Suppose a utility generates electricity with a 36 percent efficient coal-fired power plant emitting the legal limit of 0.6 lb of SO2 per million Btus of heat into the plant. Suppose the utility encourages its customers to replace their 75-W incandescents with 18-W compact fluorescent lamps (CFL) that produce the same amount of light. Over the 10,000-hr lifetime of a single CFL,
How many 2,000-lb tons of SO2 would not be emitted?
