Making Lighting More Efficient Could Increase Energy Use, Not Decrease It
September 7, 2010
Solid-state lighting, a souped-up version of the light-emitting diodes that shine from the faces of digital clocks and on the front panels of audio and video equipment, promises illumination for a fraction of the energy used by incandescent or fluorescent bulbs.
If history is an indicator, however, the consequence may not just be more light for the same amount of energy, but an actual increase in energy consumption rather than the decrease hoped for by those promoting new forms of lighting, says The Economist.
- The light perceived by the human eye is measured in units called lumen-hours -- about the amount produced by burning a candle for an hour.
- In 1700 a typical Briton consumed 580 lumen-hours in the course of a year, from candles, wood and oil.
- Today, burning electric lights, he uses about 46 megalumen-hours -- almost 100,000 times as much.
Jeff Tsao of Sandia National Laboratories in New Mexico and his colleagues predict that the introduction of solid-state lighting could increase the consumption of light by a factor of ten within two decades.
- Assuming that, by 2030, solid-state lights will be about three times more efficient than fluorescent ones and that the price of electricity stays the same in real terms, the number of megalumen-hours consumed by the average person will, according to their model, rise from 20 to 202.
- The amount of electricity needed to generate that light would more than double.
- Only if the price of electricity were to triple would the amount of electricity used to generate light start to fall by 2030.
Source: "Making lighting more efficient could increase energy use, not decrease it," The Economist, August 26, 2010.
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