LED Lamp Life: Calculating Your Maintenance Savings in a Lighting Project Part 1
November 17, 2020
This is the third article in our latest series: Calculating Your Savings and ROI on any Lighting Project. Please also see: Calculating your Lighting Only Energy Savings, Calculating your Maintenance Savings, Calculating your Labor Savings, Calculating your ROI.
Lamp life is something that’s often forgotten when companies are calculating their savings before and after an LED lighting retrofit project. Halogen, CFL, and incandescent lamps have a lifespan that averages between 1,500 to 15,000 hours. If your lights are on 12 hours daily for 250 days, you’ll find that your lamps are replaced two to three times a year. Depending on how many light fixtures are used in the workplace, and the number of facilities owned, the total lamp replacement cost can be prohibitive.
One of the benefits of installing energy-efficient lighting is the maintenance savings from the lighting. Compared to other lamps, LED lights typically have a lamp life of 35,000 to 100,000 hours. It is a noticeable difference that is reflected in annual product and maintenance reports. Adding to the benefits of LED lights is the 3 – 5-year warranty that is standard with most energy-efficient lamps.
If you want to stay on top of your maintenance savings in a lighting project, the below calculations will provide you with the necessary figures.
Step-By-Step Calculations for Maintenance Savings using LED Lamp Lifespan
You will need information on the new lighting system, along with hours and days the lights are on annually. You’ll also need your electricity rate that is listed on the utility bill.
Step 1: Collect Your Information
To determine how much you’re saving in lighting maintenance, you will need to gather a few numbers that include,
- Rated lifespan for the old product. In this example, the lamps used have an estimated life of 1,500 hours.
- Rated lifespan for LED lamps. In this sample calculation, we’re using LED lamps commonly installed in businesses. Each lamp has a lamp life of 50,000 hours and comes with a five-year warranty from the manufacturer.
- Cost to replace the old lamps. The average cost of a replacement halogen lamp is $4.50.
- Cost to replace an LED lamp. A replacement LED lamp averages $25.00 nationwide.
- Total running time. In Calculating Your Lighting Only Energy Savings in an LED Retrofit, you learned how to calculate total running time. This is the figure you need to complete the equation. For this example, the total running time is 4,320 hours.
Step 2: Calculate How Often Annually the Old Product Needs Replacing
Different types of lamps burn out at varying rates. You will need to check the product information for the lamp rating. We’re using the 1,500 lamp life rating in our equation.
You’ll subtract the total annual running time from the existing product’s lifespan rating. The total will indicate how often the lamps need replacement annually.
4,320 (annual running time) – 1,500 (lamp life) = 2.88 times each lamp in the lighting system needs replacing.
Step 3: Calculate the Cost of the Old Replacement Lamps
You now know that you or your employees are replacing each lamp in the building close to three times a year. Depending on the facility’s size and the number of lights, lamp replacement, and time spent switching them out will add up.
To calculate how much you are spending annually on replacement lamps, you’ll multiply the cost of the replacement lamp from how many times it needs changing annually.
2.88 (times replaced annually) x $4.50 (replacement cost) = $12.96 spent annually on replacement costs.
Step 4: Calculate Annually How Many Times the LED Bulbs Need Replacing
LED lamps do have a longer lamp life, which means you’ll replace them less often. It will save you money, and there’s an equation that will show you much your saving on lamp replacements.
It is the same calculation you performed in step 2 for the old lamps. Now, you input the information for the LED. For example,
4,320 (hours of annual run time) ÷ 50,000 (lamp life rating) = 0.09 times a LED lamp is changed per year.
Step 5: Calculate the Cost of Replacing LED Lamps
You’ll use the same equation as you did in step 3. Only now, you’ll input the information about the new LEDs.
0.09 (number of times LED lamp is changed annually) x $25.00 (cost of a LED bulb) = $2.25 to replace each energy-efficient lamp per year.
To learn more about LED lifespan vs. traditional light sources, we suggest reading Understanding LED Lifespan. You will find an in-depth view on how an LED’s lifespan is measured.
Step 6: Calculate Maintenance Savings
You’ve already noticed that it’s less expensive to maintain LED lighting, but it’s also helpful to have exact figures. There are two methods you can use to calculate savings and both are valid.
The First Method
The first equation is basic. You subtract the yearly replacement cost for LED lamps from how much you’ll spend to replace the old ones.
$12.96 (replacement costs for old lamps) – $2.25 (cost for new LED lamps) = $10.71 in material savings every year.
The Second Method
The second method also isn’t difficult. You take how much you spend on maintenance with the new product under warranty from how much it costs with the previous lamps. Your equation will look like the following,
$12.96 (replace old lamps) – $0 (warranty costs to replace new LED lights) = $12.96 in maintenance savings per lamp annually.
When you multiple either method’s totals by the number of light fixtures, the maintenance savings from lighting only increases.
To learn more about LED maintenance savings and to calculate your labor savings, read the next article in this series, Labor Savings: Calculating Your Maintenance Savings in a Lighting Project Part 2 (Coming November 24, 2020).
Know Your LED Maintenance Savings
You do get maintenance savings from LED lights whether you have a small shop or a large corporation. The lower cost for the replacement lamps combined with the multi-year warranty will save businesses money over the fiscal year. To speak with an Action Services Group lighting specialist, call Action Services group today at 800-223-0982 or email email@example.com.
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