[dreghgh]

Natural gas is perfect for peaking as it can spin up quickly and costs little when not burning fuel. Natural gas especially newer more efficient installations will probably be profitable for a while because as renewables become a bigger proportion of generation there will be less GWh delivered from gas but at higher prices. Or to reverse that, if you need the natural gas to be available, you have to pay what it costs to keep it around, regardless if that's for 10%, 1%, or 0.1% of the time that it's actually generating. But as that number drops - because of storage and overcapacity of renewables - you reduce emissions even if you don't reduce cost.

Fans of nuclear claim that sceptics are either radical leftists who want to reduce energy use, or anti-environmentalists don't care about emissions. But I see the pragmatic, diversified way of drastically cutting emissions being renewables + storage + gas turbines.

[AnthonyMouse]

The problem with operating a natural gas plant only 0.1% of the time is that you have to cover its fixed costs over whatever time it is run, and if that's only 0.1% of the time then the fixed contribution per kWh becomes enormous. Worse, people like to point out that a high proportion of the cost of a natural gas plant is fuel, but the fuel cost also includes fixed costs. If you're using only 0.1% as much natural gas at scale then you have to recover the costs of all the pipelines and other infrastructure over 0.1% as much sales volume.

You end up paying a significant fraction of the cost of having the generating plants producing power 100% of the time, but only get power 0.1% of the time.

The main advantage of not running them all the time is that then you're not emitting CO2, but nuclear plants have that advantage even when you do run them all the time.

[notTooFarGone]

How is "have to run nuclear all the time" a benefit with solar?

If solar blasts through the day you are unprofitable and have to deal with extra excess power.

Maintaining gas power plants is something that can be shared by the grid and is 100% cheaper than building new nuclear plants.

[AnthonyMouse]

If you build so much solar that rates are consistently zero during the day then solar is unprofitable. But if rates are normally non-zero during the day then generating power generates revenue -- and then your alternative generation method gives you the additional benefit of needing less solar, which isn't free even if it's cheap.

And, of course, the main benefit is at night, because solar is cheap but solar + storage is significantly more expensive, so you get to generate all night -- and get the higher rates from generating at night -- without emitting CO2.

[notTooFarGone]

The business plan then says something like "we run nuclear 24/7 and in the pasts it's been ok from a cost perspective. Now we actually only get money half of the time but trust me this is economically viable"?

With batteries there is no "too much solar", only too few batteries because they compliment each other so good and batteries are now at a price where adding it to solar is a no brainer economically. Building nuclear now would take 10+ years and then we proabably don't need it anymore. Why take the risk if the new state of the art works?

[AnthonyMouse]

You're assuming they would only get half as much money, but you're not considering how generation volatility affects prices.

Suppose you have 1000 MW (constant) of nuclear and 1000 MW (daytime average) of solar. Therefore on the average day you're getting 2 GW total. The daytime price on that day is $0.04/kWh, which is just enough to make solar viable. If every day is like this, solar is doing fine.

But then there's a day when it's extra sunny. Solar is generating not 1000 MW but 1800 MW. Is that good for solar's profitability? No, it's bad, because that means there is oversupply and the price per kWh is zero. Nobody is making any money that day. Solar generated 1800 MW for 12 hours and got zero return. Solar's average is now down to $0.014/kWh. That's below sustainability. Oops. Nuclear also got zero return that day, but only generated at 1000 MW, so its average wasn't negatively affected by as much.

Then, another day, it's extra cloudy. Solar only generates at 300 MW. It's a supply emergency and the wholesale price per kWh rises to $0.28/kWh. Finally everyone is given an opportunity to bring up their average. So solar generates 300 MW for 12 hours and nuclear generates 1000 MW for the same 12 hours and they each get $0.28/kWh. At this point solar's average is back up to $0.04/kWh, which is its breakeven. Meanwhile the nuclear plant's average -- during only the daytime hours -- is $0.1067/kWh.

Then you have the nighttime hours. To play here solar needs storage. Storage is something like $0.14-$0.50/kWh by itself. If you charge it with solar, you're up to $0.18+/kWh. But that's on average again. On the day it was extra sunny, the batteries were already completely full, so that night the price didn't stay at zero and the nuclear plant made some money. On the day it was extra cloudy, the batteries got low, and then the nighttime price wasn't just $0.18/kWh, it was much higher.

Then, once in a while, it's cloudy for a whole week. The batteries aren't just low but completely drained, even before sunset. Solar + batteries can't address this case at all because an entire week's worth of battery storage is prohibitively expensive for something that only happens once a year or so. The nighttime price that week -- because of the volatility created by solar -- goes through the roof. Nuclear plants gets all of that money while the solar plants get none of it, because they're the only available source of electricity.

The economics aren't the same as before because now the prices fluctuate all over the place. But that only means that a generation source that supplies power all the time can make up for the times when rates are low because there is oversupply during the times when the rates are much higher because there is undersupply. Whereas the power source causing the supply fluctuations can't, because its ability to supply power inversely correlates with the price.

[guerby]

"Storage is something like $0.14-$0.50/kWh by itself"

LFP at the cell level is below $100/kWh, 5000 cycles means $0.02/kWh out of the cell (maximum since after 5000 cycles battery is still at 80% capacity so the real price is even lower).

Current LFP cell price look more like $50/kWh these days and still going down...

Also about near $0 or below $0 prices, they exist only because we don't currently signal those prices to consumers. Anyone with electric car (parked 95% of the time) or batteries at home or business would charge them at $0.01-0.05/kWh no question asked and price would never go to zero or negative.