With subsidies from the EC Joule II programme, BONUS and its co-contractors are developing a 750 kW wind turbine.
The project determined that the low and medium wind regimes that cover most of continental Europe, coupled with the step-wise increase in component costs, limited the potential generator rating to 750 kW, although the design of the turbine would still support a 1 MW rating. New aerodynamic profiles of 24m long blades were designed and manufactured. The natural frequencies of the rotor and nacelle were tuned for load reduction by changing their structural dynamics. Noise levels were reduced to 101 dB(A) with no single tones in the frequency spectra, by improving the gearbox and nacelle design and applying a special winding for the asynchronous generator. The construction period of the turbine was also found to be similar to that for a smaller turbine. The project experienced a temporary setback in October 1995 when a severe rotor failure occurred, but this was rectified soon after the project had finished.
The expected achievement of this project is a reduction in the energy price of 25% compared with current Danish wind turbines. This reduction is made possible by an up-scaling of known and competitive design features and by the high efficiency of the new rotor.
With 50 m rotor diameter the turbine is in the size range generally assumed to be very important in the future application of wind power in Europe, as the 750 kW wind turbine is well adapted for the low and medium wind regimes which are typical for large regions of the continental Europe.
Funding SchemeCSC - Cost-sharing contracts
BS2 0QD Bristol