Bouncing off the rebound

  • Posted on: 1 July 2016
  • By: Yamina SAHEB

I may be an engineer by training, but I’m still tolerant. So tolerant in fact, that I can go so far as to willingly enter a room full of economists. That’s precisely where I was last month, enjoying some excellent presentations by distinguished economists on the macro-economic benefits of energy efficiency.

And then someone had to mention the rebound effect. Or rather, the existence of a rebound effect on energy efficiency. I was about to valiantly raise my hand and question the gentleman’s expertise on the topic, when someone else intervened - fortunately with much milder words.

This other participant replied that there is no rebound effect on energy efficiency. He then explained that energy efficiency policies can’t deliver energy savings on their own.

The room looked rather befuddled.

Indeed, there seems to be a lot of confusion among experts about energy efficiency, about what it can and can’t deliver. To get to the root of this mystery, I went back to the source: the 1974 Agreement on an International Energy Program.

As you probably know, following the 1970s oil crisis, the IEP Agreement established the IEA. Since 1974, the Agreement has only been amended once, in September 2008. Yet surprisingly, neither versions of the document include the phrase “energy efficiency”. But one of the areas of co-operation listed in Article 42.a does refer to “energy conservation”:

The Standing Group on Long Term Co-operation shall examine and report to the Management Committee on co-operative action. The following areas shall in particular be considered:

(a) Conservation of energy, including co-operative programs on:

  • exchange of national experiences and information on energy conservation;
  • ways and means for reducing the growth of energy consumption through conservation.

The puzzle deepens: when did “energy efficiency” replace “energy conservation”?

Google, as often, has some light to shed on the issue. When analyzing millions of books, it appears that after a meteoritic rise, energy conservation started to abruptly fall out of fashion when oil prices came crashing down in the early 1980s. Meanwhile, energy efficiency was steadily gaining mindshare, waiting for its time in the spotlight.

After some more time spent in the dusty binders of the IEA archives, I have uncovered the turning point. The “shared goals”, adopted at the IEA Ministers meeting of June 1993, are the first official document where “energy efficiency” became the foremost policy instrument to secure our energy future:

Goal 5: Improved energy efficiency can promote both environmental protection and energy security in a cost effective manner. There are significant opportunities for greater energy efficiency at all stages of the energy cycle from production to consumption. Strong efforts by governments and all energy users are needed to realize these opportunities

Interestingly, ”reducing the growth of energy consumption” disappeared along with the concept of energy conservation. From a physical standpoint though, the authors of article 5 do not contradict themselves: improving energy efficiency doesn’t imply reducing energy consumption growth.

We’re finally lifting the veil on an apparent paradox: it would seem that the energy community decided to replace the concept of “energy conservation” by that of “energy efficiency” while still hoping to achieve the same results. When we collectively realized the expected savings were nowhere to be found, we invented the rebound effect on energy efficiency.

This is just lazy thinking. How could there be a rebound on efficiency? Sounds like it’s time for a little trip down energy 101.

Energy efficiency is the ratio between the energy service delivered and the energy consumed to deliver said service. An energy efficient product is therefore a product that uses less energy to provide the same service.

So energy efficiency doesn’t aim at reducing the overall energy consumption. It’s only about doing the same with less; or conversely, doing more with the same. It doesn’t question the possible expansion of energy services - which energy conservation does.

I would love to know how our rebound fan proposes to use efficiency to reduce energy consumption without questioning the expansion of energy services!

And that would assume that the reported energy efficiency of products is accurateA bold claim to say the least!

Let’s take refrigerators. In the developed world, we all have at least one at home. But did you know that aside from Japan, none of the other IEA member countries measure the energy consumption of fridges at more than one ambient temperature? As if your kitchen had the same temperature all day, every day…

It gets better: during tests, the fridge is left completely empty and its doors are never opened. Freezers don’t get much more love: tests are only conducted for 24 hours while freezer compartments are loaded with test packages that require many days to stabilise.

That’s what IEC 62552 will do for your refrigeration test procedures. So don’t come back asking for a refund when you discover that your electricity bill is higher than the label claimed. In fact, estimates show that fridges consume around 15% more than what their manufacturers claim.

Yet, when it comes to wiggle room, some may feel that ill-designed test procedures are not enough. How about claiming a 10% bonus on the real energy efficiency? Don’t thank me: that’s what most energy regulations around the world offer today. I doubt we would accept 10% tolerances on soda cans for very long: we’d miss the last gulps far too much. Yet you can bet that soda retailers would happily deprive us of the last 10% of each can and pocket the difference if they could. One has to wonder what your neighbourly appliance manufacturer does with his “free” 10% tolerance on energy consumption?

It becomes harder to put the blame solely on the industry when you consider that most IEA countries do not check the accuracy of the energy consumption claims. In my experience with cooling products, I’ve observed that every year at least one-third of the products on sale did not comply with minimum energy performance (MEPS) requirements - some with deviations above 50%.

Now let’s try to put together a little worst-case scenario to explain the observed higher-than-expected energy consumption: +15% to account for actual usage patterns in the field, +10% for an unnecessary statistical tolerance (as measurement uncertainties are already included in test procedures), and +50% for lack of compliance checking thrown in for good measure. Et voilà: without any intervention from the user, the energy consumption is already 65% higher than what the label claimed!

But at the end of the day, the real killer is that energy efficiency doesn’t question the need for energy services. In practice I can choose to light my home all the time; hesitate between two flavours of ice cream in the open freezer several times a day; decide that my computer fan should heat the office all night long because I can’t be bothered to wait for it to start the next morning; prefer to linger in long hot baths when a quick shower would do, or to bury myself into debt to get the latest SUV and 5-bedroom house that will blow the Joneses away.

So for ECEEE, who was recently asking ”Is efficient sufficient?”, I have one word: no.

But I wouldn’t call this a rebound effect on energy efficiency. Rather, to paraphrase a famous sax player: “It’s the energy policies, stupid”.

This post was published for the first time on Februray 19, 2013 on the IEA sustainable building centre web site,