ignoring the fact that energy can be plentiful with solar and other renewable sources.
But can it? and with what consequences? The EROI (Energy Return On energy Investment) of solar and wind are not great (wind better than solar), they are very resource-intensive, they need storage (effectively making their EROI lower and their resource-intensivity larger) and there needs to be over-capacity of production. In addition, they use space, a lot of it if we want to produce most of the energy demand with them -AFAIK, eg. UK basically do not have enough land to produce the energy they’d need (yes, there is off-shore wind as well, it is a comment to illustrate the magnitude), and the only way we have to transport it, batteries, have low energy-density and is again very resource-intensive.
Note: low EROI basically means that a bigger share of the energy produced needs to be reinvested to produce energy (a larger share of the economy is dedicated to produce energy). It is very useful to plot “Energy available for consumption” vs “EROI”. It shows that energy sources with too low EROI are basically useless for society. I don’t go into numbers here because EROI calculations are very difficult to be made consistent between different energy sources and are difficult to calculate for the whole system. But the concept is clear and a system run with renewables is, at least, much closer to the energy cliff than we would like.
The idea of a net energy cliff was about comparing fossil fuels, solar and wind, and corn ethanol. Solar is near the letter f on your graph—not nearly as efficient on an EROI basis, but clean, renewable, and well within the sustainable and useful range of the graph. But if you’re arguing against corn-ethanol, I’m on your side.
Regarding the UK specifically, renewables currently provide close to half of UK power, so it’s strange to claim they can’t provide more. Storage tech is mediocre at present, but the focus of a lot of investment, and rapidly falling in price over tiem. And they have accelerated their nuclear power plans for coming decades.
Sorry, the claim “UK basically do not have enough land to produce the energy they’d need”… misses “with solar”.
According ESO, in 2022 the UK renewals mix was Wind − 26.8%, Biomass − 5.2%, Solar − 4.4%, Hydro − 1.8%, less than 40%. And wind is roughly half-half regarding on- and off-shore. Many countries are not big islands, or are more or less close to the equator, or have a lot of land. Really hard to scale.
EROI: low but acceptable EROI + storage + need to overinstall = pretty bad effective EROI. And EROI is not all that counts, of course.
While taking a look around the forum for some answer before, I came across this post series (so far I have only skimmed it) that seem to flesh out pretty much my concerns and does it much better I could have. Have you seen it?
But can it? and with what consequences? The EROI (Energy Return On energy Investment) of solar and wind are not great (wind better than solar), they are very resource-intensive, they need storage (effectively making their EROI lower and their resource-intensivity larger) and there needs to be over-capacity of production. In addition, they use space, a lot of it if we want to produce most of the energy demand with them -AFAIK, eg. UK basically do not have enough land to produce the energy they’d need (yes, there is off-shore wind as well, it is a comment to illustrate the magnitude), and the only way we have to transport it, batteries, have low energy-density and is again very resource-intensive.
Note: low EROI basically means that a bigger share of the energy produced needs to be reinvested to produce energy (a larger share of the economy is dedicated to produce energy). It is very useful to plot “Energy available for consumption” vs “EROI”. It shows that energy sources with too low EROI are basically useless for society. I don’t go into numbers here because EROI calculations are very difficult to be made consistent between different energy sources and are difficult to calculate for the whole system. But the concept is clear and a system run with renewables is, at least, much closer to the energy cliff than we would like.
All this EROI issues are far easier to follow when you use the inverse of EROI (energy auto consumption).
https://www.bde.es/f/webbde/SES/Secciones/Publicaciones/PublicacionesSeriadas/DocumentosTrabajo/12/Fich/dt1217e.pdf
I’ll try to read it, thanks
The idea of a net energy cliff was about comparing fossil fuels, solar and wind, and corn ethanol. Solar is near the letter f on your graph—not nearly as efficient on an EROI basis, but clean, renewable, and well within the sustainable and useful range of the graph. But if you’re arguing against corn-ethanol, I’m on your side.
Regarding the UK specifically, renewables currently provide close to half of UK power, so it’s strange to claim they can’t provide more. Storage tech is mediocre at present, but the focus of a lot of investment, and rapidly falling in price over tiem. And they have accelerated their nuclear power plans for coming decades.
Sorry, the claim “UK basically do not have enough land to produce the energy they’d need”… misses “with solar”.
According ESO, in 2022 the UK renewals mix was Wind − 26.8%, Biomass − 5.2%, Solar − 4.4%, Hydro − 1.8%, less than 40%. And wind is roughly half-half regarding on- and off-shore. Many countries are not big islands, or are more or less close to the equator, or have a lot of land. Really hard to scale.
EROI: low but acceptable EROI + storage + need to overinstall = pretty bad effective EROI. And EROI is not all that counts, of course.
While taking a look around the forum for some answer before, I came across this post series (so far I have only skimmed it) that seem to flesh out pretty much my concerns and does it much better I could have. Have you seen it?