Understanding How Energy is Consumed Energy in the U.S. is consumed by five major sectors of the economy electricity generation, industrial production, transportation, commercial business activity, and residential households. The percent of total 1995 U.S. energy consumption accounted for by each sector is shown in the pie chart below. Since electricity is produced to sell to the other four sectors, data is sometimes presented where the energy consumed by the electricity generation sector is allocated among the other four in proportion to their electricity consumption. The next pie chart shows how allocating the energy used in electricity generation to the sectors consuming electricity would change the relative shares. The following chart shows which energy sources we use the most.
Natural gas is the next most used energy source, followed closely by coal and nuclear far behind.
To limit carbon dioxide emissions we must reduce the consumption of energy that contains carbon. Follow the carbon. The chart below shows how much carbon each of the major energy sources contains. The vertical axis of the chart measures tons of carbon for each million Btus of energy. What we see is that coal contains the most carbon, followed by gasoline, petroleum products other than gasoline, natural gas, and nuclear power which is a carbon free source of energy.