Republication of Postings from the U.S. Department of Energy (DOE) Solid-State Lighting Program
by Jim Brodrick, U.S. Department of Energy
Although solid-state lighting has come a long way in the past few years, it still has quite a ways to go to fulfill its considerable potential to save energy and improve the way we deliver and use light. The efforts of the U.S. Department of Energy (DOE) and others have helped the market avoid some problems with early SSL products, and DOE’s strategy in supporting the development of SSL has drawn heavily on lessons learned from the development and commercialization of compact fluorescent lamps (CFLs). With LED lighting now available for most applications, and with several years of market and installation experience accumulated, DOE has come out with a new report that documents early challenges and lessons learned in the development of the SSL market.
Entitled Solid-State Lighting: Early Lessons Learned on the Way to Market, it summarizes early actions taken to avoid potential problems that were anticipated based on lessons learned from the market introduction of CFLs, and identifies issues, challenges, and new lessons that have been learned in the early stages of SSL market introduction. These new lessons are based mainly on insights from DOE’s SSL Market Development Support Program, which coordinates with a wide range of stakeholders that includes manufacturers, utilities, energy efficiency programs, lighting designers, retailers, distributors, and end users.
The report identifies and characterizes 12 key lessons distilled from DOE’s SSL Program results, with a focus on areas for which ongoing challenges exist and/or useful information can be applied going forward. These lessons correspond with technological challenges (related to performance and lifetime of LEDs, color quality and measurement, flicker, glare, dimming and control, and serviceability), challenges related to developing LED product lines and families, and complications and limitations experienced when trying to fit LEDs into existing lighting infrastructure.
The key lessons are the following:
* Rigorous testing requirements adopted in the early days of SSL industry development were necessary to counter exaggerated claims of performance by some manufacturers, but they eventually led to unreasonably high testing costs.
* Despite the promise of long life, there is no standard way to rate the lifetime and reliability of LED lighting products.
* Specifiers prefer complete families of products, but the rapid evolution of LED lighting technology presents a challenge to manufacturers in creating and maintaining complete product lines.
* The range of color quality available with LED lighting products, and the limitations of existing color metrics, may confuse users.
* The color delivered by some LEDs shifts over time, enough to negatively impact adoption in some lighting applications.
* Some LEDs flicker noticeably, which may negatively impact adoption in some applications.
* LEDs can cause glare, which may negatively impact adoption in some applications.
* Achieving high-quality dimming performance with LED lamps is difficult but improving.
* Greater interoperability of lighting control components, and more sensible specifications of lighting control systems, are required to maximize the energy savings delivered by LED light sources.
* Lack of LED product serviceability and interchangeability has created barriers to market adoption in certain sectors.
* Existing lighting infrastructure limits the full potential of SSL; more effort is needed to open the doors to new lighting systems and form factors.
* Programs that provide ways to identify quality LED products have helped support market adoption.
Thanks in part to lessons learned from CFLs, the development and market introduction of LEDs has gone much more smoothly than CFL market introduction. However, the unique technological characteristics of LED lighting have presented a host of new challenges and lessons. This early assessment of the LED general illumination market is intended to aid in the continuous course corrections needed to reach the technology’s full potential.
For a much more in-depth treatment of this topic, we encourage you to read the full report, which is available at www.ssl.energy.gov/tech_reports.html.
