When it comes to electricity, California has it rougher than most states. It’s home to more electricity-consuming residents than anywhere else in the country, and when demand for electricity spikes (often during summer heat waves), the state is sometimes unable to supply all of those residents with power. For this reason, California’s energy authorities will occasionally implement planned power outages known as rolling blackouts. If you’ve ever been caught in 100-degree heat with no air conditioning, you know that’s less than ideal.
One of the ways California is planning on dealing with this problem is by setting up large battery grids that state officials hope will keep things running when extreme weather hits. These batteries can be charged by the state’s growing network of solar panels and wind turbines, and they can kick in when there’s an energy shortage to supply power.
But the batteries that the Golden State is building aren’t the same as the batteries you’ll find in your smartphone, or even in your electric car. Those devices typically use lithium-ion batteries, which are great for electronics and other small-scale devices, but aren’t exactly ideal when it comes to grid-scale energy storage. They’re too expensive and aren’t designed to deliver power to entire cities.
Instead, the state is investing in an array of flow batteries. A flow battery is a large, grid-scale battery that stores energy in electrolyte liquids, as opposed to a solid electrode like lithium-ion. These batteries can put out power for longer durations than lithium-ion batteries, and they come with many other benefits.
Going with the flow
Joe Worthington, director of communications at the flow battery company Invinity Energy Systems, says it’s working with the state of California to show why flow batteries are the way to go for battery grids. “We’ve received funding for four projects from the California Energy Commission,” Worthington says.
Worthington says lithium-ion batteries max out at a four-hour duration, and lithium-ion systems typically don’t even have that capacity. The flow batteries Invinity produces can go beyond that because, Worthington says, you can just add more of the electrolyte liquid to a flow battery to make it hold a charge for longer. The company currently has a 10-hour flow battery system operating at a fire station on a Native American site in California.
Beyond duration, one of the perks of flow batteries is they essentially “do not degrade,” Worthington says, and they’re almost entirely recyclable. Lithium-ion batteries are famously difficult to recycle.
“A lithium-ion battery lasts seven years or so. A flow battery lasts 20,” Worthington says. “If you’re going to have it on your site for 20 years, you’re going to have to buy that lithium battery maybe twice more. You’ll have the same flow battery you bought on day one in year 20.”
The one downside with flow batteries is their size. They’re a lot bigger than lithium-ion batteries, which is why Worthington says they’re best for energy grids, rather than cars or other things that need to move around. In terms of price, flow batteries are catching up to lithium-ion batteries, which have become quite cheap in recent years.
“Today, we’re probably about commensurate with lithium-ion on an upfront-cost basis,” Worthington says. “When you get to the massive projects … lithium-ion definitely has the advantage today just because they’ve got this huge global supply chain and we’re still scaling up as a business.”
The business of big batteries
Michael Gravely, deputy division chief of the Energy Research and Development Division at the California Energy Commission, tells Digital Trends that California is very interested in flow battery technology and hopes to show the market that they’re a worthwhile investment.
“The challenge is there aren’t many technologies that are as far along as lithium-ion right now in the commercial process,” Gravely says. “There’s an understanding that we need more than four hours of storage, and it depends on how much, but no one knows.”
Gravely says flow batteries are probably the “next technology” in this space, and he believes they could soon be cheaper and simultaneously power things for longer than lithium-ion systems. He says they’ll be working on demonstrating the usefulness of this technology for the next few years while the technology becomes more established in the utility industry.
A battery that can hold a charge for longer, may soon be cheaper, is recyclable, and has a longer life span than lithium-ion is surely attractive. Lithium-ion won’t be replaced anytime soon when it comes to powering consumer electronics and electronic vehicles, but it could become the less-favored option for utility energy storage in the not-too-distant future. That would help states deal with extreme weather and help make sure the power keeps coming when the sun isn’t shining or the wind isn’t blowing.