The U.S. Energy Information Administration (EIA) recently issued a report that details construction costs for new electric generators at utility-scale power plants installed in 2013. Most new capacity in 2013 was from natural gas, with average construction costs of $965 per kW of installed nameplate capacity. Solar construction costs averaged $3,705 per kW, and wind averaged $1,895 per kW. The report also includes information on biomass, hydro, geothermal, and petroleum liquid generation.
EIA notes that, of course, construction costs alone are not the only financial factor; depending on the generation type, fuel costs can be substantial. Utilization rates also factor into overall economics.