separsons writes "A team of scientists recently created the world's first underwater robotic vehicle powered entirely by renewable ocean thermal energy. Researchers from NASA, the Scripps Institution of Oceanography and the US Navy developed Sounding Oceanographic Lagrangrian Observer Thermal RECharging (SOLO-TREC), an autonomous robot that runs on a thermal recharging engine. The engine derives power from the natural temperature differences found at varying ocean depths. SOLO-TREC produces about 1.7 watts of power each dive, enough to juice the robot's science instruments, GPS receiver, communication device, and buoyancy control pump. SOLO-TREC is poised to revolutionize ocean monitoring; previous robots could spend only a limited amount of time underwater because of depleting power sources. SOLO-TREC can stay beneath the surface of the waves for indefinite amounts of time. Based on SOLO-TREC's success, NASA and the US Navy plan to incorporate thermal recharging engines in next-generation submersibles."