Tidal turbine blades

Marine current turbines derive their power from the tides, which unlike wind flow, is in two directions only. A major difference is that since water is some 800 times denser than air, the thrust on the blades is so much greater and the blades tend to be shorter and sturdier. The turbines are designed to operate in a current of 4.5 knots (2.3 ms ) but a 1 MW turbine operating at full power would have to withstand some 900 tons s of water passing through its blades, which is indeed onerous [107a]. 

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Abstract This chapter will introduce advances in properties, production and manufacturing techniques of the advanced polymer/fibre composite materials that are utilised in the manufacture of machines that produce sustainable energy. Chapter 19 discussed the various methods of transferring wind, tidal, wave and solar energies into electrical power and this chapter will show how advanced composites are utilised in these various machines. Furthermore, it will suggest methods for the repair, maintenance and recycling of advanced polymer composite wind turbine blades. Finally, the future trends of sustainable energy systems and the role that polymers and polymer/fibre composites will have in their manufacture/fabrication will be evaluated. 

A prototype power station featuring RP blades is running in a northern Norway strait. Hammerfest Strom s 120 tonne submerged turbine uses similar principles to a wind turbine, with 10 m long glass reinforced plastic (GRP) blades capturing the energy of tidal currents. The installation is located in a narrow strait where the current speed is both fast and uniform. 

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