But rolling out EV chargers—especially fast chargers that can quickly power up cars but demand as much electricity as 300 homes, each—isn’t easy to do. “We want to unlock mass EV adoption, but the grid is simply not in a position to accommodate that,” says Vince Wong, chief operating officer for ElectricFish, a startup pioneering a new type of charger. Instead of pulling power from the grid whenever a car plugs in, the new device uses a large battery. Throughout the day, the battery charges when excess renewable energy is available. “We can store that energy and then detach the EV charging load from the grid itself,” says Anurag Kamal, the company’s CEO.

The approach helps solve a second problem: As more renewable energy is added to the grid, producing power at only certain times of the day, more storage is needed.