Using more efficient lights like LEDs will not necessarily lessen human impact on the environment, according to a perspective published in the Journal of Physics D: Applied Physics. Though artificial light sources are increasingly efficient, scientists point out that people may even the keel on energy costs by using light sources more and more. To get the efficiency to translate to energy savings, energy providers may have to raise their prices.

The perspective paper focuses on human use of artificial lighting, an energy expenditure that accounts for 0.72 percent of the world's gross domestic product. Artificial lighting has become more and more efficient, from oily lamps to incandescent bulbs to fluorescent bulbs, and LEDs are poised as the next efficiency jump.

While a more-efficient fixture on its own consumes less energy than its predecessor—an LED as bright as a 60-watt incandescent bulb consumes only 7 watts of power—but that doesn't mean its owner will carry the energy savings, the authors point out. As lighting becomes more efficient and less expensive, they say, people will likely elect to use more and more of it.

Based on past usage, the authors also project that our energy and light usage has not yet reached a saturation point. Between more efficiency and a greater desire to use light for productivity purposes, our energy usage stands to increase, rather than decrease, even as our lights become more efficient.

In order to get people to save energy, the authors suggest that the best way may be to force the savings at the source by increasing the cost of power. They hope that this would hold energy consumption constant, at least, while preserving some of the productivity that could be gained by using more light.

Journal of Physics D, 2010. DOI: 10.1088/0022-3727/43/35/354001 (About DOIs).