Question 1

There are 20 lights and ballasts that consume 440W (400W high intensity discharge (HID) bulbs with a ballast that consumes 40W). The cost of electricity is $0.10/kWh and $7/kW-month demand and the lights are on 24 hours a day, seven days a week. How much electricity do the HID lights and ballasts consume monthly? What is the estimated cost of operating the 20 HID lights and ballast monthly?

Question 2

For the same lights in Question 1, you are able to install a timer of the lights and instead of operating 24 hours a day, they operate 8 hours a day. How much electricity do the HID lights and ballast consume monthly? What is the new estimated cost of operating the 20 HID lights and ballasts monthly?

Question 3

For the same lights in question 1, you are able to install the same timer as Question 2, reducing daily operating hours from 24 hours to 8 hours. However, you are also able to replace the 400W lights and 40W ballasts with LED luminaires that consume 150W of power each. How much electricity do the LED luminaires consume monthly? What is the new estimated cost of operating the 20 LED luminaires monthly?