[dalyons]

I think it is actually the pro nuke case that often has misconceptions of how a modern grid works, repeating terms like “base load” etc

Because actually nuclear is terrible in a grid increasingly full of nearly-free variable sources (solar&wind). The nukes need to stay at 100% all the time selling their power at a high fixed price to have any remote chance of being economical. Cheap variables push nuke's expensive power off the grid during the day, and increasingly into the evenings with batteries. This is unavoidable in an open energy market, and is fatal to the economics of nuclear.

Yes they are building a bunch but Chinas grid share of nukes is actually declining y/y and is projected to continue to decline. Renewables are too cheap.

[pu_pe]

What happens in days where renewables can't produce enough energy? Or the evenings where we don't have enough batteries (all evenings so far and for the next decade at least)? You can call it base load or whatever you want, but that energy is coming either from hydro, nuclear or a carbon-based source. And those carbons are hard to come by these days, so even if nuclear power is expensive, at least it is reliable.

[dalyons]

It takes a decade at least for any new nuclear starting today to come online in the west. In that decade you’ve built an awful lot of batteries for the same amount of money.

No one wants to bet $10s of billions of nuke capex against the relentless progress of batteries and other tech over the next 10 years, and then the 30+ years of plant operations. It’s a suckers bet , so the only ones who can take it are nation states.

[selfmodruntime]

How about you answer his question?

[dalyons]

given that we dont have nukes, and we wont for 10 years even if we started today, and we arent going to start them because theyre economic disasters...

in the medium term its going to be batteries + solar/wind + gas backups for rare weather events. If we get the total annual use of gas down to a very achievable 10% we're still massively winning climate wise. California is getting there, 45% gas in 2022, 25% gas in 2025, and adding batteries at massively increasing rate. Full coverage of an average night is within sight, using gas just for shortfalls.

We can hopefully transition the last peaking gas backup usage to something else in the long term (hydrogen? SMRs if they ever exist?) but it isnt _that_ important in the grand arc of saving the climate.

[pu_pe]

So now the discussion is not about whether base load is a thing or not, it is that you firmly believe that batteries are the answer to everything.

First it should be said that this thread is primarily about decomissioning existing nuclear power plants. It makes enormous sense to keep operating those plants until we have a world like the one you describe, regardless of how much newer plants would cost.

But more importantly, your assumptions about the future are very optimistic. I'm sure the Germans also thought they were being very smart when they decided that nuke capex was not worth it because gas was so cheap and easily available, and then now we are finding out that this decision crippled their economy because it caused a dependency. In my opinion throwing all your chips into a technology that requires materials and production capacity you don't have, and in some cases doesn't even exist yet, is a real sucker's bet. All your rosy scenarios would fall apart in one second if China decides to stop selling batteries to you.

[dalyons]

> So now the discussion is not about whether base load is a thing or not, it is that you firmly believe that batteries are the answer to everything.

Nope, im still talking about the economics of base load. It exists insofar as there is base load _demand_, aka the minimum demand point the grid has. Base load _supply_ is not a thing - there is no rule of nature or economics that says you have to match that minimum demand with static allocation of unvarying power sources like slow thermal (coal, nukes). That worked for awhile as an economic optimization, but now on grids with variable sources like wind, solar, batteries, it doesnt work. If your plant has to run at 100% at all times to be profitable (nukes), your economic model is now broken.

> First it should be said that this thread is primarily about decomissioning existing nuclear power plants. It makes enormous sense to keep operating those plants until we have a world like the one you describe, regardless of how much newer plants would cost.

Yep, I have absolutely no objections keeping existing plants running, thats a smart thing to do. Its building new ones that doesn't make economic sense anymore.

> All your rosy scenarios would fall apart in one second if China decides to stop selling batteries to you.

true, but its easier to build a homegrown battery manufacturing industry than it is a nuclear industry.

[Moldoteck]

wouldnt be so sure about this considering northvolt. And it's irrelevant anyway, the plan is, including germany, to use gas firming

[adev_]

> Yes they are building a bunch but Chinas grid share of nukes is actually declining y/y and is projected to continue to decline. Renewables are too cheap.

No. Nuclear energy production in China continue to increase and will probably continue to increase for the next 60y.

Its relative percentage in the global mix decreased. And this has nothing to do with Solar, but with the insane amount of Coal power plants that China had to setup quickly to match the increasing electricity demand of the developing country [1]

> The nukes need to stay at 100% all the time selling their power at a high fixed price to have any remote chance of being economical.

Nuclear plants are mainly CAPEX based. And yes, excessive solar capacity tend to decrease nuclear profitability and increase global electricity cost.

But that is mainly a problem of public policy, not a technical one.

In country without tremendous of Hydro storage (e.g Switzerland or Norway), the most balanced economical combination tend to be Nuclear for baseload and Wind+Hydro+Storage for peaks.

[1]: https://www.iea.org/countries/china/electricity

[dalyons]

A lot has changed since the 2023 data in your link.

Chinas coal use declined in 2025, and is projected to continue to decline in 2026 and into the future [1]. Not share, absolute. Despite overall generation growing by 5%. And it’s all driven by guess what, renewables growth.

1 https://ember-energy.org/countries-and-regions/china/

https://www.carbonbrief.org/analysis-coal-power-drops-in-chi...

Edit: love to see a source for how cheap renewables _increase_ energy costs as you claimed

[adev_]

> Edit: love to see a source for how cheap renewables _increase_ energy costs as you claimed

That is just economics.

The intermittent nature of renewable means that overcapacity is structurally required to arrive to match partially the demand.

As an example, Germany has > 100GW of Solar installed capacity for a country where the average power demand is around ~60GW *total*.

Overcapacity means that the price of electricity naturally goes to zero (or even to negative) as soon as the sun shine. And this is very visible on the EU electricity market currently [1].

It is (obviously) terrible for the profitability of the means of production and it is not sustainable: No investor sane of mind would put money on the table for a system that sell at negative price when it produces...

To compensate that, most EU countries created the CfDs (Contract for difference) system. A minimum price is guaranteed by contract to the investor and the State pay the difference when the price are too low. The UK did it (and it costs billions) [2], France did it (and it costs billions) [3] and Germany is doing it [4].

So we are subsidizing and using public money to create an artificial profitability on top of an industry that we know is not profitable due to overcapacity caused by bad public policies.

Considering that this overcapacity is also reducing the profitability of nuclear powerplants in the first place (because nuclear is CAPEX based).

The pain is triple: The final consumer pays (1) the cost of the Grid restructuring for renewable (2) the cost of the Cfds to maintain the system alive due to overcapacity (3) the additional €/MWh to the now reduced profitability of the historical production means.

So yes, at the end, the price increase.

And it is what we see currently everywhere in Europe: Electricity price are increasing continuously even if Solar/Wind LCOE is lower than ever.

[1]: https://ibb.co/6cf99PfZ

[2]: https://davidturver.substack.com/p/another-record-year-cfd-s...

[3]: https://www.enerdata.net/publications/daily-energy-news/euro...

[4]: https://www.aoshearman.com/en/insights/germany-to-reset-gove...

[dalyons]

I don’t know about the particulars of the EU schemes, but it doesn’t have to be that way.

Elsewhere in the world, Australia is saving money due to the rollout of renewables [1]. So is the UK [2] 3. A billion in march alone.

1 https://www.afr.com/policy/energy-and-climate/record-battery... 2 https://www.theguardian.com/environment/2025/oct/28/wind-pow... 3 https://www.carbonbrief.org/analysis-record-wind-and-solar-s...

[Moldoteck]

UK and SA have one of the highest prices for households globally...

[tialaramex]

The CfDs pay either party the difference. Their effect is to make the cost of that electricity guaranteed, it's actually a remarkably cost effective mechanism.

The subsidy is that different technologies secure a premium on the CfD. For a UK solar farm the strike price most recently was £65 per MWh. In case you were wondering no, nobody will run a gas power plant for £65 per MWh, even before Trump's war spiked price 50-100%

Yes, the offshore wind farms are significantly more expensive than a solar CfD, their strike prices were close to £100 and for that much money (adjusting for inflation) you could definitely get interest from gas plants, especially before the war - but now we're into the weeds about platform diversity. A Middle East war seems like a particularly stupid time to insist we shouldn't desire diversity...

Because of how summer works, this "But solar energy is expensive, gas is cheaper" is going to take a break for a few months because it will seem very silly, but it won't go far, expect it back in autumn.

[mpweiher]

Yeah, but solar is "whenever I want to deliver" electricity, not "when I need electricity". Not the same product.

[tialaramex]

For wind this makes a little bit of sense, but for solar "whenever I want to deliver" is largely once per day as regular as clockwork for several hours and that means you can bridge with BESS.

You can already see it in charts, initially BESS shifts some of that peak midday sun energy to evening usage where it's worth more to us, but gradually competition drives down that evening price and so the BESS cuts deep into the night chasing those higher prices. It's most exaggerated in Australia today, where the reason the power is relatively cheap when you wake up before dawn isn't that somehow coal is less expensive at night - it is because much of that is solar power from yesterday and if they don't sell it to you now for whatever price they can get they've wasted a whole cycle, 'cos the sun, with free power, is coming up like it or not.

[dalyons]

the last offshore wind auction was 90, and that beat gas at 40% even before the war. https://electrek.co/2026/01/14/uk-offshore-wind-record-aucti...

The next one in july should be interesting!