Jevons paradox: why making things more efficient doesn’t always reduce energy use
In 1865, Englishman William Jevons predicted in “The Coal Question” that coal consumption would increase, not decrease, as steam engines became more efficient. He was correct.
Increasingly cheaper coal power drove the Industrial Revolution, increasing the rate of economic expansion and increasing coal use. Subsequently, cheaper oil and natural gas have driven further growth and increased fossil fuel use.
This phenomenon has been seen repeatedly in many markets. Take, for example, the case of adding lanes to highways. Theoretically, it increases the efficiency of traffic flow; however, typically, it does not solve the traffic congestion problem. Increasing ease of travel drives more people to drive more often.
Jevons' underlying premise that efficiency improvements in a product or service drives market demand became known as the Jevons paradox. The implication is that improving energy efficiency does not reduce overall energy use, and improving energy efficiency is not enough to address climate change.
Consider light-emitting diodes (LEDs). They have provided a step change in energy efficiency from incandescent and fluorescent bulbs. However, because of energy efficiency and format, LEDs are used in many places besides traditional lighting. The Las Vegas Sphere and the LED-lit building facades of Las Vegas and Shanghai are extreme examples.
There are a couple of ways to think about this paradox.
First, increasing energy efficiency is insufficient to address climate change because the Jevons paradox results in "efficient over-consumption". Increasing efficiency alone is not going to solve the problem. Efficiency, therefore, must be partnered with sufficiency. For example, in buildings and homes, questions are: How big is big enough? Do we need to build a new one, or can we update or repurpose the old one?
I have written about Kate Raworth's Doughnut Economics, which states that to be economically, socially and environmentally sustainable, society must exist below the “ecological ceiling” and above the “social foundation.” Much of the rich world exists above the environmental ceiling, and many of the poorest in the world live below the social foundation.
The Jevons paradox offers an opportunity for the glazing industry: The more energy-efficient fenestration systems become, the more windows will be installed. With code stringency increasing, there is pressure to reduce window-to-wall area. Yet there is much evidence that comfortable daylight and quality outside views are critical to human health, wellness, healing and learning. Having highly energy-efficient fenestration available from our industry is critical to allowing sufficient glazed area in buildings. It also supports achieving the human health element of the Doughnut’s social foundation.