Not all renewable energy is created equalThere are good and bad news in a recent report by the U.S. Energy Information Administration (EIA). First, a nice milestone: Renewables are now as big a part of the mix as they were back in the 1930s, during the depression years when wood was a much bigger player than it is now, compared to the other sources at the time. In 2014, Renewable energy accounted for 9.8% of total domestic energy consumption. You can see that in the graph below by looking at the black line.
The other lines show how much of the energy consumption is renewable by sector. That's when the bad news start to appear...
"Renewable" is a very nice-sounding word, and all else being equal, you'd rather something be renewable than a one-time-use and then it's gone (like fossil fuels). But something being renewable isn't enough by itself to make it green. If I clear cut a beautiful old growth forest and burn the wood for heat, technically that wood is renewable, but it's still not a green practice.
That's the problem with a lot of renewable energy in the US. As you can see in the other graphs above, one of the fastest-growing sources in the past few years is biofuels, and right now most biofuels in the US aren't very green. They're mostly made with food crops like corn, raising the price of that commodity and everything made with it, and they require a lot of energy inputs to make, making the final results barely carbon neutral if we're lucky.
So that nice bump in the graph for the transportation sector might be renewable, but it's not so green.
A similar thing applies to one of the oldest sources of energy in the world, wood. It represents about 2% of U.S. energy use, and it's renewable, but in practice, some of it is green and some isn't. Sadly, sustainably harvested forests are still not as widespread as they should be.
Back to good news: Most of the rest of the recent growth in renewables comes from wind and solar power, which have been growing rapidly and are just getting started (Worldwide solar power capacity is 53X higher than 9 years ago! Wind power 6.6X higher!).
Of course, the best chart to visualize U.S. energy sources and uses (and waste) is the classic from Lawrence Livermore Labs:
Via U.S. EIA