A 25-W compact fluorescent lightbulb (CFL) produces the light equivalent of a 100-W incandescent bulb. The population of North America is estimated to be about 305 million. Estimate the amount of coal needed to light one 100-W incandescent lightbulb for each person for one year and the amount of coal that would be saved if each incandescent bulb were replaced with a CFL. Assume the coal has a NHV of 28.5 MJ · kg−1 and the power plants are 33% efficient.
