Saving energy even before the light's on

The International Herald Tribune, November 30, 2009 Monday - A study by Osram shows that over the life of the bulb, from manufacturing to disposal, incandescent bulbs use almost five times as much energy as compact fluorescents and LED lamps.

Does the latest generation of energy-efficient light bulbs save energy? A comprehensive study conducted by Osram, the German lighting company, provides evidence that it does.

While it might seem like a no-brainer, the answer had remained unclear until the release of the report Friday.

That was because no one knew whether the production of LED lamps required more energy than was needed for standard incandescent bulbs. It is indisputable that LEDs use a fraction of the electricity of a regular bulb to create the same amount of light, but it was unclear whether more energy was used in the manufacturing and distribution process.

The study results show that over the life of the bulb - from manufacturing to disposal - incandescent bulbs use almost five times as much energy as compact fluorescents and LED lamps.

Importantly, the energy used during the manufacturing phase of all lamps is insignificant - about 2 percent of the total. Given that both compact fluorescents and LEDs use about 20 percent of the electricity needed to create the same amount of light as a standard incandescent, both lighting technologies put incandescents to shame.

''We welcome these kinds of studies,'' said Kaj den Daas, chief executive of Philips Lighting North America. The Osram study ''provides facts where we often have only emotional evidence.''

Philips recently became the first entrant for the U.S. Department of Energy's L Prize, a race to develop the first practical 60-watt LED equivalent to a standard light bulb.

To calculate what is known as a lifecycle assessment of LED lamps, Osram compared nearly every aspect of the manufacturing process, including the energy used in making the lamps in Asia, packaging them and transporting them to Germany, where they would be sold. It also looked at the emissions created at each stage and calculated the effect on six different indices of global warming.

Those included the amount of greenhouse gas emissions created by each process; the acid rain potential; eutrophication, or algae buildup; photochemical ozone creation; and the release of harmful chemical compounds.

Compact fluorescents also contain mercury, which can pollute soil when disposed of.

In addition to the amount of electricity needed for each process, the energy used to create that energy, and the emissions created as a result, was also calculated. In China, where some of the lamps are made, that meant coal. In Malaysia, where LED production was done, electricity is usually created from natural gas. And in Germany, where the lamps would be sold, electricity is created from a mix of coal, nuclear and renewable sources.

The methodology followed the practices set down in ISO 14040, an industry standard. The results were certified by three university professors in Denmark and Germany as adhering to the standard.

''The difference in energy use between incandescents, compact fluorescents and LEDs is definitely significant,'' said Dr. Matthias Finkbeiner of the Technical University of Berlin, the chairman of the study's review committee. ''The results are very stable.''

While 60-watt lamps are more popular light sources, they were not used in the study, as Osram does not yet have a commercial version. The amount of energy used to illuminate 60-watt-type lamps would increase, but the increase would affect all types of lamps and therefore not change the relative results, according to Dr. Berit Wessler, the head of innovations management at Osram Opto Semiconductors in Regensburg, Germany.

Dr. Wessler said she expected the results to shift even more in favor of LEDs as newer generations of that technology become even more efficient, requiring less energy to produce the same amount of light.

''Everything I've seen strengthens the assumption that LED efficiency will increase,'' she said. ''There has not been much improvement in incandescent efficiency in the last 10 years.''

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