Study on Shallow Geothermal and Hydrogeology at Fukushima Renewable Energy Institute, AIST

Abstract

Ground-Source Heat Pump System (GSHP System) has been increasing in Europe and the United States when the oil shocks of the 1970’s occurred. Initial cost of the GSHP System in Japan, however, is higher than that of air-source heat pump system, therefore, such systems are not quite increasing in Japan. One of the causes is that thickness of Quaternary system in Japan is different from continental countries. Most of the topography of major towns in Japan is alluvial plain or basin, therefore, basement of Quaternary system is deeper than that of continental countries. Thickness of Quaternary system in Kanto Plain, the largest plain in Japan, is estimated deeper than 3000m. Quaternary system has high value of hydraulic conductivity and includes fine aquifers. Subsurface thermal regime is affected not only by thermal conduction but also by advection owing to groundwater flow. The effect of thermal advection is especially large in shallow sedimentary layer with active groundwater flow. This paper introduces some research in GSHP System considering evaluation of potential for GSHP System based on hydrological data at Fukushima Renewable energy Institute, AIST.