Potentials for site-specific design of MW sized wind turbines

The potential for site specific design of MW sized wind turbines is quantified by comparing design loads for wind turbines installed tit a range of different sites. The sites comprise on-shore normal flat terrain stand-alone conditions and wind farm conditions together with offshore and mountainous complex terrain wind farms. The design loads are established for a 1 MW active stall regulated wind turbine with the aeroelastic code HAWC. The load analysis is limited to fatigue loads. We do not consider ultimate loads in this paper. The results illustrate the differences in design wind conditions for different sites and the related differences in design loads for the 1 MW wind turbine. Based oil the difference in the design loads, the potentials for site specific design of the wind turbine main components are identified. The results show that the variation in aerodynamically driven loads and energy production can be more than 50% between the different sites. It is concluded that site specific design is feasible for some of the main components. In particular site specific changes are feasible for the tower nacelle components, and for the blades in the flapwise direction. It is also evaluated whether the IEC61400-1 standard [see Ref. [4], International Electrochemical Commission (1999)] is representative for the different sites. A comparison with design loads based on the IEC61400-1 illustrates thar the six different sites can be described by the standard design classes.