Energy Consumption in 2050
It’s Hard To Find A Straight Answer
As I mentioned last time, future energy usage is an important input to many questions about how the green transition will play out. How many solar panels will we need to manufacture? How much land will they require? How much do we need to beef up the grid’s transmission lines? How much lithium will we need for grid storage? These questions all depend on the amount of energy being used.
In this post, I’ll explore what we found when exploring the literature… and challenges we encountered along the way.
We specifically looked for projections for the year 2050, and when possible, scenarios that involve achieving net-zero emissions in that year1. Why 2050, and why net zero? Well, my overarching goal is to help optimize the path to a net-zero planet. To do that, we should think about scenarios that are aspirational, but not impossible. (We’re trying to shape the future, not passively predict it.) That seems to point to net zero somewhere around 2050, and it’s a nice round number.
It’s Hard To Find A Straight Answer
The Internet is, of course, awash in reports, studies, white papers, explainers, and the like. All of which are full of numbers. So many numbers!
And yet, when you’re looking for a specific number – a straight numerical answer to a specific question – it can be surprisingly difficult to find. This email that Eliana sent while doing the research beautifully illustrates the challenges:
I couldn't find raw data for the IPCC 2018 report. I found supply data in the second chapter in table 2.6 but had no such luck for demand. Maybe we have to eyeball it from Figure 2.14. Figure 2.19 also has demand/consumption data so we could try to eyeball it there. Looks like the median is just over 200 EJ for electricity and maybe 420 EJ for total energy for 1.5 degree scenarios.
In the 2019 IRENA report, Figure 8 suggests total final energy consumption will be 351 exajoules in 2050. Electricity will be 86% of that (177.99 EJ or 47,775 TWh). In Figure 9, though, the consumption is only 47,056 TWh. Do you think it's worth trying to understand the missing TWh there? Does my math/approach make sense?
Also confusing in the IRENA reports--the 2018 report says that electricity consumption in end-use sectors will be "over 42,000 TWh" (see page 38 here). Scroll down a bit though and the infographic on page 40 shows a different number: 41,508 TWh. Do you think that difference is worth trying to figure out? It's possible the consumption number is pre-loss.
I wanted to find the estimates for the reference case in the IRENA report but all I could find was energy supply (which I equate to generation but maybe incorrectly? My research suggests they are equivalent for these purposes) and electricity consumption.
For the IEA data, they have an export of raw data (attached) but it seems to differ from what is in the report. For example, page 113 of the report says electricity demand will be 60,000 TWh in 2050. Electricity demand in the raw data = 169 EJ (~47,000 TWh).
In general, I aimed to find the raw data instead of trying to estimate from a chart/infographic but IPCC and IRENA did not make it possible to do that.
Numbers presented without adequate explanation; apparent inconsistencies within a single report; critical values that have to be eyeballed from a chart; values not presented in the form you need. I used to think, when I had difficulty finding a number I needed, that it was a personal failing – I had forgotten some critical library science lesson from middle school, or I was too lazy to do the proper legwork2. But in actuality, this is just legit difficult!
To be more precise: it’s often not difficult to find “sort of” the number you’re looking for. But finding a clear and direct answer to precisely the right question – even a seemingly straightforward question – can be another matter.
To Get a Clear Answer, You Need a Clear Question
“Energy usage” isn’t really a very good number to look for; it’s surprisingly ambiguous. We wound up looking for four numbers from each source:
Energy generation
Energy consumption
Electricity generation
Electricity consumption
You may be wondering about the difference between “generation” and “consumption”. The amount of power used is less than the amount generated, because there are losses along the way. When burning natural gas to produce electricity, quite a bit of the energy in the natural gas disappears up the smokestack as waste heat. Some electricity is lost to resistance in the transmission and distribution lines. And so forth.
I had planned to give precise definitions of what we’re measuring when we talk about “generation” vs. “consumption”, but to make a long story short, I failed. I’m not even convinced that the various data sources we’ve drawn on here are using consistent definitions. To give you an idea of how messy this gets when you dive in, the IEA definition of “primary energy consumption” contains 15 bullet points, one of which is:
Geothermal electricity net generation (converted to Btu using the average annual heat rate of fossil-fuel fired plants), geothermal heat pump energy and geothermal direct-use energy
I could try to explain what I think “converted to Btu using the average annual heat rate of fossil-fuel fired plants” means, but that would be missing the point. The point is that these seemingly simple terms, when applied to the real world, turn out to defy simple definition.
Enough Words, Show Me The Data!
OK, OK, here you go. (See the “Appendix” at the end of this post for an explanation of the six data sources we used.)
Looking over these figures, plenty of oddities stand out. I list some below. Feel free to skip the list; the theme is that the models disagree with one another in ways that imply there is a lot of uncertainty here, and there is likely a considerable amount of miscommunication, if not outright errors.
The “all energy consumption” figure for the EIA report is a major outlier, over twice as high as the next-lower projection. Presumably this is because it’s assuming “business as usual”, unlike the other sources we picked.
Even setting aside the EIA figures, the projections vary substantially, generally by 40 to 50 percent.
All of the models show overall energy usage as being much higher than electricity usage, i.e. they show quite a lot of usage of energy in forms other than electricity. I’m not sure how this is compatible with the net-zero and/or 1.5°C scenarios used by some of these models. There are some ways to use non-electrical energy while maintaining net-zero emissions3. But I’m skeptical that a realistic global scenario would involve a large proportion of this sort of thing, and this makes me think that there is a communication gap somewhere.
The IEA figures show a very large gap in generation vs. consumption, especially for electricity4. I have to think that this represents a mistake of some sort (possibly ours). Never Trust a Number!
Electricity figures for IRENA 2.0°C scenarios are lower than for IPCC 1.5°C scenarios. Since electrification is closely associated with emissions reduction, this seems difficult to reconcile, unless IRENA is assuming much slower economic growth.
The IRENA numbers changed noticeably from 2018 to 2019, emphasizing how these projections are a moving target.
You can find the numerical data in copy/pasteable format, along with Eliana’s complete research notes, here.
What Can We Conclude?
Suppose you’re trying to model one of the questions I discussed at the top of the post; for instance, land usage for solar panels in 2050. What figures should you use for overall electricity demand?
If there is one single lesson I’m taking away, it’s that there is no single figure. We, the collective global “we”, are simply not in a position to make a precise prediction 28 years out. Not by a long shot. Solar eclipses: predictable. Solar power: no way.
However, we shouldn’t throw up our hands and walk away, either. We can’t usefully project a single figure, but we can get some sense of a plausible range. Taking electricity consumption as an example:
The six data sets project values ranging from 126 to 190 quadrillion BTU.
The higher figures come from scenarios that project lower emissions (presumably these scenarios assume a more rapid shift away from other types of energy). If we are trying to model an aspirational, 1.5° scenario, we should focus on those higher figures.
None of these sources provide confidence intervals (sigh), but the IPCC report at least includes a graphic showing the amount of variation between the 19 separate models5 on which it is based. I struggle to draw anything from this graphic more concrete than “there is a lot of variation”6. This is not the same thing as getting confidence intervals from the individual models, but it at least gives us some view into the amount by which these projections will change based on differing assumptions or methodologies.
The upshot is that in an aspirational, 1.5°C and/or net-zero-by-2050 scenario, global electricity consumption in 2050 could easily reach 190 quadrillion BTU, and the range of plausible scenarios extends quite a bit higher. For rough napkin math purposes, if I were thinking about potential bottlenecks in electricity production and distribution – which is exactly why we did this research! – I would be inclined to plan for figures as high as, say, 250 to 300 quadrillion BTU. That is of course a very hand-wavy number, but I don’t know how to do better.
To be clear, 300 QBTU is my figure for “we might need that much electricity, so let’s make sure there aren’t any bottlenecks that would prevent us from getting there if we need to”. The actual figure is likely to be quite a bit lower.
Seriously, After All That Work, We Just Get “I Dunno, Could Be 300 Quadrillion”?
I know, right?!?
This isn’t as bad as it sounds. It’s important to keep in mind the purposes to which we might put these projections. If you’re trying to make concrete business decisions – whether to start construction on another wind turbine manufacturing plant, or how much raw material to order for your solar panel factory – you need much more precision. But no one is making decisions like that for 2050 yet!
The applications I have in mind are order-of-magnitude questions, like “will we have enough land for all the renewables we’ll need to deploy in the next few decades”. For a question like that, it’s not critical to have a precise figure. But it is critical to have a clear idea of the range of plausible scenarios. I’m happy we’ve done this exploration, and I look forward to building on it.
There’s certainly room to dig deeper into the published work, but that’s beyond the scope of what we’re likely to undertake right now.
It Shouldn’t Be So Hard To Compare Sources
A lot of work went into this post. For the most part, that’s not because the question was inherently tricky. It’s because the sources are hard to work with. News articles and executive summaries present conclusions, but don’t provide enough detail and context to allow you to check their assumptions, or make apples-to-apples comparisons with other sources. Academic and quasi-academic sources drown you in detail, while still not doing a good job of presenting data in a systematic or standardized way or explaining assumptions and terms.
We can do better.
I’ve talked before about the need for better resources to explain the range of expert opinion on climate topics. This will start coming up more often in this blog, as we explore more of these uncertain or controversial topics. I’m hoping that this blog can serve as one small part of the solution. To that end, if you have any light to shed on the topic of this post – energy trends to 2050 – please comment!
Appendix: Data Sources
The projections discussed here come from the following sources:
EIA
A branch of the US federal government, “The U.S. Energy Information Administration (EIA) collects, analyzes, and disseminates independent and impartial energy information to promote sound policymaking, efficient markets, and public understanding of energy and its interaction with the economy and the environment.” They have published the International Energy Outlook every year since 1985. In this report, they model global and regional energy generation and consumption based on existing laws and regulations. It assumes current trends/relationships between supply, demand, and prices. The EIA develops this model as "a baseline for estimating the effects of policy or technology changes" (https://www.eia.gov/pressroom/releases/press487.php). In other words, this is a “business-as-usual” model, minimizing the impact of future technical, commercial, or policy developments.
IEA
The International Energy Agency “is a Paris-based autonomous intergovernmental organisation, established in 1974, that provides policy recommendations, analysis and data on the entire global energy sector, with a recent focus on curbing carbon emissions and reaching global climate targets, including the Paris Agreement. The 31 member countries and 11 association countries of the IEA represent 75% of global energy demand” (Wikipedia).
The IEA special report, titled Net Zero by 2050: A Roadmap for the Global Energy Sector, was requested by the UK government to inform conversations that would occur at COP26. It purports to be "the world's first comprehensive study of how to transition to a net zero energy system by 2050" (https://www.iea.org/news/pathway-to-critical-and-formidable-goal-of-net-zero-emissions-by-2050-is-narrow-but-brings-huge-benefits) and examines three scenarios: Stated Policies, Announced Pledges, and Net-Zero Emissions. The Stated Policies Scenario only takes into account existing policies. The Announced Pledges Case takes into account all commitments by governments, regardless of whether policies exist to support those commitments. Net-Zero Emissions models the actions required to achieve net-zero emissions by 2050. We used the figures from the Net-Zero Emissions model.
IPCC
The Intergovernmental Panel on Climate Change is a UN organization that undertakes the herculean task of consolidating the scientific literature on climate change (and mitigation) and producing consensus reports. The IPCC's special report Global Warming of 1.5º C was drafted in response to an invitation by the United Nations Framework Convention on Climate Change as part of the adoption of the Paris Agreement. The report aims to identify the impacts of global warming of 1.5 degrees Celsius above pre-industrial levels to inform policy decisions and strengthen the global response. There were 19 modeling frameworks and 529 scenarios utilized, all of which represented possible scenarios in which a warming of 1.5 degrees would occur.
IRENA
From the web site:
The International Renewable Energy Agency (IRENA) is a lead global intergovernmental agency for energy transformation that serves as the principal platform for international cooperation, supports countries in their energy transitions, and provides state of the art data and analyses on technology, innovation, policy, finance and investment. IRENA drives the widespread adoption and sustainable use of all forms of renewable energy, including bioenergy, geothermal, hydropower, ocean, solar and wind energy in the pursuit of sustainable development, energy access, and energy security, for economic and social resilience and prosperity and a climate-proof future.
IRENA's 2018 report builds upon a joint report published with the IEA in 2017 titled Perspectives for the Energy Transition: Investment needs for a low-carbon energy system. With the publication of Global Energy Transformation: A Roadmap to 2050, IRENA updates its analysis based on rapidly changing policies and markets. The report sets out to provide a framework for the energy transition for a scenario in which global warming is limited to 2 degrees Celsius with 66% probability.
We present three distinct sets of figures from IRENA:
The 2018 report described above.
Another set of figures from the 2018 report, representing a “business as usual” scenario (rather than assuming sufficient progress to limit warming to 2°C).
Figures from an updated report issued in 2019:
This 2019 edition updates IRENA’s analysis of key countries and regions, and it presents a deepened perspective on electrification with renewable energy – the key enabling solution of the energy transition. The report also details new findings related to the costs, subsidies and investments needed for the transition. IRENA’s socio-economic footprint analysis delves into the implications of the transition, providing footprint measurement in terms of GDP, jobs and welfare. A discussion of the socio-economic implications of carbon taxation is presented. Climate damages have been included into the macroeconomic analysis, bringing about important socio-economic consequences. The need for holistic employment and just transition policies is highlighted by analyzing the implications of the transition on whole-economy and energy sector jobs. The focus also has been strengthened on how high shares of variable renewable energy (VRE) can be integrated into energy systems. In addition to discussion on the role of electrification, solutions for decarbonising heating, cooling and transport demand are also presented.
Alternatively, some of the scenarios target 1.5°C of warming, which corresponds loosely to achieving net zero by 2050.
OK that last one might be a little bit true.
For instance: using renewable heat sources (geothermal or concentrated solar) to drive industrial processes; combusting biofuels; capturing smokestack emissions; or offsets based on true negative-emissions activities such as CO₂ DAC.
We’re using figures from the “Annex A” spreadsheet in the IEA report. The “World_Elec” tab, under “Electricity Generation”, lists “Total generation” for 2050 as 71,167 TWh, which is about 256 EJ. For consumption, the “World_TFC” tab, in the Electricity entry under “Total final consumption”, lists 169 EJ for 2050. I don’t see how these figures can possibly be consistent, but we’ve cross-checked to the best of our ability against other data in this spreadsheet and if this is our error in reading the figures, we’re unable to spot it.
Never let it be said that the IPCC doesn’t do its homework.
I’m referring to figure 2.14, reproduced here. This box plot in fact summarizes several hundred distinct models. I think the “19 models” we’ve been referring to are a particular subset which project 1.5°C of warming, but I’m not sure how that group of 19 models relates to the categories in this box plot.