Back to CESC

Modeling Utility-scale Wind Power Plants Part 2: Capacity Credit


National Renewable Energy Laboratory


Michael R. Milligan


1 March 2002

This paper—the second in a two-part study of the overall economics of wind power plants using various modeling approaches—focuses on wind plant capacity credit as measured with power system reliability indices. Reliability-based methods of measuring capacity credit are compared with wind plant capacity factor. The modeling results found both energy benefits and capacity benefits of wind power to be significant, and that the capacity credit of wind power plants varies with the characteristics of the wind site and utility characteristics. Wind forecasts can optimize the use of the availability and timing of the wind power, and thus have an impact on the capacity value of wind power plants.