A university campus has 200 classrooms and 400 faculty offic

A university campus has 200 classrooms and 400 faculty offices. The classrooms are equipped with 8 fluorescent lubes, each consuming 120 W, including the electricity used by the ballasts. The faculty offices, on average, have half as many tubes. The campus is open 230 days a year. The classrooms and faculty offices are not occupied an average so h a day, but the lights are kept on. If the unit cost of electricity is $0.080/kWh, determine how much the campus will save a year if the lights in the classrooms and faculty offices are turned off T during unoccupied periods.

Solution

Electricity Savings per year in class rooms = 200*120*5*230/(24*1000) kW = 1150 kWh

Electricity Savings per year in faculty rooms = 400*60*5*230/(24*1000) kW = 1150 kWh

Total Energy savings= 2300 kWh

Cost savings= 2300*0.08 = 184 Dollars/yr