Car batteries could be used to store excess solar energy

The high cost of powerful lithium-ion batteries electric cars  run on could be  offset their cost by earning money for their owners, reports Helen Knight in New Scientict.

Electricity companies and car makers are looking  at  using electric cars to store power for the grid (say, on a day of an abundance of solar or wind power on a day of hot sun or gale) when they are in the garage. But all that  additional discharging and charging would shorten the life of the battery.

However, used lithium-ion batteries that no longer hold charge well enough to power a car could provide electricity storage for the grid, says Sankar Das Gupta at battery maker Electrovaya, based in Mississauga, Ontario, Canada.

Once a battery  can only be charged to 80 per cent of its original capacity, its life in the car is over. But it would be fine for  storing energy for the grid.

Gupta’s company is involved in a project with partners including Eric Bibeau at the University of Manitoba in Winnipeg, Canada, in which they will combine used lithium-ion batteries to build a 150 kilowatt-hour prototype storage system.

Hopes for future energy supply are pinned on intermittent sources of electricity generation such as wind and solar power. So it has become more important to be able to store electricity.