LED Streetlight Application Assessment Project

Abstract

Recent studies have found that LED technology is becoming competitive for streetlight applications compared with commonly employed high-intensity discharge light sources, such as high-pressure sodium (HPS) and metal halide. The expectation is that LED street lighting technology will not only provide more efficient light distribution and increased uniformity but will also save energy and reduce maintenance costs. Seattle City Light (SCL), Washington, has a street lighting system of nearly 84,000 street and area lights that predominantly use HPS light sources. Because of the potential benefits of installing LED luminaires as replacements for these lights, SCL launched the LED Streetlight Application Assessment Project pilot study to evaluate LED luminaires for photometric performance, energy efficiency, economic performance, and other impacts on the SCL streetlight system. The project findings will be used by SCL to create a strategy for the installation of LED streetlights to develop an energy-efficient lighting system. The major elements of this project included LED luminaire selection, simulated photometric performance evaluation of selected LED products, field photometric performance evaluation at selected test sites, and economic performance evaluation in comparison with HPS luminaires. In addition, because combining LED roadway luminaires with new light control systems provides many new options to enhance overall light control, facilitate maintenance, increase luminaire life, and reduce operating costs, a preliminary review of current cutting-edge lighting control systems was conducted.