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> 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.

I didn't want to overstate it given I wasn't bringing any data to the conversation, but your account matches my recollection as well.

https://www.publicadvocates.cpuc.ca.gov/-/media/cal-advocate... has some data.

Yep. The previous high was in 2006(!). Overall, statewide energy consumption seems to be flat or declining.

In 2020, there were extremely high heat days in August, with wildfire smoke covering the state. Thankfully I was out of town, but my wife was suffering, unable to cool the house OR open a window. In 2021 or 2022 I finally broke down and bought a window-mounted AC unit for my office, as I work from home. In 2024 and 2025 I didn't even bother installing it, the summers have been so mild.

https://www.caiso.com/documents/californiaisopeakloadhistory...

Equipment dies and needs to be replaced. When that happens a more energy efficient unit is usually available and is often the best option for replacement.

That's the whole other side to this curve which isn't seen very clearly in grid analysis.

This definitely plays a huge factor. Even people who get airco for the first time are already beginning with a different mindset. They also tend to run the units very conservatively because they aren’t used to living in an air conditioned space and often find it uncomfortable after a certain point.

I moved to Western Europe from a US state where airco is mandatory. I purchased a split unit here and on the worst summer weeks, it still only cost me €10 to run the unit on its coldest setting for a week (almost continuously since I was using it with a fan to blow cooler air around the rest of the house). Back in the US, I had summer electricity bills of hundreds of dollars every year.

Sure, the weather is a bit more mild here, but there have been heat waves, and I’m definitely an outlier when it comes to usage. But that just goes to show how efficient these new units are!

What's the kWh price in these two places? That's a huge variable.

That happens on a larger scale too. When an energy-intensive facility reaches some sort of lifetime limit, it too is replaced with something more efficient -- but also it will be replaced in a location where costs, including energy costs, are lower. So over time such facilities will tend to migrate to places where energy costs aren't too high.

Statewide grid demand is somewhat declining because distributed small-scale solar is massive. It now has an aggregate capacity of 20GW. This is usually ignored by people who are only looking at ERCOT v. CAISO grid statistics. Texas basically doesn't have any small-scale solar.

Are you saying Texas doesn't have much rooftop solar? That's surprising. I suppose largely due to low electricity costs making the investment not worth it? (And, I suspect, secondarily, utilities not really incentivizing it)

And the hail, I suppose.

I never thought about the impact of Texas hail storms on solar energy. Is there an industry standard practice to shield the panels during hail storms? Or do they use stronger glass? I am curious to learn more.

UL has a standard, this article goes into some details https://www.ul.com/news/manufacturers-say-hail-yes-solar-pan...

The title of the article gave me a real laugh!

    > Manufacturers Say Hail Yes to Solar Panel Testing

Tracker systems with "hail stow"[0] mode. They bring the panels as vertical as possible.

[0]: https://www.energy.gov/femp/hail-damage-mitigation-solar-pho...

I'm in a hail-prone region, and the general wisdom is that solar panels are more resistant to hail than typical shingles are.

Gardens and vinyl siding get shredded by hail and vehicles get smashed up, but solar panels generally do fine.

In Dallas where I grew up, it wasn’t necessarily rare but it wasn’t a given by any stretch. Maybe 10% of homes the last time I lived there (2022)? The neighborhood also made a difference.

Where I live now in the Netherlands, it feels like 30-40% of private homes have solar and 80%+ of business and government buildings that use more energy during the daylight hours so the payoff is much more realizable.

Texas has rooftop solar, but it doesn't have the same incentives as California, and in fact, the Texas grid itself has a million little different franchises that repackage Centerpoint and/or Texas and New Mexico Power generated electricity with different usage plans you have to renew annually to semi-annually.

Our dear leader has been busy decimating small businesses that rely on federal incentives to build renewable power generation lately. This hit particularly hard in Texas.

The boss move is buying a plan with cheap to free electricity at night in exchange for a ludicrous day rate, bonus points for buying batteries to self-consume and/or charge at night as needed.

Going strictly by the numbers, it's a judgment call as to whether it's "worth it" or not, but the power independence for doing so is fantastic IMO YMMV. My Maslow hierarchy may not match yours.

While usage of aircon during heatwaves stressing the grid is a valid concern, I think massive increase in solar could offset it. Solar will also generate maximum energy during sunny days with minimal cloud cover, meaning there shouldn’t be a shortage of energy if there’s enough solar.

Since 2022 California has energy from solar by roughly 50%, while the population has decreased. Solar is now the biggest source of energy in California, and continues to grow. That means that future heatwaves should be handled well enough.

It doesn't solve the problem- its the end of the day when solar has ramped down that the crises happens. Its the duck curve. Where its still hot and air conditioning is still running hard.

Solar depresses the energy demand during the middle of the day. Energy storage smooths out the load profile.

Knowing about the duck curve and taking advantage of the essentially zero marginal cost of solar, can't most folks just crank down their AC temps at 11 or noon such that there's no end-of-day demand ramp?

I know folks in Phoenix who are on a time-of-day plan and they max out the AC overnight and then barely use it during the day (same goal, just they don't have solar)

This is indeed what I do when it's going to be very hot (105+) out.

I run the AC down to 64 overnight, and it's usually comfortable until well into the afternoon before it starts running at 73-74.

> It doesn't solve the problem- its the end of the day when solar has ramped down that the crises happens. Its the duck curve. Where its still hot and air conditioning is still running hard.

Isn't that scenario a problem only when the output from solar is insufficient to meet the aggregate demand?

From a naive point of view, it looks like this issue would be easily mitigated if supply from solar was increased enough to allow energy to be stored during peak hours so that it could be introduced back in the grid during sunset. Why is this scenario being ignored in a thread on how California is investing in battery energy storage?

You’re in a thread about California adding record amounts of battery storage. These batteries charge at noon a discharge in the evening while demand is peaking. This smooths out the supply across the day so it can meet the demand.

California did struggle with the duck curve but it’s less of a problem now. When the next heatwave comes, evening aircon demand won’t be a problem.

> California did struggle with the duck curve but it’s less of a problem now. When the next heatwave comes, evening aircon demand won’t be a problem.

The point of my top-level comment was that we don't actually know that. Not yet.

I'll be thrilled if that's the case. I'll also be very surprised.

GP is basing their comment on 5 year old data. As of April 2025 the duck curve problem is solved - https://blog.gridstatus.io/caiso-solar-storage-spring-2025/. Mid day demand increased because of battery charging, smoothing out the load. The California grid is looking immensely healthy, being a net exporter most days.

Will it handle an extended heatwave that also affects other states simultaneously? You’re right, we can’t know that with certainty until after it happens. But based on what I’ve read I’m confident it will.

I doesn't have to solve the problem.

It just has to help the problem.

Rooftop home solar+storage also doesn't have to SOLVE THE PROBLEM IN TOTALITY. It just has to help.

Energy is a cornucopia of solutions, which is a good thing. We aren't going to get everything from nuclear, it is far too expensive and can't function as a peaker (unless we had LFTR but oh well). Geothermal has a lot of potential, but it isn't perfect and probably investment heavy. Gas peaking is regrettable, but necessary currently. Solar and wind are by far the cheapest, but intermittent.

The goal should be stable, available, cheap energy. The path to that is solar + wind + battery + peaking + home solar/storage, but the grid monopolists aren't interested in cheap energy or the loss of control that home solar/storage comes with.

The fact that wind and solar are so cheap but grid prices are so expensive is an absolute SCANDAL.

I feel like the additional unstated context is that nothing has changed.

Power outages are still a common threat, it's just that now they are caused by the power companies under the guise of wildfire prevention.

I don't care if my power goes out because of lack of supply or because you didn't maintain the transmission lines properly - the result is the same - I'm angry.

Shouldn't you control your emotions depending on the reason?

Sure, there might be cases beyond their control - but in general if I pay them to provide a service and they fail to deliver, I think my annoyance is justified.

If they are busy counting their profits instead of focusing on providing a safe, reliable service, then I think it's reasonable to be angry with them.

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.

Or 3 days ago in Palm Springs, California, and my power was shut off for 2 hours even though it was only 92 degrees outside.

> the URL slug

when will it replace the headline in editorial importance?

Usually slug, headline and teaser are all considered important parts to optimize. My wife works for a big online news company and while news journalists write headline and teaser, they have editors in chief who edit those again and a separate SEO team who will assign slugs.

hey you aren't supposed to notice :)

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

> sunshine linked demand

The demand lags the sunshine which is why it's a non-trivial problem.

With a lot of overlap though. The correlation with sunshine is still helpful.