Used Electric Car Batteries Get Second Life as Home Storage

  • Used batteries in stationary storage cost half as much as new
  • About 95 gigawatt-hours to be extracted from cars by 2025

Aging batteries from electric cars will soon find a second life as power-storage systems for homes and offices, according to Bloomberg New Energy Finance.

About 95 gigawatt-hours of lithium-ion batteries are expected to come out of cars by 2025, and about 26 gigawatt-hours of them will be converted to stationary systems as demand for both electric cars and solar rooftops increases, Claire Curry, a New Energy Finance analyst in New York, said in a research note Thursday. That compares with about 0.1 gigawatt-hours of used car batteries that are available today.

Used batteries cost about $500 a kilowatt-hour to convert to stationary storage systems, about half the cost of batteries fresh off the factory floor. That will provide an opportunity for solar installers to cheaply add storage to rooftop systems until new battery costs come down.

“There’s a sweet spot now where new batteries are still expensive for stationary use,” Curry said in an interview. Developing a secondary market for batteries that can still hold 70 percent of their original capacity will help reduce the cost of ownership as well as delay the expense of end-of-use recycling.

The window for developing a vibrant secondary market for these batteries may close as prices comes down, sometime in the next three to five years, Curry said. That’s because the used ones will have shorter life spans and may not come with warranties like new ones do.

“The cross-over will happen when the costs drop to $200 a kilowatt-hour,” she said.

Before it's here, it's on the Bloomberg Terminal. LEARN MORE