New Battery Technology Could Offer Cheap Renewable Energy Storage

New battery technology that uses cheaper and safer materials to store large amounts of energy may soon enable utility companies to use more renewable power,
Enervault iron-chromium flow batteries
Iron-chromium flow battery technology
according to MIT Technology Review. The new device is a type of flow battery, and it uses liquid materials that rely on iron-chromium chemical reactions to store energy. California-based startup Enervault, developer of the new battery, figured out how to use materials that had been tried in batteries decades ago; Enervault overcame a key technical challenge that had caused the earlier batteries to quickly degrade. The new battery is large — it can store one megawatt-hour of electricity, or enough to run 10,000 100-watt light bulbs for an hour — and the materials last more than 20 years, according to its developer. Although the battery is inefficient compared to conventional batteries — it loses 30 percent of the energy used to charge it — it is still economically viable, the company says. The iron-chromium flow battery costs 80 percent less than vanadium flow batteries, a competing technology. The batteries are currently in use at a small power plant near Modesto, California.