Dear Colleagues,

Psychologists call it the anchoring effect - the tendency of humans to adopt a familiar yardstick (such as the familiar electric light bulb) in using as a benchmark in predicting savings. As a result most people tend to underestimate energy savings. Well, according to the latest research.

When looking at energy savings, we tend to focus on upgrading light bulbs (to LED types) and twiddling thermostats. Most people grasp basic issues about energy savings; but they are decidedly unsure about the details, especially when estimating. Apparently participants in recent research underestimated both energy use and savings by almost a factor of 3. And also tended to grossly underestimate the massive energy savings that could come from tweaking larger machines such as heaters and clothes dryers. Most people tend to focus on small savings such as switching off lights and ignored (as a typical example) the great savings from moving their washing machine from a hot to a warm setting thus saving 4kWh for each load of laundry.

The estimates of savings thus tend to cluster around this yard stick (psychologists call this process ‘anchoring’) and thus we tend to grossly underestimate the savings that could be made. Naturally, if the average person used a larger yardstick (beyond the light bulb), the problem may be less pervasive. And if you are intuitively good at maths (or arithmetic), you are likely to have a considerably lower level of error.

Based on this, there is probably a case for idiot proof energy saving devices that indicate exactly how much energy you consume.

What can you do about it?

  • If you want to calculate energy savings, then try and do this systematically taking into account the real energy numbers.
  • Look at energy savings by examining the great opportunities to squeeze a tiny percentage saving from larger machines, resulting in significant savings – rather than replacing a few lightbulbs.
  • And when estimating other items in your engineering work watch out for the ‘anchoring’ effect – practised unintentionally either by yourself or others.

Naturally, I am not knocking looking at the small things when undertaking energy savings. But merely pointing at the need to also aim at making a tinier % saving out of a considerably larger item resulting in a larger absolute energy saving. Hopefully this makes sense?

Thanks to the National Academy of Sciences (and the Economist) for an interesting piece of research.

Never overestimate what others do. As Cory Doctorow said: Engineers are all basically high-functioning autistics who have no idea how normal people do stuff.