US Energy Consumption Dropped 7.3 Quads in 2020

The Chart That Explains Everything about energy had some big changes last year.

Closed power plant UK
A decommissioned coal-burning power plant.

Getty Images

Every year, the Lawrence Livermore National Laboratory and the Department of Energy produce Sankey flow diagrams showing where energy in the U.S. comes from and where it's going. Every year, Treehugger has a look at these to see what shocking news we can discern from it. Here's the 2020 version:

2020 sankey drawing

Lawrence Livermore National Laboratory and the Department of Energy

The single most important number here is the total estimated energy consumption of 92.9 quads. A quad is a quadrillion BTUs (1015) and is equivalent to the energy in 8,007,000,000 gallons of gasoline–it's big. In 2019 the total consumption was 100.2 quads, so the reduction in energy consumption was pretty much exactly what we have to do every year between now and 2030, a pandemic's worth of energy savings every year. That sounds somewhere between daunting and impossible, but if you study the chart you can get a lot of ideas about where our priorities should be.

2019 Sankey

Lawrence Livermore National Laboratory and the Department of Energy

Here is the 2019 chart for comparison, since it is probably a more realistic look at a normal year. The first thing that grabs attention every year is how much of this energy consumption is "rejected energy." That's what is wasted as heat going up the chimney or out the exhaust pipe; they assume 65% efficiency in electricity generation and only 20% in transportation.

Most of that orange electricity is going into residential and commercial buildings, and these days, that's mostly cooling. So reducing demand by making buildings more efficient can reduce the demand side, but as Saul Griffith has pointed out, there is no rejected energy from solar, hydro, and wind power, there is no chimney. That means you need a lot fewer quads; eliminating the rejected energy from electricity production alone reduces overall energy consumption by a quarter.

The other big source of rejected energy is transportation: Over 20% of the total energy use is going out the tailpipe because cars are such inefficient converters of heat into motion. In 2020 the amount of electricity going into transportation is an almost invisibly tiny 0.02 quads, but look at the total amount of energy actually being used in cars; it's only 5.09 quads, all the rest is wasted and is turned into heat and carbon dioxide. Electric vehicles are almost 90% efficient, so they need in total about a quarter of the energy needed to move cars.

Of course, we can blow a lot of that if we just change over to Ford F-150 Lightnings instead of promoting efficient electric vehicles and alternates such as bikes or e-bikes, When you look at the total energy flows, reducing consumption does matter.

Industrial consumption

Energy Information Agency

In 2020 the industrial sector was bigger than transportation, at 25.3 quads. As shown by this older chart that probably still represents the approximate distribution, most of that is going into aluminum, steel, concrete, and glass, most of which is going into cars, roads, and buildings. All of which could be reduced through design choices and regulation.

Carbon flows

Lawrence Livermore National Laboratory

The most obvious and disturbing number on the chart is the total of petroleum, coal, and natural gas, totaling 80.2 quads of energy consumption, which produce almost all of the CO2 we emit every year. As the most recent CO2 emissions chart shows, the vast majority of our CO2 problems come from pushing cars and making electricity from coal and gas. There are other greenhouse gases we have to worry about like methane, but they are not tracked here:

2014 quads
credit: Lawrence Livermore National Laboratory and the Department of Energy

Looking back to 2014, you can see how far we have come. Solar and wind have grown tremendously, Coal is down by almost half, and overall consumption in 2019 had not grown that much in five years. Some things are going in the right direction. But every chart of every year tells the same story, the big honking green bar at the bottom.

Our biggest problems are fossil fuel-powered cars, cars, and cars. They are grossly inefficient, and our world is designed around them. When we electrify them, the total energy going to them is only a quarter of what it is now.

One could spend hours looking at these charts. See a selection here going back to 1950 and you can watch the U.S. develop as sprawl happens, as air conditioning allows the growth of the sunbelt, as the oil crunch of the 70s hits, as the nuclear industry stagnates. There is so much history here, but you can also read the future, and it is one without oil.