Sansui Geothermal Power Plant begins operations in Kumamoto- Renewable energy made possible with hot spring operator together with local and global partners

April 26, 2022

Baseload Power Japan in collaboration with Furusato Power generation and Ryokan Sansui begin operations of 99 kW Sansui Geothermal Power Plant.

The first power plant is in the foreground (center), the second power plant is in the back (right of center). The hot spring well is to the upper left. The steam obtained from one hot spring well is transported to the two generators.

The Sansui Geothermal Power Plant generates electricity by utilizing steam from an existing hot spring well to turn turbines (manufactured by Climeon, Sweden) at two locations. The annual power generation is estimated at 700 MWh, which is equivalent to the annual power consumption of roughly 200 households.

The electricity generated will be sold to Kyushu Electric Power through a feed-in tariff (FIT) mechanism. In addition, the surplus of hot water, both hot spring water from the source and water from condensed steam used in the power generation process, will be provided to Ryokan Sansui to be utilized as bath water.

Development of the new power plant was led by Baseload Power Japan in collaboration with Furusato Power generation and Ryokan Sansui. The goal is to produce clean, sustainable power that generates income for local residents. Moreover, the electricity sold supports the “RE100 hot spring inn geothermal power generation project” a nation-wide initiative, promoted by Kyushu Electric Power.

Utilizing a local, sustainable resource

Japan is rich in geothermal resources and hot springs are an integral part of Japanese culture. Today there are roughly 20,800 hot spring facilities operating in Japan. Geothermal hot springs account for 90% of the heat used by such facilities – benefitting local operators and hot spring enthusiasts alike.

Binary geothermal power generation

Binary geothermal power generation is the process of evaporating hot water and steam from hot spring wells to turn a turbine. Beyond the fact that the energy produced is a non-polluting renewable resource, the surplus of hot water used in the power generation process can be provided to the hot spring facility for bathing.

Toward carbon neutrality

The Japanese government has committed to carbon neutrality by 2050 and expanding the use of renewable energy is central to achieving that goal. Geothermal power generation, which can be sourced and consumed locally, will become an increasingly important part of the country's energy mix. While Japan is estimated to have the third largest geothermal resources after the United States and Indonesia, the ratio of geothermal power generation in the county stands at only 0.2%. 

Baseload Power Japan, Representative Director Ryuta Hiratsuka says, "By constructing and operating power plants to take advantage of Japan's abundant geothermal resources, we want to promote the increased use of renewable energy while revitalizing local communities."

The role of renewables in society

With Japan's aging and declining population, especially in rural areas, it has become difficult for some hot spring owners to maintain their facilities. Moreover, the covid-19 pandemic has hurt business in these regions.

Furusato Power generation, CEO Kazuyuki Akaishi says, "Together with hot spring inns we can generate geothermal energy, helping revitalize the region while providing a new source of income for the inn operators. I would like to see such efforts made nationwide."

A region rich in renewables and tourism

Ryokan Sansui is part Waita Onsenkyo, an area of Kumamoto prefecture consisting of many popular hot springs. Like other rural parts of Japan, the area is experiencing depopulation and the elderly now make up 50% of the 7,000 population. The first geothermal power plant in the area went into service in 2015. Since then, more geothermal plants have been constructed, including hot spring binary power generation plants. With further development of geothermal power in the region, Ryokan Sansui and other hot spring operators show optimism for the future.


About Baseload Power Japan

Baseload Power Japan is a wholly owned subsidiary of Sweden-based geothermal investment company Baseload Capital. Founded in 2018, Baseload Japan works with local communities and power companies to license, build and operate geothermal power plants. Our vision is to realize a planet in balance with societies that run on renewable energy.

About Furusato Power generation

Furusato Power generation Co., Ltd. develops and operates geothermal power generation and is based in Kumamoto prefecture. Together with Baseload Power Japan, the company is operating its first geothermal binary power plant which utilizes the surplus hot water as a power source.

About Ryokan Sansui

Ryokan Sansui is a hot spring inn located in Kuammoto prefecture and one of the six hot spring areas belonging to Wata Onsenkyo. Ryokan Sansui boasts 10 types of hot springs on the premises, including mixed bathing, open-air and cave baths.



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