The light emitting diode (LED) is part of a family of lighting technologies called solid-state lighting. LEDs surpass the quality and efficiency of existing technologies however, not all LED lighting is created equal.
LED lamps are more rugged and damage-resistant than compact fluorescent lamps (CFL) and incandescent lamps. LEDs don’t flicker and don’t require a warm-up time; they also have eco-friendly characteristics since they don’t emit ultraviolet (UV) radiation.
The useful life of LED lamps is about 35,000 hours compared to 1,000 hours for an incandescent lamp. The lifetime for LEDs is a matter of the overall system reliability that includes the LED lamp, the ballast or driver, electrical connections, the housing and lenses. The key to long lamp life is thermal management; the LED must be kept cool. Since LED lighting is a rapidly developing technology, many products have not been on the market long enough for the lifetime claim to be put to the test.
Group A – ENERGY STAR ® List for LED Products
- Recessed, surface and pendant-mounted down luminaires
- Under-cabinet, shelf-mounted task luminaires
- Wall wash luminaires
- Omni-directional: A, BT, P, PS, S, T
- Decorative: B, BA, C, CA, DC, F, G
- Directional: BR, ER, K, MR, PAR, R
The six product categories listed above require an ENERGY STAR rating and only luminaires from the ENERGY STAR Bulb List (PDF) and ENERGY STAR Fixture List (PDF) are eligible for Connecticut Energy Efficiency Fund program incentive.
Group B - DesignLight Consortium Qualified Product List for LED Products
- Outdoor pole/arm-mounted area and roadway luminaires
- Outdoor pole/arm-mounted decorative luminaires
- Outdoor wall-mounted area luminaires
- Wall-wash Luminaires
- Parking Garage Luminaires
- Fuel Pump Canopy
- Track or Mono-point Directional Lighting Fixtures
- Vertical Refrigerated Case Lighting
- Horizontal Refrigerated Case Lighting
- Display case luminaires
- Linear Panels: 2x2 Troffers
- Linear Panels: 1x4 Troffers
- Linear Panels: 2x4 Troffers
- High-bay and Low-bay fixtures for Commercial and Industrial buildings
- High-bay-Aisle Lighting
- Retrofit Kits For Outdoor Area and Roadway Luminaires
- Retrofit Kits For Outdoor Decorative Luminaires
- Four-foot Linear Replacement Lamps
The requirements for the seven product categories listed above can be found on this link. Products not in these categories must be submitted and approved by DesignLight ™ Consortium.
Effective, June 1, 2010 Group B Luminaries must be identified on the DesignLights™ Consortium Qualified Product List (PDF) to be eligible for Energy Efficiency Fund incentives. This includes any product which has previously been approved by CL&P/UI.
Is there ENERGY STAR ® qualified LED lighting?
Yes, currently there are ENERGY STAR qualified light fixtures and decorative light strings that use LEDs. ENERGY STAR qualified LED lights consume 75 percent less energy than conventional incandescent lights. Because the specification for ENERGY STAR qualified LED light fixtures was made effective in late 2008, there are a limited number of qualified products available today.
Are there ENERGY STAR qualified replacement LED bulbs?
No, currently there are no replacement bulbs for the typical screw in light socket that use LED technology and qualify for the ENERGY STAR label. The only screw in light bulbs, that have met the energy efficiency and other performance requirements for ENERGY STAR, use fluorescent technologies. These bulbs -- known as CFLs -- offer energy savings of 75 percent relative to incandescent bulbs.
The Department of Energy (DOE) is in the process of developing ENERGY STAR requirements for LED replacement bulbs. Once those requirements are in place, manufacturers will need to test and submit information to the DOE.
Because LED is an emerging technology, quality is not yet consistent across all products. The ENERGY STAR specification process will put in place test procedures to ensure a high level of quality for these bulbs. In the interim, if you purchase LED replacement bulbs, check for warranty information, and save your receipts in case there is an early failure or you are not satisfied with the quality of the light.
- Which LED supplier did you choose and why?
[Is it a reliable company you have heard of? What references can be provided?]
- Can you supply an IESNA LM-79 test report from an independent third party laboratory for your fixture, and an .ies data file?
[This is a critical data point. The LM-79 report will give you the assurance that the photometrics reported in the marketing literature (lumens, spatial distribution, CCT, CRI, etc.) have been verified by a third party. The LM-79 report also gives total fixture efficacy (lumens per Watt), Power Factor, and a data file in an .ies format. Without this assurance, the marketing literature is subject to question.]
- Has your LED supplier provided an IESNA LM-80 test report?
[Any good LED supplier will be able supply this; if not, why not, when? Also, be particularly careful about 5mm LEDs and the cheaper, plastic SMD LED lamps. These LED products are often marketed as having >50,000 hours of rated life, but may not be able to deliver it under all temperature and environmental conditions.]
- What is the operating temperature range specification and what is the maximum junction temperature (Tj) of the LED lamps over that operating range?
[This is a straight-forward calculation based on the maximum temperature inside the fixture and drive current your fixture manufacturer has selected for the LED lamps. Your fixture maker should be very familiar with this concept and readily able to provide this information. Some LED products are not capable of being operated in high ambient temperature conditions without violating maximum LED junction temperatures (Tj). In colder climates some drive electronics may not function properly. It is important to look at both temperature extremes to make sure the fixture is suitable for your application.]
- What is the expected L70 lifetime of your fixture? How did you calculate it?
[If the answer to this question is anything like “My LED company told me so”, you should look into the matter much more closely. In the long term, any fixture L70 lifetime should be based on the IESNA LM-80 test report for the LEDs used, and also the worst case expected internal ambient temperature the LEDs will see, as well as the maximum junction temperature of the LEDs. These latter two points are critical and must be provided by the fixture manufacturer. The LM-80 report alone from the LED supplier is almost meaningless without these other two data points. Over the short term – until the LED makers have time to comply with LM-80 – you may have to rely on vendor data, but don’t let that stop you from asking the question.]
- What are the delivered lumens and LPW of the fixture (Lamp and Driver)?
[It has unfortunately fallen into common marketing practice that some fixture makers take the number of lumens on the LED data sheet in optimal test conditions (say, 100lm) and multiply the answer times the number of LEDs in the system (say, 10), and report that they have a 1,000 lumen luminaire system. This is not only misleading, it is not physically possible. LEDs lose lumens through thermal stabilization and optical losses, and all LED driver types have conversion losses. Make your fixture maker do his homework and report the data in terms of delivered lumens for the application and LPW in terms of wall-plug efficiency.]
- Is the chromaticity of the fixture in the ANSI C78.377A color space and is it stable over time? How do you know?
[This is especially important for indoor luminaires. If it is not in the ANSI color space, then the color of the luminaire is could be a pinkish or greenish in hue. Color-point stability is a common problem in lower-quality LED fixtures. It can be a result of poor LED selection, poor thermal management, or both. Make your fixture supplier convince you that the LEDs he has selected are right for the application (i.e., lighting-class LEDs -- not 5mm lamps designed for toys and novelties), and that the fixture design has a good thermal management capacity for the worst-case expected operating environment (e.g., an insulated ceiling).]
- What is the Power Factor of your fixture? How much power does it consume in the “off” state?
[Power Factor should be at least 0.7 for residential applications, 0.9 for commercial (U.S. DOE ENERGY STAR criteria). This is easily achieved with a fairly standard driver design, but also often ignored on lower quality luminaire products. Poorly designed LED systems can consume almost as much power in the “off” state as they do in the “on” state. The U.S. DOE ENERGY STAR requirement is for no more than 0.5W. Make your fixture supplier check these boxes now to save you heartache – and energy – later.]
- Have you applied for the DOE ENERGY STAR for this fixture? Why/why not?
[The U.S. Department of Energy (DOE) has a very well thought-out set of criteria required to get an ENERGY STAR. It does not yet apply to all lighting fixture types, but the ENERGY STAR criteria are a rigorous way to assure the quality of a fixture, and it could be instructive to know if a manufacturer applied for this (or not).]
- Is your fixture lead-free, mercury-free and RoHS compliant?
[This is a key question regarding sustainability. Lead-free and RoHS compliance – all the way through to the packaging the luminaire arrives in – are easily achievable with modern manufacturing technology. You should insist on this.]
- What is your warranty and do you have the means to stand behind it?
[A reasonable warranty should be about one-third to one-half of the expected L70 lifetime (e.g., for an expected 50,000 hour L70, 15,000-25,000 hour warranty is reasonable), and the company giving the warranty should be of reasonable size and solid financial means. The U.S. DOE ENERGY STAR program requires a three-year warranty, for example.]
- What constitutes a failure of the fixture?
[Different manufactures have different rules on what constitutes a fixture failure. For instance, a manufacture considers a failure when 50 percent of the LEDs on a fixture do not turn on.]
- How does the light output of the LED compare to my current lamp/fixture?
[Lumen output may be less than the technology it is replacing. Make sure to look at the delivered lumens for an equal comparison. Installing a sample will give a better idea if LED is the right solution for your application.]