This page contains links to technical reports and briefs published by the U.S. Department of Energy, plus information on current studies under way. These reports are intended to present objective technical analysis based on the most recent, referenceable data available at the time of preparation of the reports. As new information becomes available, DOE will make efforts to update these studies as necessary. While coordinated with other DOE data sources and policies, these reports also include data from a variety of non-governmental sources in order to produce, to the extent possible, unbiased analysis. These reports are intended solely for the benefit of the public, in order to help regulators, manufacturers, energy program managers, and others make informed choices and decisions related to solid-state lighting. Readers of these reports are urged to conduct their own due diligence and research before using the analysis presented in these reports.
- True Colors
A technical brief about spectral emission of LEDs and the relationship between correlated color temperature, color rendering index, optical safety, material degradation, and photobiological stimulation. (8 pages, October 2014)
- Hammer Testing Findings for Solid-State Lighting Luminaires
Provides findings from the DOE LED Systems Reliability Consortium Hammer Test on commercial SSL luminaires, a highly accelerated life test method intended to produce failures in SSL luminaires in a reasonable test period, and provide insight into potential failure modes. (48 pages, December 2013)
- Lumen Maintenance and Light Loss Factors: Consequences of Current Design Practices for LEDs
This article, from the IES journal LEUKOS, discusses the complications related to lamp lumen depreciation (LLD) and LEDs, compares the performance of some conventional and LED products, and examines alternatives to the current recommended approach for determining LLDs for LED products. (December 2013)
- Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products
This three-part DOE study assesses the life-cycle environmental and resource costs in the manufacturing, transport, use, and disposal of LED lighting products in relation to comparable traditional lighting technologies.
- Part 1: Review of the Life-Cycle Energy Consumption of Incandescent, Compact Fluorescent, and LED Lamps (54 pages, February 2012—Updated August 2012)
- Part 2: LED Manufacturing and Performance (79 pages, June 2012)
- Part 3: LED Environmental Testing (211 pages, March 2013)
- Complete Report Summary
- Accounting for Uncertainty in Lumen Measurements
This study provides a detailed and step-by-step method for determining uncertainty in lumen measurements, working closely with related standards efforts and key industry experts. This report uses the structure proposed in the Guide to Uncertainty Measurements (GUM) for evaluating and expressing uncertainty in measurements. (35 pages, March 2011)