Automobiles are not the only category in which greater efficiency has failed to translate into reduced energy consumption. Lighting efficiency has improved during the last three centuries by many thousand-fold, from sputtering candles to modern LEDs, as Jeff Tsao and his colleagues from the Sandia National Laboratory note in the July 2012 issue of the journal Energy Policy. But the result “has been an increase in demand for energy used for lighting that nearly exactly offsets the efficiency gains.” The authors note that “when lighting becomes cheaper, economic agents become very creative in devising new ways to use it,” such as illuminating office ceilings with LED virtual skies. In coming decades, Tsao et al. predict, increased demand for lighting probably will again swallow up any new gains in energy efficiency.

(Dr. Benny Peiser)