Incandescent light bulbs create a cogeneration benefit by warming the indoor spaces they illuminate.
Carl R. Danner is director at Wilk & Associates/LECG LLC. Contact him at firstname.lastname@example.org. The author acknowledges helpful discussions with Michael Crew, Gary Gibson, Cliff Hamal, and Colleen Pastore.
Consider the old-fashioned incandescent light bulb. Many public agencies promote replacement by compact fluorescents that consume less electricity. However, incandescent light bulbs create a cogeneration benefit by warming the indoor spaces they also illuminate; they can be viewed as little resistance heaters attached to a source of light. A consumer willing to use them selectively in winter can save fossil fuels otherwise used for heating, while avoiding the corresponding increase to summer air conditioning demands that year-round use would cause.1
Compact fluorescents also give off heat, but less, because their wattage is lower for the same light output. As well, some consumers may prefer an incandescent for other reasons, such as the color (or temperature) of a light, how quickly it turns on, whether it can be used with a dimmer switch, whether it will fit an existing lamp or fixture, or whether it has a pleasing appearance.2