Compact fluorescent lamps (CFLs) have become required in recent years, but do they make financial sense? Suppose a typical 60-watt incandescent lightbulb costs $.37 and lasts for 1,000 hours. A 15-watt CFL, which provides the same light, costs $3.00 and lasts for 12,000 hours. A kilowatt-hour is 1,000 watts for 1 hour. Suppose you have a residence with a lot of incandescent bulbs that are used on average 500 hours a year. The average bulb will be about halfway through its life, so it will have 500 hours remaining (and you canât tell which bulbs are older or newer). If you require a 10 percent return, at what cost per kilowatt-hour does it make sense to replace your incandescent bulbs today? (Negative amount should be indicated by a minus sign. Do not round intermediate calculations and round your answer to 6 decimal places, e.g., 32.161616.) Break-even cost $
Compact fluorescent lamps (CFLs) have become required in recent years, but do they make financial sense? Suppose a typical 60-watt incandescent lightbulb costs $.37 and lasts for 1,000 hours. A 15-watt CFL, which provides the same light, costs $3.00 and lasts for 12,000 hours. A kilowatt-hour is 1,000 watts for 1 hour. Suppose you have a residence with a lot of incandescent bulbs that are used on average 500 hours a year. The average bulb will be about halfway through its life, so it will have 500 hours remaining (and you canât tell which bulbs are older or newer). If you require a 10 percent return, at what cost per kilowatt-hour does it make sense to replace your incandescent bulbs today? (Negative amount should be indicated by a minus sign. Do not round intermediate calculations and round your answer to 6 decimal places, e.g., 32.161616.) Break-even cost $
Related questions
| Compact fluorescent lamps (CFLs) have become required in recent years, but do they make financial sense? Suppose a typical 60-watt incandescent light bulb costs $.55 and lasts 1,000 hours. A 15-watt CFL, which provides the same light, costs $3.90 and lasts for 12,000 hours. A kilowatt-hour of electricity costs $.131, which is about the national average. A kilowatt-hour is 1,000 watts for 1 hour. If you require a return of 11 percent and use a light fixture 500 hours per year, what is the equivalent annual cost of the compact fluorescent lamps (CFLs)? |
| Compact fluorescent lamps (CFLs) have become required in recent years, but do they make financial sense? Suppose a typical 60-watt incandescent light bulb costs $.41 and lasts 1,000 hours. A 15-watt CFL, which provides the same light, costs $3.20 and lasts for 12,000 hours. A kilowatt-hour of electricity costs $.117, which is about the national average. A kilowatt-hour is 1,000 watts for 1 hour. If you require a return of 9 percent and use a light fixture 500 hours per year, what is the equivalent annual cost of each light bulb? (Negative amounts should be indicated by a minus sign. Do not round intermediate calculations and round your answers to 2 decimal places, e.g., 32.16.) |
| Equivalent annual cost | |
| 60-watt incandescent light bulb | $ |
| Compact fluorescent lamps | $ |
