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Used EV car batteries find new life storing solar power in California

Putting theory into practice, hopefully without a lithium fire

As researchers continue to debate the merits of turning old electric vehicle batteries into energy storage for renewables like solar and wind, a California startup says it has already built out a facility to do just that.

B2U Storage Solutions has reportedly deployed more than 1,300 used EV batteries at a solar facility in Lancaster, California, where it claims it is able to store more than 25 megawatt-hours of electricity, enough to supply power to a couple of hundred homes.

Speaking to Reuters, B2U CEO Freeman Hall said that he believes the project is the first of its kind selling power on the wholesale market, and claimed the company earned $1 million last year from the Lancaster site.

Even better for offsetting costs, B2U said its technology, which it calls EV Pack Storage (EPS), doesn't require any disassembly or reconfiguration of EV batteries to get them connected to a shipping container-sized climate-controlled storage pod, meaning batteries are essentially plug-and-play, the company claimed. B2U said batteries can be installed using their existing casings, and are managed using their existing onboard management software.


A B2U EV battery storage container

According to Hall, B2U's system could reduce grid-scale battery capital costs by around 40 percent, saying the batteries included in B2U's system are up to eight years old and mostly come from former Honda and Nissan electric vehicles.

We have to do something with all those batteries

There's no denying it: EVs are here, and they're gradually displacing more gas-powered vehicles. Car companies are already wondering what to do with the batteries no longer suitable for automotive use, which can hit a wall quite early in their life cycle.

According to a recent study that found EV battery addition to the grid could ease renewable transitions, researchers from the Netherlands determined that EV batteries lose their automotive efficacy at around 70-80 percent of their original capacity, at which point they're typically replaced.

That study also found that plugging old EV batteries into the grid could, along with assistance from vehicle-to-grid equipped cars, add between 32 and 62 terawatt-hours to the grid by 2050 – enough to power a lot more homes.

The paper's authors said "short-term grid storage demand could be met as early as 2030 across most regions," but noted that the study was still a conservative estimate, so the benefits could be even greater.

And while that recent study was all about attaching EV batteries to the grid, researchers from Utah State University found in 2021 that used EV batteries could be repurposed for off-grid home energy storage as well.

According to their research, using EV batteries as home energy storage could reduce the costs of home solar systems by as much as 50 percent and, more crucially, keep all that valuable lithium and nickel (and toxic battery byproducts) out of landfills.

But just because they aren't in landfills doesn't mean there's not a risk. Stationary battery problems aren't unheard of, like last year when a Tesla Megapack in California burst into flames after less than six months in operation, and another Tesla battery in Australia spent four days on fire in 2021. Lithium-ion battery packs, the type used in Tesla Megapack batteries, are also used in Toyota and Nissan units repurposed by B2U. ®

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