Underwater kites could bring clean power to Alaska
SRI’s Manta project uses tidal currents to generate reliable power for coastal communities, Energies Media reports.
SRI’s Manta is an underwater kite that “flies” through tidal currents the way a kite rides the wind. A twisted-string tether spins a generator as the kite sweeps outward, letting Manta harvest energy from slow tidal flows, typically too weak for fixed seafloor turbines. Manta’s design offers a simpler, more compact, and less expensive alternative than today’s tidal technologies.
A prototype in San Francisco drew 100 watts at peak flow, and a pilot now under evaluation is projected to average 1 kilowatt over a full tidal cycle. Under a Department of Energy contract, the Manta team’s current trial is with the Metlakatla Community in Alaska, one of many remote villages that rely on costly, carbon-heavy diesel. For a community that needs reliable power for lighting, refrigeration, and communication, a small, portable kilowatt-scale device like Manta is a practical fit. A full efficiency analysis is expected by the end of 2026.