Preliminary Resource Assessment of Hot Spring Power Generation in Japan

Abstract

The Kalina cycle power generation system with the ammonia-water solution has expanded the geothermal power generation to the low-temperature hydrothermal resource region such as the hot spring water. Taking account for such the current low-temperature power generation system, a preliminary resource assessment of the 4,536 hot spring data in Japan is done. A map of the thermal output of the hot springs gives valuable aspects distinctive from the map of the discharge temperature, and suggests many candidate areas for the future small-scale geothermal power development not only from the volcanogenic hot springs but also from the non-volcanogenic hot springs. The total thermal output exceeding 25 °C from these hot springs in Japan is calculated to be 4,557 MWt. If the total recovery factor of energy from the Kalina cycle is assumed to be 5 %, the electricity generation of 228 MWe can be roughly estimated from these hot springs in Japan.