With environmental issues such as global warming and the current trend of inconsistent oil prices, it has become imperative to draw our focus onto other forms of energy such as wind power and tidal power. Tidal power can be consistent and predictable if the marine turbine is installed in locations with high tidal ebb and flow or strong ocean currents.
There are many marine turbines currently being developed and the prototypes are mostly built with conventional materials. Currently, on a few marine turbines, the only application of composite materials is on the rotor blades. The only commercial scale tidal turbine to be installed has rotor blades made from composite materials.
There is a wide scope for using composite materials on other parts of a marine turbine. One of the main advantages of composite materials is the ability to choose the material, laminate and manufacturing method to suit the design requirements.
The turbine’s rotor fits inside the turbine stator and a tight tolerance is required between the rotor and the stator. To obtain maximum efficiency, a small gap with high circumferential tolerance had to be maintained between the rotor and the stator during operation. Hence an accurate shape is required to maintain this tight tolerance and can be achieved by using composite materials and a mould.
The high strength to weight ratio and high stiffness to weight ratio of composite material makes it an ideal for underwater turbine. Excellent geometrical tolerance can be achieved with composite materials. Structures with complex shapes and geometry can be made relatively easily. Due to the environment in which an underwater turbine operates in, the corrosion resistance of composite materials is an important feature. Composite materials are also resistant to marine boring organisms. With composite materials the designer has the freedom to choose the materials, laminate and manufacturing method to suit the design requirements. This means a more optimized structure can be designed.