Are LEDs Really Environmentally Friendly?

www.tedmag.com
By: Craig DiLouie

A report from the DOE estimates the total environmental impact for typical lamps based on 15 separate environmental measures.

Over the years, the DOE has heavily promoted LED technology for its energy-saving and environmental benefits. Some, however, questioned whether LED products are truly energy efficient and environmentally friendly compared to conventional technologies when one considers total life cycle energy consumption and environmental impact—including use, manufacturing, transportation, and disposal.

The DOE explored these questions and produced two reports. The first, Review of the Life-Cycle Energy Consumption of Incandescent, Compact Fluorescent and LED Lamps, published in February 2012 (see coverage in the September 2012 issue of TED), concluded that LED replacement lamps consume 75% less energy than the average incandescent, about the same as CFL. The second Life-Cycle Assessment of Energy and Environment Impacts of LED Lighting Products—explored the environmental question as a follow-up report released in June 2012.

Based on an analysis of more than 25 life cycle assessment studies, the second report estimates the total environmental impact for typical lamps based on 15 separate environmental measures, from land use and the potential to increase global warming to waste and pollution. The best representative samples of the three lamp types were included in the study: the 60W incandescent and the 15W CFL and 12.5W LED re placement lamps (Philips Endura - LED) that compete with it for the same sockets, each producing about 850 lumens of light output.

The DOE determined that the greatest environmental impact from lamps occurs during their operation, making LED replacement lamps and CFLs more environmentally friendly than incandescent lamps. Each impact was estimated to be reduced by three to 10 times by switching from incandescent to a more efficient lamp.

Compared to CFLs, LED was only marginally better, and worse in one key measure—disposal generation of hazardous waste. This is because LED replacement lamps use a thermal sink made of aluminum to remove heat from the LEDs. Mining aluminum is energy intensive and produces hazardous waste byproducts such as sulfuric acid. The DOE expects the situation to improve in the future as LEDs continue to become more efficient, reducing the amount of heat the LEDs produce and hence the size of the heat sink. By 2017, in fact, the DOE predicts the average LED replacement lamp will have a 50% smaller environmental impact than it does today—and 70% less than today’s CFL.

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