Renewable resources such as biomass, water, wind, solar, and geothermal provide clean alternatives to the fossil fuels that cause climate change. According to the Energy Information Administration, renewable resources supplied more than seven percent of total U.S. energy (including electricity, thermal energy, and transportation fuels) in 2008. Biomass generated 53 percent of U.S. renewable energy, and it is the only renewable resource that can be transformed into liquid transportation fuels (although the electrification of the transportation sector will allow power generated from other renewable resources to "fuel" our vehicles). Hydropower provided 37 percent of U.S. renewable energy, followed by wind at seven percent, geothermal at five percent, and solar at one percent. Renewable energy has the largest impact on our environmental, security, and economic objectives when it is paired with aggressive energy efficiency strategies to reduce overall demand.

Biomass Energy
Biomass (plant or animal material) can be used to produce electricity, thermal energy, or transportation fuels. Every region has its own locally generated biomass feedstocks from agriculture, forest, and urban sources.

Hydropower and Other Water Technologies
Water technologies can be used for electricity or thermal energy all across the country. Although there are few, if any, appropriate sites left to build large dams in the United States, there are many opportunities to expand energy production at dams without turbines and by using newer technologies in both rivers and oceans.

Wind
Wind energy can be used to generate electricity for utilities or individual buildings. The best U.S. resources for utility scale wind farms are in the Midwest, Texas and the West, as well as offshore sites in the Great Lakes and off the Atlantic Coast.

Geothermal
Geothermal energy, or the heat below the earth's surface, can be used for electricity or thermal energy. Geothermal power plants require stronger resources that, in the United States, are primarily located in the West. Geothermal heat pumps, which heat and cool buildings, are effective in all regions.

Solar
Solar energy systems use the sun's rays for electricity or thermal energy. In the United States, utility scale solar power plants are located primarily in the Southwest. However, smaller scale rooftop photovoltaic cells and hot water systems are effective in all regions.

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