Over in Japan, automakers are looking at turning electric and hybrid vehicles into external power sources for the home, aiming to turn them into a type of rolling battery, the Nikkei reports. The push has been strengthened by such assistance provided by these green cars, which helped supply emergency power in areas during the March earthquake that hit Japan, the report says.

Nissan says that electric vehicles can be used as storage batteries and supplementary power sources, and the company is working to equip its Leaf EV with the ability to feed power into homes. The car can for example be used as an emergency power source during a power outage, utilising the electricity stored in its battery overnight to be used in the house during the day. Fully charged, the Leaf’s 24 kwh lithium-ion battery can power the average house for about two days.

Mitsubishi Motors, meanwhile, plans to market an optional device that will enable its EVs to supply electricity to rice cookers and other home appliances. It plans to make the device compatible with all its eco-friendly vehicles, including the i-MiEV and eight new EV and plug-in hybrids it is planning to introduce over the next five years.

And Toyota is mulling over the inclusion of a power supply function on its future eco cars, including the Prius hybrid and the upcoming plug-in hybrid it is launching next year. Conversely, there’s already a home battery system – the Smart Energy Veus – that can be used to power a Prius, with some conversion work.

Elsewhere, Honda and the city of Saitama have embarked on the E-KIZUNA Project, and as part of this will construct a house to test its Honda Smart Home System, which will feature electricity generated from solar panels, storing the power in an EV and using it in combination with electricity supplied off the grid. It will also explore the system’s potential to independently produce electricity for the household in the event of a disaster.

There’s still a fair way to go before such practice becomes the norm – utilising electricity from EVs and hybrids to power homes will require utilities to modify their power lines, and new legislation concerning electrical equipment will also be required.