“Solar and wind continue to show year-on-year growth, which is an impressive change for the energy system,” said A.J. Simon, associate program leader for Water Security and Technologies at LLNL. “Other energy resources, such as hydropower, nuclear energy and geothermal have trended flat over the past decade, despite visible annual fluctuations.”
Supply from natural gas increased by 1.1 quadrillion BTU, from 31 in 2018 to 32.1 in 2019, a 4% increase. Coal use declined 1.9 quads (14%), mostly in the electric generation sector, due mainly to the uptick in natural gas.
The shift from coal to gas also contributed to a drop in rejected energy, thanks to the higher efficiencies of natural-gas powered plants.
All energy use and conversion results in some losses, labelled on the chart as rejected energy. Last year, rejected energy was one 1 quad less than in 2018. This energy is usually waste heat, such as the warm exhaust from automobiles and furnaces. The efficiency of the nation’s cars, lightbulbs and factories determines how much waste heat is created, and how much fuel and electricity can be put to productive use.