Comment by jdlshore

15 hours ago

The economics of new nuclear plants don't make sense. They take too long to build and cost too much. By the time a new plant is ready, alternate sources (likely solar + battery and long-distance HVDC) will have eaten its lunch.

> They take too long to build and cost too much.

The global average to build one is ~7 years. People have been saying they take too long to build as an excuse for not building them for what, two decades or more? It seems to be taking longer to not build them than to build them.

> By the time a new plant is ready, alternate sources (likely solar + battery and long-distance HVDC) will have eaten its lunch.

Neither of those have the same purpose. Solar + battery lets you generate power with solar at noon and then use it after sunset. It doesn't let you generate power with solar in July and then use it in January. More than a third of US energy consumption is for heating which is a terrible match for solar because the demand is nearly the exact inverse of solar's generation profile both in terms of time of day and seasonally.

HVDC is pretty overrated in general. It does nothing for the seasonal problem and it's expensive for something that only provides a significant benefit a small minority of the time, i.e. the two days out of the year when the entire local grid has a shortage but a far away one has a surplus. It's also hard to secure because it inherently spans long distances so you can't have anything like a containment building around it and you end up with an infrastructure where multiple GW of grid capacity is susceptible to accidental or purposeful disruption by any idiot with a shovel or a mylar balloon.

  • > It doesn't let you generate power with solar in July and then use it in January.

    That’s not necessary. Solar panels are so cheap that you can massively overprovision for winter and still come out ahead of nuclear.

    • > Solar panels are so cheap that you can massively overprovision for winter and still come out ahead of nuclear.

      Only you don't. In latitudes that get winter, solar output is only about a quarter as much in the winter as in the summer. You often hear things like "twice as much in the warmer half of the year" to try and stuff October and March into the "colder half" and disguise how screwed you are in December and January. Worse, if you electrify heating then it's not just that solar supplies less in the winter, you also have more demand in the winter.

      By this point you're not just overbuilding by a bit, you'd need five times as much or more in January as in July. "Five times as much" is already over what it costs to use nuclear. Then it gets worse, because you now have a price of zero during the summer and even the spring and fall because of the massive oversupply and lower demand, so you now have to recover the entire cost of the overbuild during the three months when you're generating the least amount of power.

      Then it gets worse yet, because heating demand is higher at night and we haven't yet added the cost of storage.

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    • Lets put down some Swedish numbers.

      During the coldest winter month, solar energy produce (as per statistics from the solar industry in Sweden) somewhere around 3-7% of the amount produced during the warmest month. Households also consume around 2-4 times the amount of energy during the coldest month compared to the warmest month. Sweden is a country where only a small minority have air conditioning installed at home.

      Those are the worst month vs the best month. Overall the winter is not that bad, but it is still pretty bad for solar. Talking with people who has had solar installed here, the general story is very similar. During periods where it do produce the market price is already exceptional low, so it isn't returning a major saving. When the market price is high, the output is low, forcing them to be connected to the grid and pay whatever the electrical company demand during the highest market peaks, as well as taxes and grid fees which themselves has increased to match the cost of high variability.

      All this looks very different in countries with much warmer climates and where the major energy consumption from households are air conditioning.

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    • I selected random date in July 2025. During that time Finland produced about 10GWh of solar. I selected random one from February 2025. During that Finland produced about 0.5GWh. February also actually doesn't have shortest daylight hours, mid-December situation is even worse. Christmas Eve 2024 produced about 0.05GWh.

      You sure overprovision factor of 200x is still cheaper? This is when looking at the peak generation. From what I understand solar has about 30-40% capacity factor in summer. Just to panels (I'm not sure about total cost of grid-scale solar) seem to be about $300k per rated 1MW or $750k per 1MW during peak. $150M per 1MW during December. OL3 cost about 11B € for 1.44GW (assuming 90% capacity factor) or 7M € per MW.

      Unless there has been some huge overnight exchange rate change 7M € seems much cheaper than $150M. Latter of course would actually be much higher when you factor in rest of the equipment, labor etc. Some numbers I found say that it's probably 5x higher.

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  • The issue with them in addition to time is a huge capital expense that needs to be amortized. Nobody wants to hold 30-80 year debt on giant capital projects that could be rendered obsolete.

    For commercialization, solar makes more sense as there is a much better return on capital.

    If I were king, I’d do socialized power and have the government capitalize and own the nuclear plants, and bid out the operations to private entities. Government has better debt economics and doesn’t care about return in monetary means.

    Even then, relatively small tweaks to tax law and some grid investment would create a solar boom at lower cost. Every Walmart parking lot and some road infrastructure should be covered with solar. Interstates could be utility and generating corridors - they aren’t because federal law makes any multimodal use very difficult.

    • > Nobody wants to hold 30-80 year debt on giant capital projects that could be rendered obsolete.

      There isn't really an "obsolete" after it comes online because things get built when expected revenue exceeds construction costs + operating costs, but once built (or close enough to completion) they continue to operate as long as revenue exceeds only operating costs because by then the construction cost is in the past. When the construction cost is large, the amount the price of electricity would have to decline to fall below operating costs is equally large. And investing in something where you expected a positive ROI and you ended up with a slightly negative ROI clearly isn't what you'd have preferred, but it isn't nearly as bad as the -100% ROI you'd get from shutting down the plant instead of selling it for slightly less than what you put in. There's a reason the US is not only continuing to operate 20th century nuclear plants but even looking to reactivate some of the ones that have already been decommissioned.

      Moreover, solar has the same problem. You invest in a solar farm because you're expecting to profitably sell power at current prices, but if e.g. the AI thing turns out to be a bubble then there will be oversupply and current prices won't stick. Solar also has the added "everybody is doing it" risk. If you and everybody else add solar then the price at times when solar output is highest is going to be lowest and vice versa, i.e. if too many people invest in the same type of generation then your output gets inversely correlated with the market price, which is bad for ROI.

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How much of this is unnecessary regulatory burden, though? There probably is some margin of improvement over what the anti-nuclear lobbyists have imposed.

  • Is it unnecessary burden? We've had major nuclear accidents despite regulations and that was before 9/11 and dron wars.

    • The definition of “major accident” used in nuclear is orders of magnitude more strict than in any other industries though, which distort the picture.

      The worst nuclear accident involving a nuclear plant (Chernobyl, which occurred in a country without regulation for all intent and purpose) killed less people than the food processing industry cause every year (and I'm not counting long term health effect of junk food, just contamination incidents in the processing units leading to deadly intoxications of consumers).

      In countries with regulations there's been 2 “major accidents”: TMI killed no one, Fukushima killed 1 guy and injured 24, in the plant itself. In any industries that would be considered workplace safety violation, not “major accident”… And it occurred in the middle of, and because, a tsunami which killed 19000!

      I'm actually happy this regulation exist because that's why there ate so little accidents, but claiming that it's still hazardous despite the regulations is preposterous.

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  • MIT actually measured this, and the conclusion might surprise you:

    > Some of the driving factors are definitely regulatory. After the Three Mile Island accident, for example, regulators “required increased documentation of safety-compliant construction practices, prompting companies to develop quality assurance programs to manage the correct use and testing of safety-related equipment and nuclear construction material.” Putting those programs in place and ensuring that documentation both added costs to the projects.

    > But those were far from the only costs. They cite a worker survey that indicated that about a quarter of the unproductive labor time came because the workers were waiting for either tools or materials to become available. In a lot of other cases, construction procedures were changed in the middle of the build, leading to confusion and delays. Finally, there was the general decrease in performance noted above. All told, problems that reduced the construction efficiency contributed nearly 70 percent to the increased costs.

    > By contrast, R&D-related expenses, which included both regulatory changes and things like the identification of better materials or designs, accounted for the other third of the increases. Often, a single change met several R&D goals, so assigning the full third to regulatory changes is probably an over-estimate.

    > So, while safety regulations added to the costs, they were far from the primary factor. And deciding whether they were worthwhile costs would require a detailed analysis of every regulatory change in light of accidents like Three Mile Island and Fukushima.

    https://arstechnica.com/science/2020/11/why-are-nuclear-plan...

  • France is all-in on nuclear. Their reactors are still pretty expensive. Worth it, but expensive. Each reactor is a huge piece of infrastructure where small mistakes compound. No matter how little regulation you have reworking these giant buildings takes a lot of work, if only from the physics of it all.

    If there's magic that makes em massively cheaper someone should tell France.

  • It's not the regulations, it's the financing scheme: if it's not state backed with a long investment horizon, it's very expensive because private investors expect 10% yields in the middle of a ZIRP to cover from the possible political reversal.

    The Hinckley Point C EPR reactor would have produced electricity at a rate below £20/MWh instead of a planned £80/MWh if it was financed by government bonds.

    • It's not just political reversal risk; there's the risk of technological obsolescence. It's very much a stretch to assume a nuclear plant will remain operationally viable (in the sense of being competitive) for 40 years, never mind the 60 or 80 years sometimes mentioned, because the competition isn't standing still.

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    • ”If we compare apples to oranges nuclear power is cheap”.

      You can finance the competition in the same way and get similarly cheaper prices.

      Hinkley Point C just got a loan at a 7% interest rate to finish the plant. That is after about all uncertainty should already have been discovered.

      Now add making a profit and factor in the risk on top and you’ll end up with electricity costing $400 per MWh

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