Eroei Solar Panels

The availability and quality of various energy and material resources to a society is linked to the general trend of the settlement growth and eventual decline experienced by each civilization white 1959 tainter 1988 a society must have an energy surplus for there.

Eroei solar panels.

That s why we should compare what s comparable. Posted on december 21 2016 by gail tverberg. When the eroei of a source of energy is less than or equal to one that energy source becomes a net energy sink and can no longer be used as a source of energy but depending on the system might be useful for energy storage. Such claim if accurate would call into question many energy investment decisions.

If we do that we find that for instance photovoltaics has an eroei around 10. The energy return on energy invested eroei or eroi of any energy gathering system is a measure of that system s efficiency. If the amount of energy produced relative to the amount of energy utilized in producing that energy tends to decline at some point as the ratio approaches 1 0 or perhaps even becomes a fraction less than 1 0 there is little if any return on the energy invested and society will collapse. The energy returned on energy invested eroei concept is very frequently used in energy studies.

In today s energy mix hydroelectric power nuclear power have values 50. 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. Energy has played a critical role throughout human society s demographic economic and social development.

The concept was originally derived in ecology and has been transferred to analyse human industrial society. Eroei calculations for solar pv are misleading. In fact many readers seem to think of course eroei is what we should be looking at when comparing different types of energy. The lowest estimate produced by weissbach et al was thoroughly discredited by technology entrepreneur ramez naam as glaringly low and he estimates the eroi of solar pv at above 10 and probably above 15 and rising.

Eroei usable acquired energy energy expended it seems so simple. To be considered viable as a prominent fuel or energy source a fuel or energy must have an eroei ratio of at least 3 1. That is to say the eroi of solar panels being made in 2013 is quite a bit higher than of solar panels made in 2000. Actually solar energy has superb energy return on energy investment eroei 1 to 4 years according to the us national renewable energy lab or 1 to 2 5 years in europe.

That is use the same rules for evaluating the eroei of fossil fuels and of renewable energy. If we used only the estimates from 2010 on we d find an eroi for poly si solar of around 15. A related measure energy stored on energy invested is used to analyse storage systems.