Jenna Ladd | April 18, 2017

Each year since 2010, the Lawrence Livermore National Laboratory has released an energy flow chart that illustrates sources of U.S. energy, what it’s used for and how much of it goes to waste.

The 2016 energy flow chart quantifies energy use in British Thermal Unit “quads,” which is shorthand for quadrillion or one thousand trillion. A British Thermal Unit (BTU) is equal to the amount of energy required to raise one pound of water by 1 degree Fahrenheit. Americans used 97.3 quads of energy in 2016, which is about 0.1 quadrillion BTU more than last year.

The gray box on the upper right-hand corner of the graphic depicts just how much of that energy was wasted this year: 66.4 quadrillion BTU or 69 percent of all energy produced. It is important to remember that per the second law of thermodynamics, when raw materials are converted into energy, some energy is always lost to heat. In other words, no reaction is 100 percent efficient.

Since the 1970’s, wasted energy has surged in the United States due to a rapid increase in personal electricity consumption and private vehicular transportation, which are both extremely inefficient. Roughly 75 of the energy generated for private transportation and two-thirds of energy required for electricity goes to waste.

This year’s energy flow chart was not all bad news. Coal use fell by nine percent nationwide. That supply was replaced by rapid growth in wind, solar and natural gas energy production. Wind and solar energy did particularly well, with wind energy up 19 percent and solar energy up 38 percent.

Fossil fuel consumption for transportation rose by 2 percent this year, but residential, commercial and industrial energy use all decreased slightly. In all, the U.S. is slowly moving away from fuels that emit greenhouse gases. Total carbon dioxide emissions fell by 4.9 percent in 2016. It is uncertain, however, whether this trend will continue under the Trump administration.