Evaluating economic uncertainty of municipal wind turbine projects

Communities across the country are increasingly considering wind power to provide municipal needs as a result of increasing energy costs and concern about atmospheric emissions; however, with uncertainty in wind conditions, most municipalities lack the expertise to evaluate these proposals without outside consultants. This paper provides a simple but robust methodology that can be used by municipalities in order to determine the economic returns of a wind proposal, allowing the community to determine the probability of success and to quantify the risks associated with the proposal. Adjustable economic parameters are initial cost, annual operating cost, interest rate, loan payback period, turbine life, and energy cost and inflation. Adjustable engineering parameters are mean annual wind speed and its standard deviation and turbine performance characteristics. A spreadsheet that performs the calculations is available from the author. A case study performed for the Town of Dartmouth, Massachusetts illustrates the methodology.