| Abstract |
Geothermal power production in Japan has begun since 1967 and its installed capacity reached to 531 MWe in 2000 with 17 units and 540 MWe in 2010 with 20 units. After implementation of geothermal FiT in 2012, the number of units has rapidly increased and has been doubled by 2016 and tripled by 2017 (69 units at February 2018). However, most of these new units are quite small ranging from 10 kWe to 5 MWe with an average of 0.5 MWe. Thus, capacity increase by these new units is merely 24.4 MWe in total. Moreover in recent years, several old geothermal plants renewed their generators with smaller units, result into decreasing power capacity of 68.2 MWe. As result, it is 43.8 MWe of decrease from 2010 to February 2017. Nevertheless, two new large power plants will begin operation in 2019, adding 49.5 MWe so the expected power capacity in 2020 is approximately 546 MWe. Since many other fields are under exploration by private sectors, we may expect more increase by 2030. The number of ground source heat pump (GSHP) installation is multiplicatively increasing these years. The total installation number in Japan in the end of 2015 is 2,230 with total capacity of 134 MWt. Annual heat use (geothermal contribution) is estimated to be 162.2 GWh. Annual installation number is approximately 300 in year 2015. Note that cooling function of GSHP is even more important than heating in terms of energy saving, which is estimated to be 305.9 GWh a year. Conventional direct use in Japan is rather stable. Its dominant part has been bathing, but the number of visitors and total flow rate of these geothermal bathes are both gradually decreasing with peaks in 2002 and 2007, respectively. On the other hand, the number of other direct use facilities are slightly increasing due to subsidy from the federal government to promote geothermal energy use. |