Investment analysis calculator

This calculator indicates the payback period when investing in an LED luminaire compared to a lighting installation using conventional lightsources.  
Please insert your figures below. The payback time is calculated by dividing the difference in operating costs by the difference in investments. From this calculation you can determine how many years it would take to "earn back" your initial investment. The method returns a simplified result, i.e. all parameters like cleaning costs, discount rate, etc. are not included.

 Please input information in all cells for the calculator to work correctly.

Investment Analysis for the US - Designed for Lfforberg by Ken Rite Solutions
Description Conventional fixture/luminaire LED fixture/luminaire Difference Unit
Number of fixtures/luminaires Fixtures/luminaires
Fixture/luminaire price including lightsource Dollars ($)
Installation costs per fixture/luminaire Dollars ($)
Sum, investments Dollars ($)
Energy consumption per fixture/luminaire Watt
Energy price
Dollars per kWh($)
(2014 average US energy price was $0.1045 kWh)   
Operating hours per year Hours
Lightsource life time
(Average life time: 50,000 hours (LED), 8,000  hours (CFL), 1,200 hours (Incandescent))
Lamp exchange costs, including lightsource and work Dollars ($)
Sum, annual operation costs Dollars ($)
Payback time Years
Energy savings %