[Manuel_D]

You don't need to alter the thermal output of the reactor to modulate a nuclear plant's electrical output. You can more aggressively cool the reactor to reduce the energy delivered to the turbine. This isn't often done since it's essentially deliberately reducing the efficiency of the plant.

> Ramping is slow and can't be done beyond 20% very often or you destroy your fuel and control rods

20% is all that's necessary to accommodate most load variations: https://www.eia.gov/todayinenergy/detail.php?id=42915

[Schroedingersat]

That is also slow.

Dispatchable generation ramps in tens of seconds and you don't pay $90-200/MWh for it when you're not using it.

[Manuel_D]

It's not slow: the turbine water is can be cooled more aggressively immediately, and will start reducing output with one circuit of the generation turbine. Also, modulation only needs to vary 20-30% over the span of entire days not of tens of seconds. And no, dispatchable generation does not ramp in 10s of seconds. Natural gas plants - the most popular peaking generation plant - still takes an hour to activate. But this isn't an issue because electricity use doesn't fluctuate by 20% in the matter of tens of seconds.

[Schroedingersat]

Tell that to the power station engineers who have to watch for the ad breaks in British TV.

And it's still not dispatchable if not using it costs you anyway.

[Manuel_D]

> And it's still not dispatchable if not using it costs you anyway.

No? This just plain wrong. A dispatchable source is a dispatchable source, regardless of any associated costs. And with nuclear there isn't even any direct cost with running the plant at a reduced capacity. There's only the opportunity cost of lost electricity sales, which would happen anyway because there isn't enough demand.

If there's 100 GW of peak demand and 80 GW of minimum demand, building 100 GW of nuclear plants and reducing output during periods of non-consumption does not have any increase of costs.

[Schroedingersat]

If there's noone to sell your $150/MWh electricity to because they took one look at the price and put a solar panel on their roof, then you're not selling $150/MWh electricity, you're selling $500/MWh electricity for the 20% of power they must buy. Then when they take a look at the new price, they go buy a battery. The only way to pay it off is a government enforced utility connection fee for a product nobody wants.

The only way to sell it for $150/MWh is to underprovision or to build storage or to find dispatchable loads. Just like renewables.

[Manuel_D]

None of this has anything to do with dispatchablity. Nuclear power is indeed dispatchable, which is why you're pivoting to this strawman about pricing. If we had a primarily nuclear grid, there's be no need for solar panels anyway.

> Then when they take a look at the new price, they go buy a battery

You're making the same error a lot of renewable activists do: assuming that household electricity use is all there is. How do you power the turbopumps that make our sewage and plumbing systems? How about our telecommunications systems? We'll just deal with cell phones shutting off after dark?

Energy storage requirements are staggering. The world uses 60,000 GWh of electricity every day. Storage requirements are at least 12 hours for diurnal storage, and several days for seasonal storage. Just going out and buying a hundred terawatt hours worth of batteries is a lot easier said than done.