It’s expected to store more electricity than all but one battery plant currently operating in the U.S.

The billion-dollar project, with 680 megawatts and 2,720 megawatt-hours, will help California shift its nation-leading solar generation into the critical evening and nighttime hours, bolstering the grid against the heat waves that have pushed it to the brink multiple times in recent years… The town of Menifee gets to move on from the power plant exhaust that used to join the smog flowing from Los Angeles… And the grid gets a bunch more clean capacity that can, ideally, displace fossil fuels…

Moreover, [the power bank] represents Calpine’s grand arrival in the energy storage market, after years operating one of the biggest independent gas power plant fleets in the country alongside Vistra and NRG… Federal analysts predict 2024 will be the biggest-ever year for grid battery installations across the U.S., and they highlighted Calpine’s project as one of the single largest projects. The 620 megawatts the company plans to energize this year represent more than 4% of the industry’s total expected new additions.

Many of these new grid batteries will be built in California, which needs all the dispatchable power it can get to meet demand when its massive solar fleet stops producing, and to keep pace with the electrification of vehicles and buildings. The Menifee Power Bank, and the other gigawatts worth of storage expected to come online in the state this year, will deliver much-needed reinforcement.
The company says it’s planning “a portfolio” of 2,000 megawatts of California battery capacity.
But even this 680-megawatt project consists of 1,096 total battery containers holding 26,304 battery modules (or a total of 3 million cells), “all manufactured by Chinese battery powerhouse BYD, according to Robert Stuart, an electrical project manager with Calpine. That’s enough electricity to supply 680,000 homes for four hours before it runs out.”
What’s remarkable is just how quickly the project came together. Construction began last August, and is expected to hit 510 megawatts of fully operational capacity over the course of this summer, even as installation continues on other parts of the plant. Erecting a conventional gas plant of comparable scale would have taken three or four years of construction labor, due to the complexity of the systems and the many different trades required for it, Stuart told Canary Media… That speed and flexibility makes batteries a crucial solution as utilities across the nation grapple with a spike in expected electricity demand unlike anything seen in the last few decades.

The article notes a 2013 Caifornia policy mandating battery storage for its utility companies, which “kicked off a decade-long project to will an energy storage market into existence through methodical policies and regulations, and the knock-on effects of building the nation’s foremost solar fleet.”

Those energy storage policies succeeded in jumpstarting the modern grid battery market: California leads the nation with more than 7 gigawatts of batteries installed as of last year (though Texas is poised to overtake California in battery installations this year, on the back of no particular policy effort but a general openness to building energy projects)… California’s interlocking climate regulations effectively rule out new gas construction. The state’s energy roadmap instead calls for massive expansion of battery capacity to shift the ample amounts of solar generation into the evening peaks.
“These trends, along with the falling price of batteries and maturing business model for storage, nudged Calpine to get into the battery business, too.”