| Abstract |
Environmental benefits have been discussed and quantified according to the investigation on the environmental barriers and necessary innovations for geothermal development and utilization based on inquiry result from eastern and southeastern Asian countries (China, Indonesia, Japan, Korea, Malaysia, Philippines, Thailand, and Vietnam), which had been conducted under an ERIA geothermal project. Mitigation of CO2 is one of the most important environmental benefits of the geothermal power generation and also utilization of ground source heat pump (GSHP) systems. Mitigation of urban heat island effect and saving in land use are other environmental benefits. Additional target installed capacity for geothermal power generation by 2025 was setup first considering barriers and necessary innovations for each country as described in Yasukawa and Anbumozhi (2018). Additional target installed capacity for GSHP systems is also suggested for China, Japan, and Korea, where GSHP utilization is most active among those countries shown above. Then we tried to quantify the environmental benefits, especially for CO2 reduction by the additional capacity. For geothermal power generation, it is assumed that the current electricity mix in each country will continue in the near future. Then, CO2 mitigation by substituting geothermal for other energy sources is calculated keeping the balance of the rest of energy sources, unless specific condition of the country is described. For GSHP, net CO2 reduction compared to conventional air conditioner for heating and cooling and to oil boiler for heating was estimated. Consequently, a total of 3,829 Mtons/yr of CO2 emission can be reduced annually by additional geothermal power plants from those 8 countries, and 320 and 1,451 ktons/yr of CO2 can be reduced by GSHP systems in Japan and Korea, respectively. Although geothermal power has a significant environmental benefit in a global scale, it locally gives an environmental impact as well. Minimizing the environmental impact of geothermal development while maximizing the environmental benefit is quite important. Thus a strategy to maximize the environmental benefit of geothermal use in balance with the local environmental impact is suggested in this paper. |