Utilities Are Trying Enormous ‘Flow’ Batteries Big Enough to Oust Coal Power Plants – Slashdot

To help replace power plants, Japan’s northernmost island, Hokkaido, “is turning to a new generation of batteries designed to stockpile massive amounts of energy,” reports the Washington Post.

“The Hokkaido Electric Power Network (HEPCO Network) is deploying flow batteries, an emerging kind of battery that stores energy in hulking tanks of metallic liquid.”

[F]low batteries are making their debut in big real-world projects. Sumitomo Electric, the company that built the Hokkaido plant, has also built flow batteries in Taiwan, Belgium, Australia, Morocco and California. Hokkaido’s flow battery farm was the biggest in the world when it opened in April 2022 — a record that lasted just a month before China built one that is eight times bigger and can deliver as much energy as an average U.S. natural gas plant. “It looks like flow batteries are finally about to take off with interest from China,” said Michael Taylor, an energy analyst at the International Renewable Energy Agency, an international group that studies and promotes green energy. “When China starts to get comfortable with a technology and sees it working, then they will very quickly scale their manufacturing base if they think they can drive down the costs, which they usually can….”

Lithium-ion batteries are perfect for smartphones because they’re lightweight and fit in small spaces, even if they don’t last long and have to be replaced frequently. Utilities have a different set of priorities: They need to store millions of times more energy, and they have much more room to work with. “If you think about utility-scale stationary applications, maybe you don’t need lithium-ion batteries. You can use another one that is cheaper and can provide the services that you want like, for example, vanadium flow batteries,” said Francisco Boshell, a researcher at the International Renewable Energy Agency…

Flow batteries are designed to tap giant tanks that can store a lot of energy for a long time. To boost their storage capacity, all you have to do is build a bigger tank and add more vanadium. That’s a big advantage: By contrast, there’s no easy way to adjust the storage capacity of a lithium-ion battery — if you want more storage, you have to build a whole new battery… One major barrier to building more of these battery farms is finding enough vanadium. Three-quarters of the world’s supply comes as a by-product from 10 steel mills in China and Russia, according to Kara Rodby [a battery analyst at the investment firm Volta Energy Technologies] who got her PhD at the Massachusetts Institute of Technology studying the design and market for flow batteries. Australia, South Africa and the United States also produce vanadium, but in much smaller quantities. Mines that have been proposed could boost supply. And some flow battery start-ups are trying to sidestep the vanadium problem entirely by using different materials that are easier to buy.

The other hurdle is their up-front cost. Vanadium flow batteries are at least twice as expensive to build as lithium-ion batteries, Rodby said, and banks are hesitant to lend money to fund an unfamiliar technology. But experts say flow batteries can be cheaper in the long run because they’re easier to maintain and last longer. A lithium-ion battery might have to be replaced after 10 years, but Rodby says flow batteries can last much longer. “There really is no finite lifetime for a flow battery in the way there is for lithium-ion,” Rodby said.
Here’s an interesting statistic from the article. “Over the next six years, utilities will have to build 35 times as many batteries as there are today to soak up all extra renewable energy that will come online, according to the International Energy Agency.”