World's biggest battery will store solar electricity in Japan

The $204 million whopper is part of a renewable energy push.
Written by Mark Halper, Contributor on

Land of the rising battery. Hokkaido, home to the city of Sapporo, is also full of renewable energy projects that could sputter without the giant battery, the Japanese government says. (Click on map to enlarge)

Here's a battery you won't find in your stash of flashlight spares: Japan is spending $204 million to install a whopper that will store photovoltaic electricity at a utility substation.

The country needs the battery in order not to waste the output of new solar farms rising on the northern island of Hokkaido, Bloomberg reports. Hokkaido also has at least one new wind energy project. It is Japan's second largest island, one of its 47 prefectures, and home to the city of Sapporo.

Several accounts including the Japan Times' have described the 60-megawatt hour battery as the world's largest. Last year, Popular Science gave that distinction to a 36-megawatt hour behemoth in China. The Japanese juicer would be nearly twice that size.

Scant details have emerged on the battery's technology. Solar electricity storage is normally associated with solar thermal plants, not with photovoltaic production. Solar thermal systems heat a liquid that helps create steam to drive turbines. Some liquids, like molten salts, can retain heat and thus serve as energy storage.

Photovoltaic systems generate electricity directly, without using turbines. The giant Hokkaido battery will store photovoltaic output.

Bloomberg said the Ministry of Economy, Trade and Industry plans to install the battery by March 2015 as part of a plan "to respond to the high concentration of solar projects in Hokkaido." It noted that "the island's power grids are nearing their limit to handle the influx of clean energy, according to a ministry statement."

Japan lost about 30 percent of its electricity supply when it shut down almost all of its nuclear power stations following the Fukushima tsunami and earthquake over two years ago.

It has been filling the gap with economically and environmentally costly fossil fuel imports. New prime minister Shinzo Abe is pushing to restart nuclear.

Map from Wikimedia

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This post was originally published on Smartplanet.com

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