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Comment by ta1243 | Hacker News Reader

Nuclear is no use for the grid as it can't flex. Sometimes a grid needs 80 units, sometimes 50 units. Nuclear can't provide 80 units all the time as its unaffordable, can't increase or decrease output economically, and only makes sense when they're run 24/7 (except when it has to go offline for maintenence or other issues like heatwaves [0])

[0] https://www.euronews.com/green/2023/07/13/frances-nuclear-po...

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I must have missed the news about solar and wind being able to flex.

Unless nuclear power can provide for 100% of the demand for 100% of the time there will be a need for dispatchable power.

In the UK that would mean 48GW of total capacity. Worst case Nuclear capacity (when plants are offline etc) currently generated by the 5.6GW peak is about 3.8GW (95% of the time nuclear generated more than 3GW, 85% at least 3.7GW)

So that would mean 13 times as much nuclear production in the UK as it currently has to reach 100% use.

Which would generate about 500TWh per year, for a demand of about 250TWh per year, and a peak amount of about 73GW of capacity.

That means the real cost of a nuclear only grid would be twice as much as nuclear currently costs per MWh. Given that nuclear isn't economical today that doesn't really sound sensible.

As both Nuclear and Renewable thus both need "peaker plants" to flex the grid, the "baseload" argument is rather meaningless.

Both of them can be trivially downregulated.

Theres a upper limit though and they don't provide a great baseload, which is nuclear's specialty even among non-renewable resources nuclear is a clear winner in baseload management.

Also nuclear is a non-renewable just a long, nearly impossible to empty one, especially with the longer isotopes of thorium and uranium.

Nuclear with breeder reactors can run with known resources for 4 billion years. Renewable doesn't mean infinite (nothing is infinite). The sun will run out of its wholly finite fusion fuel in about 5-6 billion years, and will consume earth well before that. I think nuclear fission with breeders is therefore just as renewable as the solar-derived energy flows.

Renewable is a great base load power option. You supply your base load with your cheapest available supply, which is usually renewable.

You then supply all power needs above what can be provided by your cheapest power with dispatchable supply. If your base supply is intermittent, that means your dispatchable supply has to be able to supply 100% of peak.

It's that upregulation that's hard.

"in current market conditions"

Nuclear plants can load follow at around 3-5% full power per minute. They choose not to due to current market conditions that do not value their ability to provide 24/7 clean heat and electricity, but markets could be changed.

The problem is:

How will you force me with solar panels and a battery to take your extremely expensive nuclear power off your hands?

We are already seeing old paid off nuclear plants being forced off the grid because no one wants their electricity. Let alone insanely expensive new builds.

Nuclear excels at providing that 50 (or 40 or 55) though.

As long as you can force customers to pay more for their electricity than using renewables.

And new built western nuclear power requires yearly average prices of 18-20 cents/kWh.

It’s essential for charging all of the planet saving humongous electric SUV’s the car companies that fund our politicians want us to buy though.

Using expensive nuclear to charge a big battery is uneconomical. Use the expensive reliable energy for things that need reliable energy (like hospitals) and the cheap intermittent energy to charge cars.

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