Realistic calculation of wind generation capacity credits

The concept of capacity credit measures the ability of generation to support demand in power systems. This is of particular importance for wind generation, whose available capacity depends primarily on physical resource availability as opposed to mechanical availability; as a result, and differently from conventional generation, it is possible for the total available output of a system´s wind generation to be very close to zero. This paper reviews different methods for calculating capacity credits, and discusses the important considerations for a realistic calculation with reference to a new Great Britain study. The key conclusion is that the correct methodology for a capacity credit calculation is closely tied to the intended application; as a consequence, there can no one universal preferred approach for all applications.