The Race to Build a Better Battery for Storing Power

There’s the battery in your watch. There’s the battery in your mobile phone. And then there’s the battery at Green Mountain Power’s Stafford Hills solar farm in Rutland, Vt.

The lithium-ion gargantuan is housed in two trailer-truck-size green metal containers. It sits atop a 10-acre former landfill and captures electricity from 7,722 nearby solar panels—enough to power 2,000 homes on a sunny day. What’s revolutionary about this system isn’t the solar farm; it’s the size and purpose of the battery, which offers 3.4 megawatt-hours of storage, enough to supply backup power to about 170 homes for a day, if needed.

The rap on solar and wind is intermittence—they don’t produce power when the sun isn’t shining or the wind isn’t blowing, making them unreliable as the primary source for power grids. But if vast amounts of renewable energy—say, enough to power entire cities—could be captured and stored in giant batteries and deployed when needed, that downside would fade away.

read the full article in the wallstreetjournal