The Niigata Prefectural government announced on April 7, 2010, that it will conduct an experiment involving a geothermal binary-cycle power generation system at Matsunoyama Onsen – a hot spring resort area in Tokamachi City. This power generation system will be jointly tested by the Geothermal Energy Research & Development Co. (GERD) and the New Energy and Industrial Technology Development Organization (NEDO) as a three-year project from fiscal 2010. This project will be conducted in coordination with the Ministry of the Environment. These organizations aim to develop, demonstrate and promote a geothermal power generation system with no impact on the hot spring or the local power grid.
The power generation system will be constructed at one of three hot springs located in a hot spring resort called “Taka no Yu,” which opened in 2007. It will apply a binary-cycle power generation system using hot spring water at a temperature of 97.2 degrees Celsius and ammonia water with a low boiling point. Under this system, the water from the hot spring will boil the ammonia water into vapor which will then be directed to a turbine. After being utilized for power generation, the temperature of the hot water will still be around 50 degrees, appropriate for bathing. This is the nation’s first experiment to produce power from a hot spring with a water temperature below 100 degrees Celsius.
The power generator will be a 50-kilowatt micro-turbine developed by NEDO, with annual capacity up to 416,000 kilowatts. GERD and NEDO plan to conduct a development and feasibility study of the system in FY2010, and install and test it from FY2011 to FY2012. During the testing, they will also conduct a series of impact assessments including monitoring of underground water levels and temperatures of neighboring hot springs, and analyze the cause of past changes in water volume.