But what is this EROI (Energy Return on Energy Invested)? And why is it so Important?

 

If you are a lion, you don't just have to run faster than a gazelle; you have to make sure that the metabolic energy you obtain from eating the gazelle is higher than the energy you used for the chase. If not, you die. It is the harsh law of the EROI. 

The concept of Energy Return on Energy Invested (EROI or EROEI) has been around for a long time. It was introduced in its modern form in the 1980s by Charles Hall, but it is steeped in the thermodynamics of non-equilibrium systems. It can be easily understood if you see it as the equivalent of ROI (return on investment). ROI (EROI) is given by the money (energy) returned from a certain investment (energy infrastructure) divided by the monetary (energy) investment. You need a value larger than one in order for your investment to make sense or, if you are a lion, to survive. Large values of this parameter make life easy for investors, energy producers, and lions (although not for gazelles). (*)

Up to recent times, the conventional wisdom was that the EROI of fossil fuels was very high: during the heyday of oil extraction, it was said to be been around 100. Think of an investment that brings back to you back your capital multiplied by one hundred (!!), and you can understand why oil was, and remains, so important for our society. At the same time, the EROI of renewable energy was calculated to be of the order of 5-7, with some studies even placing it under 1. That gave rise to the narrative that only oil and other fossil fuels could sustain an industrial civilization and that renewables were not really so; at best they were "replaceables" as long as there was oil available. The consequence was an emphasis on social and political solutions: degrowth, energy saving, return to a rural economy, or, simply, accepting that we are all going to die soon. 

How fast things change! New studies, including one by Murphy et al., revealed that the EROI of oil may never have been so high. You need to take into account that oil in itself is useless: it needs to be transported, refined, and burned inside inefficient engines to provide energy for society. So, it is correct to calculate the EROI of oil at the "point of use" rather than at the "well mouth." Once that's done, it turns out that oil's EROI may well be (and have been) lower than 10. At the same time, technological progress and scale factors led to an improvement in the EROI of renewables (wind and photovoltaics) well over 10. 

Now, the paradigm is reversed. Renewables are truly renewable, while oil never was. That gives us a chance to revisit the dominant paradigm of how to face the energy crisis. The new paradigm is that we can rebuild a society that works on renewable power. It won't be the same as the one created by oil, and we may have to accept a considerable economic contraction in the process to get there. But it gives us a fighting chance to create a resilient and prosperous society. 

Of course, not everyone agrees on these concepts and there is a lively discussion in which several people are defending the old paradigm. One argument in the discussion says that if you use oil energy to refine oil, that energy should not be  counted in the denominator of the EROI ratio. And, therefore, that the EROI of fossil fuels is much larger than what the recent calculations indicate. This is silly: energy is energy, it doesn't matter where it comes from. Nafeez Ahmed discusses this point in detail in his blog, "The Age of Transformation" saying, among other things, that:

.... petroleum geologist Art Berman published a post also claiming that Murphy et. al’s paper is fundamentally incorrect. He concluded that if Murphy and his co-authors were right, then decades of EROI research showing extremely high values for fossil fuels would be wrong. He repeats the same argument as Hagens, and then uses it to offer a new calculation:

Nearly 9% of the total post-extraction costs for oil are for refining. Yet most of the energy for refining comes from the crude oil and refined products used in the refinery. It is, in effect, co-generated. That doesn’t negate the energy investment needed to operate the refinery but it is not a cost to society as indicated in the table… I divided their 8.9% for refining investment by 3 to account for the co-generation described above (it is probably much lower). The resulting oil EROI is 18. That completely removes the good news from Ahmed’s and Bardi’s proclamations of ‘mission accomplished’ and restores oil EROI to the consensus range for the last two decades.

The key error in this argument is where Berman says: “That doesn’t negate the energy investment needed to operate the refinery but it is not a cost to society as indicated in the table.”

But that is incorrect. The term ‘cost to society’ pertains precisely to energy invested which is not available for use by society. While the energy used to refine the crude oil is co-generated, it is still an input into the refinement process before the oil becomes available for actual work in society at the ‘final energy’ stage. In other words, the energy is being used to refine the oil and is therefore not available for society in any case.

What Berman and Hagens are effectively trying to do is classify the energy used to refine oil as an ‘energy output’ that represents useful work for society outside of the energy system. But this classification doesn’t make sense when we consider that it represents work that is specifically related to making the energy usable for society in the first place - because the oil must be refined and processed before it can actually be converted into usable energy for society.

Berman further questions that if EROI for fossil fuels was much lower, how could it have been so profitable?

As earth system scientist Ugo Bardi has pointed out, the profitability of an industry depends on numerous factors outside the energy system related to credit, markets, economic policy, investment, currency values and beyond. But in addition to that, the bottom line is that Murphy et. al’s research suggests that if oil has been profitable with EROI much lower than previously believed, then previous assumptions about economic prosperity requiring much higher EROI levels are questionable.

Because of the huge efficiency losses of converting energy from oil into useable forms (between 50 and 70% of energy is lost converting primary energy to final energy), as renewables avoid those losses they can produce about 50% less energy to meet demand. This means that the presumed minimum EROI to sustain a viable civilisation derived from fossil fuels could be much lower in a more efficient system.

As Marco Raugei points out, the shift to renewables and electrification “may open the door to achieving the required services with much lower demand for primary energy, which in turn entails that a significantly lower EROI than previously assumed may suffice”.

To learn more about EROI, you can look at these papers

The Role of Energy Return on Energy Invested (EROEI) in Complex Adaptive Systems, by Ilaria Perissi, Alessandro Lavacchi, and Ugo Bardi), Energies, 2021

Peaking Dynamics of the Production Cycle of a Nonrenewable Resource, by Ilaria Perissi, Alessandro Lavacchi, and Ugo Bardi, Sustainability 2023

A Christmas Post: The Miracle of Renewables

by Ugo Bardi

This is a post that I wrote for the Italian newspaper "Il Fatto Quotidiano." For this reason, it is simplified and short, yet it says what's needed to understand the revolution we are going through that will change the world in the coming years. If you are interested in the source of the data on which I am basing my considerations, you can find them on Lazard.com. So, Merry Christmas, and never despair. Sometimes, miracles happen! 

Miracles are not so frequent and, if one has serious health problems, it is not probable that a swim in the Lourdes pool will solve them. However, it is also true that sometimes things change quickly, opening up new possibilities. That's what's happening with renewable energy. Talking about a "miracle" is a bit much, I know, but recent technological developments have made available to us a tool that until a few years ago we didn't even dream of having. And this could solve problems that once seemed unsolvable.

For years, I've been lecturing about climate change and other looming worries, such as oil depletion. Usually, the people who came to listen to me were prepared for a message that was not exactly reassuring, but the question was what to do about it. At the end of the conference, a debate normally ensued in which the same things were said: ride a bicycle, turn down the thermostat in the house, install double glazing panes on the windows, use low energy light bulbs, things like that.

It was a little soothing ritual but, in reality, everyone knew that these weren't real solutions. Not that they're useless, but they're just a light layer of green on a system that continues to depend on fossil fuels to function. We have been talking about double glazing and bicycles for at least twenty years, but CO2 emissions continue to increase as before. Actually, faster than before. If we don't go to the heart of the problem, which is to eliminate fossil fuels, we will get nowhere. But how to do it? Until a few years ago, there seemed to be no way except to go back to tilling the fields by hand, as our ancestors did during the Middle Ages.

But today things have changed radically. You probably didn't notice it, caught up in the debate on politics. But it doesn't matter whether the right or the left wins. Change, the real one, is coming with renewable technologies. Wind and photovoltaic plants have been optimized and scaling factors have generated massive savings in production costs. Today, a kilowatt-hour produced by a photovoltaic panel costs perhaps a factor of 5-10 less than a kilowatt-hour from natural gas (and maybe a factor of 5 less than a nuclear kilowatt-hour) (source). We used to call renewables "alternative energy," but today all others are "alternative."

Furthermore, producing energy with modern renewable technologies does not pollute, does not require non-recyclable materials, does not generate greenhouse gases, does not generate local pollution, and nobody can bomb the sun to leave us without energy. Now, don't make me say that renewables have automatically solved all the problems we have. It is true that today they are cheap, but it is also true that they are not free. Then, investments are needed to adapt energy infrastructure throughout the country, to create energy storage systems, and much more. These are not things that can be done in a month, or even in a few years. There is talk of a decade, at least, to arrive at an energy system based mainly on renewables.

But it is also true that every journey begins with the first step. And now we see ahead of us a road ahead. A road that leads us to a cleaner, more prosperous, and hopefully less violent world. I haven't stopped going around giving conferences but, now, I can propose real solutions. And it's not just me who noticed the change. In the debate, today you can feel the enthusiasm of being able to do something concrete. Many people ask if they can install solar panels at home. Others say they've already done it. Some mad (and rightfully so) at the bureaucracy that prevents them from installing panels on their roof or in their garden. You see the changed trend also on social media.

There is always someone who speaks out against renewables reasoning like the medieval flagellants who went around shouting "remember that you must die". But there are also those who respond in kind, like, "good riddance, live happily in your cave together with the other cavemen." If you have a south-facing balcony (and if your municipality doesn't sabotage your idea), you can already install photovoltaic panels hanging from the railing that will help you reduce your electricity bill. No paperwork needed! (another small miracle). One step at a time, we will succeed!

Flash Gordon's Revenge: the Campaign for Small Wind Turbines

 

By Ugo Bardi

We are seeing the development of a small (or maybe not even so small) PR campaign designed to convince people that small wind turbines are better than PV panels. It goes (or should go) without saying that these turbines are much less efficient than PV panels, they are expensive, unreliable, noisy, require maintenance, and - about the fact that they are "silent" wait a few years to hear the noise of the worn out ball bearings. And let's skip the description of what could happen if they are hit by a serious gust of wind. The one above is especially clunky, it looks like Flash Gordon's spaceship. Fortunately, it seems to be just a rendering of something that doesn't exist in practice.

It is, likely, a rear-guard battle of the fossil lobby to try to slow down the diffusion of photovoltaics. Unfortunately, some people seem to believe that these micro-turbines are useful for something. It shall pass, but, as usual, it will take some time.

https://www.informacion.es/medio-ambiente/2022/12/06/liam-f1-pequeno-silencioso-aerogenerador-79633542.html

The Miracle of Renewables

 

This is the translation (slightly retouched) of an article that I published in the Italian Newspaper "Il Fatto Quotidiano." Apart from a few insults from the usual people, it was a remarkable success. I had many favorable comments, personal contacts, and question on how to move on, in practice, to install renewable plants and produce energy. 

From "Il Fatto Quotidiano" Oct, 8, 2022 

By Ugo Bardi 

We all know that miracles are not so common and, if you have a major health problem, it is not likely that a little swim in the pool at Lourdes will be enough to solve it. However, it is also true that sometimes things change quickly, opening up new possibilities. That is what is happening with renewable energy. To speak of a "miracle" is too much, I know, but recent developments in technology have made available to us a tool that until a few years ago we did not even dream of having. And this may solve problems that once seemed unsolvable.

For years, I went around lecturing about climate change and other troubles ahead, pollution, oil depletion and the like. Usually, those who attended the lectures were people who were prepared for a not-so-optimistic message, but the problem was what to do about it. At the end of the lecture, a debate would follow in which the same things were said over and over again: riding a bicycle, lowering the thermostat in the house, putting double-paned glasses on the windows, using energy-efficient light bulbs, things like that.  

It was a small reassuring ritual but, in practice, everyone knew that these were not real solutions. It's not that these things don't do any good, but they are mostly the spraying of a little green paint on a system that continues to depend on fossil fuels to function. Thus, we have been talking about double glazing and bicycles for at least 20 years, but CO2 emissions continue to rise as before, in fact, faster. Unless we get to the heart of the problem, eliminating fossil fuels, we aren't going anywhere. But how to do it? Until a few years ago, it seemed that there was no way except to go back to tilling the fields as our ancestors did during the Middle Ages. 

But today things have changed dramatically. You probably haven't noticed, caught up in the election debate. But whether the right or the left wins, it changes little: change, the real kind, is coming with renewable technologies. Wind and photovoltaic plants have been optimized, and factors of scale have generated massive production cost savings. Today, a kilowatt-hour produced by a photovoltaic panel costs perhaps a factor of ten less than the kilowatt-hour from natural gas (and also a fifth of the nuclear kilowatt-hour). We used to call renewable energy "alternative," but today it is all the others that are "alternative." Moreover, producing energy with renewable plants does not pollute, does not require non-recyclable materials, does not generate greenhouse gases, is not susceptible to penalties, and no one can bomb the sun to leave us without power. 

Now, don't make me say that renewables have automatically solved all the problems. It is true that they are cheap today, but it is also true that they are not free. Then, it takes investment to adapt the energy infrastructure across the country, create energy storage systems, and much more.  These are not things that can be done in a month, or even in a few years. We are talking about a decade, at a minimum, to get to an energy system based primarily on renewables. But it is also true that every journey begins with the first step. And now we see before us a road ahead. A road that leads us to a cleaner, more prosperous, and hopefully less violent world. 

I haven't stopped going around lecturing but, now, I can propose real solutions. And it is not just me who has realized the change. In the debate, today you can hear the enthusiasm that we can do something concrete. Many people ask if they can install photovoltaic panels at home. Others tell of having already done so. Some are mad (rightly so) at the bureaucracy that prevents them from installing PV panels on their roof or in their backyard. You also see the change in the discussions on social media. There is always someone who speaks against renewables by reasoning like the medieval flagellants who went around shouting "rememberthe  you must die." But there are also those who respond to them in kind, like, "so go ahead and live happily in your grotto with the other cavemen." 

If you have a south-facing balcony (and if your municipality doesn't get in your way), you can already install photovoltaic panels hanging from the railing that will help reduce your electricity bill. One little piece at a time, we will succeed!

The Gold Rush of Photovoltaic Energy: scams are unavoidable, but they might not be a bad sign!

 

Recently, Fox News investigated some companies engaged in selling PV plants to individual customers. As you would have expected, there have been cases in which the customer was promised impossible results. The customer had to pay for plants that didn't work as promised or that could not be connected to the grid for lack of the needed permits. 

It is nothing new. It also happened in Italy some ten years ago, when the government provided a relatively high financial support for PV plants. That led to plenty of people to rush into the market, many of them without the necessary competence, and some being pure scammers. 

It happens every time a market starts lifting off: do you remember the story of the California gold rush of 1849? Lots of scammers would cheat in all possible ways: selling fake digging permits, selling plots where they had "planted" gold nuggets but contained none, or simply robbing the forty-niners. Bad. But is also true that the gold was there for real. 

It is the same for photovoltaic energy: it is the gold of our times. And the gold is there for real: it is the sun. Scams are just a symptom of a true "PV rush" that will lead us out of the current mess. 

The EROI of Photovoltaic Energy is now Higher than that of Crude Oil has Ever Been.

This is an article that I published today in the Italian newspaper "Il Fatto Quotidiano." As a discussion, it is not very deep -- of course, it is written for the general public and these articles have a limit of 650 words. Yet, I think not many people, even among energy specialists, have realized the silent revolution that has turned photovoltaic energy from an expensive, niche technology into something that has an EROEI higher than that of petroleum in the "golden days." Don't expect it to "replace fossil fuels," as some people would expect it to do. It is a different technology, with different capabilities, different applications, with its strong and weak points. But it is starting to change the world, and it will. 

How about hydrogen, the subject of this blog? Well, if we have cheap and abundant energy from PV, we could use hydrogen to store it. But that is an expensive storage solution and will be used (if it is ever used) when all the other possibilities have been exhausted.

 

Photovoltaic Energy is an Opportunity that the Country Should not Miss

Imagine a bank account that pays you 100% interest  That is, after you have deposited 1000 euros, it gives you another thousand euros at the end of the year, and so on every year. You would like a bank account like that!

Obviously, there is no bank account that yields so much, but there are technologies that yield at such levels, albeit not in monetary but in energy terms. There is an article published this month by Fthenakis and Leccisi which reviews the situation and finds a truly excellent yield of photovoltaic technology due to the technological improvements of the last 5-7 years. In practice, for good insolation, as we could have in Southern Europe, a photovoltaic system returns the energy needed to build it in about a year! We are now at the levels of oil during its heyday, when it was abundant and cheap, and perhaps even oil was not doing so well at that time.

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That of Fthenakis and Leccisi is not the only article that comes to this conclusion, all recent studies on the subject come to similar conclusions. A very recent article in “EDP Science” . Basically, the electricity produced by photovoltaic plants is often the cheapest in absolute terms, the growth of installations continues to exceed forecasts, and we are now talking about the "photovoltaic revolution." We face the real possibility of eliminating fossil fuels once and for all from the global energy system.

Now, I know that you are already with your fingers on the keyboard to write in the comments "but the variability?" "I don't want to see panels in front of my house!" "And how about waste ?" and things like that. I know. Everyone knows these things. However, think about that.

We have a technology that costs less than the others, and which is particularly suited to Italy, “the country of the sun.” It allows us to produce energy in our home without having to import it at a high price. We also have the added benefit of having mountains that we can use for storing  energy in the form of hydroelectric reservoirs. There are many other ways to manage variability - it's not an unsolvable problem . Then, about waste and recycling, we will have to invest in it, of course. But keep in mind that photovoltaic systems do not use rare or polluting materials. They can be recycled without major problems and we will certainly do so in the future. At the moment, it is a marginal problem.

In short, photovoltaic energy is an opportunity that we should not miss to relaunch the "country system" in Italy. And, indeed, things are going pretty well. In Italy we have reached 10% of electricity production from photovoltaic energy and it is a good result from which we can start decarbonise to truly the energy system. Certain things seem to have been understood nationally. You can read it in the "Pniec", Integrated National Plan for Energy and Climate, which provides for a fundamental role for renewable technologies, and in particular for photovoltaic energy.

But there remains a resistance rearguard formed by a rather ill-matched coalition that includes the oil companies, the diehard nuclearists, the cold fusion miracleists, those who are still paying the bills for the diesel car they bought, and, in general, a whole section of the environmental movement that rejects any change in the name of a "degrowth" thinking that we'll be happy to stay in the dark and in the cold.

To everyone their opinions but, in practice, at this point the only thing that can block the photovoltaic revolution is bureaucracy, perhaps the only truly "infinite resource" in the universe. On this point too, the government seems to be willing to do something to streamline and speed up the procedures of installation. It won't be easy, but with a little patience, we will get there.