Jevons' Paradox

Energy efficiency has been called “the fifth fuel” (after coal, petroleum, nuclear power, and renewables); it is seen as a cost-free tool for accelerating the transition to a green-energy economy.

The fact of life is that energy efficiency gains lead to doing more with less, rather than doing the same with less.

In 1865, the English economist William Stanley Jevons observed that technological improvements that increased the efficiency of coal-use led to the increased consumption of coal in a wide range of industries. He argued that, contrary to common intuition, technological progress could not be relied upon to reduce fuel consumption.

A futuristic example

It is anticipated that in the near future (less than 15 years) that the majority of passenger road travel will be provided by ‘autonomous EV carshare’. This should reduce the cost of road travel dramatically, due to ownership and maintenance overhead costs being shared by many users as well as the efficiency gains of an electric power train. However this will lead to a dramatic rise in total number of road kilometers travelled by light passenger vehicles. Why?

There are two reasons;

  1. Cost is a limiting factor for many people’s desire and need to travel.
  2. The carshare vehicles will be traveling empty between pick ups and drop offs.

So it is quite likely that light passenger vehicle kilometers will double thus offsetting the efficiency gains of transport electrification.