"United States. Department of Energy. Office of Energy Efficiency and Renewable Energy," . . "Wind power industry Subsidies United States Evaluation." . . . . "Federal aid to energy development United States." . . "National Renewable Energy Laboratory (U.S.)," . . "Energy policy United States." . . "Tax credits Government policy United States." . . . . . . "Implications of a production tax credit extension on United States wind deployment"@en . . "Implications of a PTC extension on U.S. wind deployment"@en . . . . . .