Monday 12 August 2013

In 1979, a period dominated by high oil prices and deep concerns about the future supply of energy resources, Gerald Leach and a team from the International Institute for Environment and Development (IIED) wrote an important book called “A Low Energy Strategy for the UK”.  It was controversial at the time as it stated that “the United Kingdom could have 50 years of prosperous growth and yet use less primary energy than it does today”.  This, the study argued, could be achieved by improving thermal performance of new buildings, implementing energy performance standards for cars and major household appliances, and improving industrial energy efficiency.  Leach’s scenario was similar in message to Amory Lovin’s more famous  “soft energy path” for the USA, published in “Energy Strategy: the Road Not Taken” in 1976.  Both advocated a bottom-up approach to energy modeling rather than the prevailing top-down approach and forecast future energy consumptions much lower than the prevailing official forecasts – both turned out to be more accurate than the official forecasts when it came to actual energy consumption.


Leach’s conclusion (and that of Lovins in the US) was controversial at the time as official government scenarios were still based on the belief, (perhaps still current in some circles), that there was a rigid link between energy use and GDP – something that was probably true between 1953 and 1973 – a period when affluence was increasing along with the ownership of cars and energy using appliances.  The Department of Energy projections for primary energy use were between 32% and 63% higher than the 1976 consumption (460 to 570 million tonnes coal equivalent (mtce) compared to the 1976 consumption of 349 mtce).  The Leach analysis was widely considered to be unrealistic by the energy establishment at the time so nearly 35 years later it is interesting to compare the Leach scenarios with what actually happened.


Table 1 summarizes the Leach scenarios, the official UK Department of Energy scenarios of the late 1970s, and the actual out-turn for UK primary energy consumption.  To avoid confusion over energy units (Leach used mtce, now primary energy is reported in mtoe – million tonnes oil equivalent) and different inflators for GDP I have converted everything to indices starting at 100 in 1976.


Table 1. Summary of Leach scenarios, Department of Energy scenarios and actuals.


1976           1990           2000           2010           2025
Leach GDP scenario (low) 100.0 141.3 172.3 188.5 203.1
Leach GDP scenario (high) 100.0 141.3 191.8 231.4 293.7
Actual GDP 100.0 144.5 189.9 226.1
Department of Energy primary energy forecast (low) 100.0 132.0
Department of Energy primary energy forecast (high) 100.0 164.0
Leach primary energy (low) 100.0 102.5 94.5 88.5 84.5
Leach primary energy (high) 100.0 108.8 103.3 102.2 99.9
Actual primary energy use 100.0 103.9 114.2 105.4



Interestingly enough the actual GDP out-turn has been squarely in the Low-High scenario range outlined in Leach which were in-line with the official reference forecasts used by the Department of Energy at the time.  So the economic forecasts were basically good.  Two things really stand out:


  • the big difference between the Department’s forecast for primary energy use in 2000 and the actual out-turn
  • the actual 2010 primary energy use is close to Leach’s high scenario.


Looking at energy use per GDP ratios we can see that the official Department of Energy forecast a range between 0.76 and 0.85 for 2000, Leach’s scenario was between 0.54 and 0.55, (considered outrageously low and impossible by the establishment), and the actual out-turn was 0.6.


Whatever the causes, we are practically living in what was defined in 1979 as a radical, low energy future.  


Now this is a very simple analysis and of course there are a number of factors that turned out to be different to the scenarios and will affect the conclusions including:


  • the sectoral breakdown of the economy now looks different to the scenarios of the late 1970s, (industry making up 30% of GDP by 2010 compared to an actual of 24%)
  • the sources of primary energy projected also look different to reality.  The use of gas was seriously under-estimated, Leach projected 14% of primary energy in 2010 would be gas, in reality the number was more like 35%, as the use of gas for power generation was restricted until the 1980s.


Given the importance of energy forecasts at the current time it is useful to review old future energy scenarios and see what we can learn.


There is an interesting quote in Leach (p.186) in response to the then government’s plans to expand generating capacity and nuclear power that has a strange resonance today:


The enormous investments for new power stations assumed in official forecasts are vastly reduced.  The current Department of Energy forecast estimates that 83 GW of new plant must be built in the UK by 2000.  Our figures are 26 and 30 GW for the Low and High cases respectively.  At an estimated £500 per kilowatt installed capacity for plant only (at 1977 costs) the investment savings on our projections are of the order of £26 – £30,000 million, or well over £1,000 million a year.  We should be very surprised if this sum did not amply cover the costs of all the energy conservation measures assumed in this study.


Interestingly, the 83 GW of new plant needed by 2000 referred to here is about the same as the total UK generating capacity today.  The Department of Energy’s “reference forecast” for 2000 also included 40 GW of nuclear capacity (compared to the actual today of 10 GW).


Maybe we haven’t learnt very much about energy forecasting.  A lot of the basis of the planning for the current Electricity Market Reform (EMR) was built on DECC scenarios which showed significant increases in electricity demand, up to a doubling of demand by 2050, based partly on assumptions about the electrification of heat and the spread of electric vehicles.  Other scenarios, some of which showed demand going down, were discounted.  For details see the report, “A corruption of governance” by the Association for the Conservation of Energy (ACE):


My conclusions from reviewing Leach’s “low energy strategy”, Lovin’s “soft energy path” and other studies are as follows:


  1. government forecasters and indeed most mainstream analysts have trouble seeing outside the perceived wisdom of the time – the prevailing paradigm.
  2. official forecasts tend to overstate future energy use.
  3. bottom-up, technically based, demand led models may be more reliable than economic top-down models.
  4. the link between energy and GDP is more complex than we thought – but it is weakening over time.
  5. we achieved significant improvements in overall energy efficiency consistently over a 35 year period, during which energy efficiency was really only a major concern for about ten years between the mid-1970s and mid-1980s.
  6. energy efficiency has effectively delivered more energy services than any other source of energy.
  7. the Leach book should be required reading for energy analysts and policy makers.  Although long out of print copies can be found on Amazon and Abe Books.


The final point – if we effectively achieved a “low energy” future without paying attention to increasing the rate of reduction in energy intensity the question is what could we achieve if we actually do pay attention to the energy efficiency resource?


There is 1 comment on “Surprise! You are living in a low energy future…….(almost)”:

  • Conscious uncoupling? | Only Eleven Percent on March 9th, 2015 at 2:44 pm said:

    […] ever more energy. This fed into (and still feeds into) all official projections of energy use (see here for example), as well as the technical fantasies of the government of the day and bodies such as […]

Dr Steven Fawkes

Welcome to my blog on energy efficiency and energy efficiency financing. The first question people ask is why my blog is called 'only eleven percent' - the answer is here. I look forward to engaging with you!

Get in touch

Email Twitter Linkedin Skype

Email notifications

Receive an email every time something new is posted on the blog

Energy Efficiency

Energy Efficiency by Steven Fawkes

My book Energy Efficiency is available to buy now

Outsourcing Energy Management

Outsourcing Energy Management by Steven Fawkes

My book Outsourcing Energy Management is available to buy now

Only Eleven Percent