Three teams of engineers are locked in a race to harness what may be the most powerful form of green energy: swift tidal currents and battering waves, the power of the oceans. Each team believes it can solve a portion of the world's energy needs. They're testing three different machines designed to be placed in the water and convert oceanic energy into electricity. But getting the machine from the design stage to implementation is a difficult challenge and now each team prepares to install their systems and turn them on for the first time. If they succeed, they could radically change the way we power our planet. (thetvdb.com)