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Stereocene: The Future of  Earth’s Ecosystem

June 17, 2021

Stereocene: The Future of  Earth’s Ecosystem

During the “golden age” of science fiction, a popular theme was that of silicon-based life. Above, you can see a depiction of a silicon creature described by Stanley Weinbaum in his “A Martian Odyssey” of 1934. The creature was endowed with a metabolism that would make it “breathe” metallic silicon, oxidizing it to silicon dioxide, hence it would excrete silica bricks: truly a solid-state creature. It is hard to think of an environment where such a creature could evolve, surely not on Mars as we know it today. But, here, on Earth, some kind of silicon-based metabolism seems to have evolved during the past decades. We call it “photovoltaics.” Some reflections of mine on how this metabolism could evolve in the future are reported below, where I argue that this new metabolic system could usher a new geological era which we might call “Stereocene”, the era of solid-state devices.
An abridged version of a paper published in 2016 in 
“Biophysical Economics and Resource Quality”
The history of the earth system is normally described in terms of a series of time subdivisions defined by discrete (or “punctuated”) stratigraphic changes in the geological record, mainly in terms of biotic composition (Aunger 2007a, b). The most recent of these subdivisions is the proposed “Anthropocene,” a term related to the strong perturbation of the ecosystem created by human activity. The starting date of the Anthropocene is not yet officially established, but it is normally identified with the start of the large-scale combustion of fossil carbon compounds stored in the earth’s crust (“fossil fuels”) on the part of the human industrial system…
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Negative energy return of solar PV in Northern Europe

June 17, 2021

Negative energy return of solar PV in Northern Europe

Preface.  I once yanked this paper after huge blow back, but in the past few years, I have no reason to doubt Ferroni and Hopkirks methods, boundaries, or conclusions, so I’m putting this post back.

An ERoEI of less than 1 means there is a net energy loss. In this paper Ferroni and Hopkirk found the EROEI of Solar PV to be negative, just .82 (+/-) 15%) in countries north of the Swiss Alps.

The problem with EROEI is that there is endless arguing over the boundaries.  For example, Prieto and Hall’s 2013 book, “Spain’s Photovoltaic Revolution-The Energy Return on Investment” had energy data for over 20 activities outside the production process of the modules, typically NOT included in EROEI studies. But these steps are necessary, or the solar PV installation won’t happen, and Pablo Prieto built several large installations and was in charge of the finances, so he knew everything required — the road built to access the site, the new transmission lines, the security fence and system and more that EROI studies typically don’t include.

This paper goes beyond Prieto and Hall’s boundaries because it includes labor, the costs of the energy required to integrate and buffer intermittent PV-electricity in the grid (i.e. storage via pumped hydro, batteries, natural gas or coal backup plants), and the energy embodied in faulty equipment.  If Prieto & Hall had included these then their paper would have found a negative EROI, as Prieto wrote here. Though Prieto and Hall’s EROI of 2.6 : 1 in sunny Spain is still far less than the EROI of 10 to 14 many scientists believe necessary to maintain our current civilization.

Another important finding of this paper is that based on recycling rates of PV in Germany, solar panel lifespan is closer to 17 or 18 years than 25.  And that doesn’t count the solar panels that are abandoned or tossed in the trash…

…click on the above link to read the rest of the article…

EROEI Calculations for Solar PV Are Misleading

December 21, 2016

EROEI Calculations for Solar PV Are Misleading

The Energy Returned on Energy Invested (EROEI) concept is very frequently used in energy studies. In fact, many readers seem to think, “Of course, EROEI is what we should be looking at when comparing different types of energy. What else is important?” Unfortunately, the closer to the discussions of researchers a person gets, the more problems a person discovers. People who work with EROEI regularly say, “EROEI is a tool, but it is a blunt tool. An EROEI of 100 is good compared to an EROEI of 10. For small differences, it is not so clear.”

Because of the idiosyncrasies of how EROEI works, different researchers using EROEI analyses come to very different conclusions. This issue has recently come up in two different solar PV analyses. One author used EROEI analysis to justify scaling up of solar PV. Another author published an article in Nature Communications that claims, “A break-even between the cumulative disadvantages and benefits of photovoltaics, for both energy use and greenhouse gas emissions, occurs between 1997 and 2018, depending on photovoltaic performance and model uncertainties.”

Other EROEI researchers with whom I correspond don’t agree with these conclusions. They recognize that in complex situations, EROEI analyses cannot cover everything. Somehow, the user needs to be informed enough to realize that these omissions result in biases. Researchers need to work around these biases when coming to conclusions. They themselves do it (or try to); why can’t everyone else?

The underlying problem with EROEI calculations is that EROEI is based on a very simple model. The model works passably well in simple situations, but it was not designed to handle the complexities of intermittent renewables, such as wind and solar PV. Indirect costs, and costs that are hard to measure, tend to get left out.

…click on the above link to read the rest of the article…

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

May 29, 2016

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

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?
…click on the above link to read the rest of the article…

Olduvai IV: Courage
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Olduvai II: Exodus
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