Nobody is talking about doing that. Nuclear plants are baseload. They always run 100% of the time because even if the current price of electricity is low, their incremental cost savings from reducing output is basically zero, so any positive price means they remain at full output.
This means you don't want 100% nuclear generation, because you don't have constant load. If you have 10GW of demand at night and 20GW during the day then you don't want 20GW of nuclear and nothing to do with half of it at night. But having 5 to 10GW is good, because you never need less than that anyway.
The thing people don't seem to have caught onto yet is that the combination of solar being cheap and solar not generating anything at night means that the price at night is going to be higher not just than it is during the day, but than it has been historically, because now whatever you're using to supply power at night -- regardless of what it is -- has to recover most of its capex exclusively at night. That's not great for nuclear but it's even worse for most other things. On top of that, the most competitive real alternative to nuclear there is natural gas, which doesn't work if you want to stop emitting CO2.
(Yes there is a small amount of legacy nuke in California too.)
So it seems like even if you run nuclear 100% of the time, you’re not going to earn much of anything or may even need to pay the negative rates if you don’t stop feeding into the grid, for a number of hours per day, so I don’t see how you get around having fewer hours per day to cover nuclear’s existing (noticeable) amortized costs?
And the trend line of renewable and storage costs getting cheaper doesn’t seem to be stopping.
There is a huge difference between prices hitting zero from time to time and the year-long average daytime price being zero. The latter is the thing that would bankrupt solar because that's when all of its generation occurs.
> with storage we’re also already seeing solar cover significant demand even after sunset.
Which is completely expected, because a moderate amount of storage can be used to smooth out time of day misalignment of demand with supply, and it makes sense to charge that with solar during the day whenever it's available. But the thing that's displacing is peaker plants rather than baseload.
> I don’t see how you get around having fewer hours per day to cover
It's not about being exactly 24 hours every day. It's about averaging 20+ hours every day instead of 12, and getting not just all 24 hours but also the higher price for all 24 hours on the days when the output of other generation methods is lower.
Expect that the price per kWh at any given time is inversely correlated with renewable output. What does that do to the profitability of renewables and what does it to do the profitability of something whose output is uncorrelated with renewable output?
Pretending they can just do “baseload” in 2026 doesn’t work. They can bid negative, but that’s just extending the life of the plant a few extra years.
And you still haven’t been able to explain why consumers should buy ruinously expensive nuclear electricity when cheap renewables or stored renewables are available.
And this is today a purely physical problem. You only need to look to Australia to see grids where rooftop solar today crowds out all other sources, even utility scale renewables. How do you force them to buy ruinously expensive grid based nuclear?
A new nuclear plant only making its money during the night becomes stupidly expensive. And nuclear is hit harder by this than say an open cycle gas turbine running carbon neutral fuels.
Gas turbines are cheap in CAPEX and expensive in OPEX. They can cope with it, although even they have trouble with the sliver of hours left after solar, wind and storage make up the bulk. Since that’s a far slimmer portion than their bread and butter peaking style of operation
You're kind of answering your own question when you can't call them "cheap stored renewables". Ask yourself why the price is lower in France than in Spain.
"Stored renewables" are fairly expensive even on the days when renewable output is high. When renewable output is low they're not even available because you had no surplus generation to charge the batteries during the day and now the sun is down and they're empty.
> A new nuclear plant only making its money during the night becomes stupidly expensive. And nuclear is hit harder by this than say an open cycle gas turbine running carbon neutral fuels.
A nuclear plant is hit lighter than this than a gas turbine because it still generates during the day. And when your concern is cost, are you aware of what it costs to produce "carbon neutral fuels"? That's original electricity generation cost + fuel production infrastructure cost + conversion losses + fuel storage cost + conversion losses again + capital cost for the rarely used fuel-burning generators. That's the thing that's ruinously expensive.
Wind has a slight positive correlation to demand, but the storage requirement for wind can be calculated as weeks/months compared to hours for solar.
Sweden also has a free market for electricity without any price roofs. That mean prices can be zero for long periods during the summer when solar is overproducing, but it can also reach over €1 per kw/h during periods of supply shortage. Have the record price for 5 days and have the remaining 360 days free of charge, and you would still end up paying more than if you paid the average cost for a full year (to be fair, in the cheapest of the 4 energy regions).
To add some more aspect for the Swedish energy grid, currently the south of Sweden that is connected to the Danish and German grid are suffering from significant supply shortage. The main power plant to address this is an old Oil power plant that was supposed to exist only as reserve energy, but have since a few years now been running every day throughout the year.
There is construction of more new thermal power plants. The two main strategy to solve the shortage, split along the two political lines, is either nuclear or to combine wind power with power plants burning bio fuel and then carbon capture the emissions (both being technologies with absolutely zero controversies). The later is what is being constructed right now, while nuclear might see construction in the future.
System studies find that renewable energy systems are cheaper than involving new nuclear in both Denmark and Finland.
The thermal plant you are complain about mothballed one of its two burners last autumn when the contract for firm emergency reserve capacity ended.
The final burner stayed open only with a new emergency reserve contract. Last time I checked it has ran like 50-100 hours per year. Never being called in as emergency reserve, although stepping up to hot standby a few times.
They also reactivated a mothballed CCGT plant in the same region for emergency reserve duties. But that was based on the war in Ukraine and ensuring local preparedness rather than needing the electricity.
And if you want to believe a different reality, please convince the political parties in Sweden, Denmark, Finland and so on to replace existing thermal power plants with renewable energy, and to stop construction of new ones! The green party in Sweden went into the election that we had just a few weeks ago on a energy platform that said: Thermal power plants are essential to enable renewable energy and keep prices low. Not even they believe that you can replace thermal power plants with only renewable energy and storage. Their local branch in south of Sweden is part of the coalition that approved and support the current construction of the new thermal power plant, together with the carbon capture plan.
Not that people read sources, but here is the reality check (all naturally in Swedish):
https://www.energinyheter.se/20251021/33900/nytt-varmekraftv... - The construction of the new thermal power plant
https://www.energinyheter.se/20261002/35404/oresundskraft-in... - The addition of carbon capture and storage (CCS)
https://www.mp.se/politik/energi/ and https://www.di.se/debatt/sank-priserna-satsa-pa-fjarr-och-kr... - The Swedish Green Party and their view of thermal power plants
Either way. France is wholly unable to build new nuclear given the outcome of Flamanville 3 and the ruinously expensive proposed subsides for the EPR2 fleet.
While Germany still pays for expensive early renewables. Back before the industry exploded in scale.
The relevant question is where to spend the next 100b to get the most decarbonization the fastest, today.
I searched wholesale costs - the first result - click 'Monthly' for the easiest view to digest: https://ember-energy.org/data/european-electricity-prices-an...
I also wonder how much of electricity costs in recent years have more to do with things like:
- Did France previously largely pay off the cost of building their old nuclear plants, while Germany has been spending heavily in recent years to majorly change their generation mix and build new generation? I've also heard that even France is now facing some significant challenges with the needed replacement of nukes nearing their retirement age being costly.
- How much of French and German generation buildouts were covered by the gov instead of ratepayers, if any?
However, I haven't researched the above questions.
The 100b should be given to France to build its EPR2 fleet and save the italian electrical grid and provide backup to spanish solar production.
The problem with nuclear is that it doesn’t solve stability. When cold spells hit Europe the French exports turn into imports. So all the French neighbors needs enough backup capacity, generally fossil based today, to both make up for the French exports vanishing, they experiencing the same cold spell, and exporting to France.
Stick two French grids next to each other and they would quickly collapse due to how brittle they are.
All renewable are still subsidized now, at all time, without subsidy no renewable would be installed in europe currently, they would be crushed by nuclear production (who can sell at loss event when renewable are available). Most of the modulation of nuclear reactor is cause because nuclear is pushed out of the marked by subsidized renewable would be sold at loss otherwise.
https://analysesetdonnees.rte-france.com/en/electricity-trad...
You can look at the graphs there is no correlation between winter and imports and France mostly export at all time. You are just making things up. Nuclear production does not depend on the weather and the french production is exactly sized for the french consumption. Historically France used hydro as the other pilotable part of its mix (before the pan european electric grid and exchanges at spot price). Don't look at special events since 2020, look at the graphs for the last forty years.