The pie chart on the left displays the percentage of each energy type that was produced in the United States.

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

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

The bar graph on the left displays the amount of each energy type that was produced in quadrillion BTU. BTU is the British Thermal Unit. One BTU is a very, very small amount of energy. 1 quadrillion = 1,000,000,000,000,000.

1 quadrillion BTU is equal to the amount of energy in 45,000,000 tons of coal, or 970,000,000,000 cubic feet of natural gas, or 170,000,000 barrels of crude oil.

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

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