One of the most curious facts about energy is that economies use more of it even as they use it more efficiently. This strikes us as strange because many of us have heard that making cars, buildings, and factories more energy efficient is the key to cheaply and quickly reducing energy consumption, and thus pollution.

But energy experts have never seen this as particularly mysterious. As energy historian Vaclav Smil writes, “Historical evidence shows unequivocally that secular advances in energy efficiency have not led to any declines of aggregate energy consumption.” A group of economists beginning in the 1980s went further, suggesting that increasing the productivity of energy would have the same effect on the economy as making labor more productive, and that making labor more productive meant using more energy – that is, supplementing and then altogether replacing human labor with energy.

Efficiency advocates have long dismissed the evidence that there is significant “rebound” of energy use, suggesting it is only roughly 5 percent and thus fairly inconsequential. But these advocates typically focus on the relatively direct behavioral changes at the household or business level that are easiest to measure, while others note that the most significant rebounds are indirect and occur in places we consumers never see – in the production of energy, of raw materials, and consumer goods — not in “end use” consumer products.

Below, one of the leading energy efficiency economists, Harry Saunders, explains why energy efficiency does not decrease energy consumption in the way we are conventionally under stand it. In the process, Harry clarifies the controversy over his recent co-authored study for the Journal of Physics reviewing 300 years of lighting history and the likely impacts of new solid-state lighting technologies (e.g. LEDs). Against the claims that new lighting technology will reduce energy consumption, Saunders and his colleagues found that they will likely increase it – greatly expanding the global use of lighting in the process, especially in developing countries. Saunders clarifies some important questions, and explains the basics of “the rebound effect.”

With the new study, rebound has firmly moved from the theoretical to the empirical, and the implications of it must now be dealt with by all of us who were counting on efficiency to be an easy way to reduce greenhouse gas emissions.

Source: The Breakthrough Institute.