Snippets on Energy #4

Affordability and high EROEI

8 min readDec 13, 2021
Coal mine. Image source: Pixabay

The concept of energy return on energy invested (EROEI) is nothing new: before you can harness any energy resource, you have to invest energy in order to tap into it. In other words: you have to chop down a tree before you can burn it in your stove. There are plenty of studies (see the list of references below) on this metric describing the EROEI of various energy resources. One thing however, gets rarely discussed in relation to this topic. It is a combination of two trends intersecting in the not so distant future... Something, that will have a very profound effect on where we are headed as a civilization.

First, before we delve too deep into the topic, let’s define the basics (skip this and the next paragraph if you feel comfortable with this topic). In order to generate — let’s say — electricity you have to build a power plant (or a hydroelectric dam, a solar panel, wind turbine etc.). Before you could build such an equipment however, you have to mine the raw materials first (recycling does not come into the picture yet), carry them on trucks, trains, ships to a factory, then melt it, forge and manufacture parts from it. Finally you need to deliver and install the end product on site. The same goes for mining coal (using huge machinery, which needs to be built first, then fed with diesel). As well as drilling for oil, using drilling rigs. You have to power these processes all the way through, in order to get the energy you want.

The bad news is, that no equipment lasts forever. Parts break. Materials degrade through wear and tear. Finally, when the bitter end comes for your power plant, solar panels, turbines, etc. you have to decommission them, and start the process all over again. The original energy invested in building them has to be measured against the energy obtained throughout the entire useful lifetime of your equipment. It is basically a comparison of two finite numbers like 10:1 — meaning that you get 10 times the energy during the entire lifetime of the equipment compared to what has been spent on building the said device in the first place. Therefore statements like “infinite EROEI” is a complete nonsense: it would entail an infinite lifetime for the given energy producing equipment (be it a solar panel, wind turbine etc.) — which in reality (even with maintenance) is 20–25 years at best.

Here comes the interesting part. It is extremely difficult to calculate an exact EROEI for a given power source. This is especially true with “renewables” where energy production is highly dependent on the weather and location. Thus, instead of going into details (see the studies below on the topic if you are interested) I would like to highlight a couple of trends, which at least to me, are very disturbing.

As I mentioned earlier in the previous installments of Snippets on Energy (please read those, if you haven’t done so yet) all energy conversion devices require us building stuff, which ultimately requires mining. (The world is yet to see a wind turbine made of hemp and wood — alone.) Recycling in many cases is simply not an option: it either costs even more energy than mining, or it is simply not possible technically. Besides, we are talking about building out a brand new, not yet existing infrastructure here to replace fossil fuels, right? All these new panels and turbines will have to be made from scratch. The question of recycling comes thereafter.

In order to do this, especially at an exponential rate (increasing “renewable” capacity 7–10% per year is exponential) we would require similar increases in energy supply — mostly from fossil fuels — until the new power sources take over. Remember, all this energy spending has to come up front (i.e.: burning even more carbon today to have “clean” energy later)… And it would have to take place in an already critical decade in “tackling” climate change, where emissions would need to fall 7–10% a year, and not increase by this amount…

And this is far from being the worst part. In the 2nd installment of this series I’ve already touched on the topic of degrading ores when it comes to mining. In a nutshell: humanity has mined the best ores first (containing 30 to 40 pounds of metal in every 100 pounds of ore). Now we are down to 1–2 pounds in terms of copper. In some cases below 1. For every 100 pounds of rock. The rest? Spoils. Imagine the energy used up in blasting, shoveling, carrying, grinding almost bare rocks. Only to throw away 99% of them immediately. And this is not a single occasion in an unfortunate mine. It is a trend across the entire mining industry. Sure, there are plenty of metals and silicon in Earth’s crust, but the lucky strikes with high concentrations were already depleted a long time ago. The rest is diffused, scattered and buried deep around the globe… Just like oil. It takes more and more energy, year after year to get the same amount of metals or oil — not to mention increasing their “production” by 7–10% annually (as required by the energy transition). If we would like to keep up with this trend, we would have to double the energy spent on energy every decade or so, till the energy invested (in mining, smelting, manufacturing) starts to equal the energy produced.

This is the first trend of the two intersecting lines: the exponentially increasing energy requirement and pollution load on building out new sources of power. The extreme low likelihood of all this, amidst a rapidly escalating climate crisis, depleting oil, gas and coal reserves (providing the energy for mining) is what really scares me. If this is true, we will quickly (well before the end of this century) reach a point, where we will no longer have the means to increase the intensity in mining, both for the lack of fuels to do so, and the for the ever smaller returns on our efforts. This is economic resource depletion.

The economy is powered by what is left of the energy produced, after building out and maintaining the required energy infrastructure. For your reference: back in the first half of the 20th century the energy return on oil was close to 100:1, now it’s down to 15:1 globally. The same trend is under way for “renewables”. As rich deposits of the necessary ores deplete, and ever more earth has to be mined and moved to get the desired material, we will soon see a deterioration of the energy return for wind and solar too. In 2010 solar had 11:1 — still worse than oil. While efficiency of the panels did increase, there is a physical limit to it. In the meantime ore quality is just degrading and degrading… and will soon turn energy return on investment for “renewables” into decreasing trend. Something to watch out for.

It’s no wonder we see an economic slowdown: despite increasing energy production we get a smaller and smaller amount back. And this is not a single event. Nor a bad day. This is a trend, which will continue well into the future. The increase in energy available for society will stop at some point (if it haven’t already), then will inevitable start to decrease.

This leads us to the second aspect of EROEI. Namely: we need a high enough return on energy. Not only to build new stuff, but to maintain existing infrastructure too. Dams. Roads. Bridges. Pipelines. High voltage transmission lines. All what is needed for a functioning civilization. (And none of which is part of an EROEI calculation.) All this infrastructure has grown exponentially since World War II — and as a result, an increasing amount of it starts showing its age year after year. The more we have built 50 years ago, the more we have to replace now.

The difference? Half a century (or more) ago, when a new, previously non-existing bridge or road was built, it has brought prosperity and new businesses to the area. Now? We have to rebuild them, so we do not loose these businesses. Back then, it meant growth. Now it means avoiding recession.

In a time of declining available net energy however (due to worsening EROEI and gradual depletion of oil and other raw materials) infrastructure maintenance will come as an additional pressure on surplus energy, making it disappear much faster and more suddenly than expected.

Illustrating the disappearance of surplus energy (1)

The energy available for economic activities (represented by green bars above) is thus in a double whammy. Economic resource depletion (the ever increasing energy inputs required to get less and less) eats it from the top, while growing maintenance costs eat it from below. And we haven’t factored in the losses due to climate change, already costing billions of dollars to repair — and expected to increase with rising temperatures.

We are very close to a point, where we will be loosing the energy needed to mine more minerals and as a result loose the ability to build more energy harvesting machines and repair the ageing infrastructure. This could quickly turn into a self-reinforcing feedback loop, where we would have less and less energy, materials, roads, bridges, transmission lines year over year…

If governments around the world were to stick to the myth of infinite growth and the current status quo, the “only” option to stave this rather unwelcome effect off for a few more years would be to neglect infrastructure repair. First in the hinterlands, then in rural areas, focusing every effort on maintaining large population centers (cities), then to defend the well-to-do areas exclusively. Our “renewable”, or any material future for that matter, will be increasingly “reserved” for a selected few as a result. Those who will be able to afford the increasing costs of technology (due to real material scarcity) will do relatively fine — at least for a while. The high tech, solar powered, AI driven, battery-electric future is for them, but unfortunately not for the masses. We will see how this two tier would will unfold in the coming decades (2).

The energy crunch of this autumn-winter season is just another episode in this long saga of slowly disappearing surplus energy. One, which will continue to be marked by wild price swings and physical shortages — a mix of ever increasing costs of “production” and society’s inability to meet those costs. This decade has the potential to make it clear, that cheap energy and abundant resources were the two cornerstones of the single biggest anomaly — 200 years of exponential growth — in human history. Both of which seems to be more like our past, than our future.

Until next time,



(1) The height of the bars and curvature of these trends are purely illustrative (together with the end date). My purpose was to show that these converging trends quite possibly intersect still within the lifetime of people living today. Considering the risks involved this topic, it would well deserve a decent research (if it hasn’t been done yet).

(2) The other option would be a managed de-growth — especially for the developed nations. While this would make perfect sense in an increasingly energy deprived world, lack of awareness of this topic would prevent meaningful discussion. I see a much higher chance of a populist dictator rise to power on the back of a desperate middle-class, than the wealthy shedding their wealth (and consumption) voluntarily.


Mines, Minerals, and “Green” Energy: A Reality Check

The Mining of Minerals and the Limits to Growth

Estimating decades-long trends in petroleum field energy return on investment (EROI) with an engineering-based model

The implications of the declining energy return on investment of oil production

Energy Reality for the USA

EROI of different fuels and the implications for society




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