Fibreglass Blades
Fibreglass is a composite material made using a chemical resin in combination with solid fibres, providing superior strength from only a thin layer. Construction methods using composite materials allow the blade weight to be significantly reduced leading to faster start-up and safer operation.
A mixture of resin and fibres are shaped and gradually undergo a 'curing' process to form a plastic polymer with fibres distributed throughout the plastic as a mesh.
A mixture of resin and fibres are shaped and gradually undergo a 'curing' process to form a plastic polymer with fibres distributed throughout the plastic as a mesh.
The mechanical properties of both the plastic and fibres contribute to the overall blade strength, each having an optimal percentage contribution for best results.
There are advantages to using plastic composites for the production of blades and moulds, with some improvements in accuracy for blades that taper and twist.
The increased strength and rigidity of materials maintain blade shape at high velocity and throughout the weathering process. Materials needed for construction are reduced as well as the blade weight.
The increased strength and rigidity of materials maintain blade shape at high velocity and throughout the weathering process. Materials needed for construction are reduced as well as the blade weight.
Appropriate wood types can be used to build wind turbine blades if the correct grain and drying process has been followed, as this provides some confidence that the finished product will be robust.
Wooden blades without twist or taper are fast to manufacture without a large investment in prior planning. Custom taper and twist vs length are possible to construct using wood, although the closeness to the ideal accuracy in the final product can be difficult to assess.
Changes in blade shape, caused by deformation of the wood grain during further moisture losses are made worse by exposure to heat and weather. Inconsistent wood grain properties make hub attachment a larger concern than is immediately apparent, as the wood is smaller at this point and holds both the blade weight and force during operation.
Turbines with a large number of blades or high TSR can be too thin to manufacture from wood, requiring additional coating in fibreglass composites.
Turbines with a large number of blades or high TSR can be too thin to manufacture from wood, requiring additional coating in fibreglass composites.
Although fibreglass composites have superior strength, the cost effectiveness of wood carved blades currently can't be matched, along with the ease of access to resources.
Wooden Blades
