Long-Term Prospects of Geothermal Energy Uses and Their Environmental Effects in Japan

Abstract

Long-term prospects of geothermal energy uses in Japan were estimated for sub-divisions, such as power generation, conventional direct use and geothermal heat pump The prospects show possible increases of geothermal energy uses in Japan in years 2020 and 2050, respectively, along three scenarios: 1) Base Scenario, which should be done by efforts of people involved in geothermal businesses, 2) Best Scenario, which may be full-filled if the social system will be supportive for geothermal energy development, and 3) Dream Scenario, which may be realized with drastic breakthrough in technical and/or social systems. In this paper, logical bases in our estimation are presented. The problems that should be solved to realize each scenario is also discussed. As results of calculation for Dream Scenario, in 2050, total power generation of 85.69 TWh/a, contributing 10% of electricity in the nation, and total direct use of 311.6 PJ/a, contributing 7% of heat supply, are obtained. The sum of these energy amounts equivalent to 80.1×109 l of oil, reduceing 61.6×109 kg of CO2 gas emission.