The data on the left displays the percentage each energy source contributed to generating electricity in the United States in 2007.

Sustainable (renewable) energy sources include hydroelectric, biomass, wind, geothermal, and solar.

Non-renewable energy sources include coal, nuclear, natural gas, and petroleum (crude oil).

The pie chart on the left displays the percentage of electricity that was distributed for use and the percentages lost when electricity was being made and transported across transmission lines.