In May 2013, we investigated the market for T8 tube retrofits in our blog Do retrofit T8 linear LED tubes live up to their reputation?, which focused on the widely popular 4’ tubes. We noted at the time of our analysis that pricing was largely uncompetitive at $25-$70/tube (compared to a low-end price of ~$3 for fluorescent); safety and liability concerns abounded with the requirement to remove or bypass the existing ballast (virtually all LED tubes at that time ran directly off the line voltage); and the technology was largely unrefined (high heat; poor driver lifetime and CCT retention; inferior lumen output and CRI).
In our lab testing, we found a small portion of good quality LED tubes, but in general, the business case to swap out fluorescent tubes for LED tubes—even the few of decent quality—didn’t make much financial sense. The cost of the tube and the cost of an electrician to remove the ballast was so high that the payback, or return on investment, was unreasonable. For example, $50 tube + 15 minutes of labor per fixture to remove the ballast as compared to replacing the fluorescent tube with another ($3 to $5 for the new fluorescent tube and no electrician). Even though the former provided more electricity savings than the latter, the savings was not sufficiently high to make a compelling case to install LED tubes.
According to engineering.com, labor represents approximately 40% of the cost of replacing fluorescents with LEDs, making it the largest obstacle in the transition to LEDs.
What’s changed in a year?
First of all, one of the big safety and liability concerns has been addressed, as there are now a variety of LED tubes that do not require ballast removal. Although these type of “plug and play” LED tubes are still uncommon, they nonetheless make for a compelling innovation and show a lot of promise. Stay tuned, as next week we will take a closer look at LED tubes that require a ballast replacement vs. those that do not.
Did you know?: Ballasts are required for fluorescent tubes in part because they require a high start-up voltage to overcome initial resistance. The ballast is what produces the high starting voltage and then, once the tube is lit, it begins to regulate the power to the tube. LEDs do not require this high start up voltage or regulation.
The technological refinements and pricing are the two areas where LED T8 replacement tubes have made the biggest strides over the past year. The performance has increased, especially in terms of light output and efficacy, while the costs have decreased:
- Light output can now reach over 2000 lumens per tube
- Efficacy is now generally approaching or even exceeding 100 lm/W
- Life time is approaching or equalling that of most fluorescents (40,000 hours)
- Color temperature (CCT) has improved and expanded in range (though typical is 3000K to 4500K)
- Colour rendition (CRI) has improved
- Cost has come down to $30 to $35 for a good quality line voltage driven tube, about $5 to $8 more for a tube that works with the existing ballast intact.
Even if purchasing an LED tube that does require ballast removal by an electrician, the payback is more compelling than it was a year ago. Using a troffer that contains 2 tubes as an example*:
|Cost for 2 tubes|
|LED||2 x 20 W||2 x 2000lm||Yes – $25||$85|
|Fluorescent||2 x 32 W||2 x 2700lm||No||$10|
Wattage savings = 12 Watts/tube
Energy savings (assuming 24/7 run time) = 8736 hours per year or 210 kWh/year
Electricity cost savings = $21/year at an electricity rate of $0.10 / kWh.
The return on investment (ROI) is affected by electricity rates. In the example above, the ROI is 3.5 years. However, if you pay the California average commercial rate of $0.146 circa November 2013 (Electric Power Monthly), the electricity cost savings is $30.61 per year, giving an ROI approximately 2.5 years. At the higher electricity rates, these start to approach compelling investment cases when considering just the cost of electricity and the cost of the electrician.
As a result of the performance improvements and price drops, we believe that the LED replacement tube is starting to find a place for itself: one that makes sense for your bottom line.
*In the interest of simplicity we have not accounted for ballast inefficiencies and that can somewhat shorten the ROI. We have not accounted for the fact that the 32W fluorescent tube puts out more light than the 18W LED tube because this is a complex matter that involves the directionality of the LED tube’s light, the reflectivity of the troffer amongst other factors.