Solid-state lighting (SSL) products – lighting with light-emitting diodes (LEDs) as the source of light – are a promising technology to significantly reduce the energy consumed by lighting. Current SSL products operate around 50 lumens/Watt, equivalent to compact fluorescent lights and significantly better than the 10 lumens/Watt for incandescent lights. Future SSL technology aims to reduce energy consumption to a range of 75 – 150 lumens/Watt. However, while SSL luminaires offer great energy savings during use, the net energy consumption is under question, as the upstream manufacturing processes for the individual LEDs are energy intensive. We will present results to-date of our research estimating the life cycle energy consumption of SSL lighting products, specifically a downlight replacement luminaire.

SSL luminaires consist of an array of individually encapsulated LEDs. Manufacturing of the LEDs is comparable in many ways to semiconductor manufacturing. LED manufacturing requires the use of high purity materials, closely controlled processing atmospheres, and precision equipment. Unlike silicon semiconductor manufacturing, LED processing uses a gallium-nitride (GaN) material base, smaller wafer size, and an overall processing sequence with fewer steps. Silicon semiconductor manufacturing processes have been investigated from a life cycle perspective ¹ 2002, ² 2008, but many LED manufacturing processes are developing technologies that are proprietary to manufacturers. The research will leverage the publicly available data from semiconductor LCI studies and combine it with new data and studies from LED manufacturers and related industries. The new data and studies come from a Department of Energy initiated effort to form a collaboration of LCA researchers, lighting industry representatives, and equipment manufacturers with SSL expertise.

At the present time, we have preliminary estimates for the LED manufacturing phase of less than 1 kWh for a luminaire with 10 LEDs. This is similar to the energy consumption of CFL bulb manufacturing. We are beginning research into the materials processing phase for both the LED and luminaire materials, as well as the production of components for the luminaire which are expected to be completed by August 2009 and would be incorporated into the presentation.