Toyota Repurposes Electric Vehicle Batteries to Generate Power for Mazda's Hiroshima Manufacturing Facility

In a move towards sustainable energy solutions, Toyota has installed a second-life energy storage system, named Sweep Energy Storage, at Mazda's car factory in Hiroshima, Japan. This system, developed by Toyota in 2022 with Jera, Japan's largest power generation company, aims to target production-line energy buffering via solar power integration.

The Sweep Energy Storage system functions as a power buffer between the facility's solar generation and its production line. Central to the system is Toyota's proprietary control device, which manages energy discharge by switching flow through series-connected cells. This device allows individual batteries to be bypassed as needed, ensuring the system can be reliably scaled to support production power requirements.

The system reuses entire battery packs from out-of-service electric and hybrid vehicles, including their original inverters. This not only offers an alternative to recycling or landfilling older EV batteries but also reduces the need for external control hardware due to its modular setup.

The Sweep system at Mazda's plant is currently being evaluated for stability in charge-discharge cycles. The specifics of this evaluation, such as the number of cycles tested and the results, have not been disclosed.

Toyota is exploring extended lifecycle applications for the units within the automotive and industrial sectors by repurposing these units for storage. The Sweep Energy Storage system integrates battery packs of varying chemistries, capacities, and states of health, ranging from lithium-ion to nickel-metal-hydride and lead-acid units.

It's important to note that the Sweep Energy Storage system does not appear to have any connection with the 2026 Toyota bZ First Drive event. The specifics of this event, such as its new name, increased range, and more power, are not related to the Sweep Energy Storage system at Mazda's Hiroshima plant.

Jera's version of the Sweep system delivered 485 kilowatts of output and stored up to 1,260 kilowatt-hours of energy. The system is currently in the testing phase, with the goal of determining whether the system can be reliably scaled to support production power requirements.

This collaboration between Toyota and Mazda underscores both companies' commitment to sustainable energy solutions and the circular economy, where waste is minimised and resources are reused as effectively as possible. As the world continues to grapple with climate change, such initiatives are crucial in the transition towards a more sustainable future.