The following glossary of definitions should help you to understand the information required and dispensed, and give you a better idea of how to read the Cost Savings Calculator.
Lamp Life: This represents the life expectancy of the bulb you are replacing and the LED used to replace that bulb. This number is provided by the manufacturer and is on the website's bulb description or packaging. Incandescent bulbs usually last 750-1500 hours. CFL bulbs usually are rated 6000 to 12000 hours. And LED's are usually rated 25,000 to 50,000 hours average life expectancy.
Lamp Cost: This represents the cost (what you are paying) for the bulbs in question. Incandescents usually cost $1 to $5. CFLs usually cost $4 to $12. And LED's usually cost $15 to $40 dollars.
Ballast Cost: HPS lamps generally require a ballast. When replacing those lamps with LED's a ballast is not needed, so you end up saviing that amount in future replacements.
Lamp Wattage: This represents the wattage of the old lamp and the wattage of the LED you are using to replace it.
Ballast Wattage: Ballasts use a small amount of energy to operate the lamp. Since you are not using a ballast with LED's this comes back as savings to you. If you are replacing HPS lamps and don't know the wattage you can estimate this amount by using 10% of the HPS wattage.
Total Power Consumption: This is a calculation based on the above criiteria telling you how much energy you are using for the bulbs in question.
Total operating Hours: How many hours per day are these lights used? This number should be the same in both columns.
Labor rate ballast: If you hire someone (or someone on your staff) to replace the ballast please estimate the hourly rate. This rate would probably apply a one time for rewiring or removing the ballast for LED installation
Labor rate Lamp: This may be the same as above, or if a different person installs the lamps, this would be their hourly rate.
kW Cost: This is your kW per hour rate for your location. This information should be on the electric bill, or you can go to this website to get an estimate based on your state. http://www.eia.gov/electricity/state/
Number of Lamps: This represents the total number of comparable lamps you are replacing for your particular installation.
The followiing items are calculated for you based on the above information and represent the Annual Operating Costs of the lamps.
Lamps and Ballasts: Total annual operating costs of lamps and ballasts.
Labor (lamp and ballast): Total annual operating costs of Labor.
Electricity: Total annual energy costs.
Total each bulb: This is the total cost of the bulbs
Total System: This is the total annual operating expense of all the above items.
-The followiing items are calculatied for you based on the above information and represent the Total Annual Savings potential for switching to LED's.
Annual Savings: How much $$ you can expect to save on an annual basis.
Simple Payback/Years and Return on Investment percentage: How many years (months) you can expect to see for your return on your investment in LED's.
Energy Cost Savings over Life: Represents the energy cost savings over the life of the bulb
Total Savings Over Life: Represents the total energy cost savings and labor savings over the life of the bulb.
Annual energy savings kW: Represents how much energy in kW you are saving by switching to LED's
Annual Carbon Footprint Savings: Based on DOE estimates, this represents how many pounds of CO2 your efforts are saving from entering the atmosphere.