Tidal Power

2398 WordsApr 23, 201110 Pages
Engineering Design for Sustainability TIDAL WAVE ENERGY Introduction Tidal power is a form of energy which derives directly from the relative motions of the Earth/Moon system, and to a lesser extent from the Earth/Sol system. Tidal energy is gained from the exchange of large bodies of water. Changes in water levels, and associated tidal currents, are due to the gravitational pull of the Sun and Moon. This makes Tidal Power completely predictable; furthermore, because it is created by relative motion of the special bodies, it is in-exhaustible. Therefore Tidal power is much more reliable than other renewable sources such as wind or solar power and will long outlast fossil fuels. Tidal Power in the UK It is estimated that tidal power…show more content…
At high tide sea water flows into the reservoir through a one way gate. The gate closes when the tide begin to fall and when the tide is low enough, the stored water is released at pressure through turbines, back into the sea. The rotation of these turbines generates electricity. The first commercial-scale tidal generating barrage rated at 240 MW was built in La Rance. There is smaller plant in Nova Scotia, rated at 20 megawatts (enough power for 4,500 homes). The Dam for the tidal power plant on the estuary of the Rance River, Bretagne, France The viability of Barrage systems has been questioned due to high civil infrastructure costs and environmental issues. Although this method have proven very durable, barrage-style power plants are very expensive to build and are fraught with environmental problems from the accumulation of silt within the dam catchment area (requiring regular, expensive dredging). There are only a few potential sites across the globe and there are only three functioning plants worldwide (Rance River, Bay of Fundy and Kislaya Guba). Tidal Stream Systems Engineers have created two new kinds of devices to harness the energy of tidal currents and generate renewable, pollution-free electricity. These are: Vertical-axis and Horizontal-axis models. They are determined by the orientation of a subsea, rotating shaft that turns a gearbox linked to a turbine with
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