| Abstract |
Estimated theoretical potential of geothermal energy in Japan to a depth of 3 km is 20 GWe. or larger. However the present total capacity of geothermal power plant is merely 517.8 MWe and there opened no new geothermal power plant for more than a decade. It is mainly due to lack of economic competitiveness with other power sources and of social systems which limits geothermal development. However after the nuclear accident in March 2011, the government re-started giving incentives for geothermal development, such as financial supports for exploration drillings and PA activities, cost incentives by FIT price, and mitigation of constraints in national parks. A guideline for geothermal drilling license was also newly authorized, which may shorten the period taken for drilling permission. Such supports by the government encouraged new geothermal exploration activities by private sectors as well as quick installation of small binary systems. As of year 2014, over forty prospects are under exploration or development; nineteen prospects over 10MW, seven prospects from 1 to 10 MW, and eighteen prospects under 1 MW. Seven small binary systems (0.003 to 2 MWe) are installed in years 2013 and 2014. Although expansion of ground source heat pump (GSHP) systems is rather slow, the number of installation is multiplicatively increasing these years. The total installation number in Japan in 2014 is around 1,000. On the other hand, conventional direct use in Japan is rather stable, allowing dominant part to be bathing. |