The Creation of the 2,200-m-deep Reservoir at Hijiori HDR Test Site

Abstract

Hot dry rock power generation, like other geothermal power generation concepts that use ordinary geothermal steam and hot water , exploits underground geothermal energy for electric power generation . However , conventional methods cannot use underground heat of even very high temperature if very little or no natural steam or hot water exists in the ground , because such natural steam water is indispensable for conveying the heat to the surface to drive a generator . On the other hand , a hot dry rock system needs no natural steam or water . Hot dry rock power generation is thus a novel concept of using geothermal energy that has never been used before. In hot dry rock power generation system , water is injected at a high pressure into an injection well that penetrates into high-temperature rock . Thus , a set of fractures is created artificially in a basement rock to from an artificial geothermal reservoir in a region between production well separately drilled nearby . Then , water is injected into the injection well and flows though the artificial reservoir . After being heated , it extracts the heat energy of the hot dry rock in the form of either steam or hot water though the production well to the surface for power generation.