The US Department of Energy has developed an LCA report to help evaluate the energy and environmental benefits of LEDs when compared to incandescent and fluorescent lighting. This analysis follows the four steps outlined on the Conducting LCA page. When using LCA to compare equipment, it is important to establish a common unit of performance by which each will be judged. For lighting, the useful life of the three alternatives below varies greatly. When comparing lighting options, it is important to consider the labor and disposal impacts of bulb replacements.
Figure 1: Number of Lamps Needed to Supply 20 Million Lumen-Hours.1
The figure below sums up the results of DOE’s study: though the manufacturing of LEDs may have a greater environmental impact than its competition, the dominant source of impact is the lifetime energy use. In 2011, LEDs were roughly equivalent to CFLs with respect to LCA. According to an updated LCA study conducted for the Illuminating Engineering Society in 2018, new A19 LED lamps "all perform better than the 2011 A19 LED on environmental impacts and all are now significantly better than traditional lighting technologies".3
Figure 2: Life-Cycle Energy of Incandescent Lamps, CFLs, and LED Lamps.2
1,2 US Department of Energy, "Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products," Februrary 2012 3 Illuminating Engineering Society, "Environmental and Energy Improvements of LED Lamps over Time: A Comparative Life Cycle Assessment", October 2018