Saturday, 17 December 2011
The Jevons paradox
Greenbelt: they should know better. Now, as Christmas approaches, I noted once again that there is hardly a house without its tree lit up, visible through the unclosed curtains. Worse still is the number of houses with flashing lights festooned over their exterior.
And, yes, the roofs of some of those houses even sport photovoltaic panels. Thus supporting the theory of W.S. Jevons, writing some 170 years ago: Jevons argued that improvements in fuel efficiency tend to increase, rather than decrease, fuel use: he observed that England's consumption of coal soared after James Watt introduced his coal-fired steam engine, greatly improving on the efficiency of earlier designs. Watt's innovations made coal a more cost-effective power source, leading to the increased use of the steam engine in a wide range of industries. This in turn increased total coal consumption, even as the amount of coal required for any particular application fell. At that time, many worried that coal reserves were dwindling: some thought increasing efficiency would reduce consumption. Jevons however argued that further increases in efficiency would tend to increase the use of coal. Hence, increasing efficiency would tend to increase, rather than reduce, the rate at which England's coal deposits were being depleted.
Similarly, those benefiting from the feed-in tarrif are saying, perhaps: "What the heck? Now we don't need to worry about turning the lights off!" What prospect therefore of fossil fuels being left in the ground?