Renewables are cheap but storage isn't.

Storage is cheaper than peaking power which is why it’s common to add huge battery bank to solar power plants. It’s simply more profitable to add storage.

Net result renewables currently save you money until ~80% annual electricity supply. At which point adding more batteries and generation to cover overnight demand is cheaper than adding nuclear to the mix. In such a mix, Nuclear saves a little per kWh overnight and cost way more per kWh during the day, net result it’s more expensive as baseload. But, operating nuclear only at night drives up per kWh costs above storage.

Due to plant lifespans, new nuclear is already a poor investment which is why it’s rare, which then drives up construction costs. It’s a viscus cycle which ultimately dooms nuclear without massive subsidies which become hard to justify.

▲

Closi 9 hours ago | parent [-]

> Net result renewables currently save you money until ~80% annual electricity supply. At which point adding more batteries and generation to cover overnight demand is cheaper than adding nuclear to the mix.

Assume you mean more expensive than nuclear in the second point?

Agree with your point although it's about wind in the uk rather than solar, and about being able to last a few weeks if there is calm weather rather than a day without sun, which is when having a nuclear baseload makes sense.

	▲	Retric 9 hours ago \| parent [-]
		> Assume you mean more expensive than nuclear in the second point? No, but I clarified the comment. My point is when taken in isolation nighttime nuclear costs less than nighttime batteries on a near zero carbon grid, however the economics operate 24/7/365. Nuclear heavily favors 24/7 operations so gaining 3c/kWh at night while losing 6c/kWh during the day is a net loss. Operating only at night almost doubles nuclear’s cost per kWh so you’d lose money anyway. > weeks if there is calm weather rather than a day without sun, which is when having a nuclear baseload makes sense. If you don’t have enough energy for a few days randomly you need peaking power generation not baseload. Nuclear is really bad at ramping up to meet sudden shortfalls. The scenario you described is one of the very few cases where hydrogen might make sense assuming all fossil fuel use is banned. Without that natural gas is going to win to prevent random outages every few decades.

▲

epistasis 9 hours ago | parent | prev | next [-]

In 2025 storage is cheap too, it's just that there's no need for it until you already have a large amount of renewables.

2025 is the year that storage is really being deployed in a serious manner in the US, more than 18GW most likely:

https://www.eia.gov/todayinenergy/detail.php?id=65964

You can see on the map at the bottom of this page that almost all the batteries are in areas that already have high amounts of renewables:

https://www.eia.gov/todayinenergy/detail.php?id=64586

And the prevalence of batteries in Texas means that they must be cost effective, because all grid assets in Texas are from private investors risking their own capital, and there is zero incentive for batteries except for their profit generative capacity.

▲

Closi 9 hours ago | parent [-]

> You can see on the map at the bottom of this page that almost all the batteries are in areas that already have high amounts of renewables:

It could be - but the battery investments map also align with the map below which shows that these states (Texas & California) are also states suffering from blackouts.

https://worldpopulationreview.com/state-rankings/power-outag...

So while this could mean that storage is cheap, it could also mean 'Texas's mix and grid is unstable, particularly as it's not connected to the national grid, and this has opened the opportunity to profit from higher levels battery arbitrage that doesn't exist in a better balanced grid'

	▲	abathur 7 hours ago \| parent \| next [-]
		There's quite a lot of pricing data available for the energy market and it might be possible to approximate battery profitability by rerunning normal and long-tail history. See https://www.ercot.com/mktinfo/prices and https://www.ercot.com/gridmktinfo/dashboards and https://www.ercot.com/gridmktinfo/dashboards/energystoragere... for example.
	▲	epistasis 8 hours ago \| parent \| prev [-]
		That looks to be a population map: https://xkcd.com/1138/ Which is what you would expect of a stat of "number of outages per state". If it's not normalized for land area, population, and all the other primary contributors to the total number of outages it's a useless stat. San Francisco has more people in it that the entire state of Wyoming. Texas' power is also cheap, so to justify batteries they would have to not raise the cost of electricity that much. The current cost of grid batteries is hidden, but it's not too hard to find out, and it is indeed quite cheap. But if there's no mechanism to get paid, ie ability to do time arbitrage in the energy market, then they do not get deployed. Electricity market design and the ability of ISOs/PUCs/utilities to adapt to changing technology are bigger barriers to batteries than their price.

▲

detritus 9 hours ago | parent | prev [-]

...just quite yet.