Startup taps underwater volcano as energy source in "proof point" test

Generating electricity from deep-sea geothermal vents now works and has generated net-positive power, a critical technical hurdle overcome.

Endurance Energy, a startup, has conducted the world's first demonstration of a subsea geothermal power plant near an underwater volcano. The three-week test deployed a 3-ton prototype power plant, named Adélie, at a depth of approximately 5,000 feet. The test aimed to prove the technical feasibility of generating electricity from hydrothermal fluids. Although the prototype generated less than 10 seconds of net-positive electricity, it achieved a peak of 16.5 kilowatts. The deployment involved drilling two holes in the seafloor and casing one to create a well, though this initial well did not provide sufficient fluid flow. The plant was then repositioned to a natural vent for the net-positive power generation test, which was ultimately halted by a software issue and a subsequent power cable failure. Endurance Energy plans future deployments, including a commercial 2-megawatt generator for the Kingdom of Tonga in 2027, to commercialize this renewable energy source.

This "proof point" test demonstrates the nascent viability of subsea geothermal energy, a renewable source that could significantly alter the energy landscape for coastal nations, particularly those reliant on expensive fossil fuel imports. The technology taps into the constant heat from the Earth's core, offering a potential solution for baseload power that is independent of weather conditions, unlike solar or wind. Endurance Energy's ambition to provide this for Pacific island nations, which often face volatile energy costs, highlights a significant market opportunity. The company's ability to overcome challenges like drilling in extreme environments and managing subsea infrastructure will be key to its future success and influence on global energy diversification.

The successful, albeit brief, net-positive electricity generation from a subsea geothermal source signals a new frontier in renewable energy. While technical and cost challenges remain, especially compared to land-based geothermal, the deep ocean offers a potentially vast and untapped energy resource. The next steps will involve demonstrating sustained operations and cost-effectiveness, particularly as Endurance Energy aims for commercial deployments in places like Tonga. This development could spur further investment and innovation in marine energy technologies, potentially creating new markets and reducing reliance on imported fuels for energy-vulnerable regions.