Japan builds a head of steam for an alternative to nuclear

Spread over a hillside high above this city lies Ogura, a quiet neighborhood of single-family homes and traditional inns. White plumes of steam billow from dozens of metal chimneys that sprout from rooftops across the neighborhood, fed by the hot springs that lie underground and pipe scalding spring water into baths known in Japan as onsens.

When Kazunori Ueda sees this steam, he doesn’t think of a two-hour soak in a tub (not that he minds taking one). He sees untapped geothermal energy that can help power Japan, an industrial nation that relies on imported fossil fuels to keep the lights on, all the more so since the 2011 Fukushima nuclear-reactor meltdown.

Mr. Ueda is in Ogura and is building another one in the nearby neighborhood of Horita. The generators are small, about 70 to 110 kilowatts each, but represent a modest geothermal boom in Japan, with support from a government mindful of the backlash against nuclear power.