When I first learned about the “Life Cycle Assessment of Illuminants: A Comparison of Light Bulbs, Compact Fluorescent Lamps and LED Lamps” and its key finding — that LEDs are indeed energy efficient — I thought: Is this for real? Was this study conducted by the same people who revealed that movie theater popcorn is bad for you? I mean, duh, right?
Actually, the research came from Osram Opto Semiconductors (and was verified by independent experts at Siemens Corporate Technology Centre for Eco Innovations) and the conclusion is not as blatantly obvious as it may seem on the surface. The energy consumption of a light source while it is in use — the standard by which LEDs have had their fluorescent and incandescent alternatives squarely dominated — is just one measure of true efficiency. Osram wanted to analyze the overall environmental impact of an LED lamp over its entire life and compare that to other sources, using life span as the common denominator. So that includes materials and energy used to manufacture the product and transport it from its country of origin.
When all of that is factored in, more than 98 percent of the energy used still results in light generation, according to the study. Compare that to standard incandescent lighting, where only 10 percent of the energy in use produces visible light (with the other 90 percent just giving off heat), and that’s before you’ve even made the bulb or shipped it to its destination. This challenges assumptions LED critics have made that the production of LED lamps uses more energy than is saved by its lower light output.
What’s more, LEDs were shown to be comparable to CFLs in terms of their cumulative efficiency. Either source offers 80 percent energy savings compared to incandescent over the lifetime of the lamps, using less than 670 kilowatt hours of primary energy compared to 3,302 kilowatt hours for incandescent.
Those impressive results reflect LED lamps that are available in the market today, and we all know how rapidly this technology continues to advance. As efficacy increases and performance improves, the life cycle assessment for LEDs stands to make future strides as well.
What might be less obvious, and what I hope is never lost in the race to the newest/hottest/latest/most efficient, is the aesthetic value of great lighting. Each lamp type brings something to the table, whether it’s a candle-like warmth or optimum lumens per watt. And that’s the truth.