Thursday, May 26, 2016

The real EROI of photovoltaic systems: professor Hall weighs in.


Charles Hall is known for his multiple and important contributions in the field of sustainability, and in particular for having introduced the concept of Energy Return on Energy Investment, EROI or EROEI. He is now emeritus and still active in research; among other things as chief editor of the new Springer journal: "Biophysical Economics and Resource Quality, BERQ. Here, he intervenes in the recent debate on the EROI of photovoltaic systems, sending me this note that I am happy to publish, with some comments of mine at the end.






by Charles Hall


The EROI of our various energy options, and its associated issues, may be the most important issues that will face future civilizations.  The present discussion tends to vacillate between people who accept (or advocate) very high EROIs for solar vs people who accept (or advocate) very low such EROIs.   I trust only one study, the one I did with Pedro Prieto, who has a great deal of real world experience and data. This study attempted to (conservatively) estimate all the energy used to generate PV electricity in Spain by following all the money spent (per GW) and using physical analysis where possible, and energy intensity of money where necessary. We found that the panels and inverters, which are the only parts measured in most studies, were only about a third of the energy cost of the system.  As noted in the responses to Ugo’s last post we estimated an EROI of 2.45:1 in 2008 assuming a lifetime of 25 years and at the juncture with the distribution system.   Studies that we think used more or less appropriate boundaries (Palmer, Weissbach) got similar results.

We recognize that subsequent studies to ours would probably have generated higher EROIs because of using panels of lower energy costs or higher efficiency.  But there are many ways that it might be lower too.  For example Ferroni and Hopkirk, who (despite, perhaps, some issues) have done us a good service by attempting to get actual lifetimes for modules, which were much closer to 18 years than infinity.  This agrees with what happened in Spain when, due to post-2008 financial turmoil, manufacturers did not honor their guarantees and legally "disappeared", leaving broken systems unfixed.   (And what happened to all those "surplus" Chinese panels that were never used?   Should we factor in their energy costs, as we factor in dry holes for oil analysis?)  My point is that we need to include empirical, not theoretical, estimates of ALL the energy used to make these systems work.

This is what Prieto and Hall did, imperfectly I am sure, using conservative assumptions of energy costs, many of which now appear too low.  Mostly I do not see others doing this, so I mistrust their analyses. I do not know whether Bandhari et al. included only studies using appropriate boundaries, but I would guess that many are for just the panels (and maybe converters), not the whole system required to deliver the electricity.  Another way that we were conservative was to not include the (pro-rated) distribution system, as Ferroni and Hopkirk did (i.e. EROIpou, for point of use).  It seems to me that we should do this routinely, at least as sensitivity analysis. If you are really analyzing the EROI of solar you need to get the electricity to the factory, the gravel and panels to the installation site etc. etc,

There are at least three reasons that EROI estimates appear much wider than they probably really are:

1) They are often done by advocates one way or another, not by experienced, objective (and peer reviewed) analysts.

2) a common protocol is not followed.  Murphy et al. 2011  should be followed or good reasons given for not doing so. They recommend that all investigators generate a "standard EROI (EROIst) so that different studies can be compared, but then suggest that investigators may define in addition other criteria/boundaries as long as they are well defined and the reason for their inclusion given.    This protocol is being updated at this time to deal with various concerns.

3) Related to above appropriate boundaries are  often not used.  For a start "follow the money" as money is a lien on energy.  Where there is controversy (e.g. include labor or not, and how) this should be dealt with through sensitivity analysis.   Energy quality (e.g. electricity vs fossil) also needs to be considered, as Prieto and Hall did in their final chapter.

The largest problem with EROI studies is that although the concept has been around and even lauded since at least 1977 it has essentially never been supported by legitimate and objective funding sources such as the US National Science Foundation (which however has recognized this as a large failure and is starting a new program on EROI.)  As any investigator knows it takes money to do a good job, and this we have not had.  Most of the best work has been done on a shoestring or pro bono. This appears to be changing now, especially in Europe, and we hope to see some kind of objective, high-quality Institute/Program in the future.  We also need better governmental statistics on energy use and the development of appropriate energy I-O analyses to get a better handle on energy costs.  These had been done to high quality in the US 40 years ago but the official Bureau of Census energy use data has degraded, and we have ceased undertaking appropriate energy I-O analyses while the real experts have retired or died.

If these issues can be resolved, which is not too difficult at least in principle, and if the protocols are followed, then I think we will narrow the range of published EROI estimates considerably.  In the meantime I have done a fair amount of sensitivity analysis (e.g. Guilford et al 2011; Prieto and Hall 2012) that suggest that at least for the studies I have been involved with the range of uncertainty is well within plus or minus 25 percent (except when using the assumptions of using the energy cost of the full salary of labor or electricity is multiplied by a quality factor of three, in which case the range is two to three).   At this time, we do not recommend either of those two factors for general use.   This range of uncertainty is much less than the EROI range among the different technologies, as shown in Euan Mearns most recent post.

Guilford, M., C.A.S., Hall, P. O’Conner, and C.J., Cleveland. 2011. A new long term assessment of EROI for U.S. oil and gas: Sustainability: Special Issue on EROI. Pages 1866-1887. 

Murphy, D., Hall, C.A.S., Cleveland, C., P. O’Conner. 2011. Order from chaos: A Preliminary Protocol for Determining EROI for Fuels. Sustainability: Special Issue on EROI. 2011. Pages 1888-1907.

Prieto, P., C.A.S. Hall. 2012 Spain’s Photovoltaic Revolution: The energy return on investment. Springer, NY. (about $50) 


A comment by Ugo Bardi

This note by professor Hall highlights some elements of the debate and let me comment on it. Basically, I think that there is nothing wrong in the work by Hall and Prieto that arrived at relatively low values of the EROI of PV (note, however, that there is a lot that's wrong in the recent paper by Ferroni and Hopkirk, but that will be addressed elsewhere). The discrepancies are due to different initial assumptions, as Hall correctly states here, and, obviously, different assumptions lead to different numbers.

Then, the question is, what are the "right" assumptions in these estimates? Evidently, it depends on what one is trying to measure. Here lie the problem and the remarkable confusion surrounding the debate. Basically, there are two main possible aims for an EROI calculation: 1) determining whether a technology is an energy source or an energy sink and 2) determining whether a technology can support an industrial civilization similar to ours (maybe including SUVs and plane trips to Hawai'i for middle-class families).

Once this point is clarified, we see that answering these different questions requires different assumptions. For the first question, energy source or sink, the estimate is defined by the life-cycle analysis (LCA) of the plant. For PV, that includes the cycle of all the components of the plant (surely not just the cells!). Within the LCA framework, the result is an EROI of about 11-12 for the most common technologies available today. There is no doubt that a PV plant is an energy source, not a sink.

For the second question, can PV support a civilization, we are dealing with something very different and it is for this purpose that professor Hall defines  the "extended EROI" (EROIext). However, how the term "extended" is to be understood is open for discussion. If you think that a civilization should include plane trips to Hawai'i for middle-class people, then the energy required should be factored in the calculation. Without arriving at these extremes, the more elements you add to the energy cost, the lower the final EROI turns out to be and it is not surprising that Hall and Prieto arrive at values between 2-3. These values still make PV an energy source and not a sink, but find it to be hardly able to support plane trips to Hawai'i. But that should have been obvious from the beginning!

There are a few fundamental problems with the concept of "EROIext" that I think make it a scarcely viable idea, but it might become a standard if we all find an agreement on it. The main problem, I believe, is that when we deal with such a thing as the survival of our civilization we move into a very slippery set of questions. One problem is that EROI is not the only parameter that we need to consider, and PV not the only renewable technology available; to say nothing about defining what we mean as "our civilization". So, claiming that PV, alone, cannot support the present civilization may be true, but it is also totally irrelevant. If our civilization has to survive the ongoing crisis it has to go through profound changes that are difficult even to imagine for us. For sure, however, all the renewable technologies able to produce a positive net energy, such as PV, have a role to play in our future.




Note: the current standards of EROI measurements are described in this document.  




24 comments:

  1. RENEWABLE ENERGY SURVEY UPDATE

    The RE Survey is now in TRIPLE DIGITS in respondents in pre-release!

    Formal Education remains very high, now @ 16% Doctorates.

    General Release will be Sunday, including more of the early demographics.

    Add your opinion now! Especially if you are FEMALE! Females not well represented on the survey @ only 10%.

    http://freeonlinesurveys.com/s/Wixv2RMd

    RE

    ReplyDelete
  2. Kudos to Bardi and Hall for this exchange . As an outside observer,this whole area has been very confusing. Its seems like an excellent tool is going to waste. I am hopeful that EROI would be helpful , not merely to tell a sink from a source, but to give some idea of what to expect as we move into RE. Bardi says trips to Hawaii are less likely. OK, what else? As a citizen and a parent, this is something worth knowing. A recent speech by Nate Hagens, (on his website) suggests we should expect a significant reduction in energy as we move forward. To me, this suggests he thinks we will go past the "net enegy cliff" ( He doesn't provide footnotes, so we may have to wait for his book to get the details) .
    Bardi's recent post suggests, if we invest a lot of money, we can make a conversion to RE. But also hints that it is unlikely that we will make that investment. So, if the RE transition continues to be an incremental one, until the price of FF becomes a major driver, what then? How much will we be able to afford ? What is the EROI of solar, using high EROI FF to build it?
    Thanks again for airing these important issues
    Walter

    ReplyDelete
    Replies
    1. Good questions, Walter, I wish I were able to answer. The only thing I can say, as a citizen and a parent myself, is that the more we invest in the future, the better the future will be. And I think that investing in renewable energy is the best investment we can make. Our children will thank us if we can leave to them working PV plants, rather than pictures of our trip to Hawaii!

      Delete
    2. First off, as a social scientist and university teacher in psychology and sociology I have followed the EROI research with great interest and I lift my hat to Prieto & Hall and Ferroni & Hopkirk, and others, for unravelling the many layers of the most accurate “big theory” of today’s society that I’ve come across. It has made me connect the dots into a coherent narrative surrounding the post-Bretton Woods modern society.

      The concept of EROI finally gives us THE measure which relates to that energy constitutes value which in turn is a philosophically eternal idea and is conceptualized through gold’s role as money that dates back 5.000 years. It is a philosophical concept because it alters the overall perception of measured value and it therefore underlies the grand societal theories (class, function, gender theory, Bourdieu’s hierarchical models, modernism, postmodernism, risk theory, network theory and globalization). Although I use it mainly, in my teaching, for explaining the flaws seen in modernism linear-modelling of economics (value creation) – I can see an overall modern biophilosophical sociology paradigm that takes back the concept of energy values from new age mysticism to science.

      Before I further comment on the many layers the studies conducted by Prieto & Hall and Ferroni & Hopkirk – I think a lot of readers would be enlightened to see the importance of the direct relationship of declining access to cheap energy (measured by EROI) to zero interest rate policies and the unsustainable debt loads:

      http://www.acting-man.com/blog/media/2016/04/3-debtmore-debt-GDP-and-FF-rate.png

      Please have a look at the graph above and relate it to the economic events leading up the currency collapse of 1971 and the exiting of Bretton Woods. The key events of 1971, 1981 and 2008 have energy as the common denominator. A rapidly declining EROI and the peak of US conventional in 1970 together with the additional costs from the Vietnam War lead us out of the dollar/gold connection and into the petrodollar. The spike in the oil price in the late seventies and early eighties, and an additional decline in the EROI for oil, lead to stagflation and peak interest rates and the dismantling of Gibson’s Paradox. The cost of borrowing/price of money (measured by CPI) in correlation with interest rate policies has since then devalued salary work (the energy production of ordinary people) and savings over lending. The rise of debt in society has also forced policy makers to alter the CPI at least 20 times, to make sure it doesn’t measure any real inflation, since 1980 to keep the unfair and failing system going. It all culminated in 2008 when debt saturation kicked in along with a spike in the price oil at $151 and declining EROI which lead to a near system collapse. Instead of changing fundamental policies and financial structures, by rethinking Gibson’s paradox, the can was kicked further down the road with the inception of quantatative easing (QE). Deficit spending has since then almost become equal to GDP. And it is deficit spending that has induced the North American shale oil- and gas boom and the, at least, 1 trillion euro investment in renewables in the EU over the last couple of years. The implications of the economic events in 1971-2008, underlain by the chase for cheap energy, are enormous for the whole world and has seen the rise of the unipolar dollar-index and sparked a global currency war among other undesired results

      Delete
    3. First off, as a social scientist and university teacher in psychology and sociology I have followed the EROI research with great interest and I lift my hat to Prieto & Hall and Ferroni & Hopkirk, and others, for unravelling the many layers of the most accurate “big theory” of today’s society that I’ve come across. It has made me connect the dots into a coherent narrative surrounding the post-Bretton Woods modern society.

      The concept of EROI finally gives us THE measure which relates to that energy constitutes value which in turn is a philosophically eternal idea and is conceptualized through gold’s role as money that dates back 5.000 years. It is a philosophical concept because it alters the overall perception of measured value and it therefore underlies the grand societal theories (class, function, gender theory, Bourdieu’s hierarchical models, modernism, postmodernism, risk theory, network theory and globalization). Although I use it mainly, in my teaching, for explaining the flaws seen in modernism linear-modelling of economics (value creation) – I can see an overall modern biophilosophical sociology paradigm that takes back the concept of energy values from new age mysticism to science.

      Before I further comment on the many layers the studies conducted by Prieto & Hall and Ferroni & Hopkirk – I think a lot of readers would be enlightened to see the importance of the direct relationship of declining access to cheap energy (measured by EROI) to zero interest rate policies and the unsustainable debt loads:

      http://www.acting-man.com/blog/media/2016/04/3-debtmore-debt-GDP-and-FF-rate.png

      Please have a look at the graph above and relate it to the economic events leading up the currency collapse of 1971 and the exiting of Bretton Woods. The key events of 1971, 1981 and 2008 have energy as the common denominator. A rapidly declining EROI and the peak of US conventional in 1970 together with the additional costs from the Vietnam War lead us out of the dollar/gold connection and into the petrodollar. The spike in the oil price in the late seventies and early eighties, and an additional decline in the EROI for oil, lead to stagflation and peak interest rates and the dismantling of Gibson’s Paradox. The cost of borrowing/price of money (measured by CPI) in correlation with interest rate policies has since then devalued salary work (the energy production of ordinary people) and savings over lending. The rise of debt in society has also forced policy makers to alter the CPI at least 20 times, to make sure it doesn’t measure any real inflation, since 1980 to keep the unfair and failing system going. It all culminated in 2008 when debt saturation kicked in along with a spike in the price oil at $151 and declining EROI which lead to a near system collapse. Instead of changing fundamental policies and financial structures, by rethinking Gibson’s paradox, the can was kicked further down the road with the inception of quantatative easing (QE). Deficit spending has since then almost become equal to GDP. And it is deficit spending that has induced the North American shale oil- and gas boom and the, at least, 1 trillion euro investment in renewables in the EU over the last couple of years. The implications of the economic events in 1971-2008, underlain by the chase for cheap energy, are enormous for the whole world and has seen the rise of the unipolar dollar-index and sparked a global currency war among other undesired results

      Delete
    4. Continued

      What the studies like Prieto & Halls’ and Ferroni & Hopkirks’ points the finger to is that the top-down driven decision-making processes among policy makers may be implemented based on underlying faulty policies. The many layers of this research can be best understood by reversing into bottom-up processing and look at the connection between, in this case, the EROI for solar PV, environmental-, political-, financial- and geopolitical issues. In every subjective reality there is a build in danger - that is confirming what we want to believe in instead of trying to falsify these beliefs. There is a public desire to transition into renewables from fossil fuels and the mainstream media coverage are often reporting about the success of this transformation by mentioning the increasing percentage of renewables in use for a country or continent. They very seldom relate it to EROI and economic issues, and there is an adverse approach to negative results and any critical thinking that might reveal anything flawed in the underlying policies. One might called it a societal confirmation bias. And since I started to follow the EROI research in general, through reading some up-to-date articles and following the debate on pages like this one, the picture has become more and more clear that there is a confirmation bias within a large part of the renewables community with a suppression of problems and quick dismissals of negative results. And I find this nicely displayed in Mr Bardi’s above comment to Mr Hall in which he is critical of EROIext but can’t give any real reason why and by trivializing it into a context of middle-class Hawaii trips, then he turns to the greatness of EROI studies exclusively on solar panels (which he refers to as the REAL energy return measure in a blogpost posted earlier in May) which makes up only 1/3 of the energy cost for Solar PV, and he concludes with that the EROI for Solar PV after all is not enough, which in a way is what the EROIext actually is trying to address, and somehow irrelevant anyway because we need to save our civilization at all costs. Interpreted “as long as your research don’t confirm my beliefs it’s irrelevant”.

      There is a danger that the underlying effects of this presumable confirmation bias within the research community can be easily exploited and captured by political interests and the world of financials. Frankly put, by politicians who want to be do-gooders and juice up the GDP with debt and by the financial community who can turn tax money into their own profit. The studies by Prieto & Hall and Ferroni & Hopkirk tell the underlying tale of how a debt-ridden and stagnated EU force fed of European climate crisis industry without the sufficient knowledge how do it. Easily understood by looking at companies like, e.g, Abegona and the ramp up of debt since 2008 in economical basket cases like Spain and Italy in relation to their non-performing loans (360 billion euro in Italy) – who are kept from defaulting by their too-big to fail status and by the economic conjuring tricks from Ms Yellen & Mr Draghi. Are the findings of Mr Hall et al negative in any way? No, their findings should be considered, and critically debated and be subject to replications, to underlie energy policies and public debate and ultimately direct funds to where utility is the highest. The transfer to health should not become the transfer of wealth where debt is being socialized and gains being privatized through misdirected subsidies and bail-outs. And it is important that the environmental research issue can be scientifically exploited, without the interference of political agendas, to maintain public confidence and as accurately as possible underlie political policies.

      Delete
    5. Continued

      It is not farfetched to see and realize that non-critical biased-driven populistic interpretations of research can lead to crony capitalism which in turn can lead to severe geopolitical consequences. And who’s to blame if, when, the western economical and energy narrative fails? Research tells us that the collective societal self-bias will be looking for external exogenous factors to attribute the cause to, the same way individuals protect the self with overconfidence in one’s knowledge and in the proneness to attribute negative aspects externally. It’s of uttermost importance that we do not let that happen. By critically examining our overall societal conventional construction, and not resorting to rigid beliefs and rampant propaganda, this might be overcome and lead to raised awareness of the acute actual problems that our society are facing. The importance of energy, cheap energy, to maintain the modern welfare state has clearly been publicly understated in its relation to economics and that the pursuit for this cheap energy can spin into a series of geopolitically unintended consequences that could mark the end of our civilization. These geopolitically (un)intended consequences can be referred to when high net energy consumers who base their consumption-driven GDP on debt, like the EU and US, starts intervening in energy hubs (e.g Syria & Ukraine) and net energy producers (e.g Iraq and Libya) – look no further than to US political- and military interventionism which changed in the late seventies from targeting communism to explicitly targeting of net oil producers. And as we speak we are seeing the largest military ramp up in Europe since 1941. I’ll leave it at that.

      And for Mr Bardi’s narrative surrounding the “Syrian Sickness” from an earlier blogpost, maybe it should be looked upon with European declining EROI and falling gas production and competing pipelines in mind. Robert F Kennedy Jr has written an insightful piece in Ecological Watch regarding the issue.

      http://ecowatch.com/2016/02/25/robert-kennedy-jr-syria-pipeline-war/

      If we really want to invest in our children’s future the first thing to do would be to give them truthful concepts so that they later can work with the details that constitutes them.

      Delete
  3. Charlie and Ugo,

    Thanks for this helpful presentation. Equally as important as EROI in this debate is the efficiency of artifacts which employ energy. Charlie's claim that society needs a minimum EROI of 10:1 may hold weight in a fossil fueled society. The first productive steam engine by James Watt was less than 2% efficient, and the final steam locomotive in the 1930s (just before diesel took over) was 6% efficient, and today's internal combustion engines are net 13% in practice (per RMI). The incandescent bulb at 10% efficient is another example. So the ease of extracting coal and oil (e.g., with an EROI of 100:1) helped bootstrap modern civilization. But now things are different.

    By today's energy standards, the Industrial Revolution was very primitive... and its legacy artifacts (coal power plants, automobiles, incandescent bulbs...) remain very primitive energetically. As the Solarevolution continues, we will abandon those artifacts rapidly, and discover in the process (1) the EROI of solar becomes as high as, or higher than fossil fuels, further leveraging the transition, or (2) that we can live with EROIs lower than those of the past.

    We just might discover that we can do way more with way less.

    ReplyDelete
  4. When dealing with EROI folks use to regard solely the quotient. It might be a minor thing, but I think the denominator is already relevant, at least when considering labor costs. Labor costs for the plant, for the panels, inverters, installing, maintaining and so on. Those are energy workers, in the same sense that a farmer takes care of his crop. So this energy goes to society, because a person (many people) lives with this "energy making" wage. Should this denominator, a flow of energy through people, not be counted as useful?

    ReplyDelete
  5. A word to civilization : for me it is education. If knowledge and education is preserved, civilization is preserved, may there be flights to Hawaii or not. So you don't need an awful lot of EROI to preserve knowledge.

    ReplyDelete
  6. EROI of the plant is not enough. What should be into account is the whole infrastructure to connect a distributed energy source, and, more important, to deal with its intermittent nature. Energy to build and operate batteries, smart grids, hydrogen factory, gaz powered backup, and pumped hydroelectric energy storage have to be taken into account, and that's change the picture.

    Another concern is energy cannibalism. PV produces today around 2% of world energy. If we want that to change that fast, we need to have very high global EROI. Pierce theorem gives an hard limit to the rate it's possible to change the system, according to EROI. Even with a Energy payback time of 4 years (that is optimistic in many OECD regions and/or if dedicated infrastructure is taken into account), then at 25% rate no net energy is produced and no greenhouse gas emissions are offset.


    ReplyDelete
    Replies
    1. Thierry, that's why we still need fossil energy. We cannot bootstrap renewables (or even nuclear) by themselves to the level needed. It is a delicate balance that consists in using as much fossil energy as needed, but not more. You find all the calculations here: https://arxiv.org/abs/1602.01203

      Delete
  7. We still have slavery (wage) and coercion (taxes, etc.) within a crony-capitalist plutarchy (BAU/governpimp) context/model.
    I would worry about what that context does when faced with less energy more than a decline in energy, itself.
    Still, though, it was big oil/energy that got us big governpimp.
    Empire.
    So maybe smaller energies will atrophy its contemptible reach and keep it out of places like Syria and away from civilians.

    "A low-energy policy allows for a wide choice of lifestyles and cultures. If, on the other hand, a society opts for high energy consumption, its social relations must be dictated by technocracy and will be equally degrading whether labeled capitalist or socialist." ~ Ivan Illich

    ReplyDelete
  8. Just one question: why there are no other options than electric renewables at those EROEI studies? Why this obsession with electricity?

    I wonder if EROEI of ACS (Solar Heated Tap water for shower, central heating, and other thermal uses) is bigger than PV, and since heat is much more demanded than electricity, why not betting for ACS? In China ACS:PV ration is >10, but it seems that nobody cares about that. Why?

    At my home electricity:heat is 1:3, so I find much more efficient for me to install ACS than any other kind of renewable, with some benefits: cheaper, storing included, and no meter (thus no taxes, no control, no whatosever from 'outer interests').

    Thus, again: why this effort in electricity ONLY? Can some one explain to this simple minded guy?

    Beamspot.

    ReplyDelete
  9. Pollution caused by the manufacture of renewables is never factored.

    “There’s not one step of the rare earth mining process that is not disastrous for the environment.”
    http://instituteforenergyresearch.org/analysis/big-winds-dirty-little-secret-rare-earth-minerals/

    “Polysilicon production produces about four tons of silicon tetrachloride liquid waste for every ton of polysilicon produced.”
    http://www.truth-out.org/news/item/31478-china-s-communist-capitalist-ecological-apocalypse

    “Whenever somebody with a decent grasp of maths and physics looks into the idea of a fully renewables-powered civilised future for the human race with a reasonably open mind, they normally come to the conclusion that it simply isn’t feasible.”
    http://www.theregister.co.uk/2014/11/21/renewable_energy_simply_wont_work_google_renewables_engineers/

    “new Green technologies designed to save humanity from CO2 may kill humanity through energy starvation”
    “If we used more energy to get the energy we need to survive then we will surely perish.”
    “ERoEI = energy gathered / energy invested” “net energy = ERoEI-1”
    “An inevitable consequence of this aspect of human nature commonly known as greed is that we have already used up the highest ERoEI fossil fuel resources and as time passes the ERoEI of new resources is steadily falling.”
    “The greatest risk to human society today is the notion that we can somehow replace high ERoEI fossil fuels with new renewable energies like solar PV and biofuels.”
    http://euanmearns.com/eroei-for-beginners/

    “Models often limit their life cycle or EROI analysis to just the solar panels themselves, which represents only a third of the overall energy embodied in solar PV plants. These studies left out dozens of energy inputs, leading to overestimates of energy such as payback time of 1-2 years (Fthenakis), EROI 8.3 (Bankier), and EROI of 5.9 to 11.8 (Raugei et al).”
    “Solar has too many energy costs and dependencies on fossil fuels throughout the life cycle to produce much energy. It’s more of a fossil-fuel extender because PV can’t replicate itself, let alone provide energy beyond that to human society.”
    http://energyskeptic.com/2015/tilting-at-windmills-spains-solar-pv/

    “despite a string of optimistic choices resulting in low values of energy investments, the ERoEI is significantly below 1. In other words, an electrical supply system based on today’s PV technologies cannot be termed an energy source, but rather a non-sustainable energy sink or a non-sustainable NET ENERGY LOSS.”
    https://collapseofindustrialcivilization.files.wordpress.com/2016/05/ferroni-y-hopkirk-2016-energy-return-on-energy-invested-eroei-for-photo.pdf

    ReplyDelete
    Replies
    1. Olde Musket, I could cut and paste ten times more paragraphs and references that say exactly the opposite of those you pasted. Why so much hatred against renewable energy?

      Delete
  10. A comment from Pedro Prieto, under the title of "An attempt to reconcile" - first part

    Ugo,

    I think it is time to seat calm and think about some important considerations in what is the real life net energy that modern renewable systems may offer to our global society.

    As I have said before, what it's at stake is very important for two main reasons. This beyond that we all basically agree between renewable energy supporters (a majority here) and people who think they may not be sustainable or offer global solutions to our form of living (a minority in which I side), that fossil fuels are not going to be here forever.

    Reason 1. You have been (or still are) a relevant member of ASPO and know about the consequences of peak oil, gas and peak coal and even peak uranium. We all know we have a huge problem here to maintain the present fossil fuel energy flow (not just to keep the growth rate pace of the last century). We all know we have very little time to react (in historic terms), whatever is the outcome of our debates.

    Reason 2. We also basically agree that even the present dwindling fossil fuels, if totally burnt, will aggravate the Climate Change and Global Warming nightmare.

    So, modern renewables are the last silver bullet our global society has to imagine of believe that they could replace fossil fuels both in terms of volume required and time left. Even some studies like those of Jacobson et al, Antonio García-Olivares, believing that if we make substantial changes (but without renouncing to more or less our present level of living or living standards) could be somehow lowered from the present 17 TW to some 12 TW or so, which is still a lot of energy and assuming a lot of conditional “if”, like a voluntary end of growth, a stand-still society, the end of capitalism (in the case of García-Olivares) and so.

    In conclusion and by chance, modern renewables have suddenly found themselves with the dire responsibility on their shoulders of replacing fuels to some extent or another. Under this assumption, the importance of discovering a real life, complete, comprehensive and irrevocable EROI for those renewable energy systems is of essence.

    ReplyDelete
  11. Second part of the comment by Prieto

    In your comment to professor Hall, you hit the nail on the subject: what methodology is (more) right among the two main considered ones, despite our obvious acceptance that the high EROI you advocate for, has much more references than the low EROI estimates (or EROIext considerations) that we consider. I agree with you that it is not the time to throw each other all the quotations, citations and links.

    The methodology is precisely the point that needs to be clarified. It is not, in my opinion, just a question of Life Cycle Assessment (LCA) of an isolated system, because what is at stake is not to observe the behaviour of an isolated energy system and compare it with another isolated energy system. They are all necessarily embodied in a society, a very complex and interrelated society, that consumes energy in all the complex societal value chain.

    It is not, as you said, with your appreciated sense of humor, that we need to include the energy spent by plane trips to Hawaii for middle class people, because this is obviously an energy expenditure that could be avoided in our global civilization without harming much the quality of life (although we could harm very much the people living from the one billion tourist touring the world every year)

    (I could enter a small side note here. The Canary Islands have 2 million inhabitants and receive every year 12 million tourists from long haul flights, in average waves of 200,000 a week with an average one week stay and they are the main source of income of the Island, where the Instituto Tecnológico de Canarias, a leading research group where I have good friends, in wind and solar,. This ITC has a budget paid by the regional government. Do you find a small link here?)


    But of course, we did not arrive to our low EROIext of solar PV for Spain including the trips of Swedish tourists to Canary islands or British tourists to the Sun Coast. All our extended boundaries were EXCLUSIVELY related to energy expenses directly associated with the solar PV systems and without which, we understand these systems could not have been manufactured, sold, transported, installed, operated and maintained (not even we considered decommissioning costs, which is one of the concerns of some people).

    We of course, we neither included second or third derivatives of the directly related energy invested expenses. And there are some, certainly there are, in their due proportion to the solar PV related Ei, and some of them may represent in some cases feasibility important bottlenecks. For instance, the proportional energy of a heavy four axles trucks transporting towers and blades for wind parks, not only for the fuel spent in the trip from the factory to the site, but also the energy cost of manufacturing this specific truck in the exact proportion devoted to transport wind energy parts in its life time.

    ReplyDelete
  12. Third part of the comment by Pedro Prieto

    So, I still believe, with all respects, it is time to rethink and reformulate the extended energy expenses, at least considered as CONDITIO SINE QUA NON for these systems to be up and running and to factoring them in.

    It is time to seat and reflect a little bit why one group is reaching to EPBT's for solar PV as low as ...5 months! for an energy system producing energy during 30 years more, according to them (see How Long Does it Take for Photovoltaics To Produce the Energy Used? At https://www.bnl.gov/pv/files/pdf/236_PE_Magazine_Fthenakis_2_10_12.pdf), and why such and impressive energy recovery is so much divorced from real life economic and financial payback recovery, which usually takes 10 to 15 years to be recovered.

    Even admitting that monetary units are divorcing more and more form physical and energy units due to Quantitative Easing ever-growing explosive programs, there must be something important missing here that I have the impression many do not want to explore in detail.

    It is simply not sensible the 30 times difference between recovering the energy (EROI) and recovering the money (Financial https://www.bnl.gov/pv/files/pdf/236_PE_Magazine_Fthenakis_2_10_12.pdftment or FROI) in a system that serves to generate energy that has a known price in the market

    Two reasons probably support my statement. Still the global relation of yearly GDP versus Btoe/year of primary energy, show a quite direct correlation (y=6.8899x-17.394; R2 = 0.99313 according to Gail Tverberg at https://ourfiniteworld.com/2016/03/17/our-economic-growth-system-is-reaching-limits-in-a-strange-way/) , at least in the past 30 to 50 years, even the acknowledged imperfection of GDP as measure of wealth.

    The second reason is that something is grinding in the world of modern renewables global installed power in the last three or four years. We have the obligation to ask ourselves: why on Earth, the installed power has passed from exponential growth from years 2006 through 2011 to a quite more lineal (arithmetical) growth in the period 2011-2015 and even there are recent signs of global tiredness?

    Shouldn't it have been for China, who has taken a big baton to the apparently exhausted Europe, the growth could have almost been reduced even more and vanished the necessary exponential growths during the next three decades.

    The growth of China has been due more to the need to swallow their own idle manufacturing capacity (they were very good in the last years in shifting that global capacity to China and capture the big part of the global market share), while expecting a global recovery, that has not yet happened, than to the illusion of converting Chnia into a renewable country.

    Why is that, precisely in a moment when modern renewable supporters were claiming that prices of solar modules went from 3 euros/Wp in 2007 to 0.6 euros/Wp, there has not been the necessary exponential boom -but just the opposite- worldwide, a boom which is required to reach the proposed levels by Jacobson et al or Greenpeace, for instance? The same for the hailed cost reductions in wind turbines and systems.

    What its being missing in the equations? Perhaps a clue is the statement of Jacobson et al when they say that their studies prove the technical and economical feasibility, leaving to others the social and political actions.

    Perhaps it is time to think as well that if scientists dare to have economical, apart from technical and scientific conclusions, why confining themselves in their high level scientific papers and forget about interactions with social and political realities as well? Perhaps what we are lacking is more Leonardo da Vinci, universal thinkers and less and less ultraspecific professionals in one single technical subject.

    Let's seat and think together.

    Bests

    ReplyDelete
    Replies
    1. Dear Pedro,

      first of all, I appreciate the attempt of a reconciliation and of a civilized discourse. This debate often slides into the most uncivilized discourse on the part of some people who seem to think that a high EROI for PV is tantamount to an insult to their ancestors.

      Then, a couple of comments to your note.

      You seem to be making two main points: one is that there is a large spread in the results of the EROI calculation. That's true and it leads me to repeat my initial statement that we badly need to adhere to standards. If we are good scientists (I think we all are, although personally I am no Leonardo da Vinci!) we must adhere to the accepted standards in the field, and only later we can add second order corrections. If from now on we'll do so, I am sure that the discrepancies will fade out.

      The second point you make is why, if PV is so good and so cheap, it doesn't keep growing exponentially. On this, I hope you don't mind if I say that it is a rather weak argument. I think that it is already a small miracle if PV installations keep growing in the face of a generalized decline of everything else!

      But it is true that some proponents of PV expect it to "explode" in terms of growth and it is not doing that. And I am not surprised: the fantastic growth of crude oil that was observed in the past was for EROIs of the order of 50 or even higher. With EROIs around 10-12 PV can't manage the same kind of leap forward.

      Again, I think it is a question of being realistic. I don't think that, alone, PV will save the world. But it is a net energy producer which can help us in the difficult years ahead.

      Delete
  13. Here's a nice summary from Euan Mears

    http://euanmearns.com/net-energy-trends/#more-14059

    With a range of ERoEI from 1 to 12, anarchy reigns in the PV ERoEI business. There are a number of issues at play here. The first is that different energy boundaries are being used. I personally favour a wide boundary that includes direct energy use, materials and labour. And for intermittent technologies a reasonable energy cost needs to be apportioned to mitigating that intermittency. The second is that solar PV is site specific. A sunny tropical site may yield three times the lifetime energy of a cloudy high latitude site. The third is that the efficiency of PV is improving all the time. Mixing these factors to varying degrees underpins the anarchy. But adding battery storage to a good tropics-based system is going to substantially reduce the ERoEI. Proponents of Solar PV seem set to continue to promote optimum performance without backup while others will observe that normal performance is sub-optimal and that in the real world the sun does not shine at night.

    ReplyDelete
  14. My apologies if I'm somewhat stirring the subject, but there is something in the whole Hall's EROI picture with which I've always felt unconfortable. Were the luxuriant EROIs of the Good-Old-Days fuels really that profitable? If you have 100 barrels of oil, 10 are used as material instead of energy sources, 10 others are used for refining, and say 3 for transportation, so to get 77 units of usable energy you have to spend about 10 (the remaining 13 1ess the amount that would be necessary to make them usable) assuming that the oil comes out of the ground for free (as sunlight does from the sky). Such EROI of 7,7 is not only comparable to most "unextended" calculations of PV-EROI but well below the avowed minimum for "civilization". If current Oil&Gas well-head EROI is about 15, as many sources suggest, then the EROI of usable fuels, including the cost of extraction, is below 5, excluding the infrastructural costs of the societal backup (by the way, if your energy source can pay for a supporting society, what else do you want it for?). In the case of coal, the avowed EROIs of almost 100 would be dramatically reduced if grinding, transporting and burning for electricity were added to the denominator as the costs they actually are. My point os that a crude-oil tanker or a coal pile aren't much more of an energy source as a sunny day unless their energy is harnessed and made usable. I can't see such an obvious Achilles' heel in PV EROI, land-reclamation and storage systems being more serious disdvantages in my eyes. But even if all these problems with PV could be somehow overcome, there is still plenty of room for despair, insofar our crazy race to "prosperity" has no shortage of chinks in its sham armor. Best regards.

    ReplyDelete
  15. Finally I have found something which helped me. Appreciate it!
    solar photovoltaic systems

    ReplyDelete

Who

Ugo Bardi is a member of the Club of Rome and the author of "Extracted: how the quest for mineral resources is plundering the Planet" (Chelsea Green 2014)