For a few seconds on a sunny afternoon last April, renewables broke a record for California’s main electric grid, providing enough power to supply 94.5% of demand. The moment was hailed as a milestone on the path to decarbonization. But what happens when the sun sets and the breeze stops?
Handling the fluctuating power production of renewables will require cheap storage for hours or even days at a time. New types of iron-based batteries might be up to the task.
Oregon-based ESS, whose batteries can store energy for between four and 12 hours, launched its first grid-scale projects in 2021. Massachusetts-based Form Energy, which raised $240 million in 2021, has batteries that store power for up to 100 hours. Its first installation will be a one-megawatt pilot plant in Minnesota, slated to be completed in 2023.