Since more efficient (and cheaper) energy will also lead to faster economic growth, it's suspected that improvements in energy efficiency may eventually lead to even faster resource use. This was postulated by economists in the 1980s and remains a controversial point in home energy. Or does it?
Here's a blog post I wrote two years ago on the topic (It's everything I know about it):
Recent articles in USA Today and California's Flex Your Power e-Newswire discussed the phenomenon known in energy efficiency circles as "take back" or the "Snackwell Effect" (see "Consumers Can Sabotage Energy-Saving Efforts," and "The Snackwell Effect: Consumers Sabotage Energy-Saving Efforts").
Stanley Jevons first described the take back effect in 1865, so this is nothing new. Jevons observed that new efficient steam engines decreased coal consumption, which led to a drop in coal prices. But the lower prices meant that more people could afford to use coal, and so coal consumption increased.
The "Snackwell Effect" takes it's meaning from the habit of people on diets who eat lots of low-cal snacks that add up to many times the calories of a regular snack. The example given in both articles mentioned above is a West Virginia couple that bought an energy efficient washing machine to replace their old inefficient one. Their energy bills were no different after the conversion. Turns out they were doing more loads of laundry, even washing one piece of clothing in one load, because they were lulled into complacency by their energy efficient purchase.
I asked Jim McMahon, the head of the Energy Analysis Program at Lawrence Berkeley National Laboratory (LBNL), about the Snackwell Effect and appliance energy use. I recently heard him speak about the great efficiency gains made between the first energy crisis brought on by the Arab oil embargo in 1973, and today. Those gains are significant; refrigerators today use about half the energy on average than they did in the 1970s. "This effect [Snackwell Effect] has been studied for a long time, [it was] formerly called the rebound or take back effect," he says. One 2001 study concluded that for every gain in energy efficiency, about 10% is taken back by an increase in energy use. Greater air conditioner efficiency, for example, may mean that people lower their thermostats, since they expect their energy bills to be lower, and this eats into the efficiency savings. "I think that there are a number of energy-using devices where consumers do not exhibit the Snackwell effect, such as refrigerators or televisions. In those cases, in my view, the usage behaviors are unrelated to the cost of energy, at least for most households in the United States," says McMahon. He does admit that more study is needed in this area. A 10% take back effect is significant, but certainly not a barrier to serious energy efficiency improvements.
Karen Ehrhardt-Martinez, a sociologist, studies human behavior and energy use for the American Council for an Energy Efficient Economy (ACEEE). "The relationship between energy efficiency and energy consumption is not as straightforward as it may initially appear and as some people like to portray it."
The trends show that: 1) residential energy consumption increased by roughly 57% between 1970 and 2005; and 2) residential energy consumption per capita increased by only 7%".
According to Ehrhardt-Martinez, a bigger problem than the 10% of energy lost due to the take-back effect-or the Snackwell Effect-is the proliferation of energy using, albeit more efficient, devices in American homes; lifestyle choices, such as the dramatic increase in the size of homes while families got smaller; population increase; and the "invisible" energy, such as standby power or phantom loads, that is hidden from consumers. "However," says Erhardt-Martinez "if we were able to combine efficiency improvements with better lifestyle choices (i.e. smaller, more energy efficient houses), smart purchasing behaviors, and improved information mechanisms that allowed consumer to actively manage their energy consumption, then we could have a much more dramatic impact on both household level consumption as well as state and national level consumption."
I guess it all boils down to Customer/Client education.Try to persuade them their energy consumption habits will help a lot.
As long as we're talking about "the big picture" with respect to energy use...
Irrespective of how large or small the true macro-scale rebound effect is for energy efficiency, if our ultimate concern is about sustainability, then we would do well to look at the efficacy of efficiency gains within a more comprehensive context. Energy saved is money saved, and in order to evaluate how much more sustainable those energy savings have made us, we need to look at how the money we have saved is being spent elsewhere. In the current economy, it is nearly impossible to spend money without creating carbon emissions. All indications are that an increase in GDP cannot be completely decoupled from an increase in overall material and energetic throughput. That is, the more money we spend, the more we increase the rate at which we turn raw materials to waste, and trash the planet and its climate in the process. All this to say, as long as we have an economy whose perceived "health" is predicated on perpetual growth, saving energy will not move us closer to sustainability.
I really like your wording "perpetual growth". It is not enough in today's economy to have a stable company with solid recurring profits. If you tried to get investors or a bank loan for your business they wouldn't touch it unless your balance sheet showed promise of perpetual growth. That in itself stunts our industry. Why invest in energy efficiency when there might be a 10 year payback? Not fast enough for investors or bankers. Is Perpetual growth sustainable? Absolutely not unless sustainability is coupled with that growth which unfortunately will not happen in my lifetime.The only perpetual growth that is guaranteed is human population. More people = more finite resources consumed. Reduce energy use of the current population by 50% and population could double (which it will) and still use the same amount as today. Simplistic? yes but I am a simple man. Snackwell effect? We just need to go on a diet that we stick to. And learn to eat (use energy) properly
Here's a thought on that topic:
When I was introduced to the Rebound concept, I noticed that it directly applied to situations where capacity was flexible. For example, if my coal powered chair factory makes 100 chairs for every ton of coal I burn, it behooves me to pursue efficiency. Now my chair factory can make the same 100 chairs but only burn half a ton of coal. So what do I do? I still burn the ton of fuel but now I make 200 chairs. Then I realize my profit margin has grown so now I burn 2 tons of coal to make 400 chairs so I make more money. And so the cycle begins with no end in sight. Capacity is the key here.
But capacity is not always flexible. Let me explain: if I am comfortable in my house at 68 degrees F and it takes me 1 therm to reach that level of comfort, then I burn 1 therm. But I tighten and insulate my home, now it only costs me half of a therm to reach the same 68 degrees capacity. I am not tempted to burn the remaining half of therm because I can't make 68 degrees F more comfortable. The objective has been reached and rebound doesn't come into effect.
My point: yes, rebound is real and will clearly have an effect on overall carbon emissions. But, we are not doomed to an inescapable future as rebound does not necessarily apply to every situation.
Just a thought!
And now, here
"The rich do not roast" (Amory Lovins) says it all - you can not increase energy services beyond a certain limit; on the other side, as long as optimal service is not reached, we can not blame the user for using some of the efficiency to increase comfort. With 10 fold efficiency (reducing consumption prior to rebound by 90%) it is not a problem, if the rebound is e.g. 30% - that will just reduce the savings from 90% to 87%. Therefore, the answer is really high efficiency - high enough, that any rebound will not be of any significant impact. That is of course also working for the whole economy. We'll have to improve all efficiencies significantly - but that is, what we will have to do anyhow and it makes a lot of sense. The passive house is a real scale demonstration of factor 10 efficiency (AFTER rebound). We discussed the issue during the last passive house conference.
Found: a paper on the limits of energy efficiency, Limits of EE , from the oil company point of view on CO2 emissions, none the less, worth reading.
The final solution in the end is population reduction. We can either do it ourselves ie China one child law, not a best practice but it does address the problem, or we can sit back and allow mother nature to work it out with climate change, famine, strife and revolution. It has been said that for the earth to support our population at the level of the USA we would need six earths or we could reduce our population ............ very scary ether way. It is something that needs to be addressed.