Why you shouldn't use those fluorescent tubes before upgrading to LED [Calculator]

If you operate a large facility, you probably keep stock of fluorescent tubes so you can promptly replace any failed bulbs. Often times, we talk to customers who want to use up their existing fluorescent tube stock before they move forward with an LED upgrade.

This had us curious. What's the cost of waiting to switch to LED?

You start saving on electricity on day one of an LED upgrade, so how long would it take to pay for the LED upgrade and cover the cost of your unused inventory of fluorescent tubes?

We decided to do each step of the math on this with our retail pricing. This means your pricing should be lower, so your payback could be even better. But it will give you a sense for the impact an LED upgrade could have for you.

Spoiler alert: You will likely earn payback in about a year. Let's dive in.

Step 1: Figure out the cost of your existing fluorescent inventory

You want to add up the total cost of the unused fluorescent tubes you have in inventory.

Here are the details we’ll work with:

• $3.97 per fluorescent tube (4-foot)
• $119.10 per case of 30 tubes
• Let’s assume you have four cases of tubes in stock

$119.10 per case X 4 cases = $476.40 in inventory

Step 2: Figure out the cost of your LED upgrade

Now, let’s figure out the total cost of buying the LED tubes you want to replace your fluorescent tubes. There are a bunch of options, so you may want to look at this article or contact us for more guidance on picking the right tubes.

Here are the details we’ll work with:

• $8.97 per 4-foot LED tube
• Let’s assume you’re going to replace a section of 240 tubes

$8.97 per LED tube X 240 tubes = $2,152.80 in LED tubes

Step 3: Figure out your annual energy savings for the replaced tubes

This is a longer step, but stick with us. If you’d like support on this, you can use our calculator, download our guide, or talk with one of our lighting specialists.

Here are the details we’ll work with:

• You’re replacing a 32W fluorescent tube with a 17W LED tube. Ballasts complicate this a little because a typical 32W fluorescent tube when paired with a normal ballast will actually use 30W. Similarly, a typical 17W LED plug-and-play tube will actually use 19W when paired with a normal ballast. We won't go into the technical details, but we also want to make sure the calculations set a reasonable expectation for savings and payback. This means each bulb will save 11W in electricity (30W — 19W).
• If you’re a healthcare facility, you probably have some areas that operate 24/7. Let’s start with these fixtures for the upgrade, which means your annual burn time is 8,760 hours (24 hours X 365 days)
• Let’s assume you pay $0.11 per kWh for electricity, which is a reasonable national average.

240 tubes X 11W saved per tube ÷ 1,000 = 2.64 kW saved

8,760 hours X 2.64 kW saved = 23,126 kWh saved per year

23,126 kWh saved per year X $0.11 per kWh = $2,543.90 in annual energy savings

Step 4: Figure out the payback on your LED upgrade

We’ll look at the payback on the LED upgrade as well as the amount of time it will take to cover the cost of the upgrade and the unused inventory.

Let’s recap a few details:

• You have $476.40 in existing fluorescent tube inventory
• Your LED upgrade cost was $2,152.80
• Your annual energy savings from the LED upgrade is $2,543.90

LED Upgrade Payback:

$2,152.80 in LED cost ÷ $2,543.90 in savings X 12 = 10.2 months

LED Upgrade + Unused Inventory Payback:

$2,152.80 in LED cost + $476.40 in inventory = $2,629.20 in cost to recoup

$2,629.20 in cost to recoup ÷ $2,543.90 in savings X 12 =
12.4 months

While the details around your prices, burn time, and electricity cost may vary, this example illustrates the potential savings your organization can reap from an upgrade. Even if you have existing inventory in stock, you can still experience a payback in about 12 months. And if you're upgrading more than 240 tubes to start, this payback will happen even faster.

If you'd like to use our calculator to customize your results, click here.

Recycling fluorescent tubes

So, what do you do with all those unopened boxes? You probably don't want them collecting dust in your inventory space. Because fluorescent tubes contain mercury, it's best to recycle them. You can look at your options and talking to a lighting specialist here.