Break-Even Cost The previous problem suggests that using CFLs instead of incandescent bulbs is a no-brainer.

However, electricity costs actually vary quite a bit, depending on location and user type (you can get information on your rates from your local power company). An industrial user in the Scottish Highlands might pay £0.04 per kilowatt-hour, whereas a residential user in Essex might pay £0.25. What’s the break-even cost per kilowatt-hour in Problem 9.36?