Where America Gets Its Electricity

California warms to solar. Texas leans into wind. And the East Coast is switching to natural gas.

The way the U.S. generates electricity has changed a lot over the past decade.

The Big Switch

Net electricity generation by source, trailing 12 months

This chart ran with the electrical utility industry's seeming conviction that its reliance on natural gas and renewables is just going to keep growing, regardless of the Donald Trump administration's efforts to engineer a coal resurgence.

The chart only included the top five sources of electrical power in the U.S. 

1 Perhaps surprisingly, solar power doesn't make the cut. Even when you include the Energy Information Administration's estimate of the power generated by rooftop panels and other small-scale solar, it's still in seventh place behind biomass (burning wood, mainly).

Solar is gaining fast, though, and in a few places, it has already arrived. In sunny, renewables-obsessed California, for example, solar recently nosed out nuclear for third place among large-scale electricity sources:

Solar and Wind on the Rise in California

Net electricity generation by source, trailing 12 months

With the estimated contribution of small-scale solar added in, the sun is now California's No. 2 source of electricity. Coal has not been a significant part of the state's electricity-generating mix for a long, long time, although that's somewhat misleading given that California imports coal-generated power from its neighbors. The state is heavily reliant on natural gas generation, but its natural gas use has been declining lately thanks in part to the growth in solar and wind and in part to a very wet winter that's been great for hydropower generation. Also, geothermal energy has long been a major source of electricity in California, and was only passed by solar and wind in 2015.

California's energy mix, and the changes in it in recent years, is very different from those of the nation as a whole. Now, we all know California can be weird. But it turns out that most states' electricity-generation charts don't look much like the national one. Consider Texas, the second-most-populous state after California (and, thanks in part to its ridiculously hot summers, a much bigger electricity user than California):

Wind Gains in Texas

Net electricity generation by source, trailing 12 months

Texas has seen a bit of the natural gas gains and coal declines that the rest of the country has -- with a marked if probably temporary reversal in recent months driven by higher natural gas prices. But the most significant change in its electricity picture has been the rise of wind power. This hasn't resulted in big drops in generation from other sources, though, because the fast-growing state has seen overall electrical generation increase by more than 20 percent since 2007.

Then there's Pennsylvania, a slow-growing longtime coal state that quite suddenly became the nation's second-biggest producer of natural gas:

Pennsylvania Trades Coal for Gas

Net electricity generation by source, trailing 12 months

Similar coal-to-gas switches can be seen in generation data from states up and down the Eastern Seaboard. In much of the Midwest, though, the changes have been more muted:

Slow Change in Wisconsin

Net electricity generation by source, trailing 12 months

What's apparent here is that the U.S. doesn't have a national market for electricity. It has lots of different regional and state markets, with energy mixes determined by the availability of fuels and other generation sources, and by the priorities of state and local politicians. Yes, national energy and environmental policies matter. But they're far from the only things that matter.