Flick on the lights and darkness disappears, thanks to rooftop solar panels or far off power plants. Our cars and trucks can cruise for hundreds of miles on tanks of gas or diesel. And our factories, farms and computers likewise tap a mix of fuels, from natural gas to fire furnaces, to propane to dry crops, to wind farms that help cool the data centers that keep the web humming.

Energy animates practically everything we do. Yet, we rarely stop to think how it all happens. And surprisingly, energy’s story is changing faster than many realize.

As the country continues towards a zero-carbon future, our energy mix will evolve even faster. Lower carbon fuels like natural gas and propane are growing, helping to lower emissions. Additionally, renewables are now the cheapest way to generate electricity and windmills and solar farms are popping up everywhere.

Learn where we’ve come from and how this complex web of energy sources is evolving today by scrolling ahead and clicking on each of the interactive graphics.

What Does Our Energy Story Teach Us?

America’s energy story can be surprising. Though we’re an oil powerhouse today, our primary energy source has changed every few generations since the country was born.

Until the late 1800s, the economy ran mostly on wood and hydropower, the original renewables. Then coal rose to dominate until the 1950s when petroleum nabbed the top spot.1 Today, the mix is even more complex. Natural gas is ascendant and wind, solar and other renewables now supply more energy than coal or nuclear. 2

Yet, in every era, even as new sources emerged, legacy sources persisted. Today, for example, we use more wood and biomass more than ever before.

Why Are Our Emissions Falling?

The recent flux in our energy sources is helping the U.S. move towards a zero-carbon future. Annual US emissions fell to around 4.8 billion tons in 2019, down by a billion tons since 2000 — the most significant absolute decline by any country over that time.

What’s behind this trend? By replacing oil or coal with natural gas or propane, emissions can fall by more than 80% and even more with renewables.3 And since coal is our most carbon-intensive energy source, as it leaves the grid, overall emissions are falling. In 2019 emissions from coal-fired power plants fell by 15%. 4

How Do We Use Energy Today?

How we use our energy has been changing too, with America’s millions of cars, trucks, ships, trains and planes recently emerging as the top sector. This sector is driving significant changes in energy use too, as vehicle makers develop ways to cut on-road emissions, like using electricity, natural gas or propane.

For years, industries like carmakers and steel mills used the greatest share of U.S. energy. Yet manufacturers’ energy use has retreated due to a mix of efficiency gains and offshoring. Heating, cooling and powering our homes consume a sixth or so of the total. Commercial sites such as stores and office buildings use about 12%. 5

Which Energy Sources Are Growing Fastest?

Since 2000, U.S. energy consumption grew by 2%. Yet remarkably, in that same period, our economy expanded by 45% while emissions fell by nearly 20%. This shows how we’re learning to do more with each unit of energy. 6

In that time, natural gas and renewables have surpassed coal, primarily driven by falling costs and the goal of lower carbon emissions. Renewables spiked by 86% in that time. Natural gas grew by 35%, led by growth in both utilities and households. And in 2019, propane consumption surged by 11% year on year.

How Does Propane Fit In?

As we continue to lower emissions, propane’s role has been growing. In many homes, propane has become a mainstay for heating and cooking since it burns cleanly and can be stored and shipped conveniently. On farms, factories and in warehouses, propane is gaining attention as a lower-carbon, less-polluting alternative, too. 7

And for similar reasons, municipal and school bus fleet operators have been turning to propane. During the pandemic, propane-powered heaters took on new importance, helping restaurants from Manhattan to Vancouver survive by extending service outdoors even on the coldest winter days.


Energy has never been more central to how we live and work. And as consumers, businesses and policymakers reckon with changing energy needs and the urgency to move towards a zero-carbon future, our energy story will continue to evolve. In this mix, propane can be part of an affordable, low-carbon path to zero. Learn more about propane’s place and promise in America’s energy story at propane.com/environment.


  1. U. S. Energy Information Administration, Monthly Energy Review, November 2020: Appendix D1, Estimated primary energy consumption in the United States, selected years, 1635-1945; Table 1.3, Primary energy consumption by source, 1950-2019.
  2. Eia.gov, 2019. https://www.eia.gov/todayinenergy/detail.php?id=44277
  3. Lifecycle Emissions by Primary Fuel Type
    1. https://archive.epa.gov/epawaste/nonhaz/municipal/web/html/airem.html
    2. https://ascent.aero/documents/2018/06/ascent-032-2016-annual-report.pdf/
    3. https://www.eia.gov/tools/faqs/faq.php?id=427&t=3
    4. “IPCC Working Group III – Mitigation of Climate Change, Annex III: Technology – specific cost and performance parameters – Table A.III.2 (Emissions of selected electricity supply technologies (gCO2eq/kWh))” (PDF). IPCC. 2014. p. 1335.
  4. “Global CO2 Emissions in 2019 Analysis.” IEA, 2019. https://www.iea.org/articles/global-co2-emissions-in-2019
  5. Source: U.S. Energy Information Administration, Monthly Energy Review, Tables 1.3 and 2.1-2.6, November 2020.
  6. For real GDP growth estimate of 45%, 2000-2019, see U.S. Federal Reserve, St. Louis. “Real Gross Domestic Product.” Stlouisfed.org, 2020. https://fred.stlouisfed.org/series/GDPC1#
  7. Blinder, Alan and Clifford Krauss. “Too Much Winter, and Not Nearly Enough Propane.” The New York Times, February 2, 2014. https://www.nytimes.com/2014/02/08/us/as-propane-prices-rise-worries-grow-for-millions-of-americans.html
  8. Dezember, Ryan. “Propane Is Cheap. Go Ahead, Buy a Patio Heater.” The Wall Street Journal, November 25, 2020. https://www.wsj.com/articles/propane-is-cheap-go-ahead-buy-a-patio-heater-11606300203

About the Author

Adam Aston is a Brooklyn-based writer/editor focused on the business, technology and financial impacts of climate change and the energy transition. Find him on Twitter (twitter.com/adamanyc) and at LinkedIn (www.linkedn.com/in/adamaston).