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by g_sch 2394 days ago
This is a great point - solar/wind and nuclear are, as the grid currently works, not drop-in replacements to each other, but complements. Nuclear provides base load (because it's difficult and slow to ramp a nuclear plant up or down), Wind/solar provides as much daytime load as practical, and meeting any remaining demand (especially peak evening demand) will require a peaking source that can dynamically be ramped up or down to meet demand.

The optimist in me believes that we'll eventually get good enough at solving the unit commitment problem in the energy grid that we'll reduce the need for carbon-intensive peaking sources and eventually even eliminate nuclear power. But we're not there today.

2 comments

Nuclear ramps just fine. French nuclear plants reportedly ramp routinely between about 50-100% capacity, so this isn't just theoretical. Going from full power to less than about 40% tends to run you into a Xenon pit, which causes a two day shutdown, but fortunately nighttime load is roughly half of daytime load, so this point is moot.
They all suffer from the same problem, none of them are ramping sources. You need a peaker plant for all of them (though, you'll need more for solar and wind).

Storage is a problem that simply needs to be solved for any green solution. Nuclear and wind included.

A big issue is that solar, wind, and nuclear simply don't play well together. Nuclear wants to be a base load, solar and wind push down the maximum base load feasible.

Without storage to smooth out the demand curve, you can't efficiently operate either.

The question isn't whether you'll need storage at all. It's whether it's cheaper to build enough storage for windless nights, or baseload nuclear and enough storage for remaining demand discrepancies.

I think the latter is more feasible without too much wind, since solar predictably goes to zero when demand is lowest. I don't think it's at all clear that a grid with high amounts of wind instead of nuclear would be cheaper.

Yeah, hard to tell given the dramatic drop in storage costs.

Today, I agree that if we could make the switch overnight that solar + storage would probably be a lot more expensive than nuclear + storage.

However, who knows in 10 years. I could see liquid metal batteries becoming extremely economical.