Mitsui Fudosan has completed drilling a coaxial double-pipe well in Ibusuki and plans to conduct a demonstration in fiscal 2027-28, targeting commercialisation in fiscal 2029. Taisei Corporation launched a feasibility study in September on geothermal power generation using CO2 as a heat-transfer medium.
Japan's geothermal resource potential is estimated at approximately 23.47 million kW, ranking third in the world, while geothermal power accounts for only about 0.3% of domestic power generation (fiscal 2022). The introduction of next-generation geothermal technologies has faced challenges for many years. The government has set out a policy targeting the start of operations in the 2030s, with 1.4 GW to be installed by 2040 and 7.7 GW by 2050.
Mitsui Fudosan and others have completed drilling a coaxial double-pipe well at Medipolis in Ibusuki and plan to proceed with a demonstration of a system that circulates water without using hot water from underground. Construction is scheduled to begin in the second half of fiscal 2026, followed by a demonstration in fiscal 2027-28, with commercialisation targeted as early as fiscal 2029. This could become Japan's first demonstration of its kind.
In September 2026, Taisei Corporation launched a feasibility study to assess the potential for geothermal power generation using CO2 as a heat-transfer medium. The method circulates supercritical CO2 underground to recover heat, with the dual aim of storing CO2 and exchanging heat. The company will next organise the technical challenges, estimate power-generation costs and develop a commercialisation roadmap.
The two companies differ in that Mitsui Fudosan is advancing a demonstration of a system that does not use hot water, while Taisei Corporation is conducting a long-term technical assessment using CO2. Both companies share the view that external factors, including the development of transmission networks and regulatory arrangements, will also affect the expansion of geothermal power.