Exponential Growth Towards a Sustainable Future: the Limits of Solar Panel and Wind Turbine Production

Solar plant near Rüdersdorf, Germany 2014, © Molgreen, CC BY-SA 4.0

(Reblogged from blog.wozukunft.de)

Guest post by Gregor Hagedorn

Many people, including myself, fear that the great acceleration (1, 2) of our consumption and destruction of resources such as land, biodiversity, soil, minerals, and fossil energy sources, could lead us into a catastrophe. Other people point out the positive side of near-exponential growth in various fields: renewable energy production, "biotechnology and bioinformatics; computational systems; networks and sensors; artificial intelligence; robotics; digital manufacturing; medicine; and nanomaterials and nanotechnology" (Peter H. Diamandis & Steven Kotler 2012. Abundance: The Future Is Better Than You Think). Others propose that the roadmap to prevent the climate catastrophe should follow an exponential "carbon law", modeled on Moore's law for the semiconductor industry (Rockström et al 2017).

Exponential growth models leading towards sustainability certainly offer hope. An example might be the renewable energy transition: the growth of cumulative solar energy capacity is indeed almost exponential.

Exponential Growth in Renewable Energy Production Capacity. The gray target final energy capacity is assumed to be slowly increasing as a result of a combination of energy savings in rich countries and equitable growth in poor countries. (© Gregor Hagedorn, CC BY-SA 4.0)

However, looking at the graph, it is clear that the assumption of unchecked exponential growth makes no sense. An extrapolation of the historical annual growth rate (39.14%) means that the final doubling of capacity occurs in the last 25.2 months. Huge productions facilities would have to be built for the necessary solar panel and wind turbines – to be used only for a very short time.

Most scientist and economists are aware of this, but I have experienced many lay people and politicians taking “exponential problem solving” at face value – which may be a problem.

Renewable energy capacity growth as an example

What would a more realistic model be? As a biologist, I am acquainted with logistic growth models limited by a capacity factor such as the available food or land. But organisms will reproduce until the capacity is exhausted, often going into overshoot followed by a period of population collapse (die-off). Humans have foresight (at least sometimes). And investors usually calculate the profitability of investments.

Bardi & Sgouridis 2017 evaluate the effect of time of return on energy investment of renewable energy production installations (e.g. photovoltaic installations, wind parks). In my understanding, this is relevant but different from the effect of the economic return on investment on the factories producing the solar panels, wind turbines, etc. What effect does a minimum life-span of these factories have on the energy transition? As I could not find a publication (please comment, if you know one!), I decided to investigate this.

As I could not find a publication (please comment, if you know one!), I decided to investigate it myself. I will focus on a single of these transformation dynamics, the economics of investing. This is not meant to be a comprehensive model, encompassing the complexities of the real world and aimed at making actual predictions. I think of it more as a thought experiment to estimate the difference between exponential growth and a reasonable return-on-investment on production facilities under otherwise ideal growth conditions. Basically, I assume that any new factory should be running, with reinvestments and upgrades, for 30 years. The following indented text documents the assumptions behind the model (skip ahead, if you like).

1. To simplify, I use the capacity growth value for solar photovoltaic panels (0.105 GW 1992 to 405 GW projection 2017, = 39.14% annual or 2.78% monthly growth) as representative for the entire renewable energy mix needed in the future (the combined growth rate of wind turbines, concentrated solar, geothermal, etc. would lead to a more complex and more realistic picture).

2. Global Final energy consumption values are from Wikipedia (partly interpolated and partly estimated from primary energy supply).

3. After 2014, consumption is extrapolated using assumptions about energy savings and equitable growth needed for poorer countries. I assume that the combination of energy savings and additional energy needed for equitable growth for a good life on 9-12 billion humans will be doubling global final energy consumption between 2014 and 2100 to about 220 PWh/year. The slope of this increase is significantly smaller than the past increase, but the sudden transition into linear growth is a strong simplification. The end result roughly matches the common assumption of a demand of 2kW average equivalent power/person in 2100 (see., e.g., Bardi & Sgouridis 2017); 12 billion people * 2 kW = 24 TW average = ca. 210 PWh/year.

4. Global final renewable energy capacity is calculated by assuming we need 8 × average output as peak output; compensating for within-day volatility, seasonal volatility requiring long-term storage, average capacity factor (cloudy/non-windy days), regional volatility (if Portugal and Germany are to supply each other to reduce volatility, they both need large excess capacity). This is a wild guess. The capacity factor for solar in Germany is around 10%, wind between 20 and 50%, but we talk global here and I have not good data for a global average. Please help if you can provide better global, cross-technology estimates for the relation between peak capacity and annual final renewable energy consumption!

5. The model assumes that factories producing solar panels, concentrated solar plants, wind turbines, etc., require a production time of 30 years for an economic return on investment.

6. During this time, re-investments occur making production cheaper or increasing the production capacity (higher wind turbine/solar panel output, or more efficient technologies, generating more power per item). Since both solar panels and wind turbines are relatively mature technologies, I assume an increase in capacity for a given factory of 30% over the 30-year lifetime (modeled as 1.32% per year in the first 20 years, with no further investments and gains in the final years). Again, this is a wild guess; better estimates are most welcome. (Different assumption for improvement rates change the outcome only marginally since it is mostly equivalent to the addition of small factories with a shorter lifespan, decreasing the average lifespan of a factory per production capacity.)

7. The model includes a replacement rate for older renewable energy installations. The aging-related yearly capacity loss of various renewable energy solutions (e.g. 0.5-1% in solar panels) is ignored here, considering the assumptions for overcapacity above. For solar the panel warranty is usually 20-25 years, but usability may be much longer. I assume 20% replacement for yearly cohorts after each of 20, 25, 30, 40, and 50 years (i.e. max lifespan 50 years). The 20-year category includes replacements for storm damages, etc.

8. After 2051, the production time of some factories is extended for a number of years, to reduce the ensuing production fluctuations. Again: The real world is much more complex. Investment into production plants depends on many economic factors: workers, capital, interest rates, location and regional planning, regulatory conditions, supply chains for raw material and preprocessed parts, etc. And, again, this is no prediction model, but a mind-sized analysis of one factor!

The resulting graph looks like:

Factory-depreciation-limited (blue) versus exponential growth (yellow) in renewable energy production (© Gregor Hagedorn, CC BY-SA 4.0)

What did I learn?

"Exponential growth" only matters in the beginning. The vast majority of capacity increase happens between 2027 and 2051 in a near-linear fashion. Under the parameters chosen, only 7.8% of the capacity is produced under the exponential growth model. Clearly, this result depends on the growth rate and the expected lifespan of production facilities for solar panels, concentrated solar power, wind turbines, etc. The result will be similar whenever the factory lifespan is similar to the time it takes to reach the capacity growth target.

Some additional, minor observations (skip ahead, if you like):

1. Whereas under a fully exponential calculation the energy production capacity for 100% Renewable Energy is reached 2034, it takes until 2051 in the present calculation. (Note that this may still allow reaching the Paris climate goals; but also note that the calculation does not deal with issues like volatility, storage, transport, stranded assets, etc.).

2. With regard to new production capacity (factories) in the present calculation: 2027 is "peak acceleration", followed by five years in which production capacity continues to increase, but with less new capacity each year. And that is it. Under the (arbitrary!) assumption that you need at least 30 years return on investment into a new plant, it would be uneconomical to build additional production facilities between 2033 and 2051. From 20151 on, replacement of older factories and increasing demand for solar panel and wind turbine replacement creates a new market for the establishment of new production facilities.

3. Between 2051 and 2100, a period of alternating over- and underproduction occurs in the present calculation, which uses global yearly factory cohorts and an inflexible re-investment / capacity upgrade scheme. In reality, many individual factories would have different lifetimes, be upgraded at different times, and some factories might make losses and be closed prematurely. All of this would enable the markets to track demand more flexible. Still, being able to track a market which transitions from a strong growth market to a weak growth market which then transitions into an increasingly strong replacement market will be a challenge. Some Lotka–Volterra-like oscillations are in fact not uncommon in markets, see, e.g., the DRAM production in the semiconductor industry.

4. The production capacity for solar panels, wind turbines, etc. in 2017 is about 114 GWpeak/year (please comment if you think this number is incorrect!). Under my assumptions (and in order to achieve the target capacity by 2051), production capacity must very quickly rise to about 5700 GWpeak/year in 2032. It then grows slowly, through productivity increases in existing factories to a peak of 6643 GWpeak/year in 2047. The exact values and years depend on many assumptions in this calculation and are likely to be only very rough estimates. However, the estimates show that building sufficient production capacity for the energy transition is a huge challenge – and a huge market opportunity.

5. Comparing the results with the return-on-energy models from Sgouridis et al. 2016 (see the crude graph below): a) total peak capacity in 2075 is about 100 TWpeak, less than then 165 TWpeak in our calculation; b) total capacity is falling after 2050 in Sgouridis et al. 2016; c) the main growth occurs about 8 years earlier; d) the transition towards capacity is smoother, i.e. in the last 8 years capacity is added slower than in my (purely factory-output-optimized) model.

Comparison of model with result of Sgouridis et al. 2016 (© Gregor Hagedorn, CC BY-SA 4.0)

General Conclusions

The idea that a future acceleration of technological progress at an exponential rate will solve many problems has several proponents, the best known of which are perhaps Diamandis & Kotler. Their 2012 book has been widely reviewed and criticized. Patrick Tucker (2012, An Awesome Adventure to the Future) applauds them for encouraging the view that problems can be solved. But as Dale Carrico (2012, Schlock and Awesome; Or, The Futurists Are Worse Than You Think) points out, uncritical wishful thinking without regard to problems and limitations is "escapism from the real present, what it offers as solutions are nothing but distractions from problems". Gregor Macdonald (2012. 'Cornucopians in Space' Deliver a Dangerously Misguided Message – Optimism has its dangers) notes that Diamandis "is an adherent to the notion that exponential growth in technology will eventually reach a crescendo, thus offering humankind super-solutions at a kind of hyperspeed rate of change." But while technological progress is helpful and welcome, "the magnitude of the world’s present challenges cannot wait for the array of potential solutions that may start to work". He warns that "celebrating the success of solutions before they have actually arrived – indeed, well before they have arrived, is no solution at all". Michael Marien (2012, globalforesightsbooks Book of the Month) observes that the "techno-ecstatic focus of Singularity … serves to obscure the need for “soft” social technology that is of equal if not greater importance" and "questions are ignored about how the new abundance will be distributed in a world of massive and increasing inequality, where many governments are running huge deficits and hamstrung by ideological gridlock and obsolete ideas", conceding that "As inspirational futurism suggesting possibilities of a better world for all, there are certainly many good budding ideas here that may bloom."

Some of the general problems of belief in unchecked growth are very nicely exposed by Tom Murphy (2012, Exponential Economist Meets Finite Physicist) - highly recommended!

One of my own conclusions is, that exponential decay, such as the aforementioned "carbon law", makes more sense than the growth case. Overall, however, the assumption that initial large reductions can be achieved with relatively low investment, followed by decreasing reductions at increasing cost is more plausible than the case of exponential growth. Again, this cannot be repeated forever, as cost becomes prohibitive, but this is not really necessary to achieve the goals intended by the "carbon law" proposal.

My own view is that it is good to point out signs of hope and progress (some of my favorites are, e.g., Hans, Ola & Anna Rosling - do read the new book 'Factfulness', Max Roser and his co-workers, or Dina D. Pomeranz). And we all hope that innovation can solve at least some of our problems.

However, most people already expect miracles from technology. While innovation may follow exponential growth for some time, this will in all likelihood always change to a different growth model over time¹. The calculations above are only an example.

Scientific limits of the earth system, economic limits (as in the example above), sociological and psychological limits of humans and their societies, as well as the potential for exponential technological growth, need to be viewed together. Ignoring parts of the system will not lead to a solution.

But worse: I see the perceived need for and the creed in endless future technological innovation as a distraction. As misleading. as prolonging our current phase of procrastination and not solving the many problems we can already solve right now.

It is not true that we are currently desperately trying to survive and have no other option than to send our own children into a slavery of food, energy and resource scarcity. It is not true that our only chance is to hope for yet non-existent technologies.

The truth is: We have the technologies, we can solve the energy (see, e.g., Bardi & Sgouridis 2017), food, biodiversity, transportation, equity, etc. problems.

But we are not using the solutions at the necessary scale. We are procrastinating and seeking excuses: whether it is that the problem cannot be solved or that they will solve themselves thanks to a sudden explosion of exponentially growing innovation. We are celebrating ourselves in the media for deploying positive solutions at small scales. At the same time, we are directing the general economy through taxes, tariffs, and subsidies at many orders of magnitude into the opposite, destructive direction.

We are not building a house for our children, we are burning it down. Our greed for money, for personal power and sex, for eating meat and other luxury foods, for playing with ivory tower problems has us care more about ourselves than about the future of our children.


Notes
¹ I believe this even applies to the tech development under the scenario of technological singularity, wiping out humanity – but this is a different discussion...

 

References

Ugo Bardi & Sgouris Sgouridis 2017. In Support of a Physics-Based Energy Transition Planning: Sowing Our Future Energy Needs. BioPhysical Economics and Resource Quality, December 2017, 2:14, doi:10.1007/s41247-017-0031-2

Rockström, Gaffney, Rogelj, Meinshausen, Nakicenovic, Schellnhuber 2017. A roadmap for rapid decarbonization. Science 355: 1269-1271. doi:10.1126/science.aah3443

Sgouris Sgouridis, Denes Csala & Ugo Bardi 2016.The sower's way: quantifying the narrowing net-energy pathways to a global energy transition. Environmental Research Letters, Volume 11, Number 9. http://iopscience.iop.org/article/10.1088/1748-9326/11/9/094009/meta

(© Gregor Hagedorn 2018, CC BY-SA 4.0, first publ. 2018-05-15, last updated 2018-06-11. Image: a cropped version of Photovoltaic installation near Rüdersdorf, Germany, © Molgreen, CC BY-SA 4.0)

The View from Les Houches: Of Rare Metals and Cute Kittens

Les Houches, March 2018. José Halloy of the Université Paris Diderot discusses mineral depletion in his presentation. Note how he utilizes Hubbert curves to estimate the trajectory of mineral extraction. He predicted that the dearth of very rare elements will negatively affect the electronics industry, perhaps killing it completely.

José Halloy's presentation at the Les Houches school of physics was focused on the availability of rare minerals for electronics. This is a problem that's rarely discussed outside the specialized world of the "catastrophists", that is of those who think that mineral supply may be strongly restricted by depletion in a non-remote future. In this field, Halloy seemed to side with the "hard" catastrophists, that is expressing the option that depletion will make certain things, perhaps even the whole electronics industry, impossible.

The problem, indeed, is there: modern electronics is based on the unrestricted use of very rare minerals - the term "very rare" indicates those elements which are present only in traces in the earth's crust and which, normally, do not form exploitable deposits of their own. If you pick up your smartphone, you probably know that it contains several of these very rare elements gallium (for the transistors), indium (for the screen), tantalum (for the condensers), gold (for the electric contacts) and more.

Most of these elements are "hitch-hikers" in the sense that they are produced as impurities extracted from the production of other elements: for instance, gallium is a byproduct of aluminum production. Whether we can continue to supply these elements to the electronic industry in the future depends on a host of factors, including whether we can continue to extract aluminum from its ores. In this sense, recycling is not a good thing since recycled aluminum, of course, does not contain gallium, because it has already been extracted during the refining phase. Note also that recycling tiny amount of very rare elements from electronic devices is extremely difficult and very costly. So, in the future, the supply of these elements is going to become problematic, to say the least.

Does it mean the end of electronics? José Halloy seemed to be very pessimistic in this sense, but I think the question was not posed in the correct way. If you ask whether current electronic devices can survive the future dearth or rare mineral, the answer is obvious: they can't. But the correct question is a different one: what kind of electronic devices can we build without these elements?

Here, I think we face a scarcely explored area. So far, the industry has been produced all kind of devices focusing solely on performance on the basis of the assumption that there aren't - and there won't ever be - mineral supply problems. Can we make a smartphone without gallium, indium and all the rest? That is, limiting the elements used to the basic ones, silicon, aluminum, and other common materials? It is a difficult question to answer because, really, it has never been addressed, so far.

Yet, I think there are excellent possibilities to develop a new generation of electronic devices which are both using very little (and perhaps zero) rare elements and which are designed for complete (or nearly complete) recycling. The basic element of all electronic circuits, transistors, can be made using silicon and, in general, there are alternatives to rare metals for most devices, even though in most cases not with the same performance. For instance, light emitting diodes (LEDs) are currently based on gallium nitride (GaN) and there seem to be no comparable substitutes. Without LED, we would have to go back to the old cathode ray tubes (CRTs) which we consider primitive today. But, after all,  CRTs performed well enough for us up to not many years ago. So, it would be an inconvenience, but not the end of the world.

So, it is clear that we'll have to settle on reduced performance if we want an electronics without rare elements, perhaps on a strongly reduced performance. But maybe we don't need the kind of performance we have been used to in order to keep going. Think about your smartphone: it is an incredibly complex and powerful device used mostly for trivial tasks such as looking at clips of cute kittens and sending likes and thumbs-up to other machines. Does "civilization" really need these devices? It is all to be seen.

For a fascinating discussion of an industrialized world running without rare metals, see the excellent book by Pierre Bihouix "L'age Des Low Tech" (in French - alas!)

The View From Les Houches: Saving the World Using Physics

 Above, Carey King from the University of Austin, Texas, shows his Trump socks during his talk at the meeting of the School of Physics in Les Houches, France. I strongly suggest to read King's hugely interesting paper titled Information Theory to Assess Relations Between Energy and Structure of the U.S. Economy Over Time. You may find in it aswers to questions you have been asking yourself for a long time.

The School of Physics in Les Houches, France held a session on Energy Transitions during the week from March 4th to March 9, 2018. About 70 scientists, mostly physicists, gathered in a remote village in the French Alps to discuss the energy transition, the supply of mineral resources, and climate change.

It was one more attempt by scientists to save the world. Having been there, I can say that the task is difficult but this group managed to come up with several good ideas, some of which might even work.


In future posts, I'll try to summarize some of the talks at the school. For the time being, let me just thank the organizers for the good experience:


Hervé Bercegol
Marie Degremont
Zeynep Kahraman
Jacques Treiner

Why EROEI matters: the role of net energy in the survival of civilization

The image above was shown by Charlie Hall in a recent presentation that he gave in Princeton. It seems logic that the more net energy is available for a civilization, the more that civilization can do, say, build cathedrals, create art, explore space, and more. But what's needed, exactly, for a civilization to exist? Maybe very high values of the EROEI (energy return on energy invested) are not necessary.

A lively debate is ongoing on what should be the minimum energy return for energy invested (EROEI) in order to sustain a civilization. Clearly, one always wants the best returns for one's investments. And, of course, investing in something that provides a return smaller than the investment is a bad idea. So, a civilization grows and prosper on the net energy it receives, that is the energy produced minus the energy required to sustain production. The question is whether the transition from fossil fuels to renewables could provide enough energy to keep civilization alive in a form not too different from the present one.

It is often said that the prosperity of our society is the result of the high EROEI of crude oil as it was in mid 20th century. Values as high as 100 are often cited, but these are probably widely off the mark. The data reported in a 2014 study by Dave Murphy indicate that the average EROEI of crude oil worldwide could have been around 35 in the past, declining to around 20 at present. Dale et al. estimate (2011) that the average EROEI of crude oil could have been, at most, around 45 in the 1960s Data for the US production indicate an EROEI around 20 in the 1950s; down to about 10 today.

We see that the EROEI of oil is not easy to estimate but we can say at least two things: 1) our civilization was built on an energy source with an EROEI around 30-40. 2) the EROEI of oil has been going down, owing to the depletion of the most profitable (high EROEI) wells. Today, we may be producing crude oil at EROEIs between 10 and 20 on the average, and the net energy yield keeps going down.

Let's move to renewables. Here, the debate often becomes dominated by emotional or political factors that seem to bring people to try to disparage renewables as much as possible. Some evidently wrong assessments, for instance, claim EROEIs smaller than one for the most promising renewable technology, photovoltaics (PV). In other cases, the game consists in enlarging the boundaries of the calculation, adding costs not directly related to the exploitation of the resource. That's why we should compare what's comparable; that is, use the same rules for evaluating the EROEI of fossil fuels and of renewable energy. If we do that, we find that, for instance, photovoltaics has an EROEI around 10. Wind energy does better than that, with an average EROEI around 20. Not bad, but not as large as crude oil in the good old days.

Now, for the mother of all questions: on the basis of these data, can renewables replace the increasing energy expensive oil and sustain civilization? Here, we venture into a difficult field: what do we mean exactly as a "civilization"? What kind of civilization? Could it build cathedrals? Would it include driving SUVs? How about plane trips to Hawaii?

Here, some people are very pessimistic and not just about SUVs and plane trips. On the basis of the fact that the EROEI of renewables is smaller than that of crude oil, considering also the expense of the infrastructure needed to adapt our society to the kind of energy produced by renewables, they conclude that "renewables cannot sustain a civilization that can sustain renewables." (a little like Groucho Marx's joke, "I wouldn't want to belong to a club that accepts people like me as members.").

Maybe, but I beg to differ. Let me explain with an example. Suppose, just for the sake of argument, that the energy source that powers society has an EROEI equal to 2. You would think that this is an abysmally low value and that it couldn't support anything more than a society of mountain shepherds or not even that. But think about what an EROEI of 2 implies: for each energy producing plant in operation there must be a second one of the same size that only produces the energy that will be used to replace both plants after that they have gone through their lifetime. And the energy produced by the first plant is net energy fully available to society for all the needed uses, including cathedrals if needed. Now, consider a power source that has an EROEI= infinity; then you don't need the second plant or, if you have it, you can make twice as many cathedrals. In the end, the difference between two and infinity in terms the investments necessary to maintain the energy producing system is only a factor of two.

It is like that: the EROEI is a strongly non-linear measurement. You can see that in the well-known diagram below (here in a simplified version, some people trace a vertical line in the graph indicating the "minimum EROEI needed for civilization", which I think is unjustified)):

You see that oil, wind, coal, and solar are all in the same range. As long as the EROEI is higher than about 5-10, the energy return is reasonably good, at most you have to re-invest 10% of the production to keep the system going. It is only when the EROEI becomes smaller than ca. 2 that things become awkward. So, it doesn't seem to be so difficult to support a complex civilization with the technologies we have. Maybe trips to Hawaii and SUVs wouldn't be included in a PV-based society (note the low EROEI of biofuels) but about art, science, health care, and the like, well, what's the problem?

Actually, there is a problem. It has to do with growth. Let me go back to the example I made before, that of a hypothetical energy technology that has an EROEI = 2. If this energy return is calculated over a lifetime of 25 years, it means that the best that can be done in terms of growth is to double the number of plants over 25 years, a yearly growth rate of less than 3%. And that in the hypothesis that all the energy produced by the plants would go to make more plants which, of course, makes no sense. If we assume that, say, 10% of the energy produced is invested in new plants then, with EROEI=2, growth can be at most of the order of 0.3%. Even with an EROEI =10, we can't reasonably expect renewables to push their own growth at rates higher than 1%-2%(*). Things were different in the good old days, up to about 1970, when, with an EROEI around 40, crude oil production grew at a yearly rate of 7%. It seemed normal, at that time, but it was the result of very special conditions.

Our society is fixated on growth and people seem to be unable to conceive that it could be otherwise. But renewables, with the present values of the EROEI, can't support a fast growing society. But is that a bad thing? I wouldn't say so. We have grown enough with crude oil, actually way too much. Slowing down, and even going back a little, can only improve the situation.





(*) The present problem is not to keep the unsustainable growth rates that society is accustomed to. It is how to grow renewable energy fast enough to replace fossil fuels before depletion or climate change (or both) destroy us. This is a difficult but not impossible task. The current fraction of energy produced by wind and solar combined is less than 2% of the final consumption (see p. 28 of the REN21 report), so we need a yearly growth of more than 10% to replace fossils by 2050. Right now, both solar and wind are growing at more than a 20% yearly rate, but this high rate is obtained using energy from fossil fuels. The calculations indicate that it is possible to keep these growth rates while gradually phasing out fossil fuels by 2050, as described here

Prime Minister Matteo Renzi gave a powerful speech on the need of acting against climate change..... or did he?

The international media seem to be fascinated by the similarities in the physical aspect of Mr. Bean and of Mr. Matteo Renzi, prime minister of the Italian Government. There may be some similarities, indeed, but it is also true that Mr. Renzi is a shrewd politician who can be seen as a good example of a political style that privileges form over substance.

A few days ago, Mr. Renzi, Italy's prime minister, attended a meeting on the climate situation. He was praised for having taken a stance against climate change, but I think his speech is a good example of how a smart politician can say a lot and, at the same time, say nothing. It is a political style that is not specific to Italy, but is, rather, universal today.

So, I took the liberty of translating some of Mr. Renzi's statements at the meeting on climate, (as reported here) and adding their real meaning as Mr. Renzi himself could have done. (boldface: Mr. Renzi actual statements)



"I don't believe in a culture of negativity and of pessimism, I am optimist, but it is necessary to assume one's responsibilities and the time of choices is today" - So, I am starting with this remarkable platitude, and don't think I'll stop here!

"...to say that for us climate is a priority means to give back a sense of identity to our country..." which is, of course, another platitude, but it serves a purpose: note that I said "a" priority and I didn't say which are the other priorities so that, as you may well imagine, there will always be some priority higher than climate (and in a moment I'll tell you what these priorities are).

"Today, our enemy is coal", and I can say this because in Italy we use little coal, so that I can make a bugaboo out of it without offending the fossil fuel lobbies that finance my government. Besides, it is an excellent idea because it gives me a chance to say that other fossil fuels are clean in comparison.

"In 40-50 years we'll need to go well beyond the fight against coal"  And notice that what I really mean is that we don't need to do anything for at least 40-50 years. This, at least, explains what I really think about climate change.

"We need to be able to say things as they stand, that is, that renewables, alone, are not enough." Which doesn't mean I know anything about renewables, of course, but just that I represent a different lobby. 

"Neither oil nor gas will run out tomorrow morning" And, if you are really, really dumb, now I am explicitly stating what are my priorities. Are you happy, now?

The sower's strategy: how to speed up the sustainable energy transition

This text was originally published as part of "Disrupting the Future", a series of essays correlated to "2052", a book by Jorgen Randers


by Ugo Bardi - 2013

… and when he sowed, some seeds fell by the wayside, and the fowls came and devoured them up: some fell upon stony places, where they had not much earth and forthwith they sprung up, because they had no deepness of earth: and when the sun was up, they were scorched; and because they had no root, they withered away. And some fell among thorns; and the thorns sprung up, and choked them: but other fell into good ground, and brought forth fruit, some a hundredfold, some sixtyfold, some thirtyfold. Who hath ears to hear, let him hear. (Matthew 13.4-9).

Abstract. In order to survive the double threat of resource depletion and climate change we need to move as quickly as possible to a sustainable society based on renewable resources. We are already moving in that direction, but we are still investing huge amounts of money to perpetuate our dependency on fossil fuels. Here, I argue that the transition can be eased and accelerated if we adopt the “sower's strategy.” Farmers, as well know, must not eat their seed corn; they must keep some of the harvest for the future. Applied to the world's economy, the sower's strategy dictates that we use part of the energy and resources produced by means of fossil fuels to build renewable energy plants and a sustainable economy. This strategy is primarily something to be agreed upon but it could also be embodied in an international protocol (the “sower's protocol”?) that would mandate that a fraction of the worldwide revenues from fossil fuels should be invested in sustainability and renewable energy. 


“Don't eat your seed corn!” is a well known saying. It refers to the age-old farmer's strategy of saving some of the harvest of the current year as seeds for the next. Unfortunately, however, our main energy source today, fossil fuels, produce no “seeds.” Once extracted and used, they are gone forever and the same is true for all our mineral resources. This is what we call “depletion.” In addition, fossil fuel burning is the main cause of climate change; an even more worrisome problem.

So far, we have been behaving like farmers who eat their seed corn; burning fossil fuels and consuming our resources as fast as possible. And we are still investing enormous amounts of money just to continue doing that. According to the Grantham research institute, about 650 billion dollars were spent to develop new fossil fuel resources in 2012, mainly for oil and gas and, in particular, for the so called “non conventional resources” (e.g., shale oil). This is the result of our current way of thinking which emphasizes short term gains. Not only does this strategy worsen the climate problem, but it forces us to spend more and more as depletion progresses and that perpetuates our dependence on fossil fuels. Obviously, that can't continue for a long time.

Is there a way out? Yes, if we go back to the wisdom of ancient farmers: don't eat your seed corn! Of course, we can't sow fossil fuels but we can sow what these fuels provide: energy and minerals. We can use some of this energy and these minerals as seed to create the structures needed for a sustainable economy until, in the future, renewable energy eventually produces enough “seed” to replace itself and we learn how to recycle minerals much more efficient than we do now. This is the sower's strategy applied to the modern world.

We are already using this strategy. At present, most of the resources used to build renewable energy plants and other elements of a sustainable economy come from fossil fuels. It is good that we are doing that, but are we doing enough? According to UNEP, some 250 billion dollars were spent in 2012 for new renewable sources. This is much less than what is being invested in fossil energy but, so far, it has nevertheless allowed a rapid and consistent growth of renewable energy. The problem is that there is no guarantee that the necessary levels of investment will be maintained in the future if we continue giving priority to fossil fuels. Already in 2012, indeed, we saw a decline in the investments in renewables. So, if we leave choices on energy to the market alone, we risk facing runaway climate change together with rapid resource depletion without having sufficient resources available to create a new energy system. If we continue along this path we will eat all our seed corn.

Instead, we need to save our seed corn. It means investing a significant fraction of the energy and resources we are producing today into a sustainable economy even though that may not provide the largest short term returns. First of all, it means investing in renewable energy. This is to be intended as energy technologies that don't produce greenhouse gases, are efficient in term of energy return for energy invested (EROI) and don't occupy too much land; in particular photovoltaics and wind. It also includes infrastructures and industrial technologies which tend to recover resources and avoid the use of rare and disappearing mineral resources. The concept of “efficiency” can also be included, with the caveat that it must not perpetuate dependency on fossil fuels (an example of an ineffective strategy in this sense is moving from coal to natural gas). 

Then, how do we implement the sower's strategy? It may not need formal measures; we can see it as a form wisdom that already exists in people's minds and that leads to supporting investments in renewables in general. But we can also think of an international protocol (the “sower's protocol"?) mandating that a fraction of the revenues obtained by fossil fuels must be dedicated to the development of a sustainable economy; in particular renewable sources. The protocol could be based on the revenues from a carbon tax but, perhaps better, it could directly act on private or state owned energy companies. After all, investing in energy production is their job and we are not asking them to pay money, we are asking them to make money; albeit on a longer time scale. The protocol could also mandate non-monetary measures, such as for governments to ease permits and reduce bureaucracy for investments in sustainability.

No matter how implemented, the sower's strategy implies that we need to invest enough to create a new energy system before depletion (or global warming) makes it impossible to do so, but not so much that it would be an excessive burden on people's welfare. It is a window of opportunity that will not be there forever, but which probably still exists today. Consider that the 58 largest world's oil and gas companies together collected in 2012 revenues for almost 6 trillion dollars (wikipedia). If they were to re-invest just 4% of those revenues in renewable energy, that would double the amount spent today in the sector.

Independently of the actual fraction to be set apart, we can say that the sower's strategy, especially if implemented as a formal protocol, could be a true game changer in sustainability since:

1. It speeds up the transition, ensuring that sustainability and renewable energy will remain consistently supported.

2. It diverts investments from fossil fuels, forcing them to decline faster than they would if left to market forces alone. That speeds up the transition and eases the problem of global warming.

3. It stimulates the economy and creates jobs. It has the force of a positive approach: we are not asking people to stay home in the dark: we are asking them to work for the transition and make money on it!

4. The well known principle: “do not eat your seed corn” is something that everyone can understand. It will be hard for negative propaganda to distort it so much to make it appear as part of a Communist plot to enslave mankind (but never underestimate the power of PR).

The sower's strategy by itself, formally or informally implemented, does not guarantee a smooth transition to a sustainable (and cool enough) world. It can't go against the laws of physics and it can't allow humankind to continue growing forever. Adapting our economy to renewable energy requires new infrastructure, rethinking industrial processes, adapting to the gradual reduction in the availability of all mineral resources. Among other things, we'll need to learn how to use renewable energy to power agriculture, to replace rare minerals with common ones (e.g. copper with aluminum), to manage waste as a resource and not as a burden, and much more.

Clearly, building up a completely sustainable economy is a difficult task, but it is not an impossible one. The only impossible thing is to keep civilization alive without energy and resources. The sower's strategy may give us a chance for doing that.


Every year, our farmer ancestors faced a choice: how much of their harvest to keep as seeds? Save too much, and they would starve that year; save too little and they would starve the following year. But they must have been making the right choices because they survived and we are their descendants. Today, we can learn from our ancestors how to make the right choices with fossil fuels too: save enough of their energy now to have enough energy in the future and also avoid disastrous climate change. Who hath ears to hear, let him hear.

The Tao of electric vehicles

"A journey of a thousand miles begins with a single step" (Lao Tzu, the Tao Te Ching)

Myself ad my sweet wife, Grazia, on an all-electric, battery powered motorcycle. No pollution and no noise, and recharging it with my solar panels costs almost nothing. The hell with crude oil!

This post was prompted by something very silly that Bjorn Lomborg said about electric vehicles; something like: "A million electric vehicles would only slow global warming of about one hour." But if a million electric vehicles are not the solution, they would still be doing something good for the climate. And don't forget that to reach one million vehicles you need to start with one. You can see that one in the picture above.

A post in Italian about this motorcycle is here. The light blue thing in the foreground of the picture above is my 1965 Fiat "500" vintage car. Not an electric vehicle, but it could still become one!