ThinkGeoEnergy’s annual Global Top 10 Geothermal Countries report shows global installed geothermal power capacity reaching 17,173 MW by year-end 2025, with total additions of 223 MW during the year and additional net gains driven by data corrections. Geothermal power generation was active in 35 countries worldwide, though development remains highly concentrated, with the top ten countries accounting for more than 93 percent of global installed capacity.
The United States maintained its position as the world’s largest geothermal producer, while Indonesia led new capacity additions in 2025. Growth across most markets was driven by incremental expansions and optimization of existing fields rather than large greenfield developments. At the same time, advanced geothermal research efforts—including work underway at Utah FORGE—continue to lay the groundwork for next-generation geothermal technologies that are not yet reflected in installed capacity figures.
Looking ahead, global geothermal growth is expected to remain gradual through 2026, with more significant capacity increases likely beginning in 2027 as advanced geothermal projects move beyond pilot stages and into commercial deployment.