The hot springs at Tsuchiyu Onsen are beloved by bathers but also power a small geothermal plant, making use of an abundant yet barely tapped green energy source in Japan. Although the country dotted with active volcanoes has the world's third largest potential for geothermal power, the resort town's plant remains a rare example. One key obstacle to developing the industry is objection from the owners of the relaxing natural baths known as onsen, a major tourism draw across Japan. IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES