Up to Standards

New solid-state lighting standards help LED gain greater market share

On Feb. 16, 2011, U.S. Environmental Protection Agency (EPA) updated its specifications covering the qualification of luminaires under its Energy Star label. Effective October 1, to qualify for the Energy Star label under Energy Star Luminaires, Version 1.0 (Luminaires V1.0), which replaces both the RLF V4.2, “Residential Light Fixtures” specification and SSL V1.3, “Solid State Lighting Luminaires” specification, luminaires must demonstrate a 30% increase in efficiency above the current qualification level. In addition, by 2013, performance must show an additional 10% increase — a 40% higher efficiency compared to the current qualification level. Moreover, the fixtures must continue to meet other performance criteria, such as quick start-up, high-quality light output, lamps that last 10 times longer than standard lamps, reduced toxics associated with fixture materials, and be backed by a three-year warranty.

The Luminaires V1.0 specification does not differentiate luminaires by light-source technology or by indoor or outdoor use. Under the new specification, fixtures are separated into either directional or non-directional categories, with different criteria for each (directional luminaires will be evaluated by luminaire photometry, whereas non-directional luminaires will be evaluated by light-source photometry). A range of luminaire technology, including fluorescent and solid-state lighting (SSL), will be held to the same standard as other traditional luminaires, with product performance certified by an EPA-recognized third party, based on testing in an EPA-recognized laboratory. Manufacturers of the products also must participate in verification testing programs run by recognized certification bodies.

For potential future revisions of Luminaires V1.0, EPA will follow the lead of the development of new industry standards, including:

• New methods to measure and project lumen maintenance at the end-use product level (luminaire or lamp),
• New metrics for color rendering,
• Updated methods of measurement of audible noise from lighting products,
• New performance standards for dimming and for solid-state drivers, and
• New methods of measurement and recommended practices regarding the operating frequency of SSL products.

Furthermore, EPA says it is also currently reviewing existing requirements governing the use of test reports from IESNA LM-80, “Approved Method for Measuring Lumen Depreciation of LED Light Sources,” the standard passed by the Illuminating Engineering Society of North America (IESNA) in 2008 that specifies a standard method for measuring the lumen depreciation of LEDs (allowing calculation of LED lifetime test reports) — and is gathering input from LED manufacturers to determine what improvements should be made.

Taking measure

Notwithstanding the strict Energy Star qualification requirements, similar to other traditional lighting products, SSL technology sold in the United States remains subject to industry standards governing safety and performance. However, until recently, LED technology was unable to be measured and characterized by the same standards covering the mechanical forms, electrical connections, and measurement of traditional lighting technologies. In fact, LEDs could be considered the lighting industry’s ugly duckling. (For more on this topic, see “Standards Deviant” in the April 2010 issue of EC&M.)

Industry groups and standards-setting organizations, led by the SSL division of the U.S. Department of Energy’s (DOE) Energy Efficiency and Renewable Energy Building Technologies Program, have moved quickly to develop needed standards and test procedures for SSL products. To accommodate LEDs, some existing standards and test procedures had to be modified while, in other cases, new standards were required.

“There is a tremendous amount of behind-the-scenes work in SSL to facilitate the progress that drives the market and makes the headlines,” says Jim Brodrick, SSL portfolio manager, DOE. “The development of standards and test methods that consistently characterize product performance and assure safety is a key part of that behind-the-scenes work. Establishing a set of ground rules keeps the entire industry singing from the same song sheet and imposes a certain amount of order on what could otherwise become a Wild West, anything-goes type of situation.”

Since 2006, as part of its Next Generation Lighting Initiative, DOE has hosted ongoing workshops to convene the key standards organizations and foster greater coordination and collaboration among related efforts. Attendees provide updates on progress as well as input on potential additional standards needed, according to DOE. Combined American National Standards Institute (ANSI)/IESNA meetings and working group conference calls have resulted in the publishing of several significant standards and reports (see Current Standards and White Papers).

Over time, says the DOE, these and other standards will remove the guesswork about comparative product performance, making it easier for lighting manufacturers, designers, and specifiers to select the best product for an application. As industry experts continue the painstaking work of standards development, they are contributing to a growing body of information that will help support SSL innovation, as well as market adoption and growth.

For example, the National Electrical Manufacturers Association (NEMA), Rosslyn, Va., recently published the standard SSL-1, “Electronic Drivers for LED Devices, Arrays, or Systems.” In 2008, Rob Arnold, electrical engineer and proprietor of the online LED Center (http://led.linear1.org/), DeSoto, Kan., lamented the lack of standardization for drivers in the marketplace. “If there were a standardized LED driver component that certain standardized modules of light-producing light engines could plug into, that would really benefit the guy who has to specify the solution,” he explained. “The lack of standardization means that every design problem requires a unique solution.”

SSL-1 provides specifications for and operating characteristics of non-integral electronic drivers (power supplies) for LED devices, arrays, or systems intended for general lighting applications. “SSL-1 is the first in a series of NEMA SSL standards aimed at setting the foundation for quality and performance of LED systems, specifically LED drivers,” says SSL-1 Working Group Leader Tom Stimac, also of GE Lighting Solutions, East Cleveland, Ohio. “LED drivers are used in every system today, and the ability to verify key performance and quality aspects will be pivotal in achieving high-efficiency and quality LED lighting systems.”

Moreover, in addition to publishing new standards, there have been updates to already established benchmarks facilitated by DOE. Originally published in 2008, two key standards — IESNA LM-80 and IESNA LM-79, “Approved Method for the Electrical and Photometric Testing of Solid-State Lighting Devices” — are undergoing their regularly scheduled two-year committee review focused on any recently discovered issues that may need to be addressed by updates. “SSL technology is evolving so fast that things are constantly changing,” says Brodrick. “This is routinely done with technologies that haven’t yet reached maturity.”

Takeover standards

Before the development of these standards and reports, many industry professionals viewed lighting applications for LED technology as severely restricted. “For interior lighting, we limited LED to accent lights or maybe some feature
lighting, but definitely not to be used throughout a building for general illumination,” says Dave Wesemann, LEED AP, VP and principal electrical engineer for Spectrum Engineers, a Salt Lake City-based MEP firm. “Compared to the good ol’ workhorse — a T8 lamp paired with a premium-efficiency ballast — LED lighting didn’t even come close to delivering the same amount of light for a given wattage.”

However, products manufactured under the new standards have recently elevated their prospects. “I think manufacturers are coming out with some great products that are starting to challenge or compete with the efficiencies of their compact fluorescent lighting (CFL) counterparts,” says Wesemann. “Initially, we were disappointed, but year-by-year the LED lighting industry is coming back with new and improved products we can specify that really work.”

Of all the uses for LED technology, lighting accounted for only 8% — around $890 million — of the high-brightness (HB) LED market in 2010, according to Mountain View, Calif.-based Strategies Unlimited, which performs market research in photonic devices. However, by 2014, applications in lighting will lead the way in the HB LED market, reaching 39%.

Factors driving that growth include improvements in performance and price of commercially available HB LED products; stricter energy-efficiency standards and heightened awareness, and the phasing out of incandescent bulbs, according to the report “LED Luminaires Market Analysis and Forecast, Second Edition 2011.” In fact, Strategies Unlimited is predicting the market for replacement LED lamps to exceed $10 billion in 2014.

That standards addressing the widespread use of LED technology for general illumination and, specifically, incandescent lamp replacement have been recently published is no coincidence. In 2010, NEMA published several standards and white papers addressing incandescent replacement, as well as general illumination. NEMA LSD 22-2009, “Solid State Lighting — The Need for a New Generation of Sockets & Interconnects,” provides guidance for those seeking to design and build or work with SSL products intended for retrofit into systems that previously used incandescent screw-base lamps. Furthermore, NEMA LSD 45-2009, “Recommendations for Solid-State Lighting Sub-Assembly Interfaces for Luminaires,” provides guidance on the design and construction of interconnects (sockets) for SSL applications and deals with the issue of dimming LED replacement lamps.

Although LEDs are dimmable in theory, in practice this is true only if the driver has dimming capability and is compatible with the particular dimming controller used. NEMA SSL-6, “Solid State Lighting for Incandescent Replacement — Dimming,” specifies recommendations for the dimming and design of screw-based incandescent replacement SSL products and provides interface recommendations for dimming control of integrated LED lamps intended to replace general service incandescent products.

The standard addresses the interaction between the controller and the lamp, and introduces requirements to help ensure good dimming performance and prevent damage to either component. “SSL-6 is the first NEMA standard to tackle head-on the importance of dimming energy-efficient LED lamps that will replace incandescent bulbs,” says SSL-6 Working Group Leader Dr. Robert Nachtrieb, Lutron Electronics, Coopersburg, Pa.

To support the standard, the organization also published LSD 49-2010, a white paper that discusses best practices for dimming of SSL for incandescent replacement. In preparation for this switch from niche applications to general illumination, DOE has published a few reports as well. “Energy Savings Potential of Solid-State Lighting in General Illumination Applications” forecasts the energy savings potential of SSL sources compared to conventional lighting sources (e.g., incandescent and fluorescent). Using an econometric model of the U.S. lighting market, two scenarios are evaluated — one considering LEDs and one considering organic light-emitting diodes (OLEDs). Under the LED scenario, in 2030 the annual energy savings from solid-state lighting will be approximately 190 terawatt-hours — or the equivalent annual electrical output of about 24 large power plants (1,000MW electric). Over the 20-year analysis period, spanning 2010 to 2030, the cumulative energy savings are estimated to total approximately 1,488 terawatt-hours.

SIDEBAR: White Papers

U.S. Department of Energy (DOE)

• DOE white paper, “Energy Savings Estimates of Light-Emitting Diodes in Niche Lighting Applications,” takes a close look at 12 different markets and provides two kinds of estimates for each one — the energy saved last year due to actual levels of SSL market penetration and the potential energy savings if those markets switched completely to SSL.
• DOE white paper, “Energy Savings Potential of Solid-State Lighting in General Illumination Applications,” forecasts the energy savings potential of SSL sources compared to conventional lighting sources (e.g., incandescent and fluorescent). Using an econometric model of the U.S. lighting market, two scenarios are evaluated — one considering LEDs and one considering organic light-emitting diodes (OLEDs).
• DOE white paper, “Keeping Manufacturing in the United States,” outlines the current state of the SSL industry; highlights the importance of continued government/private sector collaboration in retaining manufacturing strength in the United States; and summarizes the recommendations of the lighting industry for the roles both sectors could play in this important endeavor.
• DOE white paper, “Solid-State Lighting Research and Development: Manufacturing Roadmap,” guides the DOE research and development program and helps direct funding solicitations. In addition, it provides guidance for equipment and material suppliers, based on industry consensus on the expected evolution of SSL manufacturing, which reduces risk and, ultimately, the cost of undertaking SSL manufacturing.

National Electrical Manufacturers Association (NEMA)

• NEMA LSD 22-2009, “Solid State Lighting — The Need for a New Generation of Sockets & Interconnects,” provides guidance for those seeking to design and build or work with SSL products intended for retrofit into systems that previously used incandescent screw- based lamps.
• NEMA LSD 44, “Solid State Lighting — The Need for a New Generation of Sockets and Interconnects,” describes the history of sockets and interconnects and advocates for standards development for the next generation of lamp and lighting technology.
• NEMA LSD 45-2009, “Recommendations for Solid-State Lighting Sub-Assembly Interfaces for Luminaires,” provides guidance on the design and construction of interconnects (sockets) for SSL applications.
• NEMA LSD 49-2010, “Solid-State Lighting for Incandescent Replacement — Best Practices for Dimming,” provides recommendations for the application of dimming for screw-based incandescent replacement SSL products.
• NEMA LSD 51-2009, “Solid-State Lighting — Definitions for Functional and Decorative Applications,” illustrates and clarifies the differences between functional and decorative SSL luminaires and provides guidelines for the specification of the major characteristics, performance criteria, and evaluation process needed for these products.

Source: U.S. Department of Energy, Energy Efficiency and Renewable Energy, Solid-State Lighting

SIDEBAR: Current Standards

American National Standards Institute (ANSI)

• ANSI C78.377-2008, “Specifications for the Chromaticity of Solid-State Lighting Products,” specifies recommended chromaticity or color ranges for white light-emitting diodes (LEDs) with various correlated color temperatures (CCTs).
• ANSI C82.77-2002, “Harmonic Emission Limits — Related Power Quality Requirements for Lighting,” specifies the maximum allowable harmonic emission of SSL power supplies.

International Commission on Illumination (CIE)

• CIE 13.3-1995, “Method of Measuring and Specifying Colour Rendering Properties of Light Sources,” is the official document defining the CRI metric. (Referenced by ANSI C78.377)
• CIE 15:2004, “Colorimetry, Third Ed.,” is the official document defining various CIE chromaticity and CCT metrics. (Referenced by ANSI C78.377)
• CIE 127:2007, “Measurements of LEDs,” addresses LED luminous intensity measurement; applies only to individual LEDs, not to arrays or luminaires.
• CIE S 009/E:2002, “Photobiological Safety of Lamps and Lamp Systems,” specifies measurement techniques to evaluate optical radiation hazards and eye safety risks of LEDs and LED clusters.

Federal Communications Commission (FCC)

• FCC 47 CFR Part 15, “Radio Frequency Devices,” specifies FCC requirements for maximum allowable unintended radio-frequency emissions from electronic components, including SSL power supplies and electronic drivers.

Illuminating Engineering Society of North America (IESNA)

• IESNA G-2, “Guideline for the Application of General Illumination (‘White’) Light-Emitting Diode (LED) Technologies,” provides lighting and design professionals with a general understanding of LED technology as it pertains to interior and exterior illumination, as well as useful design and application guidance for effective use of LEDs.
• IESNA LM-79-2008, “Approved Method for the Electrical and Photometric Testing of Solid-State Lighting Devices,” specifies a standard test method for measuring the photometric properties of SSL devices, allowing calculation of luminaire efficacy.
• IESNA LM-80-2008, “Approved Method for Measuring Lumen Depreciation of LED Light Sources,” specifies a standard method for measuring the lumen depreciation of LEDs, allowing calculation of LED lifetime.
• IESNA RP-16 Addenda A and B, “Nomenclature and Definitions for Illuminating Engineering,” provides industry-standard definitions for terminology related to SSL.
• IESNA TM-16-05, “Technical Memorandum on Light Emitting Diode Sources and Systems,” provides a general description of LED devices and systems and answers common questions about the use of LEDs.

National Electrical Manufacturers Association (NEMA)

• NEMA.SSL-1, “Electric Drivers for LED Devices, Arrays, or Systems,” specifies operational characteristics and electrical safety of SSL power supplies and drivers.
• NEMA SSL 3-2010, “High-Power White LED Binning for General Illumination,” provides a consistent format for categorizing, or binning, color varieties of LEDs during their production and integration into lighting products.
• NEMA SSL-6, “Solid State Lighting for Incandescent Replacement — Dimming,” specifies recommendations for the dimming and design of screw-based incandescent replacement SSL products.

National Fire Protection Association (NFPA)

• NFPA 70-2005, “National Electrical Code,” requires most SSL products to be installed in accordance with the National Electrical Code.

Underwriters Laboratories, Inc. (UL)

• UL 8750, “Safety Standard for Light Emitting Diode Equipment for Use in Lighting Products,” specifies the minimum safety requirements for SSL components, including LEDs and LED arrays, power supplies, and control circuitry.
• UL 1598, “Luminaires,” specifies the minimum safety requirements for luminaires. The requirements in this document may be referenced in other documents such as UL 8750 or separately used as part of the requirements for SSL products.
• UL 153, “Portable Electric Luminaires,” specifies the minimum safety requirements for corded portable luminaires.
• UL 1012, “Power Units Other Than Class 2,” specifies the minimum safety requirements for power supplies other than Class 2 (as defined in NFPA 70-2005).
• UL 1310, “Class 2 Power Units,” specifies the minimum safety requirements for Class 2 power supplies (as defined in NFPA 70-2005).
• UL 1574, “Track Lighting Systems,” specifies the minimum safety requirements for track lighting systems.
• UL 2108, “Low-Voltage Lighting Systems,” specifies the minimum safety requirements for low-voltage lighting systems.
• UL 60950-1, “Information Technology Equipment — Safety — Part 1: General Requirements,” specifies the minimum safety requirements for electronic hardware.

Source: U.S. Department of Energy, Energy Efficiency and Renewable Energy, Solid-State Lighting