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, according to a new report from the Pew Center on Global Climate Change.

The report, "Wind and Solar Electricity: Challenges and Opportunities," 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.

However, Congress currently is considering policies that could lead to a significantly larger role for renewables in meeting the United States' energy needs. Such policies include a cap-and-trade program for greenhouse gases and a national renewable portfolio standard (RPS) that requires increased production of energy from renewable sources. The Pew Center report, which includes a detailed analysis of the costs of wind and solar vs. other power sources, suggests that such policies could provide a critical boost in overcoming barriers to the more rapid development and deployment of renewables.

"Wind and solar power are two of our most promising renewable energy technologies, but without a price on carbon � they will face significant barriers to widespread market penetration," said Eileen Claussen, President of the Pew Center on Global Climate Change.

"Acting now to regulate carbon through a cap-and-trade system and changing the way we plan and manage our electricity grid can help to make these cleaner energy sources a more significant part of the climate solution."

"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.