Electricity generation is down by 2.5 quads since 2010. The big loser there is coal, which is down from 21 quads to 14.2. The big winner (thanks to the fracking revolution) is natural gas, up by 3.5 quads. Notable runners-up: wind, up by 1.2, and solar, up by 0.45.
To focus in even closer, here are some changes in the past year, from 2015 to 2016:
- Coal: down 9 percent to 14.2 quads
- Natural gas: up 1 percent to 28.5 quads
- Wind: up 19 percent to 2.1 quads
- Solar: up 38 percent to 0.6 quads
As you can see, wind and natural gas rose by roughly the same absolute amount over the year (around 0.3 quads), but wind is growing at a much faster rate, as is solar.
In short, US electricity is slowly but steadily decarbonizing.
(What’s a quad?
Well, a British thermal unit (BTU) is a standard unit of energy — the heat required to raise the temperature of a pound of water by 1 degree Fahrenheit. If you prefer the metric system, a BTU is about 1055 joules of energy.
A “quad” is one quadrillion (a thousand trillion) BTUs. Here, according to Wikipedia, are a few things equivalent to a quad:
- 8,007,000,000 gallons (US) of gasoline
- 293,071,000,000 kilowatt-hours (kWh)
- 36,000,000 metric tons of coal
- 970,434,000,000 cubic feet of natural gas
- 25,200,000 metric tons of oil
The US consumed 97.3 quads in 2016, an amount that has stayed roughly steady (within a quad or so) since 2000.)