California invests in battery energy storage, leaving rolling blackouts behind

> There were a few summers leading up to that where all of the major metro areas shared concurrent record high heat days, and sometimes coincided with poor air quality from wildfires (meaning more people closed their windows and ran AC even if they wouldn't have otherwise.)

This is underselling it, if anything. The multi-day heatwave around Labor Day 2022 extended across most of the western US, not just California. The electricity demand during that event set what was at the time the all time record for the entire Western Interconnection (since surpassed in 2024) and set what is still today the all time record for CAISO.

Yeah, I think you are correct, 2022 was a hot summer with a September heat wave which broke some records for power demand. Also keep in mind that there was a big increase in hydropower generation in 2023 and 2024 due to the really wet/snowy winter seasons.

There’s also the more forgiving fire season in some areas. This is relevant since a lot of the power transmission goes through forests and nature preserves.

With current technology getting through long days of sunshine linked demand is not an achievement worthy of celebration.

Electricity prices are set by the French government not the wholesale cost or cost of production. Which is why EDF - the operator of the French nuclear fleet - regularly posts massive losses. Like the €18 billion loss in 2023.

https://www.lemonde.fr/en/france/article/2023/02/17/france-s...

Quebec has them both beat. Hydro rules!

https://app.electricitymaps.com/map/zone/CA-QC/5y/yearly

(To be transparent, there's controversy around calling hydroelectric renewable.)

These maps are such a cool resource, thanks for sharing!

"The future is already here – it's just not evenly distributed." - William Gibson

Good luck building nuclear in non-generational timescales and at reasonable prices.

The future is solar simply because these electricity catchers from the sky fusion are mass producible goods that you can just keep pumping and pointing it to the sky in matter of days at dirt cheap prices.

Nothing to be proud of. Dangerous ancient reactors owned by an almost bankrupt company about to be nationalized.

https://www.lemonde.fr/en/france/article/2023/02/03/the-long...

Any time you have hundreds of megawatts of energy stored in a small area there is risk. This includes steam boilers, nuclear reactors, batteries, dams, etc. No getting away from that. Not saying that some battery chemistry might not be easier to manage than others.

People don’t talk enough about the risk of fire. The crazy thing is when a battery installation catches fire they don’t actually fight the fire. They just have to let it burn out. The resulting environmental damage is terrible.

This happened recently in the Central Valley. I can’t remember the name of the battery site but it was a huge one, and literally right next door to one of the largest Driscolls strawberry farms, on which black lithium smoke settled all over , over the course of several days/weeks in the middle of the summer.

Edit: maybe we are talking about the same fire? https://x.com/TheKevinDalton/status/1880277672393412848

The reports I read said this was an older installation - was that one setup in the same way as a modern plant would be done? That is to say - was there anything unique about this failure scenario?

The pictures I saw was that the Moss batteries were located inside a building. My mental image of battery storage is freight-sized containers offset from each other - presumably to minimize fire risk. Or was this plant a common dense configuration that is done in areas where they are heavily space constrained?

As someone who's interested in all this, I agree it would be nice to have more precision around capacity. Especially as it relates to longer term storage. But! In this context, output is more salient than capacity. You'll see a lot of stories about grid-scale storage that use output. (https://physics.stackexchange.com/q/854999 offers a fuller explanation than what I'll give here.)

This is because grid operators are most concerned with immediate power output. They need to keep the grid balanced, and if they need a gigawatt to do it, it doesn't matter if the batteries have 100 GWh if they can only discharge at 1 MW.

Since the batteries described here are used primarily to handle the peak of the duck curve (https://en.wikipedia.org/wiki/Duck_curve) it seems like 4 hours of capacity (the article mentions that the lithium-ion batteries have 4-6 hours of capacity) is sufficient to get over that difficult hump.

Anyway, to get back to your question of how many GWh, if we assume that the batteries have 4 hours of storage, then we're looking at around 4h * 15.7 GW = 63 GWh of battery capacity. (4 hours is what I've seen as standard for lithium-ion, conservative if the article's claim of "four to six hours" is true.)

Hope this helps ease the peeve!

Based on the following sentences from the article, it's probably 4 to 6 times more than 15.7 GWh (60 to 90 GWh, apparently):

"Battery energy storage is not without challenges, however. Lithium-ion batteries — the most common type used for energy storage — typically have about four to six hours of capacity. It’s enough to support the grid during peak hours as the sun sets, but can still leave some gaps to be filled by natural gas."

This also greatly annoyed me. 4 hours is the standard for grid storage batteries in California.

The ratio for LiFePO4 is between 1:3 and 1:4.

So rated power will give you that for about 3 to 4 hours.

While Sodium Ion may be the future of grid batteries, it's not the present. As long as LFP is cheaper, there is no reason to go with Sodium.

This calculus will probably change in 3-5 years, but today Sodium is more expensive and therefore has little demand without some form of discount or subsidy.

The switch will be rapid once the economics make sense, but they don't yet.

> It looks like it's relevant part of China's strategy

For grid storage? Source?

I struggle to understand why journalists consistently failed to use Wh as a unit of power. People generally can understand it because it is how they are billed and how appliances are rated.

Even on HN people will defend not using Wh because there is some grid or city in the USA that bills differently.

CAISO's own documents quote battery capacity in MW. So I don't think you can just blame journalists.

"Battery storage capacity grew from about 500 MW in 2020 to 13,000 MW in December 2024"

https://www.caiso.com/documents/2024-special-report-on-batte...

As another commenter notes, utilities are interested in "capacity on call" i.e. instant power generation.

Utilities are used using MW when discussing supply and demand. Because balancing that is critical. So power is what they care about when discussing grid connections.

The billing side and customers are concerned with total energy. So kwh.

Journalists typically don't know the difference. Which is why they list storage capacity in watts. They don't know any better and they don't care.

Far as I can tell multiply the watts by 4 hours to get watt hours.

Criminally overpriced. We're not getting shit for it either.

God forbid you live in any of the more woody parts of California either. You'll have to have your own battery or generator anyway. As someone who plans to live in the Santa Cruz Mountains long term, I will be going completely off grid as PG&E will just cut power forever rather than fix anything.

This. Electricity costs are almost 5x the cost in Nevada.

PG&E's corruption is laid bare by Silicon Valley Power, which serves the town of Santa Clara, charging less than half what PG&E does for the house a few blocks over [1].

[1] https://www.siliconvalleypower.com/residents/rates-and-fees