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  • Posted February 17th, 2016

    Strange but true: energy efficiency actually increases overall energy use

    Strange but true: energy efficiency actually increases overall energy use

    In the 1960 film School for Scoundrels, which is based on the Stephen Potter “Gamesmanship” books, there is a scene where Ian Carmichael (formerly one of life’s failures) is playing tennis with Terry Thomas. Carmichael has just finished a course in lifemanship and, having used a series of tricks and ploys to disorientate his opponent, stands in one spot with one hand in his pocket while nonchalantly hitting the ball such that Thomas has to race, panting and exhausted, from side to side across the court. Thomas = effort, Carmichael = efficiency; do not confuse the two.


    Governments are putting lots of effort into promoting efficient machines as a solution for countering global warming. Colour-coded displays encourage shoppers to compare the energy efficiency of competing appliances and gadgets; the message being that buying a higher efficiency machine can save you money and the environment. At a different level, the UK’s position in Paris last year was that global warming could be tackled by replacing existing technology with newer (and therein lies the problem) more efficient innovative products. It openly stated that this will allow UK business to sell more new technology to the developing world (1). One doesn’t have to be very astute to see that these policies cost little to implement and that they encourage consumption, sales, shareholder profits and tax income; but is there any substance to the claims that replacing existing technology with something that is more efficient can have an impact on climate change? The word “efficiency” has been adopted without adequate explanation or definition and appears to be a new “green”.

    In the Oxford English Dictionary “efficient” is described as “productive with minimum waste or effort”, and in my job as an energy engineer I am used to working with the term. It is standard practice to calculate mechanical, thermal, and fuel efficiency, for example.

    Efficiency is a quotient and it is useful because it permits the production of measured results by which systems can be appraised and compared. In fractional notation, the output is the numerator and the input the denominator (cf. equation below). Therefore, as with any fraction, increase the numerator while keeping the denominator fixed (so increase output per unit input) and system efficiency increases. Conversely, efficiency will also increase if the numerator is fixed but the denominator is decreased (this time reducing the required inputs for the same output).


    Many calculations of energy system efficiency were developed a couple of centuries ago during the Industrial Revolution, first with water power and then with steam engines. But, efficiency calculations have much broader applications. For environmental impact appraisal, total life cycle analyses can be factored in, or for simpler single units, back-of-an-envelope calculations can include factors such as maintenance costs and service contracts, all of which increase the denominator value. Thus a new machine or process method may have an efficiency improvement only at face value. It can be worse environmentally and financially if it doesn’t operate as reliably as a less efficient model, or it has higher inputs of energy from cradle to grave.

    Efficiency can also be used to qualify other aspects of life. There are economic efficiencies, i.e. income per total expenditure on resources, etc. There are also human and social efficiencies, i.e. success per unit of effort expended. And they can be interconnected: one person’s efficiency loss can result in another’s gain, which is why the internet is seen as cost effective to business. Try for example considering how much of your time is given up to bureaucracy, chasing up incompetence, searching online for savings, writing job applications (all denominator terms). Compare it with the numerator and assess how much of your time is your own, how creative have you been, how much useful or beneficial activity have you managed in comparison. Apply this to the human species in general and it becomes clear how wasteful, inefficient and enslaved we are.

    In nature, efficiency usually dictates whether a species ultimately survives of becomes extinct (trophic levels, and energy expenditure for example). It derives from the universal laws of thermodynamics, where everything tends to disorder, and the more stages or levels there are in a food chain or process leads to a multiplication of inefficiency. This is why vegetarianism is better for the environment, and why grid-supplied electricity has such a low efficiency due to multiple heat losses through the raising of steam and the transmission system.

    Now, because efficiency can be quantified, an answer to the question of whether efficient machines and appliances can have an impact on cutting global warming can be obtained. And, it turns out that the supposition is flawed. One reason is because of the laws of thermodynamics. No machine can ever be 100% efficient. In fact, even the best machines are less than 50% efficient. So, by making and operating more of these machines, the overall inefficiency and hence greenhouse gas emissions must increase; and that result is excluding the energy needed for production, transportation, marketing, and landfill, all of which must be included in the denominator term for accuracy.

    The logic can be equally flawed at the singular level. Replacing an old system that operated at say 30% efficiency, with a newer model that operates at say 34% efficiency (yes, the differences are that small), but only lasts a fraction of the time before needing repair at best (most modern circuited systems are not built for repair) increases the overall inefficiency.

    If you buy gas and electricity from the grid and have ever wondered why, with all these efficient systems and smart meters, your bills have not decreased over the years, then these are some of the reasons. There is also the fact that you are now paying an extra 9% on your bills for government-imposed incentives such as subsidising privately-owned power stations to import biomass (that’s another inefficiency story). But there is a further, more subtle reason which again is important for considering whether “efficiency” claims are credible. It is called the Jevon’s paradox.

    One hundred and fifty years ago, during the Industrial Revolution in Britain, William Jevons observed that all the striving to increase efficiency and reduce costs merely resulted in more consumption of coal. The reason, he identified, was that the increased savings from efficiency were returned through commercial upscaling in the constant pursuit of profit (2). This is as true now as it was then. In the modern context, when people have an awareness that they are making savings through efficiency, they choose to be a bit less frugal with their energy saving lifestyle or, assisted by commercial encouragement, they buy new energy-consuming gadgets. The extent of how much the Jevon’s paradox dilutes greenhouse gas emissions savings is estimated to vary over a wide range from 3% to 60% (3).

    So what can be done? Efficiency can save us, but only if the free-thinking individual realises that they have some freedom to make choices which in full or part can detach themselves from this present system. Decrease the denominator term of the efficiency quotient, and be wise enough to see past the gamesmanship.

    Andrew Rollinson


    1. H.M. Government, 2014. Paris 2015 Securing our prosperity through a global climate change agreement, DECC, Whitehall. Available from: https://www.gov.uk/government/publications/

    2. Jevons, W.S., The coal question; an inquiry concerning the progress of the nation and the probable exhaustion of our coal-mines (2nd ed), 1866, Macmillan and Co, London.

    3. Gillingham, K., Kotchen, M.J., Rapson, D.S., Wagner, G The rebound effect is overplayed, Nature, 2013, 493, pp. 475-476.

    The views expressed in our blog are those of the author and not necessarily lowimpact.org's


    • 1Dave Darby February 17th, 2016

      Coincidentally, I was looking at the Jevons Paradox yesterday. See https://en.wikipedia.org/wiki/Jevons_paradox

      The classic example is the steam engine – it was much more efficient than Newcomen’s engine, and therefore it was thought that it would reduce the amount of coal used. Of course, the opposite happened – steam engines were so efficient that they spread very rapidly, and coal use very quickly increased 1000 times over.

      So – ONE steam engine, doing the same amount of work as ONE Newcomen’s engine, will use less coal – but if there are suddenly 10,000 steam engines to replace every one Newcomen’s engine, it doesn’t work.

    • 2Dave Darby February 17th, 2016

      With energy efficient appliances, the same thing happens – a house full of energy efficient appliances and gadgetry uses a lot more energy than a house with no gadgetry at all (or very little). Plus – the money saved on energy bills will be spent on other things – things that require energy to produce, distribute and use.

      The only way energy efficiency can reduce energy use is for people to downshift and earn a bit less. That way they have the energy efficiency without having more money to spend on other things.

      Exactly the same applies to an entire economy. Energy efficiency isn’t going to reduce energy use in a perpetually growing economy. Only a steady-state economy can achieve that.

      But – corporate capitalism doesn’t allow a steady-state economy. Fractional reserve banking, interest on debt, the stock market, derivatives etc. etc. mean that the economy is primed to grow forever (until it kills its host).

      Politicians and the business world have leapt on the idea of energy efficiency because it distracts attention away from the fact that we need system change.

    • 3Dave Darby February 17th, 2016

      Horace Herring at the Open University has been writing about this for a long time. See http://web.mit.edu/2.813/www/readings/HorraceHerring.pdf

      He’s not against energy efficiency, and neither am I – it just won’t do any good within a perpetually growing economy.

      Plus it’s not about energy use in one country – it’s about global energy use. If we buy more energy efficient appliances that are manufactured in and delivered from China, it might look as though energy use in the UK has gone down, when in reality, purchases in the UK have caused global energy use to increase hugely.

    • 4Andrew Rollinson February 18th, 2016

      Improvements in water wheel efficiency were driven by the need to keep the industrial revolution going when rivers were already saturated with water wheels. It is when this “efficiency” push is attempted to be applied as a method to counter global warming that the idea is inherently flawed. For now, the greenhouse gases produced in all the lifecycle stages are an unaviodable factor, along with the intrinsic inneficiency of machines which can never by overcome because of the laws of thermodynamics. Efficiency improvements will never reduce global warming under capitalism which demands more and more sales.

      This is why the “reduce, reuse, recycle” message was tactfully dropped about ten years ago. It is absolutely spot on as it reduces the denominator term of the efficiency equation. But it doesn’t take a genius to see that if it also reduces sales. Hence why undefined “efficiency” is bandied about as a savour, and no doubt, why the Jevon’s paradox is not taught in schools.

      I suppose that in another way, its a bit like the lie sold about how machines can improve the quality of people’s lives as they save on labour allowing more time for leisure. Machines in the hands of commercial enterprise were only ever intended to improve outputs for minimum cost, and this was also identified in the1800s.

      One other ironic observation is that after twenty two (or however many) climate change meetings, political leaders who have still not stopped global warming are grossly inefficient. And, by their own definition, should be replaced by a better model. That is if their reasons for attending these meetings WAS actually to stop global warming.

    • 5John Harrison February 18th, 2016

      The only guidance as to cost of production we have as a normal consumer is the price. If I change my 30 year old freezer (that works as new) for a modern one it will save me about £15 pa in energy cost. But the new freezer will cost about £400 and probably have a life of 10 years. The reason my old freezer is so efficient is that it runs through a £20 Savaplug which near halved energy use. Sadly these went off the market – partly due to a ‘green living’ book slamming them as a scam. I tested mine.

      Getting rid of the freezer will result in higher energy use as bottling etc isn’t without an energy cost and increased food waste.

      The economics are out of sync with energy/carbon cost.

      Years back I sold a gadget that reduced fuel use for old fashioned gas and oil central heating boilers. Production cost less than £5. The savings were between 15% and 60% (usually around 30%). It worked, it was testable and demonstrable. We couldn’t get any sort of government support – much better to sell new boilers and keep those factories running.

      It’s damnably hard work been green and mind boggling as well!

    • 6Dave Darby February 18th, 2016

      I might be wrong about this, but I think that whatever it was that the savaplug did started to be incorporated into the workings of appliances at some point, and using a savaplug with the newer appliances didn’t save any more energy, and could acutally damage them. Which is why your savaplug works well with your old freezer, but I don’t think it would with a new one.

      I think.

      unless there really is some underhand stuff going on – but I think that’s the reason.

      But yes, why on earth would a government / system devoted to economic growth want you to stop buying things / make things last as long as possible?

    • 7Andrew Rollinson October 4th, 2018

      For a more thorough review of the subject see: Alcott, B. 2005. Jevon’s Paradox. Ecological Economics, 54, pp.9-21.


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