The graphic that leads this article is one of the most commonly used graphics in energy and climate discussions. It’s the Lawrence Livermore National Laboratory (LLNL) energy flows diagram for the US, in this case the 2021 version. It has been publishing variants of them in this format since 2010. When I speak to institutional investors or university seminars or corporate strategy groups, it’s rare that I do not include and discuss this chart. The charts are in quads — quadrillions of British thermal units (BTUs) — which means LLNL has taken the time to try to get all the thermodynamics right.
It’s fundamental to my first assertion in my short list of climate actions that will work, which is electrify everything. I consider electrifying all energy services to trump all other efficiency programs, and frequently get into discussions with people who keep arguing for building envelope insulation, for example, when Jevons Paradox makes it clear gas use will just rebound as people maximize comfort at a price point they are fine with, and studies make it clear that does happen, most recently a UK study of 55,000 buildings there which were insulated over 13 years yet had no persistent change in gas usage.
Parsing the diagram a bit, it starts on the left with all of the primary energy sources. Primary energy is unprocessed initial sources like wind energy coming out of wind farms, solar energy coming out of solar farms or crude oil coming out of the ground (and more on that later).
You’ll note a bunch of primary energy flows into electricity generation, almost 38%. And you’ll note that there is a fat gray bar labeled with 23.7 quads coming out of electricity generation and leading to a box labeled rejected energy. That example applies to a bunch of the other middle boxes in the chart, so let’s explain it.
Rejected energy is wasted primary energy, or energy which serves no useful purpose in our society or economy. Virtually all of the rejected energy is waste heat from burning fossil fuels. A tiny fraction is transmission losses for electricity.
Energy services are energy that actually delivers societal value, whether keeping the lights on, pushing cars down the road or keeping our buildings comfortable. Overall, the US, and hence most of the developed world, throws away two-thirds of all primary energy. It’s just up in smoke, gone, wasted.
The pattern holds true for the rest of the splits between rejected energy and energy services on the chart. Transportation is especially egregious as we waste 74% of fossil fuels pushing weight along roads, waterways, and into the air, with only 26% of the energy embodied in fossil fuels actually delivering value.
Electrifying everything, that is to say using electricity directly wherever it is possible to do so, is vastly more efficient than alternatives. The ratio of rejected to useful energy in electricity is much better than that for transportation, so even using fossil fuels to generate electricity and then using the electricity for transportation wastes less of the fossil fuels’ energy potential.
This has been fine because fossil fuels have been dirt cheap and easily accessible for centuries, and we didn’t know any better about negative externalities, or at least could ignore them. That’s changing of course, for a couple of reasons. The first is that the most accessible and cheapest to extract fossil fuels have already been dug up. That’s why there’s so much unconventional oil and gas extraction going on, with much higher energy requirements for extraction and processing. We’re drilling deep offshore and in the deep Arctic looking for more sources, and those are more expensive too. And, of course, there’s the little problem of climate change, and the necessity of putting an additional price on fossil fuels to allow us to wean ourselves off of them.
The US has been building wind and solar since the 1970s. And it’s been buying more electric cars in the past decade too. And putting in more heat pumps. So, the ratio of energy flows to energy services must have changed since 2010, right?
Hmmm… Some things have changed, for sure. First off, let’s talk about inconsistencies in methodology, as LLNL has changed the way that it counts things, and it makes this retrospective from its published data a bit more challenging.
First off, in 2010 when the first version of this chart appeared, LLNL wasn’t quite at quads, but using trillions of BTUs, which I’ve accounted for in the charts. But it’s not like US energy use plummeted from 2010 to 2011, so clearly the team refined their accounting between years, which is a great thing and which I’m not at all saying is a negative. Similarly, between 2014 and 2015 LLNL clearly made another change in methodology, one that was clearly aligned with making the entire thing more thermodynamically accurate. After all, the basics of burning fossil fuels are very well understood, and there was no way we were getting more than 50% of the energy out of them.
As a result, it’s most useful to 2015 to 2021 to see if there’s an observable trend. Incidentally, the vast majority of electric cars, heat pumps, wind turbines, and solar panels were deployed in those seven years. One clear thing is that in those seven years, US energy consumption was fairly flat despite roughly 11 million more Americans — a bit over 3% — living and consuming in the country. 2020 was a dip for obvious reasons in total energy consumption, but note that it was only a dip of about 8% and it rebounded substantially in 2021. Given that COVID-19 wasn’t over, clearly Americans were finding other ways to burn massive numbers of BTUs than commuting to work and driving to college ball games. I would assume 2022 will have proven to return to 2019 levels, or perhaps a little under, as Americans are doing more work from home and less business flying still.
As a note on methodology, I suspect but have not confirmed that the LLNL material is still masking a major source of energy waste, which is the roughly 11% (the best estimate I’ve seen) of energy required to extract, process, refine, and distribute fossil fuels. Electrical generation gets a call-out for the processing waste of electricity, but the 2.1 or more kWh of energy required to manufacture and deliver a gallon of gasoline, for example, is subsumed in ‘energy services’, when it’s actually just more of the wastefulness of fossil fuels. Similarly, the vast amounts of energy used in steam-assisted gravity drainage (SAGD) in the oil sands, or the energy required for fracking, or the energy wasted moving megatonnes of molecules around so that we can burn them all falls into ‘energy services’, when it’s actually just more rejected energy. If someone knows better, please do let me know, but I’d personally add a box for extraction, processing, and refining fossil fuels, and have all of that energy go directly to rejected energy without passing go.
Let’s look at the ratio of useful energy services to primary energy sources, as that should give us a better look at trends.
And here’s the bigger story. Ignoring methodological errors prior to 2015, we can see that in seven years of electrification and deployment of wind and solar, the US barely budged the needle, in fact declining slightly to more wasted energy in 2016 and 2017 before improving again in 2018 and onward. But even there, in 2021, there was a slight decline.
From a policy perspective, the answer appears clear. Serious national energy strategists and policymakers should be using this ratio, calculated for their country, as a key metric in whether they are succeeding in actually moving the climate needle. It is, after all and at present, a clear measure of how much energy we are wasting because we persist in burning fossil fuels instead of electrifying everything and shifting to low-carbon electrical generation.
Of course, there were deeply contrarian policies at the top in the US from January 2017 to January 2021, and fixing those deep failures takes time. It’s possible that 2022 saw the needle move more, and it’s possible that Biden’s policies will show more movement on this metric in the coming years.
There’s another chart, not by LLNL or me, but by Professor David Cebon of Cambridge. Like the LLNL energy flows chart, it’s a Sankey diagram showing useful vs wasted energy graphically, in this case of hydrogen vs heat pumps for residential heating.
I used this diagram most recently when talking at the Renpower Maghreb 2022 conference in Tunisia in December, to assist the audience to understand that Europe would not be paying for hydrogen as a carrier of energy, and that they should strategize appropriately. As it shows, just the electricity alone would be six times the amount to achieve the same energy services at homes. That’s six times as much wind and solar. That’s a lot more transmission and storage. That’s a lot of hydrogen manufacturing, storage and distribution infrastructure.
Heating buildings with hydrogen would be likely 10 times as expensive as just using the electricity directly with heat pumps.
Electrify everything very clearly does not mean making hydrogen and synthetic fuels from green electricity and using the fuels. That’s even more wasteful than what we do with fossil fuels, which is already deeply wasteful and increasingly expensive.
And this is a contrary story to Biden’s better policies. As I published in late 2022, the recent poor US hydrogen strategy — wrong department, wrong authors — is much more in line with the Cebon heating Sankey diagram than the LLNL understanding of rejected energy vs useful energy services. That’s a risk for the US. If hydrogen for energy is pushed heavily by the government, this metric would go in the wrong direction instead of the right one.
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