Where old batteries may go to die

One of the environmental quandaries that owners of electric cars may soon face is what to do with expensive rechargeable batteries that have reached the end of their useful life within the vehicle.

Dumping them in the nearest landfill would surely be distasteful to most of the car manufacturers' existing and potential customers, so the car companies are teaming up with electricity experts to develop more palatable solutions.

This week,

, the California electric car maker that is

, and the US solar services company

announced a

with the

, to investigate the possibilities of using outdated Tesla car batteries to store excess power output from photovoltaic (PV) installations for later use during peak demand periods.

"Battery storage will be an important component in the mass adoption of PV. It will make solar electricity a more predictable energy source," said Peter Rive, the chief operating officer of SolarCity.

If such an after-market for the pricey lithium ion battery packs could be developed, it would also provide a financial incentive for environmentally conscious consumers to buy electric vehicles in the first place. At US$8,000 to $18,000 (Dh29,360-66,060) apiece, batteries can account for up to one-third of the total cost of the car.

In a similar vein, the US car maker

(GM) and the Swiss power, automation and engineering group

announced a

to investigate the potential of reusing spent battery packs from GM's electric car, the

, to provide "cost-effective energy storage capacity" that could be integrated into so-called smart grids to improve the efficiency of electricity systems.

"Future smart grids will incorporate a larger proportion of renewable energy sources and will need to supply a vast e-mobility infrastructure - both of which require a wide range of energy storage solutions," said Bazmi Husain, the head of ABB's smart grids initiative.

GM said the Volt's battery would retain significant capacity to store electricity even after powering a car for several years.

"That's why we're joining forces with ABB to find ways to make the Volt batteries provide environmental benefits that stretch beyond the highway," said Micky Bly, the car maker's executive director of electrical and hybrid systems.

Last week,

and the Japanese industrial group

to research "second-life" uses for batteries powering the

electric car.

Besides storage for renewable energy and smart grids, possible uses include providing back-up power for buildings, factories and critical medical or computer equipment in the case of power disruptions.

GM and Nissan both guarantee the batteries for their electric vehicles for eight years or 160,000 kilometres of use. After that, the battery starts to deplete, significantly reducing the car's range. Nevertheless, it may still have 50 to 70 per cent of its useful life remaining if deployed in stationary applications.

But consumers should be forewarned: The cost of batteries for electric cars

in coming years, so used batteries may not be worth much.