Jera and Toyota Motor announced the construction and launch of the claimed world first large capacity ‘Sweep Energy Storage System’ built using batteries reclaimed from electrified vehicles (HEV, PHEV, BEV, FCEV) and connected to a Japanese electric power grid. It began operation recently.

The companies said in a statement: “In the future, demand for storage batteries is expected to grow as they become necessary supply stabilising tools when expanding renewable energy in the movement toward CO2 emissions reduction, a vital part of achieving carbon neutrality.

“At the same time, limited supplies of battery materials including cobalt and lithium, mean there is an ongoing need for environmentally conscious initiatives, such as reclaiming used electrified vehicle batteries for effective use as storage batteries.

“In response, JERA and Toyota began discussions in 2018 to establish battery reuse technologies, which eventually led to this large capacity, grid connected [storage system].”

Toyota’s new storage system is equipped with a sweep function which allows the use of reclaimed vehicle batteries, which have significant differences in performance and capacity, to their full capacity regardless of their level of deterioration.

The sweep function, developed by Toyota Central R&D Labs, is a device which can freely control energy discharge by switching electricity flow on and off (bypassing) through series connected batteries in microseconds.

The sweep function also enables direct AC output from the batteries while reusing onboard inverters eliminates the need for a power conditioner (PCS) which contributes to reducing costs and helps avoid power loss when converting from AC to DC by PCS, with the aim of improving effective energy use.

The project plans to operate grid storage batteries for recharge and discharge operations, connected to the Chubu Electric Power Grid power distribution system from a facility at Jera’s Yokkaichi thermal power station.

The two companies aim to introduce approximately 100,000kWh of supplied electricity in the mid-2020s, reducing the overall cost of the energy storage system and also contributing to CO2 emissions reduction.