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Nuclear is back on the table for a green future

nytimes.com

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Re: Nuclear is back on the table for a green future

#801

Post by ncmncm »

qsdf38100 wrote: post #670
WalterBright wrote: post #565

Earlier quoted context omitted.

I know a fellow who is running a startup that moves a (very) heavy weight up a hill, and going back down it provides power. He says it is something like 90% efficient at energy recovery, whereas pumped water is far less due to friction in the pipes. He also said the inertia of a falling weight is enormous, and would help stabilize the grid.

It’s actually not a good idea at all. When you do the math ( or rather the physics) gravity batteries need so much mass and height to compete with other technologies that it’s just not worth it. Now if you use water, pipes and pumps, instead of solid materials, now we’re talking. It’s called pumped hydro storage and is the number one grid scale storage in the world.

Hint: pumped hydro is, exactly, a gravity battery. A gravity "flow battery", if you like.

It is #1, just now, because a lot already existed. They cost a great deal to build, back when. New ones would cost as much, but a small variation is much cheaper, not needing a dam or a watershed.

A small variation on a bad idea can be a very good idea.

Re: Nuclear is back on the table for a green future

#802

Post by ncmncm »

qsdf38100 wrote: post #781
WalterBright wrote: post #679

Earlier quoted context omitted.

Well, his company is building a pilot plant in Brazil. I suppose we'll find out if he's a genius or not. > efficiently Are you sure about that? He said the losses due to pipe friction were considerable.

70% round trop efficiency. And it’s from actual operational data, not from an optimistic spreadsheet calculation.

70% is plenty, nowadays.

If the railroad is already built, and disused, that drives down cost.

Cost is what matters most.

Re: Nuclear is back on the table for a green future

#803

Post by ncmncm »

pfdietz wrote: post #763
redisman wrote: post #581

Earlier quoted context omitted.

But then you presumably need to build these extra power plants that can use that fuel?

A combined cycle powerplant is about 10% of the cost, per unit power output, of a nuclear power plant. So we could completely back up a renewable grid with CC plants and nuclear could still be much more expensive.

And, steam turbines cost more to keep working than CC turbines. But both are very mature, meaning costs won't change.

Re: Nuclear is back on the table for a green future

#804

Post by ncmncm »

pfdietz wrote: post #794
ncmncm wrote: post #793

Earlier quoted context omitted.

I guess they can mothball it afterward.

Why should they? The state utility regulators approved it, so it's going into the rate base. That's not a competitive electricity market down there in the Southeast.

They could disapprove it. Maybe elect better government, first?

Re: Nuclear is back on the table for a green future

#805

Post by ncmncm »

pfdietz wrote: post #765
ncmncm wrote: post #740

Earlier quoted context omitted.

Did you see https://news.ycombinator.com/item?id=31759753 ? One of the projects has a plan to get p-11B closer to working. It didn't seem immediately stupid. It would be great to have a system that doesn't depend on unobtainium. Maybe in 50 years we will be able to take down the wind turbines, or explore the Kuiper Belt at length.

I don't believe any of the p-11B schemes I've seen. Like, no chance at all.

I would value your analysis of the specific scheme detailed there.

Re: Nuclear is back on the table for a green future

#806

Post by WalterBright »

ncmncm wrote: post #800
WalterBright wrote: post #797

Earlier quoted context omitted.

How are you going to create a large enough pond?

Maybe read up? When you just make shit up as you go along, you say dumb things.

Asking a question is not making things up.

Re: Nuclear is back on the table for a green future

#807

Post by flocu »

photochemsyn wrote: post #12

Funny article in that it doesn't discuss lifecycle costs. A side-by-side comparison of the cost of grids powered by nuclear power plant relative to those powered by wind/solar/storage is what I'd expect to see from a 'paper of record' like the NYTimes. Except in some specific cases (Finland, other Arctic regions with long periods of low sunlight) I'm pretty sure this cost comparison comes down firmly on the side of w…

Those comparisons have been done and they always end up with an energy mix between hydro, nuclear, solar and wind - not 100% wind/solar.

It isn't enough to build solar and wind, you also have to build backup. This is currently done by coal and gas but in the future it has to switch to climate friendly sources of energy. A hydrogen economy is very very expensive.

Here's an example: https://www.sciencedirect.com/science/article/pii/S254243511...

Re: Nuclear is back on the table for a green future

#808

Post by flocu »

photochemsyn wrote: post #62
philwelch wrote: post #22

Earlier quoted context omitted.

> ... I'm pretty sure this cost comparison comes down firmly on the side of wind/solar/storage. Storage is the main cost barrier for 100% renewable-powered grids, but this is also an area where technological development is possible. Sure, if you handwave the unsolved-at-scale technical problems with grid energy storage and make a series of generous assumptions about future technology, that's probably true. Nuclear te…

'handwave the unsolved-at-scale' ? All you have to do is look at Australia: https://www.pv-magazine.com/2021/08/10/worlds-largest-grid-f... > Battery rollout: "AGL Energy has committed to build 850 MW of battery-based assets by 2024. To that end, Torrens Island marks the first project to be constructed at the site of a fossil-fuel power plant. It won’t be the last, however, as big batteries are planned for New South…

Batteries are not a feasable seasonal storage. They can store for a couple of hours, no more.

For seasonal storage you need a hydrogen economy. H2 is very very expensive and has never been rolled out at scale. Not a single large gas turbine to burn pure H2 has ever been build.

In the middle of a crisis it's better to go for proven and economic technologies than trying to invent something completely new and untestet.

Re: Nuclear is back on the table for a green future

#809

Post by bob29 »

Manuel_D wrote: post #795
bob29 wrote: post #785

Earlier quoted context omitted.

So wrong its funny. Maybe if you assume the pre-existance of the nuclear supply chain due to a weapons program. I challenge you to actually follow the sources on any of estimates like that, or the hilarious "12g c02/kwhr" quote. It's all ESTIMATES (not measurements) FROM The nuclear industry. But keep on believing.

The estimates are from the IPCC, not from the nuclear industry. This is stated in the article.

The IPCC did not do primary research. They cite a source. That source did not do primary research, either. The actual data comes from an estimate from the industry itself. The estimates came from costs. Estimating embodied fossil fuel energy based on cost is a not a bad estimation technique except when a huge amount of your supply chain is subsidized.

Re: Nuclear is back on the table for a green future

#810

Post by _Tev »

dane-pgp wrote: post #437
Manuel_D wrote: post #362

Earlier quoted context omitted.

Which is a lithium ion battery facility. Not a thermal batter facility.

Yes, I realise that. That's why I said "I don't know" and "for comparison". My point was that GWh-scale thermal battery proposals would be competing with already existing (and possibly cheaper) chemical batteries, and that energy storage on this scale is not unheard of.

The point is that current energy storage facilities are too small for fully renewable grid (or arguably even 60% renewable grid).

Even as a nuclear supporter I would welcome more renewables if we had cheap scalable storage, which no one has it seems. (at least no one pointed out such project in the entire thread)

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