An unusual wave-power system that pumps high-pressure water to an onshore hydroelectric plant recently began feeding electricity into the U.K.’s national transmission system. The 315 kW “Oyster device” is the world’s only functioning hydroelectric wave-powered plant, claims its Edinburgh-based developer, Aquamarine Power Ltd. Slide Show Photo: Aquamarine Power Ltd. The 200-tonne 315-kW wave-power device was installed in Scotland for six months of full-scale demonstration trials. Related Links: Wave Power: Swells Drive Onshore Generator Finland’s WaveRoller Has Seabed Generator Oyster’s hydraulic pumping power is generated at the hinge of a seabed-mounted flap that moves with waves. The 10-m-long by 18-m-wide steel
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.