Endurance Energy Demonstrates Subsea Geothermal Power at Axial Seamount
Photo by Piotr Kowalonek on Pexels
Demonstration Overview and Deployment Logistics
Endurance Energy has conducted an end-to-end demonstration of subsea geothermal power using its prototype plant, Adélie, at Axial Seamount. The three-week deployment was carried out 300 miles off the Oregon coast at an ocean depth of approximately 5,000 feet (1,524 meters). Drilling equipment for the operation was deployed from the vessel Ocean Guardian, which is operated by Stabbert Maritime.
Subsea Well Drilling and Thermal Conditions
To access the geothermal resource, a subsea lander drill bored two holes spaced less than 2 feet apart. The team completed a 52-foot (16-meter) cased and cemented geothermal well, which was capped with a valve. Hydrothermal fluid venting from the completed well flowed at a measured temperature of approximately 260°C (500°F).
Power Generation and Remote Operation
On September 27, 2026, the Adélie prototype plant successfully generated net-positive electricity on the active underwater volcano. The demonstration produced net-positive electricity for less than 10 seconds during the test. Operational control of the power plant was managed in real time from Seattle over subsea fiber via the National Science Foundation's Regional Cabled Array.