Today, more than 80% of the energy used in the United States comes from fossil fuels – specifically from petroleum, natural gas and coal. In the transportation sector, this number is even higher with fossil fuels (almost exclusively petroleum) supplying 97% of the total energy used. But, on the electric power side of the equation, while coal and natural gas still supply more than two-thirds of the total energy used, petroleum barely registers. This is why turning off the lights in your home of office probably won’t reduce your petroleum consumption.

The Energy Information Administration (EIA) publishes a data-packed graphic that shows the flows of energy between supply sources and demand sectors in the United States. In this graphic, you can see that the transportation sector is responsible for 28% of total energy demand in the US and that 94% of this energy comes from petroleum (3% comes from natural gas, and the remaining 3% comes from a mix of renewables, including biofuels). But in the electric power sector, only 1% of the total energy supply comes from petroleum.

The nation’s top two consumers of petroleum in terms of total BTUs used for electric power generation are Florida and Hawaii. But, due to Florida’s above average total electricity use, petroleum only supplies about 0.4% of its total electric power generation needs. Hawaii, on the other hand, uses petroleum-fired power plants for about three-fourths of its electricity.

For the rest of the United States, petroleum represents a small fraction of the electricity supplied. This means that, reducing your power consumption probably won’t lead to a significant reduction your indirect petroleum consumption. Instead (in terms of fossil fuels) it is more likely to reduce your consumption of coal and natural gas.

Calculation inputs:

1. Total energy from petroleum consumed by the US electric power sector in 2009 = 390 trillion BTUs (sum of residential and distillate fuel oil and petroleum coke)
2. Total energy from petroleum consumed by US electric power sector by state
   1. Florida = 97 trillion BTUs (~0.4% of total generation)
   2. Hawaii = 80 trillion BTUs (~74% of total generation)
   3. New York = 26.6 trillion BTUs (~1.6% of total generation)
   4. Kentucky = 24.2 trillion BTUs
   5. California = 18.5 trillion BTUs

Photo Credit:

1. Graphic courtesy of the United States Department of Energy, Energy Information Administration (EIA).