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CT: Marine current turbines: Pioneering the development of marine kinetic energy converters.
This paper gives the rationale and background to an already advanced research and development (R&D) programme aimed at developing technology for the commercial exploitation of kinetic energy from marine currents. This is followed by a brief overview of the characteristics of the tidal stream resource, the technical principles by which it may be exploited, and the key technical challenges that need to be overcome.
The paper includes a description of the pioneering ‘Seaflow’ Project involving the installation and testing, since May 2003, of a prototype 300 kW tidal turbine 3 km off Lynmouth. The next stage of Marine Current Turbines Ltd’s R&D programme is then described: this involves the development of a 1 MW twin axial-flow rotor system, called ‘Seagen’ which is planned for installation early in 2007. The installation and testing of ‘Seagen’ will mark a landmark stage in the R&D programme because it will form the basis for the commercial technology to follow. A brief outline of future plans beyond ‘Seagen’ is also given.
S: http://pia.sagepub.com/content/221/2/159.short (last access: 12 February 2014)
N: 1. Marine current energy is one of the most exciting emerging forms of renewable energy. Marine currents, unlike many other forms of renewable energy, are a consistent source of kinetic energy caused by regular tidal cycles influenced by the phases of the moon. Intermittency is a problem for wind, wave and solar power as the sun doesn’t always shine and the wind doesn’t always blow. These sources of renewable energy often require backup from traditional forms of power generation. However, the inherent predictability of tidal power is highly attractive for grid management, removing the need for back-up plants powered by fossil fuels. Tidal turbines are installed on the seabed at locations with high tidal current velocities, or strong continuous ocean currents where they extract energy from the flowing water.
2. Tidal turbines are very much like underwater windmills except the rotors are driven by consistent, fast-moving currents. The submerged rotors harness the power of the marine currents to drive generators, which in turn produce electricity. Water is 832 times denser than air and consequently tidal turbine rotors can be much smaller than wind turbine rotors thus they can be deployed much closer together and still generate equivalent amounts of electricity.
Devices that harness marine current energy present a unique set of engineering challenges in terms of design, installation and maintenance. During operation, the force of the tidal flow in Strangford Lough is equivalent to a 345 mph wind generating 100 tonnes of thrust on the rotors.
S: 1 & 2. http://www.marineturbines.com/Tidal-Energy (last access: 12 February 2015).
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