> 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.
For how long? 100 millis, 1 minutes, 1 hour, 1 day? There is a HUGE difference. This stuff reads like PR.
> 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.
> The batteries are [used] during the peak period, which is in the evening, typically around seven o’clock, producing as much as 40 percent of the peak capacity requirements.
In most countries the peak period is a 4-5 hour window.
Using a measurement for power as opposed to energy is dumb with batteries
I can build a capacitor bank in my garage that produces more power than a nuclear power plant. For a millisecond.
Weird units.
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.
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Talk about GW-hrs of storage. You know, the value people actually cares about?
In practice, it can be very relevant. With my own household solar/battery system, I am sometimes frustrated more by limits on how much current I can draw, not by capacity. I could add more batteries, but it seems that the inverter is the limiting factor. And 12MW of inverter is impressive, no?
UK is up there in the world rankings for batteries.
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.
this seems misleading. the article claims:
12,000 megawatts, equivalent to 12 large nuclear plants, of energy from its battery arrays.
but for how long is this battery array able to produce this amount of power? compared to the nuclear plant, where the answer is years.
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.
This is a seriously impressive achievement. I wish there was a more comprehensive engineering deep dive, but I wasn't able to find one.
So why is California's electricity the most expensive in the country?
California imports a third of its electricity, and that's expensive. It gets almost another third from natural gas. They've been changing rapidly from fossil fuels and nuclear to renewables and that's pretty capital intensive. And there have been some huge costs associated with the wildfires.
There's a bit more technical info on California battery storage here:
In general, imports are cheaper than the alternative, because if you have local gas plants that aren't maxed out, then you'd use those rather than pay more to import.
Some quick googling suggests this holds in California too.
It appears expensive electricity is mostly a policy decision. Schemes to support low carbon energy, strict emissions controls etc.
Let everyone do what they were doing in 1980, and prices would be rock bottom by now.
The problem with renewables I have is that "what's good for the earth" and capitalism simply don't mix.
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.
How do you explain that solar got 50% less expensive in the last 10 years?
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 residential solar is much less cost-effective than large-scale solar farms).
> less than 15 years
But can it pay itself in a month or two? That's the bar. I cannot financially plan for even one year later. Too many unknowns.
A really good coffee machine that can do lattes costs maybe $200. If lattes at coffee shops cost $8 including stupid high CA taxes and the stupid puppy face guilt tips, it pays for itself after ~35 lattes including supply costs, or just over a month. That's the bar for pretty much anything.
Figure out how to sell me $500 in solar panels that generates $500 worth of electricity over the next month and make it tax deductible with no income limits. That is how you cover the country in clean energy. FAST. Until politicians can get their act together, slam the hammer and make exactly this happen, we're going to be on dirty electricity for a long time.
That should especially be the bar for clean energy. Clean energy shouldn't be a luxury for the wealthy.
Well first of all TFA is not talking about individuals buying solar or anything, so do we at least agree that renewables make sense for countries/state?
It seems like you have set an impossible bar for renewables so I don't know what to say to you. I do not think you'll be able to put a mini nuclear station, gas or coal one in your garden for less than the monthly electricity fee, so it's unclear to me what you are comparing it to.
[deleted]
The break even for home solar is too long for me also. Every now and again I look at it, and even with subsidies it's gonna be about 12 to 15 years before I see any cost saving.
What if you drive electric?
Paying for wildfires is a big part of it.
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.
[deleted]
Just for a moment, try to imagine how much wind, solar and battery storage can be bought with the money required to build just one regular nuclear power plant (gigawatt output).
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.
> Just for a moment, try to imagine how much wind, solar and battery storage can be bought with the money required to build just one regular nuclear power plant (gigawatt output).
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.
Nuclear isn't the enemy here.
Well, how much is it? Nuclear costs are front loaded.
Two to four hours per day.
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.
> The batteries are [used] during the peak period, which is in the evening, typically around seven o’clock, producing as much as 40 percent of the peak capacity requirements.
In most countries the peak period is a 4-5 hour window.
A graph is easier.
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
Garbage article.
Using a measurement for power as opposed to energy is dumb with batteries
I can build a capacitor bank in my garage that produces more power than a nuclear power plant. For a millisecond.
Weird units.
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?
In practice, it can be very relevant. With my own household solar/battery system, I am sometimes frustrated more by limits on how much current I can draw, not by capacity. I could add more batteries, but it seems that the inverter is the limiting factor. And 12MW of inverter is impressive, no?
They use power units to make it comparable with the non-storage sources, see https://news.ycombinator.com/item?id=48157824
We need something like this in the UK given the constant abundance of renewable energy.
We already do.
https://www.blackridgeresearch.com/blog/latest-list-top-larg...
https://electrek.co/2026/05/11/uk-delivers-europes-largest-v...
UK is up there in the world rankings for batteries.
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.
this seems misleading. the article claims:
but for how long is this battery array able to produce this amount of power? compared to the nuclear plant, where the answer is years.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.
This is a seriously impressive achievement. I wish there was a more comprehensive engineering deep dive, but I wasn't able to find one.
So why is California's electricity the most expensive in the country?
California imports a third of its electricity, and that's expensive. It gets almost another third from natural gas. They've been changing rapidly from fossil fuels and nuclear to renewables and that's pretty capital intensive. And there have been some huge costs associated with the wildfires.
There's a bit more technical info on California battery storage here:
https://www.ess-news.com/2025/04/11/california-battery-domin...
In general, imports are cheaper than the alternative, because if you have local gas plants that aren't maxed out, then you'd use those rather than pay more to import.
Some quick googling suggests this holds in California too.
It appears expensive electricity is mostly a policy decision. Schemes to support low carbon energy, strict emissions controls etc.
Let everyone do what they were doing in 1980, and prices would be rock bottom by now.
The problem with renewables I have is that "what's good for the earth" and capitalism simply don't mix.
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.
How do you explain that solar got 50% less expensive in the last 10 years?
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 residential solar is much less cost-effective than large-scale solar farms).
> less than 15 years
But can it pay itself in a month or two? That's the bar. I cannot financially plan for even one year later. Too many unknowns.
A really good coffee machine that can do lattes costs maybe $200. If lattes at coffee shops cost $8 including stupid high CA taxes and the stupid puppy face guilt tips, it pays for itself after ~35 lattes including supply costs, or just over a month. That's the bar for pretty much anything.
Figure out how to sell me $500 in solar panels that generates $500 worth of electricity over the next month and make it tax deductible with no income limits. That is how you cover the country in clean energy. FAST. Until politicians can get their act together, slam the hammer and make exactly this happen, we're going to be on dirty electricity for a long time.
That should especially be the bar for clean energy. Clean energy shouldn't be a luxury for the wealthy.
Well first of all TFA is not talking about individuals buying solar or anything, so do we at least agree that renewables make sense for countries/state?
It seems like you have set an impossible bar for renewables so I don't know what to say to you. I do not think you'll be able to put a mini nuclear station, gas or coal one in your garden for less than the monthly electricity fee, so it's unclear to me what you are comparing it to.
The break even for home solar is too long for me also. Every now and again I look at it, and even with subsidies it's gonna be about 12 to 15 years before I see any cost saving.
What if you drive electric?
Paying for wildfires is a big part of it.
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.
Just for a moment, try to imagine how much wind, solar and battery storage can be bought with the money required to build just one regular nuclear power plant (gigawatt output).
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.
> Just for a moment, try to imagine how much wind, solar and battery storage can be bought with the money required to build just one regular nuclear power plant (gigawatt output).
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.
Nuclear isn't the enemy here.
Well, how much is it? Nuclear costs are front loaded.