Second-life EV Batteries Add Capacity to Solar Storage Facility

February 12, 2023 by Shannon Cuthrell

A hybrid solar and storage facility in California recently reached 25 MWh of capacity from 1,300 reused electric vehicle battery packs. 

This week, B2U Storage Solutions announced it reached 25 megawatt-hours (MWh) of capacity at its hybrid energy storage and solar facility in Lancaster, California. The energy storage system (ESS) runs on 1,300 reused battery packs from Honda and Nissan electric vehicles. B2U has also tested and demonstrated GM Bolt and Tesla Model 3 batteries with the system. 


A shot of B2U Storage’s hybrid storage facility in California. Image used courtesy of B2U Storage Solutions


The site, dubbed SEPV Sierra, first came online in mid-2020 and has since scaled up to its latest capacity. On its website, B2U Storage says its EV battery-based ESS can charge and discharge efficiently with a reduced levelized cost of storage and lower capital and operational costs than competing ESSes running on new batteries. The used battery packs can be installed in thermally controlled cabinets in their original casing and using their existing battery management system, thus saving on repurposing and reconfiguration costs. 

Based in Santa Monica, B2U Storage Solutions was founded in 2019 as a spinout of Solar Electric Solutions, a utility-scale solar PV developer with 100 MW of capacity across 11 projects in California. B2U later raised a $10 million Series A equity round in 2021, led by Japanese conglomerate Marubeni Corporation. 


A look at B2U Storage’s thermally controlled cabinets. Image used courtesy of B2U Storage Solutions

According to Solar Electric Solutions' website, the SEPV Sierra facility was initially developed as an ESS where batteries are charged from on-site PV capacity. It came online in early-2020 with additional phases targeting 17 MWh of battery storage (or a two-hour discharge at the 8.5 MW capacity site). The off-taker is Southern California Edison, the region’s primary electricity supplier. 

In announcing its 25 MWh capacity milestone during the week of Distributech International, B2U Storage stated the facility generated over $1 million in revenue last year. It also touted SEPV Sierra as the world’s largest operational second-life battery ESS to be certified by UL 9540, the standard for ESS and equipment safety. 


Battery Storage Projects on the Rise

The SPEV Sierra facility boosts California’s goal to source 90% of its electricity from renewables by 2035. According to the U.S. Energy Information Administration, renewables accounted for almost half of California’s in-state electricity generation in 2021. Wind and solar deployment are a significant piece of California’s clean energy strategy, but it will need to increase its battery storage capacity to make the grid more resilient in demand response events such as last summer’s record-breaking heat wave.  

Battery storage facilities like the 24/7-operational SPEV Sierra help California’s utility operators manage the natural volatility of solar PV systems, as supply declines in the evening hours when demand is highest. 


Video used courtesy of B2U Storage Solutions


Traditional battery storage facilities are one way to offset supply/demand gaps from intermittent solar energy, and they’re growing in California. The state already has nearly 5 gigawatts (GW) of storage resources linked to the grid, according to a bulletin released in December 2022 from the California Independent System Operator. And in February 2022, the California Public Utilities Commission approved plans to add 15 GW of new storage and demand response resources before 2032. 

Beyond California, battery storage projects are a growing market as more countries look for ways to reduce renewable demand and production imbalances. Globally, BloombergNEF expects cumulative energy storage installations to reach 1,194 gigawatt-hours (GWh) by late 2030–15 times the amount operational in 2021. And with the global electric car market projected to surpass 350 million vehicles by 2030, so lies an opportunity to add more stationary storage projects running on used EV batteries. One estimate from McKinsey & Company in 2019 projected that such projects could surpass 200 GWh globally by 2030. 

B2U Storage isn’t alone in this emerging market. Last November, the U.S. Department of Energy awarded $74 million in funding to 10 projects focused on EV battery recycling and reuse. One recipient was California-based Smartville, which commissioned a grid-connected ESS utilizing old Nissan Leaf and Tesla batteries. Another recipient, RePurpose Energy, is currently scaling its battery testing and reassembly operations after launching a commercial-scale demonstration in 2019. 

The market is also growing outside of the United States. Last year, Canadian ESS provider Moment Energy inked a supply agreement for second-life EV batteries from Mercedes-Benz. Meanwhile, in Europe, Finland’s state-owned energy firm Fortum spearheaded a second-life battery installation in 2021 at a hydropower plant in Sweden, using out-of-service batteries from Volvo. Norway-based ECO STOR has also developed grid and industrial ESSes running on used EV batteries. And Finnish startup Cactos operates energy storage facilities with a capacity of 100 kilowatt-hours via recycled Tesla batteries

Original equipment manufacturers are also exploring ways to reuse their battery units, including Hyundai (which is testing EV battery-based ESSes in Texas), Mercedes-Benz (building a battery recycling facility in Germany), and Nissan (which is working on repurposing old Leaf EV batteries into second-life storage systems).