A flow battery system, designed to stockpile massive amounts of energy, at a plant on Hokkaido. If the world is going to power itself with renewable energy, it needs to be ready at a moment’s notice.
China and Russia dominate the market for vanadium, the metal that makes flow batteries durable and easy to maintain. “The supply chain for vanadium is extremely precarious,” said Kara Rodby, a battery analyst at the investment firm Volta Energy Technologies. Still, flow batteries are making their debut in big real-world projects.
“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.
Here’s how it works: All of these tanks are lined up in pairs. One tank holds vanadium with a more positive charge, while the other tank holds vanadium with a more negative charge. You can think of them like the + and - sides of the batteries sitting in a TV remote or a flashlight.
“There really is no finite lifetime for a flow battery in the way there is for lithium-ion,” Rodby said. Sumitomo Electric President Osamu Inoue said his company guarantees its flow batteries will last 20 years — but the vanadium inside can be reused forever in future batteries.
A model of the flow battery system run by the Hokkaido Electric Power Network. But experts say there might be better options. 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.