An energy company wants to build another huge solar farm in the California desert — and it may come with the world’s biggest battery.

That battery would be triple the size of the one Tesla drew worldwide attention for building in Australia last year.

The Crimson solar project would span 2,500 acres of public land south of Interstate 10, east of Palm Springs at the base of the Mule Mountains.

San Francisco-based developer Recurrent Energy has asked the federal government for permission to build 350 megawatts of solar power at the site and up to 350 megawatts of battery storage. The biggest battery currently in existence is a 100-megawatt system that Elon Musk’s Tesla, the electric-car maker and solar energy provider, installed in Australia.

It’s unclear whether Recurrent will actually build a 350-megawatt battery. It doesn’t have a buyer for the electricity yet, and the federal permitting process will take several years.

An encouraging sign

Still, experts say it’s an encouraging sign for the clean energy industry to see Recurrent planning for that big a battery.

There’s a growing need for energy storage in California, where the rapid growth of solar power has led to excess electricity in the middle of the day and a reliance on polluting natural-gas plants when the sun goes down. Energy storage could help solve that problem by making solar electricity available in the evenings.

Fortunately for California, the costs of battery storage have fallen dramatically the last few years. The result is a growing market for more and bigger batteries.

“This is something that we’re going to see a lot more of — solar companies baking in the potential, if not the outright installation, of storage into their systems,” said Daniel Finn-Foley, an energy storage analyst with GTM Research, a clean-tech consulting firm. “If you’re looking ahead three, four, five years out, it’s going to be increasingly a story about storage’s ability to enhance large, utility-scale solar.”

“If they actually installed 350 megawatts, that would be a bombshell,” he said.

It’s hard to say how much electricity a 350-megawatt battery would actually store. That varies based on a battery’s duration, or how many hours it can operate at full capacity.

And ultimately, how much storage Recurrent builds will depend on market demand. Possible customers for Crimson include big utilities such as Southern California Edison and Pacific Gas & Electric, as well as city- and county-led energy programs known as community choice aggregators, or CCAs, that are increasingly replacing traditional utilities.

‘We’ll build it’

“If someone wants it, we’ll build it,” said Scott Dawson, Recurrent’s director of permitting.

Riverside County, where Recurrent would build, is already home to four big solar farms.

Conservationists have opposed many of the big solar farms that have been built or proposed in the California desert, seeing them as sprawling industrial facilities that could harm iconic but threatened species such as the desert tortoise and bighorn sheep. The California desert is one of the largest intact ecosystems in the lower 48 states, and it already has been degraded by urban sprawl, highways and other human activities.

But it’s possible Crimson will avoid the fierce environmental battles that have slowed or halted other solar farms.

Dawson, Recurrent’s director of permitting, said the company has reconfigured the project to avoid the most sensitive habitat. Crimson would disrupt 30 acres of sand dune habitat used by the Mojave fringe-toed lizard — down from 580 acres under a previous plan of development — and just 1.2 acres of biodiversity-rich microphyll woodlands, down from 95 acres under the previous plan. It wouldn’t infringe on any critical habitat for the desert tortoise, which is listed as threatened under the Endangered Species Act.

Why California leads

So far, the solar industry has grown fastest in California, driven in part by state policies to speed the transition to climate-friendly energy sources. The state got 17% of its electricity from solar and wind in 2016, the most recent year for which the California Energy Commission has data. The state also added 95 megawatts of storage last year, according to GTM Research — nearly half of the total storage added nationwide. That includes big storage projects such as those typically paired with rooftop solar panels.

But energy storage is also taking off in places such as Arizona, Hawaii and Texas, and other markets are likely to follow as costs continue to fall. Finn-Foley, from GTM Research, said lithium-ion batteries saw “spectacular price declines” of up to 30% in 2015 and 2016 and should continue to get up to 8% cheaper every year for the next few years.

Already, California officials have started rejecting proposed gas plants and asking utilities for more batteries instead. Finn-Foley thinks that before too long, economics will make the choice between a new gas plant and a solar-plus-storage facility an easy one.

“Within five years, batteries could potentially compete head to head,” he said. “Within 10 years, I think storage wins.”