Renewable energy sources represent a very small share of the metro region’s energy supply. In March 2010, 46% of the power supply sold within the ComEd service area was derived from nuclear power plants, 40% from coal-fired power plants, 10% from natural gas, and only small amounts of wind power (1%), biomass (1%), hydropower (1%), and assorted other sources (1%) (ComEd, 2010). However, wind power is a growing industry that is attracting headquarter functions to the Chicago Tri-State metro-region. Together with other Great Lakes states such as Michigan and Ohio, the Chicago-area 21-county region has one of the highest concentrations of wind energy component suppliers in the US. Thirteen wind industry corporations have set up their headquarters in the Chicago Tri-State metro-region, including some of the major international firms involved in turbine manufacturing and renewable project developers, such as Goldwind, Acciona, Suzlon, Nordex or E.On. The Chicago-area 21-county region counts over 60 wind companies, which cover a large part of the supply chain, including turbine and tower makers, manufacturers of gears, couplings, bearings and fasteners, as well legal, financial and engineering consulting and diagnostic software designers (ELPC, 2011).