17 Comments

Thanks for another interesting article.

I have followed ERoEI for a number of years and am delighted to see you talk about it so much. I think about it this way:

One can calculate an energy cost of GDP in Joules per Pound, J/£. One can also calculate the contribution of the Energy sector of the economy to total GDP, it is simply everything spent on buying energy.

If, say, EROEI of the energy sector as a whole is 10:1 then the energy sector uses 10% of all energy produced. If the energy intensity of the energy sector in J/£ of economic output is the same as the economy as a whole, then one would expect the energy sector to represent 10% of the economy, ie 10% of all spending would be on energy.

This is obviously an approximation, and depends on how much the energy sector resembles the rest of the economy. Looking at the energy sector in broad terms, it uses land, mining, capital, labour, metals, energy and other inputs and they all scale with output. So it looks, to me, similar to other GDP sectors like manufacturing. I think it is approximately right, at least in a closed economy, so at a global scale.

The implications of lowering EROEI are stark if one looks at it this way ( and if I am thinking about it correctly) Spending on energy as a %age of GDP is the reciprocal of EROEI.

Low EroEI means poverty.

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Great piece of work David. As an engineer I look at these types of analysis as directional only because accuracy is limited by the huge assumptions that necessarily have to be made. What I take from your work is that it's pretty suicidal to follow this path, but we need a way of explaining this to the layman so they can get it. Something like... to cook my turkey at Christmas it takes 3hrs this year. With our new energy system it will take 10hrs (say) and obviously the costs will increase A LOT.

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I would call that a good analysis of the theoretical maximum EROI of a hypothetical wind/solar/hydrogen electricity supply for the UK.

For the Real World EROI I would not be so optimistic.

First off, an Overbuild of 1.3 is not going to work. You have large monthly, seasonal and annual variations in Wind/Solar output. And Climate Change is going to reduce wind speeds, as the largest effect is reducing the temperature differential between the poles and tropics. The driver of most wind energy. Britain will be especially hard hit by that. So let's take a more realistic minimum Overbuild of 1.5.

Overall Electrolyzer efficiency is realistically going to be 65%, at best. The electrolyzers for the big new $590M DOE H2 Advanced Clean Energy Storage project in Utah are up to 62% efficient.

It is certain that the transmission system of both electricity and H2 will be inefficient due to it being highly peaking. Highly peaking means the economic value of reducing losses is low compared to baseload transmission. Since avg output will be much lower than the peak output. A minimum of 10% leakage, compression losses, electrical transmission & conversion losses is inevitable.

And to be realistic, you can't expect H2 generation by combustion machines to be any more efficient than natural gas is, with current gas generation efficiency in the USA at 42%.

So I would take overall efficiency of the practical, Real World Solar/Wind/Hydrogen system to be:

0.67 x 0.65 x 0.9 x 0.42 = 16.5%

That makes actual EROI more like 11.9 X 0.165 = 2.0

With Hall & Lambert, the World experts on the subject, in 2014 calculated EROI needed to maintain our civilization at 14. I would say if anything that number has increased substantially due to our incompetent and self-destructive leadership pushing Plandemics, ineffective costly vaccines, unbelievable levels of corruption, endless costly destructive wars, massive immigration of unproductive migrants, a social system based on DEI, ESG and CRT dogma rather than merit & achievement, purposeful destruction of efficient agriculture, pushing the most inefficient energy tech including such absurdities as agrofuels, solar roadways and more. You realize there is a massive energy cost to all that inefficiency. Somebody has to pay for that, both in finance and energy.

Conclusion: The proposed Solar/Wind/Hydrogen electricity supply for the UK is a ridiculous, insane fantasy.

This fellow puts H2 infrastructure at 10X the cost of gas infrastructure:

energyskeptic.com/2022/hydrogen-hopium-storage/

Hydrogen: The dumbest & most impossible renewable:

energyskeptic.com/2019/hydrogen/

naturalgasworld.com/the-hydrogen-illusion-interview-with-samuel-furfari-on-his-explosive-new-book-gastransitions-85316

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Do we know of ANY MPs that can hold a reasoned conversation on EROEI?

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Sadly, no. Some of the Net Zero Scrutiny Group might, but I haven't met any of them to discuss. Yet.

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That was a substantial set of maths and a nice demonstration of input mechanisms to construct the Rube Goldberg-esque contraption that will save England from certain death, mass starvation, disease, large scale species destruction and whatever else the "scientists" backing these idiotic claims have made.

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It's all gone quiet over there....

https://poshydon.com/en/home-en/news/

Despite Hollandse Kust Zuid offshore wind having started up over the summer and blessings from Mark Rutte and King Wilhelm-Alexander it seems there are ongoing hitches with the Poshydon offshore wind/electrolysis/hydrogen to gas pipeline project that no-one is talking about. Is the project dead in the water?

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I pinged them an email - reply came thru saying there will be an update in a few weeks, thanks for your interest

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Thanks for a thought-provoking article. Could you comment on Power-to-X technologies and coukd they potentially increase the EROIE of the system. In Denmark I heard that they are planning an overbuild factor of 2-3 and using surplus generation for P2X.

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Hydrogen is one form of "X". At even lower efficiency, you can always try make methane from the hydrogen for another form of "X". Perhaps the efficiency can be improved if this translates to commercial scale:

https://www.nature.com/articles/d42473-022-00166-2

The Danish plan sounds a little more realistic in that it will entail less storage, but also a degree of extra wastage/curtailment. It is more likely to reflect a better understanding of relative costs.

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Sorry, I have no idea what Power-to-X means, so I can't comment upon it.

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It would be useful if you separated out wind from solar. It seems to me that solar PV plus hydrogen storage will have an ERoEI of 1-2, whereas wind plus hydrogen will have an ERoEI of around 14. Thus wind plus hydrogen are feasible, whereas solar PV plus hydrogen are not, at least at UK latitudes. That is a very important finding. There is currently a consultation on installing what would be Europe's biggest solar PV energy plant, call Botley West. This calculation would be extremely useful ammunition to include in the consultation.

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That's an absolutely shocking development, covering an area roughly equal to the city of Oxford. I note they have been economical with the actualité about where the site can be seen from. Here's what heywhatsthat reckons for a northern part of the site - all the way to the Wantage Downs!

https://www.heywhatsthat.com/?view=FB9XT7F5

West of Botley:

https://www.heywhatsthat.com/?view=P2EFFEX3

I took a quick look using generic Renewables.ninja PV data for the local NUTS2 region UKJ1 which covers 1980 to 2019 which suggests that the annual capacity factor might vary between 11.2% and 12.6% with a long run average of 12% - however, that allows for e.g. suboptimal roof installations but it does correct for panel ageing and is calibrated against real world measurements. A more detailed calculation using long period data for the actual sites could be made, but I was unable to find any information on panel orientations which is an essential input. The claim that it will produce 1.23 TWh/year seems inaccurate - that is an average of 140MW, or a capacity factor of 16.7%. In reality it is more like 100MW average output - which is a sad comparison alongside Didcot B CCGT (1.44GW capacity) - and the comparison of area occupied (2500 acres for the solar farm and 56 acres for the power station, of which 3.5 acres is the separate 100MW OCGT plant is ridiculous. Didcot will find itself ramping up and down to accommodate changes in solar output, with a peak ramp rate of 310MW/hour based on the renewables.ninja data, or perhaps more if a cloud front comes in.

https://www.witneygazette.co.uk/news/23960440.botley-west-solar-farm-director-speaks-2-500-acre-plan/

The cost is alleged to be £900m for the solar farm. That seems costly, especially at realistic capacity factors.

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At our latitudes, solar on its own is about 3.9. Just solar with 30% overbuild (won't be enough) and storage on the same scale (in reality, probably more storage would be required) would bring it down below 3.

RS came up with their optimum design with about 20% solar and 80% wind to minimise cost. I think mostly because there's seasonal variations in both (more solar in summer, more wind in winter) that cancel each other out and reduce the need for storage.

So, without knowing the over-build required for a wind only solution I can't really do the calculation. If the overbuild was 1.3 and 70:30 offshore to onshore, then the EROEI of just the wind part would be about 10.7. Adding the storage and other components at the same scale would bring it down to 8.6-10.

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Your articles continue to demonstrate that the signalling of virtue is the most energy intensive activity on the planet right now.

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Would have been great to have had energy returned on energy invested (ERoEI) defined just once at the start, like i just did.

Many of us may understand scientific parlance & methodology (that includes spelling things out), just not all the myriad acronyms especially when context sensitive.

Otherwise thanks for bringing this to our attention 😊

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Fixed in the intro. Thank you for bringing that to my attention.

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