Tidal Barrage

A tidal barrage is a dam like structure built across a bay or river mouth that generates electricity from the rise and fall of the tides, opening sluice gates to let water flow in as the tide rises and again as it flows back out at low tide, with turbines mounted in the sluices spinning as the water passes through in either direction. Modern industrial scale tidal barrages date to the 1960s: the Soviet Union 1.7 megawatt Kislaya Guba plant and, far larger, France 240 megawatt La Rance barrage, which has generated power continuously since November 1966. La Rance held the record as the world largest tidal barrage for 45 years, until South Korea 254 megawatt Sihwa Lake facility began operating in 2011. As of 2024, La Rance has run for nearly six decades, has long since repaid its own construction cost, and tidal barrage power there now costs less to generate than power from nuclear or solar plants, even though few tidal barrages have been built anywhere else in the world.