Waymo to Repurpose Robotaxi Batteries for Grid Storage

B2U Storage Solutions will receive retired batteries from Waymo’s growing fleet of autonomous vehicles under a strategic supply agreement announced June 4. The deal reportedly targets energy storage projects across California and Texas, where the batteries could add hundreds of megawatt-hours of capacity to help balance renewable power on local grids.

B2U Storage Solutions repurposes used EV batteries. The firm has installed thousands of second-life batteries from multiple electric vehicle models into large-scale stationary systems. These facilities store surplus renewable generation during off-peak hours and discharge it during high-demand periods to stabilize the grid.

“Our business is getting the full residual value out of electric vehicle batteries after they’re no longer suitable for automotive use,” Freeman Hall, CEO of B2U Storage Solutions, told Ars Technica.

Waymo applies proactive battery maintenance. Under the pact, B2U will obtain both end-of-life packs and those swapped during routine servicing. Waymo’s sustainability chief Adam Lenz described the company’s approach as identifying chances to “refresh the battery to improve efficiency overall for our fleet.”

Lenz noted that even after removal from vehicles the packs retain substantial capacity, making them suitable for stationary use. The company has not disclosed typical mileage thresholds for swaps or retirements.

Robotaxi fleet sees accelerated battery wear. Because the vehicles log far higher daily mileage than consumer cars, their batteries degrade more rapidly. Waymo has acknowledged that “some of these vehicles have now been serving riders for years and have mileage beyond what a normal consumer drives.”

A 2025 Geotab study of more than 22,700 electric vehicles spanning 21 models showed average annual capacity loss of roughly 2.3 percent, leaving more than 81 percent of original capacity after eight years.

Fleet composition drives significant capacity. Waymo’s nearly 4,000 vehicles consist primarily of Jaguar I-Pace models equipped with 90 kWh lithium-ion packs. The company has also started deploying Zeekr-built Ojai robotaxis that carry 93 kWh batteries.

Hall observed that even after accounting for some degradation the remaining energy per pack remains substantial. He added that the expanding fleet could deliver large volumes of megawatt-hour-scale storage to the grid relatively quickly.

Initial battery deliveries have started. Waymo decides the timing and volume of transfers, but the partners confirmed B2U has “already started receiving smaller initial quantities of batteries” from the fleet. Over time the arrangement could supply B2U with hundreds of megawatt-hours drawn from thousands of Waymo vehicles, according to Lenz.

The partnership creates a regional loop: batteries that once powered robotaxis in certain cities will later reinforce the same grids those vehicles use for charging. B2U will process the incoming packs at its Lancaster, California site—already home to more than 1,300 repurposed EV batteries—before distributing them to additional installations in California and a 24 MWh project in Bexar County, Texas, near Waymo’s San Antonio operations. The all-electric fleet avoids 530 tons of CO₂ emissions per 500,000 weekly trips, the company estimates. US battery storage deployments hit a record 9.7 GWh in the first quarter of 2026, a 32 percent rise from the prior year, according to the Solar Energy Industries Association. B2U currently oversees more than 4,000 EV packs, including early Nissan Leaf units still performing after approximately 2,500 cycles.