As the world pivots toward renewable energy sources, the challenge of energy storage looms ever larger. The sun doesn’t always shine, and the wind doesn’t always blow — but the demand for electricity never stops. Currently, natural gas and coal are the primary ways we generate electricity. These are dirty, pollution-causing industries that will need to be phased out if we are to tackle the problems associated with climate change. Many different solutions to this problem are currently being investigated across the country and the world.

For example, the Gemini Solar + Battery Storage Project, located about 30 miles northeast of Las Vegas, is one of the largest solar battery facilities in the United States, launched in 2023. Spanning approximately 5,000 acres, it combines a 690-megawatt solar photovoltaic array with a 380-megawatt battery storage system, capable of powering about 50,000 homes and providing 10% of Nevada’s peak energy demand. By storing solar energy in massive batteries, the facility ensures a stable and reliable power supply even after the sun sets, addressing the intermittency challenges of renewable energy.

However, these facilities face significant challenges due to the inherent explosive potential of lithium batteries. The Moss Landing battery facility fire serves as a stark reminder of the challenges associated with large-scale energy storage. Housing one of the world’s largest lithium-ion battery systems, the facility experienced multiple fire incidents, raising concerns about the safety of these technologies. These fires were particularly alarming due to the potential for thermal runaway, a phenomenon where a single battery cell’s failure triggers a chain reaction in neighboring cells, leading to uncontrollable fires and explosions. While no injuries were reported, the incidents caused significant operational disruptions and prompted widespread scrutiny of fire safety protocols in energy storage systems. Investigations have pointed to the need for more robust cooling mechanisms, advanced monitoring systems, and comprehensive emergency response strategies to prevent similar events in the future.

Aside from the potential fire dangers of large battery facilities, building large-scale solar battery projects like Gemini is costly, often exceeding hundreds of millions of dollars, due to the expense of new lithium-ion batteries. A more sustainable and economical solution could involve repurposing old batteries, such as those from retired electric vehicles. These batteries, while unsuitable for cars, still retain enough capacity for energy storage, reducing costs, resource use, and electronic waste.

That’s where B2U Storage Solutions, a California-based company founded by Freeman Hall and Mike Stern, offers an innovative answer to this critical problem. By harnessing the power of old electric vehicle (EV) batteries to store renewable energy, B2U is giving these aging batteries a productive second life and helping enhance the viability of green energy grids. The effort could pave the way for not only improving solar storage but also reusing old batteries that might otherwise end up in landfills or pose environmental hazards.

According to Vincent Beiser in his wonderful new book Power Metal: The Race for the Resources That Will Shape the Future, “by 2030, used electric car batteries could store as much as two hundred gigawatt-hours of power per year. That’s enough to power almost two million Nissan Leafs.”

Founded in 2019, B2U emerged as a spin-off from Solar Electric Solutions (SES), a solar energy development company with a strong track record of success, having developed 100 megawatts across 11 projects in California since 2008. Freeman Hall, a seasoned renewable energy strategist, and Mike Stern, a veteran in solar project development, combined their expertise to address a growing challenge: how to create affordable and sustainable energy storage.

Leveraging their knowledge, B2U developed their patented EV Pack Storage (EPS) technology. This technology allows for the integration of second-life EV batteries without the need for costly repurposing, making large-scale energy storage more economically feasible. Their vision took shape in Lancaster, California, where they established the SEPV Sierra facility in 2020.

At the Lancaster site, B2U uses over 1,300 repurposed EV batteries to form a large-scale battery energy storage system (BESS). When solar farms generate more electricity than the grid can immediately use, the excess power is stored in these second-life batteries. Later, when the sun sets or demand peaks, that stored energy is released back into the grid. This process reduces waste and helps stabilize renewable energy supply.

B2U is not alone. The second-life market for EV batteries is projected to grow to $7 billion by 2033, according to a March report by market research firm IDTechEx. While most EVs rely on lithium-ion batteries, these typically lose viability for vehicle use after about eight to ten years. However, depending on their remaining capacity and “state of health”—a measure of cell aging—they can be repurposed for less demanding applications, such as stationary energy storage, the report notes.

B2U Storage Solutions has launched its second hybrid battery storage facility near New Cuyama in Santa Barbara County, California. This innovative project uses approximately 600 repurposed electric vehicle batteries, primarily from Honda Clarity models, to provide 12 megawatt-hours of storage capacity. Charged by a 1.5-megawatt solar array and supplemental grid power, the facility supplies electricity and grid services to the California energy market. By employing patented technology, the system integrates second-life EV batteries in their original casings, reducing costs and enhancing sustainability. Building on the success of its first facility in Lancaster, this project demonstrates a scalable approach to energy storage while minimizing electronic waste and supporting renewable energy adoption.

B2U claims its technology enables batteries to be repurposed in a nearly “plug-and-play” manner, eliminating the need for disassembly. The system is compatible with units from multiple manufacturers, including Honda, Nissan, Tesla, GM, and Ford, allowing them to be seamlessly integrated into a single storage system.

Renewable energy is essential to combating climate change, but its intermittent nature poses challenges for maintaining a reliable power grid. Without effective storage, surplus renewable power generated during peak periods is wasted, and fossil fuels must often be burned to cover shortfalls. By using second-life EV batteries, B2U provides a sustainable, cost-effective solution to this problem.

Freeman Hall and Mike Stern’s innovative approach at B2U addresses the pressing need for affordable energy storage while giving EV batteries a second life. Their Lancaster facility and the one in New Cuyama demonstrate how smart storage solutions can make renewable power more reliable and accessible. By extending the lifecycle of EV batteries and supporting a resilient energy grid, B2U is at the forefront of sustainable energy innovation.

As California works toward ambitious renewable energy goals and the world increasingly embraces electric vehicles, companies like B2U could play a crucial role in shaping a cleaner, more sustainable future.