Can "second life" EV batteries work as grid-scale energy storage?

Summary

Redwood Materials has long dominated EV battery recycling, but what if they could drain every last drop of energy from those batteries before recycling them? I talk with the company’s CTO, Colin Campbell, about Redwood Energy, a new division doing just that by deploying used batteries as grid-scale storage at a massive scale. This isn’t just a side project; it’s a plan to turn a massive wave of incoming used batteries into a key resource for the grid.(PDF transcript)(Active transcript)David RobertsHi everybody, this is Volts for October 22, 2025, “Can ‘second life’ EV batteries work as grid-scale energy storage?” I’m your host, David Roberts. Redwood Materials started recycling lithium-ion batteries before it was cool, before it was profitable, and before there were very many lithium-ion batteries to speak of. In the five years since, it has grown and scaled to capture the overwhelming majority of the booming automotive-battery recycling market in North America.Earlier this year, it spun off a new division called Redwood Energy. The idea is simple: it is going to hook the EV batteries it receives up to large arrays that serve as grid-scale energy storage. That way, it can drain every last bit of useful life out of them before it recycles them.So-called “second life” batteries have been discussed for many, many years, but this is the first time they have been deployed at appreciable scale. Redwood has built an off-grid facility where 20 megawatts of solar panels are powering 63 megawatt-hours of second life batteries that feed into two one-megawatt data centers.ShareToday, I am going to chat with the company’s CTO, Colin Campbell, about why Redwood hatched this initiative, how the costs of second life storage compare with the rest of the storage market, and how big he thinks this side of the business could ultimately get.All right then, with no further ado, Colin Campbell, welcome to Volts. Thank you so much for coming.Colin CampbellDavid, thanks so much for having m...