Subsea Geothermal Power Systems

Seattle-based Endurance Energy has demonstrated how subsea geothermal power systems can generate electricity using heat from beneath the ocean floor. Its Adélie test plant successfully produced more energy than it consumed, introducing a potential source of continuous electricity that operates independently of weather conditions.

During testing at Axial Seamount, approximately 300 miles off Oregon's coast, the company installed a geothermal well and remotely operated its underwater equipment from Seattle. The system achieved a peak net output of 16.5 kilowatts during an 8.7-second period of positive generation. These results provide valuable information for improving future deep-sea power systems.

Endurance Energy is now developing a 2-megawatt commercial generator and preparing a project in Tonga for 2027. This approach could create new opportunities for coastal electricity markets while helping industrial facilities and communities reduce their dependence on conventional fuel sources.