Endurance Energy Tests Subsea Geothermal Power Plant at Axial Seamount

First Subsea Geothermal Test Completed

Endurance Energy, a Seattle-based startup, successfully conducted the world's first demonstration of a subsea geothermal power plant. The three-week test deployment of a 3-ton prototype took place in September at the Axial Seamount in the northeast Pacific Ocean, approximately 5,000 feet (1,524 meters) below the surface.

Technical Feasibility Demonstrated

During the test, the prototype generated net-positive electricity for less than 10 seconds. This brief generation period served as a proof of concept, demonstrating the technical feasibility of harnessing geothermal energy from active underwater volcanoes. The deep ocean environment provides consistent cold seawater for cooling and maintains system pressure, allowing for compact plant designs.

Future Commercialization Goals

Endurance Energy plans to commercialize subsea geothermal power, targeting Pacific island nations and other regions seeking alternatives to imported fossil fuels. The company must still demonstrate consistent underwater operations and prove the cost-effectiveness of the approach, as subsea geothermal projects face different challenges and potentially higher costs compared to land-based systems.

Deep Sea Drilling Operations

The deployment involved a subsea lander drill, operated from the ship Ocean Guardian, to create two holes in the seafloor. The drilling occurred at a depth of about 5,000 feet, which is more than 2.5 times the height of the One World Trade Center building.