[swiftcoder]

Nuclear doesn't really solve this particular problem - solar is already cheaper than nuclear, so no one is going to replace their entire solar capacity with nuclear. And nuclear doesn't spin up/down rapidly like natural gas, so its a lousy solution for nighttime.

[XorNot]

This is just wrong. Nuclear is perfectly fine for nighttime because nighttime is highly predictable and doesn't fluctuate very much.

My state (NSW, Australia) for example uses no less then 6 GW at all times of day. Variable load is on top of that during the day.

If we had 6GW of nuclear plants, our grid would be almost completely green and they'd run at 100% utilization.

[ViewTrick1002]

Now calculate what it costs running a nuclear plant only at night.

You’ll end up at $400 per MWh excluding transmissions costs, taxes etc.

Your state already has coal plants forced to become peakers or be decommissioned because no one wants their expensive electricity during the daytime. Let alone a horrifyingly expensive new built nuclear plant.

https://www.abc.net.au/news/2024-10-13/australian-coal-plant...

[XorNot]

Not what I was responding to. Saying nuclear plants can't ramp for predictable night time demand is wrong.

Nuclear plants can't do instant demand response, but they can absolutely respond over windows of several hours.

[ViewTrick1002]

But not economically. And it can’t ramp twice. Once is easy.

For the French to do load following they sync their entire fleet to manage it. Letting plants take turns and spread out where they are in their fuel cycle.

[leonidasrup]

Nuclear power plants can and do load follow.

According to the current version of the European Utility Requirements (EUR) the NPP must be capable of a minimum daily load cycling operation between 50% and 100% Pr, with a rate of change of electric output of 3-5% Pr /minute.

https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-lo...

The problem with integration of solar and wind with nuclear power is that it doesn't make economical sense to build solar and wind in electric grid based on nuclear power generation. Because the fuel costs of nuclear power plants are so low and the capacity factors can be very high (nuclear power plants need only very short pauses for maintenance) building solar and wind in such electric grid doesn't lower the costs for grid customers.

This is big problem for solar and wind investors and manufacturers.

Nuclear power is a big competition also for coal and gas producers. I think coal producers in Australia are quite scary even of the idea for nuclear power production in Australia.

[ViewTrick1002]

Meanwhile to achieve load following in France they sync the fuel cycles of the entire fleet and then let the plants take turns across the week.

You have it the other way around. The marginal price for renewables are zero so consumers buy that first. Which means nuclear power, like the coal plant I linked, is forced to load follow. Which craters their earning potential.

Nuclear power is literally the worst combination imaginable for a grid with any amount of renewable penetration. They both compete for the same slice, the cheapest most inflexible, a competition which nucler power loses handily.

Which means, the window of opportunity for new built nuclear power is gone.

> Our analysis finds that even if, reversing the historical trend, overnight construction costs of nuclear half to 4,000 US-$2018 per kW and construction times remain below ten years, the cost-efficient share of nuclear power in European electricity generation is only around 10%. Nuclear plants must operate inflexibly and at capacity factors close to 90% to recover their investment costs, implying that operational flexibility – even if technically possible – is not economically viable.

https://www.sciencedirect.com/science/article/pii/S2211467X2...

This is a future you can't escape from. Flexibility is mandatory. It is coming from pure incentives. Lets explore them:

Why should a household or company with solar and storage buy expensive grid based nuclear power when their own installation delivers? They don't.

Why should this household's or company's neighbors buy expensive grid based nuclear powered electricity rather than the zero marginal cost surplus renewables? They don't.

EDF is already crying about renewables cratering the earning potential and increasing maintenance costs for the existing french nuclear fleet. Let alone the horrifyingly expensive new builds.

And that is France which has been actively shielding its inflexible aging nuclear fleet from renewable competition, and it still leaks in on pure economics.

https://www.bloomberg.com/news/articles/2026-02-16/edf-warns...