CAISO daily data shows that hot season demand in California peaks around 6 PM: the "duck curve". Batteries here help to cover that demand peak as solar fades.

Clearly you have not been to San Francisco. Summers are mild, many days it's chilly; and rarely do temperatures in the Bay Area exceed 80 in coastal areas or 90 inland. Sometimes in the summer I turn the heat on around 8pm going overnight. The 4th of july was fairly cold this year and I wore a thick jacket.

Current battery capacity only last a few hours after sunset, and starts charging at sunrise. There's a nice graph in this [1]article [substack.com] that shows about a 4 hour coverage with batteries.

Better than nothing, but the shorter daylight hours of winter tends to highlight the limitations we currently have with our battery capacity.

[1] https://samholmes285.substack.com/p/can-solar-panels-batteries-provide

We are still seeing near weekly brownouts in southern California. We've had one hour long blackout, which is better than some summers of the past.

We have also had numerous alerts that air conditioning was going to be reduced. So batteries are still insufficient, but remotely controlled smart thermostats are making a difference.

Says the guy who has no clue how power grids work.

Hint: there is a load curve. The power people draw from the net. Which is "kind of" random.

It changes constantly, in milli seconds.

A battery helps to smooth that out. Easy. More easy than pumped storage or a gas turbine.

That's no longer true.

People getting home from work and cranking up the AC tends to be more demand than daytime in modern times.

The California State government deserves many of it's very legitimate critiques, but in this case it did something right.

You're right the article is light on details. They did install 17,000 MW worth of batteries; ~13,500 was grid-scale storage and the rest was residential supported through rebates. The rebates on the batteries you earn over time, and to do so you must export some of your stored battery power back to the grid during peak hours. So about 15-20% was residential people incentivized to use their home batteries as storage and the rest was grid storage.

The article doesn't point out that California also added 27,000 MW of generation capacity also but good news it was almost entirely renewables, wind and solar mostly; natural gas power generation has been flat in it's power generation capacity. They still need the NG to help deal with the hourly volatility of the grid, but they didn't need to add any and overall usage is down around 50%.

And to your point, the other thing they did in the interim periods is halfway through this (2022) they asked people to voluntarily use less power via these Flex Alerts, sending the population alerts to limit usage. 2023 it was a colder year on average so they didn't have to go that path.

So overall it is a pretty good success story.

You're not wrong!

Rolling blackouts used to be far more common and the government would issue a [1]Flex Alert [ca.gov] to indicate that rolling blackouts would be used. California has CAISO which manage electric related stuff and they have a [2]PDF of grid emergencies since 1998 [caiso.com] which include flex alerts. Spoiler, there hasn't been any since 2022 which is shown in this [3]bar graph of flex alerts by year [brightspotcdn.com].

So now that we have established that rolling blackout haven't happened since at least 2022, the question is why.

[4]Here is a bit [utilitydive.com] [5]more info [publicpower.org] but the TL;DR version is that in 2022 CA passed law to create the [6]Strategic Reliability Reserve [ca.gov] which has multiple programs aimed at preventing power outages, including that distributed energy grid system that was featured on here a while back.

However, is it really batteries that preventing outages? Well, it's already been shown that battery systems react much faster than normal energy production methods which prevents your power from "blinking" when a source goes offline. Also, here's a graph from 2024 that [7]shows when battery power is being used and how much [gridstatus.io] (noticed it's very negative when charging from solar). The point here being that the energy stores are substantial and can be discharged ad hoc. It's not definitive evidence but I'm sure if you dig into some of the stats on [8]https://www.caiso.com/ [caiso.com] that you could find you seek.

[1] https://www.cpuc.ca.gov/industries-and-topics/electrical-energy/flex-alert

[2] https://www.caiso.com/documents/grid-emergencies-history-report-1998-to-present.pdf

[3] https://ca-times.brightspotcdn.com/dims4/default/c232c25/2147483647/strip/true/crop/690x902+0+0/resize/2000x2614!/quality/75/?url=https%3A%2F%2Fcalifornia-times-brightspot.s3.amazonaws.com%2F01%2Fb1%2Fd43d8c934ec5b9c4d0f4f65b4db2%2F5ce7bc74c8b842db946ac72b336bdc0c

[4] https://www.utilitydive.com/news/california-legislation-newsom-reliability-reserve-fund/626441/

[5] https://www.publicpower.org/periodical/article/california-energy-leaders-report-progress-grid-reliability-ahead-summer

[6] https://www.energy.ca.gov/data-reports/california-energy-planning-library/reliability/strategic-reliability-reserve

[7] https://blog.gridstatus.io/content/images/size/w1200/2024/05/batteries_taking_charge_of_the_california_grid-4.png

[8] https://www.caiso.com/

Oops! MW-h, not WM/h. That was pure dyslexic typing.

I believe that is actually the normal industry nomenclature practice: rating the storage in power available, not energy stored. I guess the rationale is that the power is usually not needed for a long time. I think the rating is for a specific period, maybe 3 hours.

> They just turn off your water heater. New heaters in CA must be grid capable. and soon will also need to be a heat pump unit killing any resemblance of reliability.

There is also a program to remotely reduce your air conditioning.

Lol reliability. Both furnaces in this house needed not just new generators but also gas valves. One of them had been replaced before.

Public Safety Power Shutoff (PSPS), there is one going on almost every week in some part of the state. I get maybe two a year, if it is going to be a windy day and it is fairly dry they'll cut my power for 6-12 hours typically.

There's several PSPS going on in the Sacramento valley and northern Sierra because it's dry and windy right now. (September 9th to 14th). PG&E has about 1000 people working on it right now.

If they're smart, they'll put batteries near the loads. And then when the wind blows, they can de-energize lines and keep peoples lights on.

Except people aren't smart. I don't know about California, but here in Washington State, communities in the woods out on the fringes of the grid are fighting a battery installation. Because Teslas catch fire. Teslas have batteries. So everything with batteries will catch fire.

You can build a fire break around a battery substation. Not so much around a garage with an E

Typo - 240 megawatts.

> It's ironic that some people still keep claiming we can't switch to renewables because they aren't reliable.

It's an Astroturf campaign designed to benefit fossil fuel companies. The same companies that donated heavily to Trump's last Presidential campaign.

"You all are wealthy enough, that you should raise $1 billion to return me to the White House," -- Trump to oil companies.

Nah, what is ironic is a one in a century snow blizzard.

Batteries that are cost effective largely solve the intermittent renewable problem. Lithium batteries aren’t even suited to anything more than very short term storage of minutes to a few hours, lithium was developed for energy and power density, able to sustain vibration and impacts without damage (such as being dropped without dents), and the cost can be relatively high as these are mobile device requirements like for laptops, power tools, and EV.

Grid storage is almost diametrically opposed. Ener

Transmission lines do not get overloaded.

Do you think a grid operator does not know what his grid can handle?

And this is how you can make a conspiracy out of any group of facts if you are inclined.

High heat and dry conditions do increase wildfire risk.

Rural areas are more prone to wildfires as they have increased vegetation.

Rural areas tend to be more conservative.

Therefore it must be the state government playing villains and shutting off the power to conservative rural areas because they are evil. They have to be evil of course so conservatives can justify supporting the most unhinged actions by their politician

US DoE averted rolling blackouts for [1]17 states [energy.gov] back in July. (California not on that list)

Texas had a rolling blackout back in 2021, which I believe was the last rolling blackout in the continental US.

And there was an unplanned multi-state blackout in the Northeast way back in 2003 due to software+human error. I'm a bit surprised with all the cyber security issues we have today that these kinds of blackouts aren't happening every year.

[1] https://www.energy.gov/articles/energy-secretary-secures-grid-across-17-states-amid-period-hot-weather

They're typically Lithium Iron Phosphate (LFP), good for 5000+ cycles before they degrade enough to be a problem. So charging every day they're good for about 10 to 15 years.

In practice, they'll have a site with multiple generations of batteries. So they're always extending their capacity and keeping old batteries in service. Eventually replacing degraded packs with new equipment when it is cheaper (in terms of storage capacity vs cost) to swap out the equipment than to simply add new.

> We really need to raise our expectations.

It's California. They get a gold star for being California.

This is America, if we're ever in a situation where we have to choose between a business or data center having power 24/7 with 99.99% reliability (1 hour or less) and residential customers having some reduced level like 99.9% (8 hours of outage a year) then you can be certain that's how it's going to play out.

Where we draw the line is really the only debate. Like 95% is more like having 36 hours a month with an outage. Maybe even rolling blackouts every week, so some people don't have power on the same day