A future study will look at how a Toyota Prius can power a home:

Pull electricity from a Toyota Prius Plug-in to a McMansion, and the lights may go out within a matter of a couple of hours. For a typical Japanese house, though, you’d be taken care of for the better part of a week.

Toyota said it will start testing a vehicle-to-home (V2H) system with the Prius Plug-in in Japan by the end of the year. The trial will involve a two-way power-supply system in which the car could supply the home with power in the event of a black-out. About 10 Toyota City homes will be involved in the testing.

The Japanese automaker says a fully-charged, filled-up Prius Plug-In can supply a typical Japanese house with 10 kilowatts, or enough for about four days. In addition to supplying power to blacked-out homes, the car will eventually be able to power up emergency shelters and other buildings.

Last August, Nissan started testing a similar system with its battery-electric Leaf, which the automaker said could provide about two days electricity for an average Japanese home when the car is fully charged. Nissan said it intended to commercialize the system, but didn’t provide further details.

So, if you are really worried about your power supply, one option is to buy a Toyota Prius and purchase a Japanese-sized home. Figures from 2003 suggest the average Japanese home has about 1,021 square feet. Or, you could go further: pair a Prius with a Japanese or American “tiny house” and have power for even longer!

In the long run, is having the Prius help power your home (or other objects) a greener outcome?