This is not how nuclear works. Nuclear sets a low price that corresponds to its cost, then lets more expensive marginal energy sources set the final price. Nuclear can by the way be modulated +20%\-20%, which makes it quite flexible in real condition. See https://www.rte-france.com/en/eco2mix/power-generation-energ... as a proof - nuclear generation in France can go from 25GW to 45GW during a day.

New small modular reactors promise great improvements, as they can be pre-built in factories, require limited maintenance, lower risk, and as a result much lower cost per MW.

https://www.rolls-royce.com/innovation/small-modular-reactor...

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mikepavone 2 days ago | parent | next [-]

> This is not how nuclear works. Nuclear sets a low price that corresponds to its cost, then lets more expensive marginal energy sources set the final price.

This may be an accurate description for fully-depreciated nuclear plants, but it doesn't reflect the economics of new-build nuclear at all. You have to consider both operating and capital costs. Nuclear plants are cheap to operate once built, but those operations have to pay off the capital costs. If the load factor is low, then each unit of generated power has to bear a higher portion of the capital costs. If your capital costs are very high, then you either need a very high load factor or very high spot prices to bear those costs.

> Nuclear can by the way be modulated +20%\-20%

Net demand on CAISO can go from about 2 MW to 30 MW in the summer. 20 MW of that ramp occurs over just 3 hours. I'm sure you can build nuclear plants that ramp that fast, but you need a lot more than the range you're mentioning here. Regardless, I'm not making an argument about the physics of nuclear power plants, just the economics. Expensive plants generally need high load factors to pay off the capital costs.

> nuclear generation in France can go from 25GW to 45GW during a day.

Most of France's nuclear plants are old and thus fully depreciated. The only one built recently (Flamanville Unit 3), is a good example of the bad cost trend in nuclear. While this was a bit cheaper than Vogtle Units 3 and 4 in the US on a dollars per nameplate capacity basis, at 19 billion euro it's still very expensive (and also way over budget).

France also has high rates of curtailment, which is not necessarily a huge problem for them since so much of their generation is already carbon-free, but it does suggest they're already hitting the limits of their ability to ramp production up and down. Whether this is an engineering problem or something to do with the structure of their electricity market is a bit unclear to me

> New small modular reactors promise great improvements, as they can be pre-built in factories, require limited maintenance, lower risk, and as a result much lower cost per MW.

This has been the promise for years, but so far the low costs have yet to materialize and they are estimated to have a higher LCOE than traditional plants. Currently only 2 are actually operational, a demonstration plant in China and a floating power plant using adapted ice-breaker reactors in Russia. There are a few more in the pipeline, but they are all at least a couple years out from actually producing power.

	▲	Saline9515 2 days ago \| parent [-]
		> This may be an accurate description for fully-depreciated nuclear plants, but it doesn't reflect the economics of new-build nuclear at all. I'm talking about the wholesale market, which works as an auction, where producers give their price for units of capacity, and the clearing price is set by the marginal producer. Typically, nuclear reactors will give their marginal cost, near 0, and let the more expensive producers set the clearing price. Given that capital cost is a sunk cost, it doesn't matter to nuclear plants as long as the market price is above the marginal one. So called "renewables" do this as well, but have to account for the risk that mother nature doesn't provide, and therefore factor in the risk of having to buy coal or gas-produced electricity on the spot. > Net demand on CAISO can go from about 2 MW to 30 MW in the summer. Well if this is the case this is not a "nuclear sized" market then and other ways of supplying capacity are better. But remember that it's estimated that blackouts are much,much more costly society-wise than whatever marginal price you could pay for electricity, so having a baseload and some excess capacity is always good. This is also why many electricity producers are nationalized. It's not a market like the others. > Flamanville France has the strictest regulator of the world, which adds a lot of costs, and Flamanville required to re-learn many things after losing the expertise from the 70's. For the record, an airliner should be able to fall on Flamanville without any problem, due to regulations. > Curtailements Excess electricity is sold in Germany, which lacks a much-needed baseload, especially since they have a big industry. Most people ignore that electricity consumption follows Pareto's law, with around 1k industrial plants consuming around 50% of the electricity (sorry no source for this, my econ teacher said in a class a few years ago!). > SMR Yes, still in development, many different designs so costs estimates are difficult to make. I'm citing Wikipedia's[0]. The good thing is that the possibility to build them serially should decrease a lot the costs as demand ramps up. [1] https://en.m.wikipedia.org/wiki/Rolls-Royce_SMR

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dalyons 2 days ago | parent | prev [-]

The massive capital costs of the plant have to be paid back in the sale price of energy, that’s what makes it expensive. France’s state built plants don’t have that accounting

	▲	Saline9515 2 days ago \| parent [-]
		But the market price asked by nuclear plant doesn't account for capital costs as the real price will always be higher. What is important is the clearing price not the asking price.