Is alternative energy worth it?

There’s not as much hype as there once was about electric cars, but I recall my surprise on learning that you would have to run one of them for 80,000 miles before all the CO2 created by the energy used in making it had been offset by the CO2 savings generated in using it.

And that led me to a series of other questions and discoveries — like, what do you do when a dam comes to the end of its useful life? I had somehow assumed that dams just went on for ever. Apparently not. Just as trees that are standing will one day fall, burn or be cut down, dams have a useful life. When they reach the end of it, you need to anticipate this and let all the water out. The dam has to be ‘decommissioned’.

And if a dam is used for hydro-electricity, how long does it take for the CO2 created by building it and running it to have been offset by the CO2 saved by generating electricity that way instead of through burning coal? A very long time, but it happens. A lot depends, of course, on the details of the dam we are talking about.

Now someone has done this for all forms of generating electricity, and I find both the methodology and the results quite fascinating. I read about it on Barry Brook’s website, Brave New Climate, in an essay by John Morgan, which in turn relied on a paper by some German scientists, Weissbach et al, a preprint of which you can obtain from footnote 1 at the end of the essay.

It is all based on a formulation called Energy Returned on Energy Invested, which is shortened to EROEI. I’ve seen it before, but not enquired further. More on that in a moment. Morgan says that, with respect to alternative energy forms, the much-discussed storage problem (how can you best store solar energy for use at night, or wind energy when it’s not needed by the grid?) is not the real problem: there is not enough surplus energy left over after construction of the generators and the storage system to power our present civilization.

What he means is that there is simply not a large enough return on investment in the alternative energy source to allow it do it anything much. The Weissbach paper, which I’ve read, is a long and systematic account  of how you would work all that out, taking into account construction, commissioning, production, maintenance and decommissioning — of all forms of electricity generation. The results look like this.


Buffered, in the diagram, means stored: there are energy costs associated with storage, so that the buffered EROEI is smaller than the unbuffered. CCGT is gas turbine generation. Morgan argues that you need an EROEI of at least 7 to be able to do anything much with the energy you’ve generated. So solar, biomass and wind, all of which need storage of some kind to be practical, all fall below that figure.

We simply can’t, on these figures, run a modern society on alternative energy alone, and that is a message that the alternative energy believers find  impossible to accept. The Morgan and Weissbach papers provide a strong suggestion that we either rely on what we have, or shift to nuclear — or of course add nuclear to our present fossil fuel system. But there are few supporters of nuclear among those who criticise fossil fuels. Barry Brook, however, is one.

During a day spent n hospital recently I was fascinated to see the degree to which every single piece of apparatus in such a place relies on electricity, and how the health system is based on the belief that there will always be sufficient power to respond whenever one turns a device on. You can gets some sense of that from the following diagram, also drawn from Morgan’s essay.


As we move up the pyramid, the blue changes to yellow , recognising the shift  from firm measurements to estimates. You can see that to run a hospital in Australia we need an EROEI of around 12. It can’t be done on solar and wind and biomass. Not on these figures.

So let me end with the corrective that these two papers, interesting and persuasive as they are, are by no means the end of it all. Morgan’s essay comes with dozens of objections from commenters, and it contains a vigorous and well-argued debate. Yet the EROEI template seems to me a great start, and in time we will have some agreed figures for the estimates. For my part, the objectors were niggling at the margins: the general picture seems to me to be that there is a basic insufficiency in alternative energy that means these forms, as suppliers of grid power, can only operate usefully within a fossil fuel electricity grid system.

They cannot, at least with our present understanding, replace such a system.

Join the discussion 6 Comments

  • RafeChampion says:

    This is running on Catallaxy

    Nice to see a Popper quote in the masthead! Off topic, but do you realise how badly the academic philosophers have misread him?

    • Don Aitkin says:

      Thanks, Rafe. When I read the comments on your site I saw that I had made an error when I re-read my earlier essay, so I’ve corrected ‘90,000 km’ to ‘80,000 miles’. That makes the point even harder.

  • Alister McFarquhar says:

    More focus on the net energy contributed by Renewables is urgently needed so I am grateful for introduction to this research

    The approach is very Germanic – thorough and technical rather than economic

    I fear tho that the approach is too comprehensive to refreeze the melting ice feared by the Eco Energy Lobby

    So solar, biomass and wind, all of which need storage of some kind to be practical

    This seems to me the wrong emphasis. Clearly storage will improve with research but to rely on this is very risky and long term.

    A more simple approach is to estimate the net fuel contributed by Renewables to a Grid at the current or target level of acceptable risk of Black Out after allowing for fuel required for back up

    The capital cost of back up must be added the the cost of the Renewable

    I seem to remember some thought a decade ago that the net contribution of energy was near to zero

    The Grids must have these estimates but I cannot find any. GWFP and other interested Groups are shy of attempting a guestimate

    My hypothesis is that the net contribution of energy from Renewables is near zero and the cost fatuous.

    Can no one refute this hypothesis?

    If so Renewables are an empty cosmetic designed to meet Treaty obligations and harness a The Floating Green Vote

  • glentonjelbert says:

    Of course the above analysis specifically excludes costs from climate change and other “externalities”. The numbers for EROI are probably not the most accurate available, but more importantly, they are missing the time trend. Fossil fuel EROI is decreasing globally (ie depletion outweighs technology improvements). Renewable EROI is increasing, and with breeder solar factories EROI becomes less of an issue.

    But, Don, the bigger issue here is that fossil fuels are not sustainable. So our problems are far bigger than simply saying “oh well, we’ll just have to stick with fossil fuels, because renewables don’t work”. The change is going to have to come eventually anyway – and society is going to have to adapt.

    The question is whether we can change in time to stop catastrophic climate change. You would probably agree that there is a CO2 maximum. An amount above which there is an unacceptable risk of damaging the climate of the only life supporting planet we know of. Scientists argue and discuss whether it’s 350, 400 or 450ppm. But we’re headed to above 1000ppm on a business as usual type of approach (which you seem to be advocating). This is completely unacceptable, but politically it seems inevitable because people seem to believe what is convenient rather than what is true.

    Here’s a more recent paper that you might be interested in, which lays out the dilemma that society faces:

    In short, you seem to be able to look at the “hard realities” of renewables (which now exceed nuclear in installed power, by the way), but somehow skim over the “hard realities” of fossil fuels.

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