Energy Efficient Housing Reaches New Heights In Japan

Daiwa House Industry Company in Japan has developed the next generation of energy efficient housing. The homes use rechargeable lithium-ion batteries that produce so much electricity homeowners may end up selling the surplus to the local grid.

At first glance, Daiwa's battery-operated house, with its rooftop solar panels, appears quite conventional.

But inside, this 2600 square foot home in Saitama near Tokyo quickly reveals itself to be a model in energy efficiency.

Daiwa calls it the eco-house. It's connected to the grid, but is designed to provide it's own electricity for 14 uninterrupted hours each day. The difference between this and other solar powered homes is the rechargeable lithium-ion battery that stores the electricity generated each day by the rooftop panels.

The power is distributed throughout the house by a centralized computer system which also keeps the home-owner informed of daily energy usage.

Daiwa's Saeki Yoshinori says the system also offers energy saving suggestions.

[Saeki Yoshinori, General Manager, Daiwa House Industry]:
"Advised by this monitor, residences can choose whether they're going to sell the stored electricity to the local grid or use it up in the house to reduce CO2."

The company believes its energy management system will reduce carbon dioxide emissions by 65 percent. And as the technology improves, it says household electricity bills will disappear entirely.

At a cost of more than $600,000 however, the house is not cheap. But Daiwa says the price of the technology will come down over time and that power storage and management will save homeowners money in the long run.

[Saeki Yoshinori, General Manager, Daiwa House Industry]:
"By enhancing the electricity storing technologies, we would be able to make this house fully self-sustainable with the energy generated in the house in the near future."

Daiwa's Eco-houses are expected to go on sale by April next year.