Problem 4. Suppose a utility generates electricity with a 36 percent efficient coal-fired powerplant 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 (CFLS) that produce the same amount of light. Over the 10,000-hr lifetime of a signal CFL. (a) How many kilowatt-hours of electricity would be saved by the switch to a single CFL? (b) How many (2,000-lb) tons of SO2 would not be emitted by the switch to a single CFL? (c) If the utility can sell its rights to emit SO2 at $800 per ton (these are called 'allowances'),how much money could the utility earn selling the SO2 saved by a single CFL?