Residential Lighting: Economic Worksheet
Introduction
This site provides data on lighting technologies, including typical prices, suggested values for hours of lamp operation in various rooms, and a worksheet that you can use to analyze the costs of using the lighting in your designs.
To complete an economic analysis, you must compare one design to another. Design 1 can be the existing lighting system, the common practice used by a builder, or any other point of reference that you find useful. Design 2 is the new lighting design that is being compared to Design 1. If your goal is energy efficiency or lower operating costs, examine several alternative designs and compare them to each other and to Design 1.
First identify two designs for comparison; then choose the analyses of interest to you:
To estimate the annual energy saved by installing an alternative design, complete the worksheet items A through I. The annual energy saved is I, the difference between the annual energy use of Design 1 and the annual energy use of Design 2.
To estimate the annual operating cost, including energy and lamp replacement costs, saved by installing an alternative design, complete the worksheet items A through Q. The annual operating cost saved is Q, the difference between the annual operating cost of Design 1 and the annual operating cost of Design 2.
To calculate the simple payback of the alternative solution, complete the worksheet items A through Z. The simple payback is Z, the number of years that must elapse before the annual operating cost savings have paid back the initial incremental cost of the lighting design.
Detailed directions for each line of the worksheet can be accessed by clicking on the worksheet fields.
The Economic Worksheet is featured in The Lighting Pattern Book for Homes - By Russell P. Leslie, AIA, IES, and Kathryn M. Conway, MS. Originally in hardcover, this 222-page book is now available online at no charge. Illustrates common home lighting installations as well as energy-efficient upgrades and redesigns.
For more information contact Jeremy Snyder, Program Director, Energy Efficiency.