SeattleA seafloor geothermal plant ran net-positive for 8.7 seconds.

Tonga runs its grid on imported diesel, which has soared in price since the Iran war began.

Fluid venting at 281°C spun the turbine to 26,000 rpm before a battery software fault and a leaking cable ended the run.

Stanford professor Roland Horne says subsea geothermal “would undoubtedly be more expensive than to do it on land.”

Endurance Energy runs an upgraded plant next winter, then plans its first commercial deployment, off Tonga, in 2027.

How each outlet framed it
Ars Technica
weighs subsea geothermal against Pacific island oil-import costs, quoting the CEO that the approach is feasible but more expensive

Sources: Ars Technica