Wind is used to produce electricity using the kinetic energy created by air in motion, transformed into electrical energy using wind turbines or wind energy conversion systems. Wind first hits a turbine’s blades, causing them to rotate and turn the turbine connected to them. The amount of power that can be harvested from wind depends on the size of the turbine and the length of its blades. The output is proportional to the dimensions of the rotor and to the cube of the wind speed. Wind-turbine size and capacity has therefore increased over time. In 1985, typical turbines had a rated capacity of 0.05 megawatts (MW) and a rotor diameter of 15 metres. Today’s new wind power projects have turbine capacities of about 8 MW, with rotor diameters of up to 164 metres.
Wind power, as with any energy source, aims to provide the maximum power output for the lowest cost, with the highest level of reliability and device lifespan. One major obstacle to this is the forces that a wind turbine has to withstand during operation, and in worst-case storm-loading conditions. Their blades have the optimal shape for generating power during normal operation, but under these extreme loads their shape generates massive forces on the turbine base and components, essentially trying to tear the blades off of the base.