Harnessing wave energy. 1891 illustration of the wave-powered pumping station built at Ocean Grove, New Jersey, USA, in the 1880s. This is using waves from the Atlantic Ocean to pump water to the top of the 12-metre-tall water tower. Wooden flaps (below the jetty to the right of the water tower) are moved by the waves. This moves the pistons of the pumps that move water to the top of the tower. Details of the system are illustrated across top. The flaps are nearly 2 metres across, and long enough to remain in the sea at both low and high tides. Even on a calm day, the system provided enough power to maintain water pressure in the surrounding area.