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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

#681

Post by ncmncm »

WalterBright wrote: post #679
qsdf38100 wrote: post #669

Earlier quoted context omitted.

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. Except if water, pipes and pumps are used, as water is heavy, and pipes and pumps can transport a lot of it very efficiently and cheaply. That’s called pumped hydro storage and is currently the #1 grid scale storage in the wo…

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.

Losses turn out not to matter much when opex is near zero and generation capex is very low. You just build a little more top-line generating capacity.

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

#682

Post by ncmncm »

sanderjd wrote: post #534
californical wrote: post #505

Earlier quoted context omitted.

I know there are options like pumped water, compressed air, spinning disc. No idea how feasible they are at scale, but I can imagine a world where physical storage like that could be lower maintenance & cost in the long-term compared to chemical batteries. Even if less efficient, you can get enormous potential storage from pumped water with relatively simple machines compared to massive battery farms.

I'm interested in those alternative technologies, but I suspect they won't scale as well as batteries. Pumped hydro has been around a long time but it hasn't scaled because it is just very geographically specific.

Batteries have the very large disadvantage that cost is per Wh stored. Flow batteries can reduce this, as capacity becomes a matter of tankage and electrolyte.

The sweet spot for storage is near-zero opex, very low per-Wh stored capex, and cheap capex per-W in and, particularly, out. Thus, weight for watt-hours, and simple motor / generator for watts in and out.

Synthetic fuel has the appeal that the stored energy is readily tanked and transported, and very saleable; enough so to overcome low round-trip efficiency, expensive electrolysers for W-in, and complicated combined-cycle turbines for W-out.

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

#683

Post by logifail »

lelag wrote: post #653
ncmncm wrote: post #608

Earlier quoted context omitted.

Quoted post unavailable.

You make it sound like I'm anti-renewable. I'm not at all. I'm all for building as much capacity as we can as long as it makes economical sense and I will selfishly have solar panel and LFP batteries installed on my home as soon as I can and before price goes up as I expect they will. What I'm saying is that we should not put all of our eggs in the same basket hoping that wind and solar are silver bullets that will f…

> [nuclear has] produced vast amount of predictable carbon-free energy

We really can't describe a commercial nuclear power plant as "carbon-free".

Sure, responsible for much less carbon than coal or gas per kW/h, but taking into account the lifecycle, almost certainly way more carbon than renewables.([0] and other sources):

"Mark Z. Jacobson, director of the Atmosphere / Energy Program at California's Stanford University, calculated a climate cost of 68 to 180 grams of CO2/kWh, depending on the electricity mix used in uranium production and other variables"

[0] https://www.dw.com/en/fact-check-is-nuclear-energy-good-for-...

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

#684

Post by ncmncm »

Andrew_nenakhov wrote: post #673
ncmncm wrote: post #662

Earlier quoted context omitted.

Nukes are concrete, steel, pumps, steam turbines, liability subsidy, decommissioning subsidy. None of those get cheaper.

Concrete and steel costs are negligible in the full costs of the nuclear plant. Complex machinery like turbines, reactors, etc have huge costs that fall of rapidly when you start mass producing them. If you make 2 plants/year the cost per item is X, if you make 100 plants/year the cost per item is X/10 or X/20. Huge part of costs goes into machinery that allows to build the thing. Once you have it, producing more par…

Steam turbines are mature tech whose capex and opex are large and will not change. Likewise, high-pressure plumbing.

Thus, costs are not falling, and new starts are negligible. Even China, which asserts they will build 220 of them, has only started 10. The rest will be cancelled as their price is undercut, unless politics forces the matter. China is not cost- or value- driven. (Cf. "Ghost cities".)

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

#685

Post by cycomanic »

cycomanic wrote: post #656
cthalupa wrote: post #619

Earlier quoted context omitted.

>the still unsolved long term storage problem (it's been >70 years of nuclear power and there still does not exist a long term storage facility in the world) Storage has /been solved/ for decades. High Level Waste is only a tiny fraction of total waste. As it stands, all of the HLW created by all the nuclear plants in the world could be kept in a football field sized area. The vast majority of the rest of the generat…

Here [1] is a picture of the temporary storage at the Yankee nuclear power plant temporary storage (sorry I could not find better pictures from above to give more accurate size). There are ~90 commercial nuclear reactor in the US. I can immediately see that this would not fit into a football field sized area. And this is for a single country and ignores waste that was already transported away. And no things will not…

Sorry here's the link: https://vtdigger.org/wp-content/uploads/2017/06/Aerial-from-...

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

#686

Post by ncmncm »

acidburnNSA wrote: post #618
ncmncm wrote: post #615

Earlier quoted context omitted.

Fossil and bio fuel are not what nukes and nuke construction are competing with, so mentioning them at all is an attempt to distract. We are not distracted.

The entire energy project right now is to decarbonize rapidly. The world energy mix is more than 80% fossil and biofuel. Nuclear is competing with fossil and biofuel. https://ourworldindata.org/energy-mix

No, nuke construction competes with renewables construction, and nuke operation with renewables operation. Nukes are absolutely obliterated on both.

Only political bias allows nukes to continue.

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

#687

Post by ncmncm »

adrianN wrote: post #674
megaman821 wrote: post #491

Earlier quoted context omitted.

I agree that hydrogen efficiency doesn't matter here, but the capital expenditure to build a giant electrolyzer with 5% utilization doesn't really make sense. The cost of the electrolyzer is the things that needs to greatly fall if hydrogen is going to be used for long-term storage.

Hydrogen has important industrial uses. Currently we get it from natural gas. That has to change in the future.

Hydrogen produced using NG will be deeply undercut by electrolysed hydrogen. Extracting NG will become unsustainably expensive as zero-opex synthesis surges.

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

#688

Post by ncmncm »

alar44 wrote: post #492
skrbjc wrote: post #484

Earlier quoted context omitted.

" the waste produced by coal plants is actually more radioactive than that generated by their nuclear counterparts. In fact, the fly ash emitted by a power plant—a by-product from burning coal for electricity—carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy" From: https://www.scientificamerican.com/article/coal-ash-is-more-... We seem to…

Yeah but that coal radiation is tiny! Nuclear reactor radiation is big! It's like a kid preferring 5 nickels to 2 quarters because 5 is more.

Both are irrelevant. Twittering about them is disingenuous.

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

#689

Post by ncmncm »

trashtester wrote: post #636
ncmncm wrote: post #451

Earlier quoted context omitted.

Arguing that leaked radioactive contamination is less harmful than often assumed does not make habitually leaky nukes seem any more attractive, vs. alternatives that leak nothing hazardous at all, ever.

For someone who understands science, it actually DOES make them more attractive, when they realize that the "contamination" is at concentrations usually associated with homeopathy.

Nobody wants to need to pay attention to them wholly unnecessarily when the alternative is overwhelmingly cheaper besides.

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

#690

Post by IMTDb »

ncmncm wrote: post #648
IMTDb wrote: post #507

Earlier quoted context omitted.

You are right, I double checked. 275 10^10 Wh are needed as per my comment above and there is 160g of Lithium in a battery per kWh of capacity [1] 275 10^10 Wh = 275 10^7 kWh => 275 10^7 kW * 160 g / kWh = 45375 10^7 g = 453 750 tons This is far less than half the resources of the planet, but it's still a non negligible 1/40. To power half the American, for half a day, assuming that we willing to mine all the Lithium…

Batteries will be a negligible fraction of utility storage, and lithium will be a negligible fraction of that. So, your concern trolling about battery materials is misplaced.

How will energy be stored then ? Where will the humongously large utility storage center located ? When does their construction start (and when are they scheduled for completion) and how are those going to be financed ?
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