The article analyzes policies to promote renewable electricity sources. A standard for renewables raises electricity prices and reduces gas-fired generation. There is a cost curve "knee" between 15-20% renewable goals for 2020. Higher natural gas prices make relying more on renewables cheaper. A tax credit for renewable energy lowers electricity prices but costs taxpayers and is less effective at reducing carbon emissions than a standard. Both policies are less cost-effective than a cap-and-trade policy for cutting carbon emissions.