The latest US energy consumption chart from the Lawrence Livermore National Lab (LLNL) is out. That’s it above. (Click here to download a high resolution version.) As always, it’s full of interesting data. You can learn a lot about how we use energy in different sectors, where the energy comes from, and how much ends up as unuseable. But I think one of the best uses for these charts is to see how things change over time. And with that in mind, I’m going to focus on this question: Are we decarbonizing?
Solar & wind
Solar and wind production are still growing rapidly. From next to nothing only 15 years ago, they’re now contributing 14 percent of the energy that goes into US electricity. The chart below is from my book but updated with the 2022 data point.Solar and wind are pretty much carbon-free, at least on the operational side. There’s some upfront carbon (also called embodied carbon), of course, but generally, the more solar and wind generated electricity we use, the cleaner our electricity is. (And the lower our rejected energy, but we’ll talk about that in a bit.)
The following two graphs are also from my book and updated with 2022 data. First is the graph showing what percent of the fuels going into US electricity generation come from fossil fuels. Those would be petroleum, coal, and gas. See the LLNL chart above for the non-fossil fuels.As you can see, the general trend has been downward for fossil fuels. But from 2020 to 2022, it stagnated. The fossil fuel contribution stayed at 57 percent. But let’s see what happened with the individual fossil fuels on an absolute scale. That’s in this next graph. Petroleum is still down to almost nothing (0.24 quads* in 2022). Coal and gas are both up a bit. Gas has been trending up for a long time, but notice the change in coal. From 2008 to 2019, it dropped by 50%. It was down another 19 percent from 2019 to 2020. And now it’s heading back up. Hmmm. Coal is one of the dirtiest fuels, so that can’t be good for decarbonization.
Looking at the contribution of fossil fuels is the main way to answer the question about if we are decarbonizing. But rejected energy is another. The chart below shows how it has changed in the same years in those charts above.Rejected energy is unavoidable when you’re burning fuels to make electricity. There’s a theoretical limit on how much useful work you can extract from a given amount of energy, and it depends on the temperature difference.
You can read more about that in my article on rejected energy, but for now, let me just reiterate an important point I made there: Efficiency isn’t the solution to rejected energy. As long as we keep burning fuels, we’ll have to burn about three units of energy for each unit of electricity we get.
Are we decarbonizing?
So, what’s the answer to the question? From 2020 to 2022, it would have to be no, we are not decarbonizing. Yes, electricity is getting cleaner. But fossil fuel contributions to electricity generation have gone up on an absolute scale (quads of fuels burned) during this period. And that means the decline in their percent contributions has bottomed out. We were at 57 percent in 2020, and we were at 57 percent in 2022.
We are increasing our carbon emissions according to these data.
Allison A. Bailes III, PhD is a speaker, writer, building science consultant, and the founder of Energy Vanguard in Decatur, Georgia. He has a doctorate in physics and is the author of a bestselling book on building science. He also writes the Energy Vanguard Blog. For more updates, you can subscribe to Energy Vanguard’s weekly newsletter and follow him on LinkedIn.
* A quad equals a quadrillion BTUs. A BTU is a British Thermal Unit, a very small unit of energy, about the same as you get from burning a match.
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