NASA demonstrated a small underwater vehicle that is able to supply itself with energy. To generate energy, the vehicle uses temperature differences in the ocean. A remarkable technology.

The underwater vehicle is called SOLO-TREC and was developed during a five year research period. The technology is cutting edge; a wax-like material on the outside of the SOLO-TREC reacts to temperature differences. The material constantly shrinks and expands. When the material expands an oil resevoir is pressurized causing the hydraulic motor to fire up. This motor charges the batteries. Simple eh?

The SOLO-TREC technology generates enough energy to power the vehicle and all research equipment on board. Over the last few months NASA did over 300 test dives. When diving to a depth of 500 meters the SOLO-TREC generates over 6100 joules. In theory, this underwater machine could go on forever.