Just a bit more info on the the Pelamis: It is a semi-submerged, articulated structure composed of cylindrical sections linked by hinged joints. The wave-induced motion of these joints is resisted by hydraulic rams, which pump high-pressure oil through hydraulic motors via smoothing accumulators. The hydraulic motors drive electrical generators to produce electricity. Power from all the joints is fed down a single umbilical cable to a junction on the seabed. Several devices can be connected together and linked to shore through a single seabed cable.

This device is known as a “point absorber” and can effectively focus energy from a wide area by interacting with an area of waves much larger than its physical size. As it is flexibly moored, it swings head-on into the incoming waves and can therefore span successive wave crests.