.

Your calculation is not very helpful either, and it’s not only because division error (10/0.2 is 50, not 20). More importantly, an average minivan most likely never reaches its full power over its lifetime. It would make more sense to consider its energy use as it cruises, which is probably something like 50-70 HP. So, one 10 MW turbine is really rather 200-250 minivans, not 20 — a whole order of magnitude.

But perhaps the most useful might be power-plant-equivalents.

The Stockton Cogeneration Facility near San Fran had a nominal output of 60MW. Thus, around twelve of these mega-windmills would roughly equal the output of that coal plant.

A large size nuke plant does about 1300 MW nominally (it is initially about 3000 MW thermally but only 35% or so is successfully converted to power for the grid).

Wikipedia says the Vestas V164, with upgrades, is the largest at 9MW.

As someone else said GE has a 12MW in development, and I swear I've heard announcements about 10MW and 11MW prototypes.

> I think someone has built over 10 megawatts but I'm not sure.

GE just announced a 12MW turbine, which will start appearing in real world projects in 2020.

50 minivans!

Related story on Bloomberg this morning:

How to Buy a Wind Farm


Anyone familiar with these "bladeless" wind turbines as an alternative to large blades?


Based on their marketing (far quieter, 40% more energy) it seems like an interesting option. I know one of the biggest complaints that farmers have is the noise they cause, so they have to be placed far from houses.

I'm curious to see if it's mostly fluff or has any potential... but I'm not expert on the subject.

Fluff... dominant factor in potential energy production is area swept out...

> Lower costs, though, have also made wind power more appealing elsewhere. Once mostly concentrated in northern Europe, Mr. Nauen is optimistic that new markets will emerge in Asia and the United States.

South America too. In just the last 12 months, installed capacity in Brazil went from 10.4 GW to 12.5 GW (source: Boletim Mensal de Geração Eólica - ONS).

What kind of cost per kwh is Brazil seeing? When the US finally got consistently below ~$0.10 in the late 1990s, it began to ramp.


According to http://www1.folha.uol.com.br/mercado/2017/12/1944853-energia... in the auctions at the end of 2017 (for new generators to be built) it was around R$ 145/MWh for solar and R$ 98/MWh for wind. I don't know where to find the cost for all currently operating generators.

The engaging cinematography on this article really drew me in. Somebody could write an article about brick laying and if it had the same Nutella-smooth video I would read the entire thing.

I happened to be driving through Indiana this week and saw the biggest wind farm I'd ever seen. It just went on for ages as we drove. I think it is this 600MW farm: http://meadowlakewindfarm.com/

I was pretty amazed to recently read that Iowa is getting ~35-40% of its electricity from wind energy. They're up over 7,000 MW of capacity (4,000 turbines) now for just three million people.

Someone can correct me if I'm wrong, but I believe that Iowa may have among the highest wind energy capacity per capita on earth, at 2.2 MW per thousand people. Denmark, which is perhaps the highest for a nation, is at half that rate (5,476 MW capacity for 5.7m people).

The future of energy is mostly wind, solar, hydro, and nuclear with grid scale energy storage and long distance HVDC transmission lines. IMHO :)

I’ve always been told that transmission of electricity is hard or inefficient. What is HVDC and why is it better?

With AC transmission, there are a couple of small loss terms that are not present in DC transmission. To the extent that the world surrounding the lines is conductive, there is a parasitic transformer between the transmission lines and the world. The parasitic transformer is particularly bad in salt water, which is why you see so many HVDC links crossing bodies of water. Also, the capacitive reactive current in the lines adds up over many kilometers.

HVAC distribution wins hands-down for short to medium distances, or when there are many places where you need to step up/down the voltage. It will always be cheaper to step HVAC up/down in voltage at any single point relative to DC. But HVDC transmission wins over sufficiently long distances or when crossing major bodies of water.

So I don't think we'll ever see a complete overhaul of the US distribution grid using HVDC. But we might see long-distance HVDC distribution to do things like ship solar power from the desert southwest to the west coast, or ship wind power from the Atlantic to the east coast.

High voltage DC. High voltage means it’s more efficient (power dissipation depends on current, not voltage, so for the same power, higher voltage means much less dissipation). DC (direct current instead of alternating) makes it easier to connect disparate grids as you don’t have to worry about phasing.

Also, I recall reading that if you run undersea cables with AC, the sea water sucks out energy from them.

Can’t tell if trolling or not.

The cables have water barriers so the conductors + insulation remain quite dry.

I believe the parent meant that the alternating current creates an electric field which is then absorbed by the water, leading to energy loss. This happens to some extent to all AC transmission, but I don't know enough to say if seawater+AC is a particularly bad combination. It would make sense though, because it's more conductive.

EDIT: brandmeyer's comment explains it well: https://news.ycombinator.com/item?id=16903431

Yes, that's precisely the thing I was referring to. Wasn't sure about the correct terminology (not an EE) so I didn't try to make the comment sciency-souding :).

I work installing these cables and never heard this discussed, maybe at the voltages / transmission subsea cables work at (220kV, 1000s of amps) makes this effect negligible?

I honestly don't know. I'm not an EE, I only reported on what I've heard reported on the topic (and that passed my "basic physics sniff test").

Are they AC? My impression was that practically all vaguely modern undersea cables are high voltage DC.

It depends, when talking about interconnecting cables between countries, yes the majority are DC, both to minimise transmission losses and also to tie together grids working at different frequencies....

In terms of km installed I think it will be HVAC just from the sheer number of offshore windfarms built over the last 10yrs in Europe. These things can be huge - 60km in length, 220kV ~1500A....

Salt water is a conductor. Two conductors separated by insulation make a capacitor. This extra capacitance makes AC less efficient.

Thanks to both of you for the details.

The future of energy is mostly black hole farming.

Nice, how you sneaked nuclear in there.

I think at extreme latitudes, wind and hydro might not be available everywhere and it may be easier to do nuclear. In general I hope nuclear isn’t a big part of the solution because of cost alone: nuclear is quite expensive and I don’t really see the pathway to make it a whole lot cheaper.

I live here in Jutland, and it is indeed heartening to see those giant wind mills spread out across the fields. Surprisingly so many can be found inland.

I wish they focus as much on micro grids as much on energy generation.

Wow glad I have great internet the footage was great/visual is more direct.

Those turbines appeared to have an upward inclination, curious why that is. Also interesting that the trailing edge near the hub isn't as sharp as the tips probably due to slowest rotation.

Good stuff, those things are seriously massive.

I also like that giant wall monitor with all the 'stats'?

Autonomous utility boats will have a significant role to play in monitoring and supplying the offshore wind industry.


These little boats can continuously monitor the foundations of offshore wind turbines for scour, and their larger brethren can quickly deliver supplies in a wide range of weather conditions -- without putting human engineers at risk.

As an aside, one of them burned last year: http://www.powerengineeringint.com/articles/2017/08/new-vest...

By the way, you can walk right up to them. They are very impressive up close.

That's a 9.5MW unit that burned up. I don't like Vestas, they still use a gearbox which is a huge amount of extra complexity.

Wind turbines, they are not milling anything. One would have hoped that a paper like NYT would something as basic as that right.

Windmill is a defacto synonym for wind turbines in most english speaking countries

In the same way irregardless is a synonym for regardless, yeah I guess so.

More like how a "bug" is a synonym for "error in a program", even though there's no actual bug stuck between vacuum tubes, not to mention there are no vacuum tubes any more, and they don't do computation like they did in the 50s any more, but I feel your pain.

Not in the industry.

I worked in the industry for three summers, and they were interchangeable there.

Additionally, they could be 'tur-bans' or 'tur-bines' as well.

Good thing the NYT article isn't a whitepaper directed at industry engineers.

They're milling electricity.

Milling electromagnetic fields, and producing electricity.

Oh god what have you guys done to my native tongue.

Referring to HAWTs by the name "windmill" is part of the common vernacular in North America

They're milling electrons ;-)

agreed! my first thought was someone had rigged electric generators in the old actual windmills of the Netherlands. My second thought was, last I checked, they're not remotely as big as jumbo's....

But then how would we keep the Don Quixote imagery?

I think storage should be decentralized with towns/cities working to store locally and forward as required.

regarding superfluous wind energy: https://en.wikipedia.org/wiki/Power-to-gas#Efficiency

Does anyone have a datasheet so we can calculate the Energy ROI?

Here you go: https://www.vestas.com/~/media/vestas/about/sustainability/p...

Money-shot on p66. About 8 months for EROEI (Energy returned on energy invested). I worked on some of these Life Cycle Analyses and can attest that they were quite rigorous.

The future of mankind lies with nuclear power. I'm distressed by it not receiving as much attention as windmills.

The cost of nuclear power seems to go up while every other zero-emissions energy source goes down. Even ignoring the fears about accidents and waste, it seems like nuclear may end up a transitional source.

clean, safe, and too cheap to meter, amirite?

three words, last one's shima.

oh, look at the time, it's 2018 already..

Also killing birds and bats though....

How much wildlife (or human life...) is killed or otherwise threatened by fossil fuels? I suspect a single oil tanker spill kills more animals than any wind farm.


No claim was made. No need for a citation.

An issue that seems very suspiciously motivated and decontextualised. One such source I've seen comes from "ABC":

First: ABC take funding from an oil company, Conoco-Philips. That's not an indictment of itself, but it does smell funny.

They're also touted by the Heritage Institute, a notorious right-wingnut / Libertarian disinformation mill.

Source: SourceWatch: http://www.sourcewatch.org/index.php/American_Bird_Conservan...

ABC claims that as of 2012 there are 573,000 birds killed from U.S. wind power installations.

That compares against:

* 100-120 million birds killed by hunters.

* 174-175 million birds killed by transmission lines.

* 365-988 million birds killed by buildings and windows

* 0.2 - 3.7 billion (with a 'b') birds killed by domestic and feral cats.

This seems exceedingly agenda-driven.



If you’re concerned about this, you should be a lot more worried about cats, tall buildings, cars, electric transmission lines, and farming, all of which kill orders of magnitude more birds.

So do buildings.

My dad worked as a general counsel for a power company for a long time, and he told me they basically had a budget for how much they'd pay in violations of the Endangered Species Act related to bird deaths around their wind turbines.

You dad (or, more likely: you) is full of shit. Penalties don’t work like a tax on misbehavior. If you are constantly being fined, you would face the loss of your license to operate.


There was foreknowledge on the company's side that it would be an issue, but not expedience in trying to resolve it (hence the notion of it being budgeted as a potential expense). It still took years for anything to happen over the issue. My dad wasn't directly involved in this case (they have many many lawyers), but it was something he was aware of enough to mention at the dinner table, especially after it started getting press coverage. Sort of an "Ugh, the company is in trouble again, why can't they just do the right thing" type of gripe.

Problem is that these are political markets not market markets. Denmark spent a lot of money on getting their windmill industry up and running and windmills still aren't solving the base problem as they aren't reliable for all sorts of weather.

Furthermore, windmilss don't really scale well, Nuclear on the other hand which is both safer and more scalable and greener would change that but right now only the Chinese seems to have realized that.

Can you please define doesn’t scale well? I work in this industry, wind farms have gone from <50MW, to 200-300MW to 1.2GW in the last 10yrs, with 1.8-2.4GW in the very near pipeline, all whilst going from huge subsidies to the latest auction (in the Netherlands) being awarded to a zero subsidy bid, with rumour of their being negative auctions for for future rounds...

For reference the new nuclear in the UK (Hinkley 3.2gw) is receiving a £93/mwh subsidy, offshore wind uk project Hornsea two (1.8gw)is going to get £72mwh, and the Netherlands projects are receiving a zero subsidy for ~750mw projects.

It is not going to solve our energy crisis but there are virtually no negatives to building them now, if you have a coastline you can have zero subsidy clean energy in the next 5-10yrs.

The amount of energy needed will increase even though we become better and better at optimizing the individual items power usage.

In other words, wind and solar are linear solutions to exponential problems.

I have nothing against wind or solar but the idea that wind and solar will be able to solve our energy problems is based on a political mandate, not on science or any realistic evaluation of the energy needs of the world.

Wind can't run as long as nuclear can without maintenance and the cost is also going to be higher to maintain because of the large area it occupies.

The cost of Nuclear is suffering under the lack of political support compared to alternatives.

Furthermore, alternatives are not without problems:

"The first thing he discovered is that solar panels, in fact, contain significant quantities of toxic metals like lead, chromium, and cadmium — known carcinogens — and yet no nation outside of Europe has a plan to safely dispose of them. Many could end up in waste dumps in poor communities in Asia and Africa and poison drinking water supplies.

How much solar waste is there? About 300 times more per unit of energy than there is from nuclear power.

As a result, if solar and nuclear waste from producing the same amount of electricity were stacked on football fields, the nuclear waste would reach the height of the Leaning Tower of Pisa (52 meters), while the solar waste would reach the height of two Mt. Everest (16 km)."


And here is a study debunking the idea of alternatives as a realistic alternative (I am not saying you claim they are but that was my main point)


You need a mix, for now that will include solar, coal, nuclear and wind.

I think in the long run this will change to renewable sources + interconnected grids (it’s always sunny / windy / geothermal / waves) somewhere.

I’m generally pessimistic on fusion, but then it would cost me my job so I’m bound to be, but is always feels like it’s “50yrs away”

Yes we need a mix but right now we need more (positive) focus on nuclear (and other forms of more exploratory but potentially civilization altering technologies) as it's been almost banned out of existence in the US and Europe.

The current discusison is not based on what's optimal technologically but politically and thats in not small part due to some the unfortunate overreach of parts of the environmental organizations IMO.

I am all for tough legislation but what the current toxic political climate has made it almost impossible to discuss this in any proper matter.

Even me posting on this lead to multiple downvotes. Thats just absurd.

Agreed on the absurd downvotes!

I think nuclear is quite bad, we've got to transport / process / store nuclear waste for thousands of years. We should probably do anything we can to avoid producing this stuff.

I grew up near where a lot of the worlds nuclear waste is processed and while it does make for lots of good jobs, that last many many lifetimes, I just can't get onboard with new nuclear when it is cheaper to build interconnected grids + renewables (in the UK at least).

said in all sincerity.

I would urge you to spend a little more time looking into nuclear you would be quite surprised of how wrong your view of it is.

New reactors can use used uranium which makes the problem even smaller. On top of that, the actual footprint needed to store it is absurdly small if we even had to do that.

In other words Nuclear is the safest greenest form of energy we have (greener than wind or solar etc)

Here is a good primer on some of the myths you probably believe in.

But don't take my word or even the artcles word for it. Investigate and I am pretty sure you will soon see that your belief about nuclear is misguided.


When some options interfere with each other, we often find ourselves facing a trade-off "You can't eat your cake and have it, too,"

Whenever this happens some people would prefer one benefit at the expense of the other, while others prefer the other benefit at the expense of the first.

At this point the choice the group will make becomes a political point of contention. No matter which benefit you prefer your preference is political.

A lot of people want to see a more decentralized world (this does not imply a world without law and order), and they prefer society moves in the direction of decentralization, cryptocurrencies are one such facet. [Off-topic, while most cryptocurrencies today are based on energy intensive PoW, this need not be the case at all, see for example the papers on Algorand, which has not yet been implemented/deployed]

On November 10, 1972 the passenger plane Southern Airlines Flight 49 was hijacked, and the hijackers at one point threatened to fly the plane in the Oak Ridge (experimental) nuclear reactor unless their demand for $10 million in cash was met. [luckily, they did not do this even after picking up the less-than-demanded amount (according to the authorities!)] They fled to Cuba, hoping Fidel Castro would allow entry, but he rejected their entry. They landed in the US again to refuel, then fled back to land in Havana, where they were arrested at gun point.

Please note that with cryptocurrencies the hijackers don't need to land at all. One can question if the hijackers really intend to crash the plane if they demand money, but that money could flow to a political organization if the hijackers are terrorists.

I assume neither of us would want to see: 1) crypto banned 2) passenger planes shot out of the sky

This presents a conflict between nuclear power and cryptocurrencies. Which would you pick? That is automatically political indeed.

Thats not the discussion. The discussion is if opposing views are allowed to exist or whether you get shamed for thinking and proposing something that is as politically valid (human flourishing).

Obviously opposing views are allowed to exist. I don't know how shaming can even be measured objectively. What makes you feel shamed? The fact that someone downvoted you? Thats merely the expression of someone's opposing views... (I did not downvote your comments btw)

There is no "the" discussion. There is a discussion consisting of commenter beliefs, and then responses challenging beliefs.

You classified some beliefs as political as opposed to technical.

Lets define 'technical' as relating to matters of fact. Lets define 'political' as relating to selection of options.

i.e. technical statements are positive statements, and political statements are normative statements.

Every technical discussion contains tradeoffs. Tradeoffs are the source of political disagreement: when the family needs a new car, the tradeoff could be price, performance, appearance,... and the husband and wife will not in general agree. The technical tradeofff generates the political difference.

In the example I gave, some people prefer cryptocurrencies, other people prefer nuclear energy, there is no objective technologically superior future. There is only the choice among viable futures. In democracy politics should belong to us all.

Nobody is censoring you (nor me!)

If I were forced to define shaming, it would be something like: a behaviour where the perpetrator(s) make an appeal to a groups supposed definitions of virtues/sins, to change the groups perception of the victim(s).

In order to identify any such thing in this thread, I first need to identify the group: hacker news users. From reading your comments I think you (wrongly) believe the cliche "we come here for technology, we dislike politics" Then I read your posts where you identify anti-nuclear ideas as political vs pro-nuclear technologies as technological. So it seems you are the one who is shaming anti-nuclear ideas.

I am not appealing to any group virtues or sins here, and if I did I would not classify "politics" as the sin, since I regularly see people discuss tradeoffs and how they feel about it.

Btw, I am not against nuclear energy in any absolute way:

we may need nuclear power for space travel, why burn it up here and now? [no, its not in nature decaying at the same rate as we use it up, in a reactor we promote radioactive decays]

research reactors are extremely important to have for scientific progress, and cryptocurrencies are very promising for humanity too, perhaps governments should simply have a clear public policy promising to neutralize any plane [passengers or not] coming too close to a reactor or surface-storage of radioactive materials: this would decrease the probability of attempted hijackings.

I think we can both agree that nuclear reactors would ideally be aneutronic, from a waste perspective, can we not focus on that instead?

If we ignore the waste threat there is still the centralized dependency threat: irrespective if it is downtime, sabotage by employees, accidents, vulnerability during war, ...

With all this on top, I think it is not crystal clear to all of us that alternative energy sources are more expensive.

You should see the number of downvotes I got for my posts in this thread. You ask Michael Shellenger how much hate he is getting for proposing Nuclear is necessary in California or you ask Alex Epstein for that matter. You go see any climate catastrophe sceptics and you will see an army of people ready to shame them. If you don't see the shaming you aren't actually paying attention.

There is almost no middle ground.

Nuclear waste isn't the problem you make it out to be that's the point. It's the only waste in the US which is actually safely secured, solar on the other hand isn't and it's contains plenty of toxic materials.

Furhtermore new nuclear power plants can reuse already used uranium again making the waste problem even less.

I guess we just see things differently, you think that we need nuclear power to meet demand, I think we will be able to meet that demand with renewables + interconnected grids.

I appreciate that nuclear waste is not what it once was, but I think it is still right not to pursue nuclear when renewables are cheaper, and an interconnected grid can provide the base supply requirement by shipping power long distances.

Problem is that there is nothing even in potential future technology that allow solar and wind to cover our need. Furthermore they pollute way more.

So not sure exactly what it is you think we are seeing differently. The facts are the facts no?

So not sure why you are so adement about those inferior technologies.

The biggest rollout of these turbines is in the UK, which is in the middle of commissioning and building new nuclear. Also, the latest turbine installations are being built without subsidy. And, the capacity factor has gone way up.

Countries have been "developing" fusion power for decades. It'll arrive shortly after quantum powered personal computers.

Good that you put "developing" into air quotes.

If I pay one single developer for 50 years to build me all technology Google has, I still won’t get anywhere.

If you want to actually develop nuclear, you need to increase investment. By a factor of ten or more.

Sure but good luck getting a country to install it in this current political climate. The US is even worse of when it comes to getting Nuclear back in vouge.

Not disagreeing with you, but how do you come to the conclusion that Nuclear is safer and also more scaleable?

I don't know about safety, but nuclear plants produce much more energy per square meter. Wind turbines must also be installed in such a configuration to not have their airflow blocked by obstacles, including other turbines. Nuclear plants also do not require external energy storage since they can run 24/7.

The first DDG hit for "electricity production deaths per kwh" is https://www.forbes.com/sites/jamesconca/2012/06/10/energys-d...

(Not saying Forbes is a reliable source on this particular statistic, but maybe you can find a more authoritative one if you search?)

As for scalability, I guess the argument is that wind is somewhat limited by suitable sites, whereas nuclear produces a lot of power on a small area, with fuel lasting for millenia?

I believe the current assessment of the saftey are based on how many people have died related to each production method. I was thinking more along the lines of it's safety should there be a disaster or more with risk in mind.

Nuclear power stations of old I thought were located by seas or other large bodies of water for the cooling in an emergency, as we saw with Fukushima. I'd guess newer designed, especially things like Fusion and Molten Salt wouldn't have this same requirement and be inherently 'safer'.

Edit to say - I'd like to see Nuclear given much more attention by governments. As we aren't using a byproduct for generation (as with those used to refine whatever for bombs) we can do it in a much easier and cleaner way without the previous constraints.

Nuclear killed a ridicules little amount of people compared to many other things even if we included nuclear bombs. Even fukushima is as big a catastrophe as many like to claim.

It's far greener than especially solar, there is almost no waste and most of it can be reused in new reactors. Problem is that it's toxic to be pro-nucleaer in this day and age. And new reactors saftemechanism are done via physics which makes the "china syndrome" impossible.

Agree we need more investment and focus on nuclear but not holding my hopes to hight in this current political environment.


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