Energy in the United States is obtained from a diverse portfolio of sources, although the majority came from fossil fuels in 2021, as 36% of the nation's energy originated from petroleum, 32% from natural gas, and 11% from coal. Electricity from nuclear power supplied 8% and renewable energy supplied 12%, which includes biomass, wind, hydro, solar and geothermal.
Energy figures are measured in BTU, with 1 BTU equal to 1.055 kJ and 1 quadrillion BTU (1 quad) equal to 1.055 EJ. Because BTU is a unit of heat, sources that generate electricity directly are multiplied by a conversion factor to equate them with sources that use a heat engine.
The United States was the second-largest energy producer and consumer in 2021 after China. The country had a per capita energy consumption of , ranking it tenth in the world behind Canada, Norway, and several Arabian nations. Consumption was mostly for industry (33%) and transportion (28%), with use in homes (21%) and commercial buildings (18%) making up the remainder.
The United States' portion of the electrical grid in North America had a nameplate capacity of 1,213 GW and produced 3,988 TWh in 2021, using 37% of primary energy to do so. The country is the second-largest producer and consumer of electricity, behind China. Natural gas overtook coal as the dominant source for electric generation in 2016. While coal use has been dropping, it remained larger than either nuclear or renewables.
History
From its founding until the late 19th century, population and energy use in the United States both increased by about 3% per year, resulting in a relatively constant per capita energy use of 100 million BTU. Wood made up the majority of this until near the end of the 1800s, meaning the average American burned eight tons of wood each year.
The Industrial Revolution in the United States saw an increased use of coal. By the late 1800s, it surpassed wood as the major source of energy, as it was cheaper for those living in cities. Lighting, heating and transportation could all be fueled by coal. Between 1925 and 1975, coal use was more stagnant, although it dominated the growing electricity sector. Petroleum and natural gas took its place, as car ownership doubled in the two decades after the war, and as the number of pipelines rose dramatically.
During the first half of the 20th century, per capita energy use doubled to 200 million BTU, and reached 300 million BTU by the late 60s. After a peak of 360 million BTU in 1979, per capita consumption generally declined, and dipped below 300 million BTU in 2020. In comparison, the world average increased from per person between 1980 and 2020.
Domestic oil production peaked in 1970 and would not recover for 40 years. However, oil imports allowed consumption to double. Oil represented the vast majority of net imports during this time. Increased reliance on imported oil coincided with the 1973 oil crisis.
Total imports peaked in 2005, when they represented 30% of total consumption. A consistent decline occurred over the next 15 years, as oil production doubled and domestic use receded. This allowed the United States to be a net exporter of energy for the first time in 70 years. As of 2021, the US net exports 3.9% of energy production.
Around 2010, many other trends began to reverse. By 2020, improvements in fracking had allowed natural gas production to increase by more than half, while coal decreased by half.
Renewables in the 20th century consisted mainly of hydro and wood. Hydro power had been relatively constant since 1970, while wood saw a bump in 1980. Between 2000 and 2020, wind, solar and biofuels increased by a factor of ten. By 2020, wind had surpassed hydro, and biofuels had surpassed wood.
Summary
Primary energy production
The United States is the world's second-largest producer of energy. It produces 16% of the world's energy, about three-fourths as much as China. Since 2019, the country has been a net exporter of energy. In 2021, 97.8 quads were produced and net exports were 3.9% of production.
Fossil Fuels
Fossil fuels have long produced most energy in the US, currently accounting for 79% of total production and 61% of electric generation. Although costs for some fossil fuels are declining, renewables are becoming cheaper faster. Despite this, use of fossil fuels has remained near 80% for the past 30 years.