I’ve blogged before about when Jevons’ Paradox applies, and when it does not. When energy consumers are price sensitive, they may respond to increasing efficiency by using more energy services. When they are not price-sensitive, they don’t.
But here is a new twist: increasing efficiency may come bundled with additional features. Those features may lead consumers to use more energy, even if the increasing efficiency alone would not.
In the case of outdoor billboards, the advent of inexpensive LED lighting may not be so much due to increased efficiency over traditional lighting technology, but the result of additional utility. LED bilboards can show animation, and also can show time-sensitive advertisements. These extra features are leading to an increased use of electricity in billboards, even as the technology is becoming more energy efficient… at least in terms of lumens per watt?
Perhaps I’m splitting hairs here, but I think the increased use of energy in outdoor signage using LEDs is due more to the additional services and interactivity that LEDs provide compared to traditional halide lighting (see this article in the Economist). Put simply, when something becomes more useful, people use more of it, not, as Jevon’s paradox would imply, that people use more outdoor signage lighting as it becomes cheaper.