To augment our understanding of emerging lighting science and accelerate the development and implementation of metrics and test methods for SSL products, DOE conducts original research and works closely with a network of standards-setting organizations. Although this work spans a variety of topics, key focus areas include:

The primary goal of efforts related to metrics and test methods is to increase energy efficiency by enabling technology development and effective application of SSL products and systems. Accurate, clear, and robust metrics, test methods, and standards are useful for manufacturers creating product development targets, for specifiers and consumers seeking appropriate products, and for regulatory or specification bodies trying to differentiate products.

Because the SSL technology platform is fundamentally different from conventional lighting technologies, it has challenged many of the long-used lighting performance metrics, and, in some cases, has exposed the need for new metrics. Accurate and effective industry standard metrics and test methods are critical for SSL to realize its full technical potential in terms of energy efficiency, improved lighting quality, and successful application. 

Since 2006, DOE has facilitated ongoing dialogue with key metrics and standards development organizations to foster greater coordination and collaboration among related efforts. Technical support from DOE has been instrumental in the development of many standards that set the foundation for SSL product development and deployment, including: 

  • IES LM-79-2008, Approved Method for the Electrical and Photometric Testing of SSL Devices
  • IES LM-80-2008, Approved Method for Measuring Lumen Depreciation of LED Light Sources
  • IES TM-21-2011, Projecting Long Term Lumen Maintenance of LED Light Sources
  • IEEE 1789-2015, Recommended Practices for Modulating Current in High-Brightness LEDs for Mitigating Health Risks to Viewers 
  • ANSI/IES TM-30-2018, Method for Evaluating Light Source Color Rendition

In most cases, these standards reflect years of technical support and committee meetings to forge industry consensus. In addition, DOE has supported a number of efforts that are poised to release standards important to the future of SSL, including: 

  • ANSI C136, Standards for Roadway and Area Lighting Equipment
  • ANSI C137, Standards for Lighting Systems
  • CIE TC1-83, Visual Aspects of Time-Modulated Lighting Systems
  • CIE JTC7, Discomfort Caused by Glare from Luminaires with a Non-Uniform Source Luminance
  • CIE TC4-52, Lighting for Pedestrians: New Empirical Data 
  • IES TM-XX-XX, Photometric and Electrical Measurements of Tunable-White Solid-State Lighting Products
  • IES LM-XX-XX, IES Method of Measuring Optical Waveforms for Use in Temporal Light Artifact (TLA) calculations
  • ANSI/IES RP-3-XX American National Standard Practice on Lighting for Educational Facilities

DOE efforts contribute to building an SSL industry standards and specification infrastructure that is widely recognized and used. Technical contributions and stakeholder education efforts inform the work of ANSI, IES, and CIE as well as ENERGY STAR®, California Title 20/24 and Non-Residential efforts, and the DesignLights Consortium. 

In addition, DOE has long offered technical assistance and hosts conference calls to facilitate the ongoing work of the LED Systems Reliability Consortium (LSRC), which has developed and published several reports that deepen understanding of LED product performance and reliability. This group of industry experts continues to work collaboratively in an ongoing effort to develop an advanced luminaire reliability model for SSL manufacturers and end users, with a current focus on color shift and stability.