The first ever subsea geothermal power plant demonstration was carried out near an active underwater volcano nearly a mile beneath the ocean’s surface. Although the system produced net‑positive electricity for less than ten seconds, it proved that extracting renewable energy from the deep sea is technically possible.
The three‑week trial involved a three‑ton prototype that was deployed at the Axial Seamount in the northeast Pacific Ocean during September. Endurance Energy, a Seattle‑based startup, is developing the technology with the goal of bringing subsea geothermal power to Pacific island nations and other markets that rely on costly imported fossil fuels.
“The deep ocean gives us unlimited cold seawater for cooling, and its weight keeps the system and the well pressurized, so our plants can be compact,” said Andrew Redd, founder and CEO of Endurance Energy, in an email to Ars.