When a group of engineers and researchers gathered in a warehouse in Mukilteo, Wash., 10 years ago, they knew they were onto something big. They scrounged up tables and chairs, cleared out space in the parking lot for experiments and got to work.
They were building a battery — a vanadium redox flow battery — based on a design created by two dozen U.S. scientists at a government lab. The batteries were about the size of a refrigerator, held enough energy to power a house, and could be used for decades. The engineers pictured people plunking them down next to their air conditioners, attaching solar panels to them, and everyone living happily ever after off the grid.
