See my review of “Spain’s Solar Revolution” for background on what follows:
Our study concluded that, when analyzed what we called “extended boundaries energy inputs”, about 2/3 of the total energy inputs were other than those of the modules+inverters+metallic infrastructure to tilt and orient the modules.
So even if the cost of solar PV modules (including inverters and metallic infrastructure) were ZERO, our resulting EROI (2.4:1) would increase about just 1/3.
Without including the financial energy inputs (you can easily calculate them if most of the credits/leasing, were requested in contracts at 10 years term with interests of between 2 and 6%, even if you consider as energy input derived from the financial costs, only the interests (returning the capital, in theory would only return, in my opinion, the previous PREEXISTING financial (and therefore, energy) surplus, minus amortization of the principal, if any (when principal is tied to a physical preexisting good, which is not the case, I understand in most of the circulating money of today, but you know much better than me about this).
We also excluded most of the labor energy inputs, to avoid duplications with factors that were included and could eventually have some labor embedded on it. And that was another big bunch of energy input excluded from our analysis.
As I mentioned before, if we added only these two factors that were intentionally excluded, not to open up old wounds and trying to be conservative, plus the fact that we include only a small, well-known portion of the energy inputs required to stabilize the electric networks, if modern renewables had a much higher or even a 100% penetration, it is more than probable that the solar PV EROI would have resulted in <1:1.
And I do not believe any society can make solar modules even with 25 30 years lifetime. There are certainly working modules that have lasted 30 years+ and still work. Usually in well cared and maintained facilities in research labs or factories of the developed world. But this far away from expected results when generalized to a wide or global solar PV installed plant. Dreaming of having them 100 or 500 years is absolutely unthinkable.
Modules have, by definition, to be exposed more than any other thing, to solar rays (to be more efficient). You just look even at stones exposed to sun rays from sunrise to sunset and to wind, rain, moisture, corrosion, dust, animal dung (yes, animal dung, a lot of it from birds or bee or wasp nests on modules) and see how they erode. Now think in sophisticated modules exposed to hail, with glass getting brittle, with their tedlar, EVA and/or other synthetic components sealing the junctures between glass and metallic frames eroding or degrading with UV rays and breaking the sealed package protecting the cells inside, back panels with connection boxes, subject to vibration with wind forces and disconnecting the joints and finally provoking the burning of the connectors; fans in the inverter housings with their gears or moving parts exhausted or tired, that if not maintained regularly, end failing and perhaps, if in summer, elevating the temperature of the inverter in the housing and provoking the fuse or blown of some vital components, etc.
I have seen many examples of different manufacturers of all types of modules (single/mono, multi/poli, amorphous, thin film high concentration with lenses, titanium dioxide, etc.) in the test chambers, after claims of the promoters to the manufacturers. I have attended to some test fields of auditing companies contracted by promoters, detecting hot spots in internal solderings just from the factory to the customs.
I have seen a whole plant of the so marketed as a promising first US brand specialized in thin film (confidentiality does not permit me to name, as yet) having to return it because it did not comply specs. Now, as I mentioned, I am in contact with a desperate promoter, seeking for more new modules to be paid (the manufacturer is broke and has disappeared) that will last a little bit more than those contracted (not Chinese) about 6 years ago and having failed about 2/7 of the total, without a sensible replacement, because present modules in the market have more nominal output power than those originally contracted for and with different voltage and currents that do not permit unitary replacements in arrays or strings, being forced to a complex and costly manipulation to reconfigure arrays in whole with old modules and creating new arrays with new modules and adapting inverters to the new currents and voltages delivered (Maximum Power Point Tracking or MPPT)
We mentioned many other examples of real life affecting functionality of solar PV systems in our book. The reality, 2 years after the publication of the book, proved us very optimistic. And we have many of the PBAs or circuits or connectors, etc. in our own country. Imagine when you install a solar village in a remote area of Morocco, or Nigeria or Atacama in Northern Chile and the nearest replacement of a single broken power thysristor or IGBT that is stopping a whole inverter and the plant behind (not manufactured in the country) and about 2,000 Km -or more- from the plant and need to pass customs like the one in Santos (Brazil), where tens of thousands of containers are blocked since more than one week (plus the usual 6 to 10 weeks custom procedures) for a fire in a refinery close to the only motorway leaving the Santos port to Sao Paulo.
I even contacted some German University (Saarland) designers of a very simple and superb device, and even they came to Spain to test it in my plant in a common attempt to commercialize it in a joint venture. The device was a flat sensor kinetic platform of about 30×30 cm., able to measure the number of hits of hail, per square meter, the size and the speed of them.
The reason was double: in one side, it could help to prevent double axis tracking plants to order from the control room of the plant to move the towers to flag position against the prevailing wind and hail fall to avoid breaking of the module glasses. On the other hand, it would be a good device, for instance to fixed plants, to be used as hail measure pattern, a sort of standard accepted device by all interested parties, to help insurance companies and manufacturers to see if the damaged modules were caused by hail below or above manufacturer specifications.
It happened that we had to abandon the project, for lack of interest of both the insurance companies and manufacturers. The first, now have a good alibi, when a promoter raises a claim of its destroyed modules, to state that the hail was below size and speed of the the manufacturer specs and that should be responsibility of the manufacturer. The manufacturer, in its turn, when claimed by the promoter, would also claim that the hail was much higher in size and speed than the specified one. The promoter, with his modules destroyed and a fully fooled face, is so caught in the middle of nowhere, with the hail already melted and the plant destroyed. This is real life, ladies and gentlemen.
100 or 500 years lifetime? ha, ha, ha.