The Aguçadoura Wave Farm was a wave farm located 5 km offshore near Póvoa de Varzim north of Porto in Portugal. The farm was designed to use three Pelamis Wave Energy Converters to convert the motion of the ocean surface waves into electricity, totaling 2.25 MW in total installed capacity. The farm was officially opened on 23 September 2008, by the Portuguese Minister of Economy.
Waves are generated by wind passing over the sea's surface. As long as the waves propagate slower than the wind speed just above, energy is transferred from the wind to the waves. Air pressure differences between the windward and leeward sides of a wave crest and surface friction from the wind cause shear stress and wave growth. Wave power is distinct from tidal power, which captures the energy of the current caused by the gravitational pull of the Sun and Moon. Other forces can create currents, including breaking waves, wind, the Coriolis effect, cabbeling, and temperature and salinity differences.
Developed by the Scottish company Pelamis Wave Power, the Pelamis machine is made up of connected sections which flex and bend relative to one another as waves run along the structure. This motion is resisted by hydraulic rams which pump high-pressure oil through hydraulic motors which in turn drive electrical generators. The three machines which made up the Aguçadoura Wave Park were each rated at a peak output of 750 kW, giving an installed peak capacity of 2.25 MW, enough to meet the average electricity demand of more than 1,500 Portuguese homes. The average output from a Pelamis machine will depend on the wave resource in a particular area. The higher the resource the higher the average output. According to information on the Pelamis website, it appears that the average power output for a Pelamis wave machine is about 150 kW.
According to Wikipedia