Seite - 147 - in Water, Energy, and Environment - A Primer

maybebroughtdowntocompetitivelevels.Forexample,ithasbeen proposedthat tidalpowergeneratorsbeattachedtothestructuresof existingbridges, thusminimizing infrastructurecosts. 8.7.3.2 History Historically, tidal power is not anew technology. Incominghigh tidewaterwas impounded as far back asRoman times, and then was used to turnwaterwheels to grind grain. Using impounded water for electricity generation was first achieved by the 240MW La Rance Tidal Power Plant in France in 1966. It remained the largest tidal power station until 2011 when the 254 MW Sihwa Lake Tidal Power Station went on line in SouthKorea. Today, smaller tidal power plants exist in Canada (20MW), China (3.2 MW), Russia (1.2 MW), Ireland (1.2MW), the Netherlands (1.2MW), and the US (1.05MW). More are under construction or being planned by several countries, includingSouthKorea,Scotland,EnglandandIndia. 8.7.3.3 Environmental impacts In-water turbinescaninjureorkill sealife, thenoisefromturbines candisruptsea-lifepatternsandsedimentprocesses,andinstalling a barrage can change shorelines, affecting local ecosystems and shipping lanes. 8.7.4 Ocean thermalenergyconversion (OTEC) OTECwas first demonstrated in the 1880s and continues to be of interest today. The world currently has only two operating OTECpower plants, both in Japan. OTEC uses the temperature difference between cooler deep and warmer shallow or surface ocean waters to run a heat engine and produce useful work, usually in the form of electricity (57). It is a baseload technology that allows for production of electricity on a constant basis. However, the Renewableenergy 147