Batteries make our world run. They’re in your remote control, your phone, your laptop, and your car. If we’re going to win the fight against climate change, we’ll need them to power our homes, too.
Solar panels don’t produce much power when it’s cloudy, and they don’t produce any power at night. Wind turbines don’t produce energy when the wind isn’t blowing. We have other sources of renewable energy that don’t have such limitations, such as hydroelectric power, but solar and wind will undoubtedly dominate the future of energy. We’ll need to deal with what is often called the “intermittency” problem to end our reliance on fossil fuels.
Batteries can be used to store energy in the long run and keep things powered when the sunlight goes out and wind stops blowing. As things stand, however, most grid-scale battery installations rely on lithium-ion batteries that can keep your home powered for hours but not for several days on end. The average American home requires roughly 30 kilowatt-hours of energy per day. If there’s a week of overcast weather or with hardly a breeze, there’s a good chance you and your neighbors simply lose power for extended period of time.
Jay Whitacre, a materials science professor at Carnegie Mellon, told The Daily Beast lithium-ion batteries have improved significantly in recent years. Most grid-scale lithium-ion batteries that are being used today hold a charge that could power a local grid for about four hours or so, but the storage capacity depends on its size. Lithium-ion is not typically used for long duration storage simply because of the high costs involved, said Whitacre.
Anyone who’s seen the charge capacity of their smartphone or laptop shrink over time knows that lithium-ion batteries can be fickle and difficult to work with for the long-term.
Multiple start-ups are also racing to produce affordable alternatives to lithium-ion batteries that could meet grid-scale demands and provide us with long duration energy storage.
One popular example is the flow battery, which stores energy in tanks of liquid electrolytes. You can increase its storage capacity by simply increasing its size. This might be a bit impractical in high-density communities, but stationing a large battery next to large renewable energy installations like, say, a solar farm should be fairly easy.
“The larger your tanks are in a flow battery—the more material that you have—the longer you can charge and discharge,” Whitacre said.
A huge appeal to these type of batteries is that they could be made of way cheaper materials than lithium, such as iron. Oregon-based company ESS recently installed iron flow batteries at a solar power installation in California earlier this year.
Another company called Form Energy, co-founded by the creator of Tesla Motor’s Powerwall battery, is working on a spinoff technology called an iron-air battery. It discharges electricity by converting iron to rust; and it converts the rust back to iron to charge back up again. Form believes its battery, about the size of a washing machine, will be able to deliver 100 to 150 hours of electricity to a local grid.
There’s been a lot of excitement surrounding Form due to its innovative battery technology and storage promises. The company raised $240 million in new funding earlier this year and is backed by Breakthrough Energy Ventures, which Bill Gates and Jeff Bezos have invested in. Form is bullish that it can get its batteries out at more affordable prices than current technologies—claiming they could come out to less than a tenth of the cost of lithium-ion batteries due to the cheaper materials and other factors. The company’s first project is set to go online at a wind power facility in Minnesota in 2023.
Donald Sadoway, a professor of materials chemistry at MIT, and his colleague David Bradwell invented what’s called the Ambri Liquid Metal Battery. It stores energy using molten metals and a molten salt electrolyte. Ambri is working on deploying its batteries as part of a 250-megawatt system at a data center in Nevada. Ambri is backed by Bill Gates, and it received $144 million in funding in August to commercialize its batteries.
Sadoway told The Daily Beast he believes Ambri’s battery could hold a charge of up to 24 hours worth of power. He also claimed the battery wouldn’t lose so much capacity over time like lithium-ion batteries do in devices like smartphones and laptops.
“We’ve got plenty of data that demonstrates that the liquid-metal battery doesn’t fade the way lithium-ion does,” Sadoway said.
Hydrogen fuel cells—which aren’t electric batteries themselves but can work in lieu of them without the need to recharge—are another potential solution to the intermittency problem. These types of fuel cells, according to Sadoway, are currently too inefficient and costly. But the Biden administration’s $1.9 trillion Build Back Better bill passed by the House and currently being debated by the Senate includes a hydrogen production tax credit that could make producing hydrogen for these fuel cells very affordable, which may make them a more viable solution.
“If that passes, some people will be able to essentially make hydrogen for free because the electrolysis is pretty inexpensive,” Whitacre said. If fuel cells can find backing through renewable sources of energy, “we’re going to see a different kind of storage,” he said.
The number of new innovations in the energy storage space might seem overwhelming, but that’s kind of the point—the industry doesn’t need to pick just one to make a clean energy grid work, and a combination might actually be the way to go. There’s “no panacea,” Sadoway said. Different storage options will become more or less popular as they’re shown to be more or less effective and practical. Some will make sense in cities while others will be more appropriate for rural communities. Newer battery chemistries that haven’t even been tested yet are also surely around the corner.
“I think there’s room for innovation,” Sadoway said. “No question.”
Whitacre said the real innovations that need to happen are ones that reduce the cost and increase the efficiency of energy storage systems. The good news is these kinds of innovations aren’t far off. Our energy storage technology is improving every year. Soon enough you may be powering the device of whatever you’re reading this on with a battery that was charged by the sun or the wind.