for exploitation of clean energy, more than 90 geothermal power plants have been constructed in japan as well as in 11 overseas countries. all of these plants have earned high reputation among the users. a two-phase flow ......for exploitation of clean energy, more than 90 geothermal power plants have been constructed in japan as well as in 11 overseas countries. all of these plants have earned high reputation among the users. a two-phase flow system and double flash cycle system, developed and employed for the first time in the world, have now become the worlds standard for geothermal power plants. worlds first double flash cycle geothermal power plant (hatchobaru power plant, kyushu electric power co., inc., 55 mw / units) geothermal power plant (iceland reykiavik energy nesjavellir thermal & electric power plant project 30 mw / units) large capacity, two-cylinder turbine for geothermal power generation (sonoma power plant, u.s.a., 78 mw)