Should I discard my still-working standard incandescent bulbs and replace them with compact fluorescents, or wait until they die a natural death and then replace them?
There are several reasons to get rid of those incandescent bulbs and replace them with compact fluorescent lights (CFLs). Incandescent bulbs turn less than 5 percent of the electricity they use into light; the rest is wasted heat. Besides being annoyingly inefficient, this can increase summertime air-conditioning costs and present a higher risk of fire. CFLs, on the other hand, are over three times more efficient, meaning they put out the same amount of light but use one-third as much electricity; they also put out much less heat.
Continue reading at: http://www.salon.com/mwt/feature/2008/02/25/ask_pablo_lightbulbs/index.html