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Nuclear energy is clean

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Re: Nuclear energy is clean

#451

Post by ben_w »

JetSetWilly wrote: post #442
ben_w wrote: post #432

Earlier quoted context omitted.

x100 over-capacity is at the level where an HVDC global power grid is easily cheaper. Why do you regard HVDC within Europe as impractical? Sure it would take a while, but there's already a grid. This is certainly achievable in my lifetime even without any interesting new tech like better superconductors or automation.

Building an HVDC grid within Europe to allow local concentrations of renewable generation to be spread about more easily, and to further interlink the EU grid? That makes sense, sure. However for the "renewables can be base load" requirement it is completely impractical because of simple back of the envelope calculations. Suddenly you need multiple TWs of wind generation capability in every spot where it might be win…

The need is 3m^2 cross section of conductor for the entire planet's current electricity usage, which at antipodal scale is 17 years of current global production of copper and aluminium. Production of aluminium is limited by electrical supply, and PV electricity is cheap enough to expand that aluminium supply. A 25% increase in global aluminium supply is significant, but not pipe-dream, and that percentage is sufficient for completing the task before the end of the century.

What I don't know is how long such a cable would last, which matters for total lifetime cost. But construction cost at current prices is on the order of a few trillion, which sure, is loads, but that's for a genuinely global infrastructure project that essentially replaces the multi trillion dollar per year fossil electricity industry.

Biggest problem is probably the geopolitics.

Re: Nuclear energy is clean

#452

Post by pfdietz »

adrian_b wrote: post #364
pfdietz wrote: post #254

Earlier quoted context omitted.

> You can store electricity from day to night, but not from Summer to Winter. Hydrogen can do that.

Synthetic hydrocarbons can do that much better than hydrogen. Also ammonia can do that much better than hydrogen. There are also several types of flow batteries which can store energy for any time desired, without losses. Compared to hydrocarbons or ammonia they have a low energy density (which is not prohibitive for stationary applications), but they have a higher energy efficiency for a charge and discharge cycle,…

Synthetic hydrocarbons requires you either capture CO2 from the atmosphere, or capture, store, and reuse the CO2 of combustion from your turbines (so you're still storing compressed gases underground; you've also made the per-output-power part of your system more costly, which is very undesirable for rarely used backup storage). The round trip efficiency with hydrogen will also be higher, since you don't have to do either of those and the process that makes hydrocarbons starts with H2 and CO2 and is significantly below 100% efficient.

Flow batteries would be better than ordinary batteries, but would still be costly for seasonal storage or rare event backup compared to hydrogen (especially flow batteries using vanadium).

Re: Nuclear energy is clean

#453

Post by belorn »

pydry wrote: post #425
belorn wrote: post #411

Earlier quoted context omitted.

The average cost of green hydrogen is 6 euro per kg, putting the price per kw/h around 18 cent. That is about 7 times more than the cost of nuclear per kw/h. No one is burning green hydrogen commercially for grid power, through a lot of people would be happy to pay the average nuclear cost (~3 cent per kw/h) if you want to provide it. Selling green hydrogen for $1 per kg would be very welcome in Europe right now, wit…

"Green hydrogen" is probably the least efficient form of energy storage talked about. The only reason it gets talked about at all is again , PR - because gas companies are keen on extending the life of their rather expensive capital investments. It's currently in the hypothetical stage and, being realistic, the gas companies promoting it probably just want to produce grey hydrogen for use with "green hydrogen" infras…

Please provide a link to a pumped storage that buy green wind power when the price is low and sell it when the price is high. I would be nice to have a working example of how much wind they buy and at what price point they sell, and how they managed to finance it (ie, how much subsidies was involved). The cost per kw/h is of particular interest.

Grid scale batteries work great when you got 365 charge cycles. Each day it charge, each night it sell and generate profits. Current economics makes it worth having a few hours of capacity, and after a few years of daily charge cycles you got profits. Wind doesn't have day and night cycles like that, but rather have periods lasting weeks or months of either good wind or poor wind. You need capacity to last the whole period, and you get maybe a 10 or so charge cycle each year.

> A lot of that storage in the alps has been used for excess nuclear power from France.

Since nuclear is presented as being the most expensive method to create energy, if you then store it in pumped hydro and add this additional storage cost, how in the world would that be economical viable?

Looking at the European report on energy storage, the answer is that it is not. Pumped storage is not used for that purpose in the alps. It is used to balance the grid when power plants ramp up or down, a role which gas and oil power plants usually do. For this, nuclear energy can be used since the profits are not from buying low and selling high, it is from the utilization of keeping the grid balanced when power plants are ramping up and down. They get paid for the service, which makes the economics of it very different from selling capacity to the market during periods of low wind.

Re: Nuclear energy is clean

#454

Post by ncmncm »

yellowapple wrote: post #234
afterburner wrote: post #190

Earlier quoted context omitted.

> We don’t need innovation in nuclear The Nuclear industry will need that innovation, in order to remain even remotely competitive with the alternatives. It's not improving faster than those alternatives though.

Nuclear is already more than competitive. The appearance otherwise is overwhelmingly artificial.

When your argument depends on promoting falsehoods, one wonders why you bother.

Re: Nuclear energy is clean

#455

Post by p_l »

pfdietz wrote: post #449
p_l wrote: post #415

Earlier quoted context omitted.

It's much more dispatchable than renewables, it's just cheaper to run it always at full capacity. Solar/wind/storage combination requires overbuilding in range of 15-25 times the nameplate capacity. Personally I'm of the opinion that we should have nuclear+renewables with less focus on storage and more on opportunistic production of, for example, green hydrogen - not for grid storage but for all other uses like steel…

Ah, so solar/wind is not dispatchable because it's more costly you claim, not because one can't actually do it? You don't need 15-25x overbuilding. That is nonsense. Perhaps you're assuming no storage whatsoever, and are oversizing the renewables to deliver sufficient power instantaneously? What terrible and foolish engineering. The round trip efficiency of power -> hydrogen -> power is maybe 40%, so if you sent the…

You use Texas (or whole of USA). Which is considerably more southern than most of Europe, and definitely more southern than Poland. IIRC Texas is also much more flat, which benefits availability of wind power.

The 15-25x numbers I get from model.energy, in fact - lowest I get is 15x assuming way too optimistic ideas about availability of salt caverns in Poland, 25x is with mainly battery power, the numbers for no storage are too hilarious too discuss.

Are there luckier locations that can get better numbers? Sure. I'm not against building renewables and storage, far from it. I am, however, against building new fossil fuel plants, including gas backup for renewables, and would rather we take the minimum average power use, fill it with nuclear, then get renewable/storage Virtual Power Plants to fill in the peaks (with some load following from reactors if necessary). If necessary, we can find new power sinks to make it more economical, in fact I'd love if we had large scale green hydrogen and synthetic fuel production backed by hydrogen electrolysers taking in overproduction.

The real problem isn't cost of nuclear, it's that we still leave profit as the main guiding principle (to the point that building new solar might crash in some states) and not optimizing for 0 emissions.

Re: Nuclear energy is clean

#456

Post by ncmncm »

tomp wrote: post #420
cycomanic wrote: post #294

Earlier quoted context omitted.

This argument has been debunked many times. A large enough grid can be based on wind and solar alone, this has been shown for the US in several studies. Storage however is advantageous because it enables to reduce the amount of overcapacity. The good thing is that the way the electricity market works, is that it provides direct economic incentives to develop storage or basing high electricity demand production indust…

Can you share some of these studies? I just don’t understand how you can power a grid at night with just wind and solar (no batteries). Even the US isn’t large enough that sun would always be shining somewhere.

Think for a moment.

Re: Nuclear energy is clean

#457

Post by pfdietz »

replygirl wrote: post #319
pfdietz wrote: post #244

Earlier quoted context omitted.

Grid connected batteries are being installed all over the place. And now hydrogen storage is being rolled out too. The hydrogen storage project in Delta, Utah could ultimately (when the salt formation there is fully utilized) store enough hydrogen to supply the entire US average grid power demand for 30 hours. BTW, electrolyzers from China are now being sold to the international market for $0.30/W. Their prices are c…

the delta project is primarily a natural gas plant for the next 25 years, btw

They might be using SMR hydrogen to start with, for demonstration purposes, but doing it with SMR at scale would make absolutely no sense; it would be cheaper and more efficient to store and use the natural gas directly.

Re: Nuclear energy is clean

#458

Post by ncmncm »

stjohnswarts wrote: post #343
joak wrote: post #324

Earlier quoted context omitted.

Solar and wind have these economic properties: - the marginal cost of energy is zero (once the investment made producing a kWh is free) - fix costs are almost zero For the nuclear energy we have the following: - the marginal cost of energy is low (the cost of the uranium mostly) - the fix costs are incredibly high (wether the reactor produce or not, the payroll is the same, the maintenance cost are the same, etc...)…

No one is going to build 10x as many wind turbines as they need to make sure the grid is still up. It's not going to happen unless someone comes up with grid scale storage that can power the entire electric grid for at least 12 hours and in a lot of places 16 hours when the sun/wind isn't available. Nuclear is the only reasonable option we have.

So, we will build grid-scale storage. It will be massively cheaper than nukes would have been. Masively cheaper even than keeping them operating, too. So they will be mothballed.

But we don't need 10x overbuild: the wind is always blowing somewhere. If not here, there. If not there, here or somewhere else.

Re: Nuclear energy is clean

#459

Post by belorn »

slavik81 wrote: post #400
smartmic wrote: post #347

Earlier quoted context omitted.

You just considered one axis of the waste properties. It must also be in the equation that the waste will remain radioactive and toxic for thousands of years, far beyond the time horizon of what a normal human brain is capable of processing. Also, the effects (spatial, biological) if the waste is released for whatever reason (which we may not even know now). So the debt we transfer to future generations goes far, too…

Spent fuel will remain toxic forever. Uranium and plutonium are heavy metals. They will have to be treated as dangerous substances from now until the end of time, much like lead or mercury.

Northern Sweden is known for its iron mines. What people might not know is that if you live anywhere near where such mining has occurred (many miles away from the actually mining site), it is strongly recommended that people have detectors for radium. Obviously, water that is close to mining sites is generally not advisable to drink. Mining just bring up a lot of toxic things that the human body react badly with.

Re: Nuclear energy is clean

#460

Post by pfdietz »

endominus wrote: post #338
pfdietz wrote: post #251

Earlier quoted context omitted.

If you have to resort to "it's better than fossil fuels" you have damned nuclear with faint praise. And you have also wasted our time, because nuclear is competing with renewables now, not with fossil fuels.

Okay, how about; it's safer than literally every other method of energy production? Less deaths per thousand terawatt-hours produced (90) than wind (150), solar (440), or hydroelectric (1400). https://www.statista.com/statistics/494425/death-rate-worldw...

I already addressed that argument.

https://news.ycombinator.com/item?id=32295591

If a statistical human life is worth $9 M, then 440 deaths per thousand TWh adds $0.004/kWh to the cost of solar. This cannot overcome the large cost advantage solar and wind have over nuclear in most places (even with storage costs included). Also, the 440 figure is, I believe, assuming rooftop solar. At scale to power the world solar will be mostly ground mounted.

If you don't agree with that statistical value, and think it should be higher, why you've just argued we're not imposing enough safety systems on nuclear plants -- because $9 M is the value the NRC uses when determining if additional safety systems are warranted.

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