Over their working life, LED lamps have a slight environmental edge over compact fluorescent lamps (CFLs), even when manufactured using technology that was state-of-the-art five years ago.
So says a new report by the DOE. Called LED Manufacturing and Performance, it compares the environmental impact of LEDs, CFLs, and incandescent bulbs from manufacturing, operation, and to disposal.
A few highlights:
The life cycle energy consumption of LED lamps and CFLs are similar at approximately 3,900 MJ/20 million lumen-hours. Incandescent lamps consume a lot more energy (about 15,100 MJ/20 million lumen-hours).
The use phase is also the most important contributor to energy consumption, followed by manufacturing of the lamps and finally transportation (less than 1% of energy consumption).
Energy-in-use is the dominant environmental impact, with 15-W CFL and 12.5-W LED lamps performing better than 60-W incandescent lamps. These three lamps all produce about the same amount of light (~850 lumens), but the environmental impacts associated with the incandescent are markedly more significant than the CFL and LED lamps because of the energy-in-use phase of the life-cycle.
While they have substantially lower impact than incandescent bulbs, CFLs are slightly more harmful than integrally ballasted LED lamps manufactured in 2012, against all but one criterion – hazardous waste landfill. There, the manufacturing of the large aluminum heat sink used in the LED lamp results in slightly greater impacts.
Researchers anticipate the best performing light source will be the projected LED lamp made in 2017, which takes into account several prospective improvements in LED manufacturing, performance, and driver electronics.
There is a lack of information in the public domain about the extent to which materials used in the manufacturing of LEDs are reused and recycled. Recycling would reduce production environmental impacts. The study assumes use only of new materials, to be conservative. So to the extent that materials are recovered and recycled, the environmental impacts will be less than those the study reports.
The DOE report is free and is available here: http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/2012_led_lca-pt2.pdf