About 1,100 residents of tourist town Kusatsumachi in Japan held a protest rally against a plan to build a geothermal power generation plant two miles from their famous Kusatsu Onsen (hot springs) resort.

Gathering around the town's symbolic natural thermal well, locals waved fans bearing slogans such as "Geothermal power generation dries up our hot springs," and "Protect Japan's hot spring bath culture."  More than 90 percent of Kusatsumachi residents earn their living from tourism-related jobs.

Natural hot water at the Kusatsu Onsen hot spring resort is scalding hot and cannot be used for bathing. In the town's hot spring baths, a practice called yumomi--stirring up hot water to lower the temperature--is preferred over adding cold water, which thins substances in the hot water believed to be healthful. Ironically, the practice of yumoni eliminates a portion of the heat energy that geothermal power generation would efficiently utilize. In modern geothermal development, steam is turned to water and returned underground for reuse, without negatively affecting nearby hot springs. Reinjection began purely as a disposal method, but has more recently been recognized as an essential and important part of reservoir management.

The earliest geothermal developments did not reinject fluids back for reuse. Initially only 10% was returned to the earth. As a result, in Wairaki in New Zealand for instance -- the second geothermal development in the world -- with only a tenth being returned, the hot pools have been depleted by geothermal drilling.

Japan could more than double its current geothermal electricity supply if it harnessed all the untapped thermal energy from the country's 1,591 hot spots. This can be done while simultaneously protecting hot springs for resorts when the fluids are reinjected after use.

Currently Japan ranks fifth in the world for geothermal power.

Via Yomiuri Online
Photography by Flickr user Marc Veraart