The debate whether or not 100% renewable electricity supply is feasible, is ongoing. 100% at the current standard of living, that is. The standard of us, here in the rich countries. There are quite a few snags in that. It has to be built more or less from scratch, (we are only at the very beginning), to be built with fossil energy for the time being, and the system involves quite a lot problems to solve: such as many conversions and their losses, storage systems, a new distribution infrastructure. That requires a lot of technologies and materials, and challenging to caluclate.
A interesting study was done 1.5 years ago by the Finnish GTK, led by Michaux.[1] A hefty report, ca 1000 pages, a very comprehensive study that addresses that challenge. And comes to the conclusion that it is impossible. In the author’s words:
“It is the author’s opinion, based on the new calculations presented here, that this will likely not go fully to as planned”.
“the power need far exceeds planetary potential. In energy mass and land . And is threatening food production and water availability”.
The report contains a huge amount of interesting data, on wind solar, hydrogen storage calculations etc, and one of the most interesting is the agriculture chapter , well worth reading ( in relation to biomass) . Some passages:
– 33% of the Earth’s soils are already degraded and over 90% could become degraded by 2050 (FAO 2015a, United Nations 2019).
The University of Sheffield’s Grantham Centre for Sustainable Futures (Cameron & Osborne 2015) has calculated that nearly 33% of the world’s adequate or high-quality food-producing land has been greatly reduced in productivity at a rate that far outstrips the pace of natural processes to replace diminished soil erosion rates from ploughed fields average 10-100 times greater than natural rates of soil formation.
You could think of that as a variant of EROI, but the SROSI: soil return on soil investment. And that alone shows that the rate of exploitation is far too high for the system’s ability to recover. Most likely, the world will also unable to feed everyone by 2050, energetically, extrapolating the current pattern. Partly due to the declining quality of agricultural land.
With regard to (agricultural-) bioenergy, it is also concluded that ” the proposed biofuel production done at a scale large enough to substitute petroleum product consumption far exceeds the planetary environmental capability and is also logistically impractical. The problem is the required volume of biofuel needed vs. the global arable land availability, and the global freshwater availability.”
Algae production is also discussed, but partly due to the negative side effects (especially the polluting water cycle) it is not a viable option ( globally speaking).
So, together with the other chapters, the conclusion is that on the whole, it is not possible, and we have to go to a completely different social model, to stay within the limits of the system.
I had already come to that conclusion along other lines, after all, the Earth is an island, and nothing more is added, but Michaux made some calculations bottom up to show the consequences in more detail.
I didn’t redo the math, of course, but it looked very solid , and I couldn’t find any major omissions, things that I thought were missing, or forgotten. On the contrary, the focus, which was mainly on the electrification of some important functions in society, had in some cases not even included the material impact, so the whole thing still tends to be too positive rather than too negative.
But there are other voices. Like an international study, (led by Finn’s again, by the way!), which states , based on a meta analysis of many studies, that it is indeed possible, a 100% renewable energy supply. [2] And that study is used in part to criticize the GTK study.
Also going through that study however raised many questions, and showed some omissions. As indeed the authors themselves write, there are things not included in parts of the study. And that weakens the case: claiming that it can be done, but leaving out whole sections: such as industry:
“However, a clear deficit and research gap exist, since a detailed description of the industry sector, i.e. separated major industries such as cement, iron and steel, chemicals, aluminum, pulp and paper, etc., is lacking in almost all cases. Therefore, a full defossilization of the non-energy feedstock demand of the industry sector has not been modeled in global 100% RE analysis.”
Well, that undermines the whole case, energy and material are inseparable, no energy without material and vice versa. We don’t have an energy problem, we have a material problem….
And even where materials are still briefly discussed in this study, it introduces optimistic assumptions, and material problems are shifted to the future for finding alternatives:
“If copper constraints exist, aluminum, which is typically regarded as a natural and practically unlimited substitute, could be used.”
This is ridiculous of course: Just ignoring that aluminum costs 10x more energy in production than other metals… And where does that come from…?
Not entirely surprisingly, these kinds of studies also always assume CCS: storing CO2 underground. That’s not solving the problem, but shoving the dirt under the rug. Somewhere in the future.
In addition, a lot is calculated in financial cost, but as argued here before, money obviously says nothing about impact or depletion, it is an artificial unit of measurement, with no physical basis….
Incidentally, counting on future CCS is no wonder, because the whole renewable energy system must still be produced with fossil fuels, with CO2 emissions therfor.
The 100% adepts react to this critic with stating that 200 years ago the transition to the fossil society was also created with the previous ‘system’ with labor and horse and carriage, to mine and transport coal, before it could be mechanized, thanks again to fossil energy. The same they claim would happen again now, first using fossil cq CO2 emissions to create that change.
But there is 1 difference: That would be possible if we had started perhaps 50 years ago, but by now we have already passed the 1.5 degree budget, and CO2 emissions should be at 0 by now. There is just no more CO2 budget and time left. Where time and more labor and horsepower were once no problem, currently more CO2 emissions, even if it is only 20 years, is already disastrous. And doing so under the guise of later negative emissions is wishful thinking, is shifting problem to the future, and gambling.
Another problem with this 100% study, is that many things are not included, such as energy for 5 billion earthlings in non-OECD countries. Under the guise of claiming that these are mainly in regions where there is an more regular climate over the year, and thus storage and seasonal differences resolve themselves there. Forgetting that that is only partly true, and that those countries also need to get to our level of energy use. After all, why should only us in the rich countries claim so much energy ?
I (again) come to the conclusion that it cannot be done, 100% renewable energy, at our current level of energy use, and that for the whole world. Or in Michaux’s words:
“In conclusion, this report suggests that replacing the existing fossil fuel powered system (oil, gas, and coal), using renewable technologies, such as solar panels or wind turbines, will not be possible for the entire global human population. There is simply just not enough time, nor resources to do this by the current target set by the World’s most influential nations.”
By the way, the main conclusions I take from the GTK report is not so much the numbers themselves, there will be for sure some room for improvement there, but 2 components that work against us: time and repetition: There is not enough time (anymore), given the volume to be implemented. And repetition, that is, it’s not about one-time installation, but regular replacement of all elements in the chain. Nothing is eternal. Something we already experience today: old wind turbines are already replaced, and charging stations for electric vehicles face already their third generation. Every few years a better model comes along, and everything is replaced again. Just regard your own lap tops and cell phones, regularly renewed and always with material and energy consequences….
“What may be required, therefore, is a significant reduction of societal demand for all resources, of all kinds. This implies a very different social contract and a radically different system of governance to what is in place today “
Again, the only real solution is far-reaching reduction, and reorganising our society.
