> For the first time, California discharged just over 12,000 megawatts, equivalent to 12 large nuclear plants, of energy from its battery arrays. That’s enough to meet over 40 percent of the state’s energy demand.
Source: https://www.energy.ca.gov/data-reports/energy-almanac/califo... under Additional Information about the Data:
> The use of the terms megawatts and kilowatts as descriptive of battery energy storage is to effectively convey the instantaneous power contribution of battery storage as comparable to the power produced by grid-level generators. We recognize that energy capacity in the context of energy storage typically refers to the total energy a battery can hold in watt-hours, kilowatt-hours, megawatt-hours, etc. However, for statewide planning and reliability purposes, understanding the peak power capability of battery energy storage systems allows for the integration of data with the nameplate capacity of traditional power generation units serving the grid. It is in this context that battery systems are able to be effectively compared for their ability to serve the grid over short periods of time, typically two to four hours per day depending upon system conditions.
In most countries the peak period is a 4-5 hour window.
Here's California: https://www.gridstatus.io/live/caiso?date=2026-05-15
Here's Texas: https://www.gridstatus.io/live/ercot?date=2026-05-15
Using a measurement for power as opposed to energy is dumb with batteries
Batteries are normally talked about in terms of energy storage, not power.
IE: Batteries overall have 0 power. Everything they make had to come from somewhere else. Actually, because of losses in the 20%ish range, it's probably more accurate to say that California's Battery Array is __COSTING__ 2 nuclear power plants worth of power in electrical waste.
----------
Talk about GW-hrs of storage. You know, the value people actually cares about?
I think they have slightly more grid batteries installed than California. UK have more people, but less money and less electricity used so I'd say they're doing better than California on battery deployment.
† Most modern power stations perversely need electricity in order to start them, so if your whole grid goes offline you're fucked, you go dark and your civilisation is now on a clock - a Black Start facility is a station which can go from black (no electricity) to running. In the case of Britain's pumped storage that's because "all" we need to do is allow the water to run through the generator. Once one or two Black Start sites are up you can use that power to start the other generators and restore supply to residents, and things get back to normal in a few hours.
[Edited to say that since we know there's about 20GWh of PSH the larger BESS can't be as small as I thought unless it's run a lot harder...]
Both doing well, but UK would need much more of a handicap for GDP than I thought to claim a win. Solar and batteries do generally pair better than wind.
12,000 megawatts, equivalent to 12 large nuclear plants, of energy from its battery arrays.
watts are power, not energy. for example, a tea kettle might require 2kilowatts. this does not tell you how much does it cost you to use the tea kettle, because it does not tell you how long the tea kettle is consuming 2kilowatts.
So why is California's electricity the most expensive in the country?
There's a bit more technical info on California battery storage here:
https://www.ess-news.com/2025/04/11/california-battery-domin...
Let everyone do what they were doing in 1980, and prices would be rock bottom by now.
Solar was fundamentally supposed to be almost-free electricity. You put a bunch of panels up and free energy from the nearest star. The stark reality though is that the people and institutions in control of solar equipment (this includes manufacturers, tariffs, etc.) reprice their stuff to match the price of the dirty electricity. And then they reprice their stuff again to assume that everyone loves to borrow money. At that point it becomes not worth it at all.
No, I don't want a solar installation to pay for itself in 15 years. I want equipment that gives me free electricity starting next month. If it costs less than a months' worth of electricity and I won't have an electricity bill starting next month, I'm interested. If not, it's outside my budget and planning horizon.
Why would people and institutions in control of solar equipment reprice their stuff to match the price of dirty electricity? You think there is no competition? Or you confuse it with the system that has been put in place where the price of electricity in the grid is set up by the most expensive producer at the time (which does make sense although you can argue against it).
Solar installation should pay for itself in less than 15 years in most cases, half the time according to that article: https://pv-magazine-usa.com/2024/10/03/average-u-s-residenti... (and rooftop solar panels aren't as cost-effective as large-scale solar farms).
Another less obvious thing is that Californians don't use much electricity due to mild climate and efficiency programs.
Fixed costs therefore get spread across fewer units.
This is a topic in some nations where electrification is seen as a way of driving down per unit electricity costs even as you use more for heating or transport.
The real thing delaying the energy transition is politics, we have the technology.
And on a really small scale, here in NL we can build our own home battery storage systems with cheap 15kWh or 32kWh battery kits from China. Combine that with dynamic energy contracts it's amazing.
A 15kWh setup is maybe 3500 Euro, and 32kWh around 4500 Euro. Lasts at least 15+ years counting battery cycles.
Assuming the most expensive nuclear power plant in the world, assuming the solar is free and you are only paying for the batteries, assuming costs in line with the cheapest grid-scale battery storage in the world, about 6.5h worth of that nuclear plant's output.
That's on the right scale to power California with renewables alone! That's within sight. Anywhere less sunny, powering things with solar and batteries alone would still be very expensive.