So what to do with old electric vehicle batteries? Here’s one approach: Toyota and Chubu Electric Power Co. will be constructing a large-capacity storage battery system that reuses recycled batteries from Toyota electric vehicles. This aims at addressing two key issues. It deals with ways to make use of aging EV batteries that have reached the end of their useful life for vehicle propulsion, while also enabling Chubu Electric to mitigate the effects of fluctuations in the utility’s energy supply-demand balance, a growing issue caused by the expanding use of renewable energy.

Initially, the focus will be on repurposing nickel-metal-hydride (Ni-MH) batteries since these have been used in large numbers of electric vehicles for nearly two decades. The focus will then expand to include lithium-ion (Li-Ion) batteries by 2030. Li-Ion batteries have generally powered the second generation of electric vehicles and plug-in hybrids in more recent years, and thus will not reach their end-of-use for electric propulsion for some time still.

The energy storage capabilities of EV batteries diminish over time and after continuous charging and discharging. Eventually they become insufficient for powering electric cars but can still store adequate energy for other purposes. Even with their diminished performance, combining them in large numbers makes them useful for utilities and their efforts to manage energy supply-demand.

Based on the results of their initial work, the plan is to provide power generation capacity of some 10,000 kW by 2020. In a related effort, Toyota and Chubu Electric will be exploring ways to ultimately recycle reused batteries by collecting and reusing their rare-earth metals. The automaker has explored battery recycling in the past including at the Lamar Buffalo Ranch field campus in Yellowstone National Park. Here, 208 used Toyota Camry Hybrid battery packs are used to store renewable electricity generated by solar panel arrays.