That might look a little confusing at first, but it’s really not all that bad. Overall, the chart shows where we got our energy from and how we used it in 2016. The left side shows the sources and where they wind up is on the right.
The main thing I wanted to highlight is the big chunk of “rejected energy” in the upper right. That’s waste — energy that’s generated but not actually used for anything productive — and it’s more two thirds of our total energy generation. Presumably it’s what’s lost in electricity transmission, unused heat or idling cars and stuff.
The good news (which you can’t get directly from the chart but you can if you follow the link above) is that we’re growing solar and wind, especially in electricity generation resulting in falling carbon emissions from electricity.
The bad news (again, please read the linked article) is that emissions from transportation are actually growing again, after falling a bit during/after the Great Recession.
The other bad news, as you can see from our chart, is that transportation is a particularly inefficient consumer of energy. Only about 21% of the energy that went into transportation last year was actually used. The remaining 79% goes to “rejected energy.” That’s right, your car both uses a lot of energy and is really inefficient about it.
As Roberts writes, one way to think about a city is as an energy system. If we design it so that the easiest way to get around is in a (single occupancy) private vehicle, it’s going to be terribly inefficient both in terms of space and energy. The only hope of being more efficient is to facilitate vehicles that use less energy (transit) or no energy (biking and walking).