Wind and solar power could become a major source of electricity for the United States, but only if the nation adopts new policies that promote renewable energy and that place a price on carbon. The report cites figures showing that renewable energy sources currently provide only a small fraction of U.S. electricity (8 percent of the total including conventional hydro power, and only 2 percent excluding hydro). A business-as-usual forecast suggests that renewables will supply 14 percent of U.S. electricity by 2030, with non-hydro renewables providing only 6 percent. Wind and Solar Electricity: Challenges and Opportunities examines three primary obstacles to deployment of wind and solar power: cost, variability of generation, and lack of transmission. The paper, authored by Dr. Paul Komor of the University of Colorado at Boulder, explains these challenges, explores policy options for addressing them, and describes the implications of future scenarios that entail significantly higher levels of electricity generation from wind and solar power.