For the same retrofit defined in Problem 11.7, (i) evaluate the cost-effectiveness of LED-integrated controls for various lifetimes ranging from 5 years to 30 years (use a 5-year increments), (ii) determine the breakeven cost that make the LED-integrated controls retrofit cost-effective as a function of the lifetime. You can consider the same 5-year increments for lifetimes ranging from 5 years to 30 years.

Problem 11.7

Assess the cost-effectiveness of retrofitting an office building with LED-integrated controls at a cost of 35/m². Before the retrofit, the building has lighting density of 9.5 W/m² for a total floor area of 5,000 m². The lighting system is operated 3,000 hours per year. The electricity price is $0.12/kWh and the LED-integrated controls reduce by 60 percent the lighting energy use. Perform the analysis for a lifetime of 20 years and a discount rate of 5 percent.