The City of Ann Arbor, Michigan (pop. 114,000) has become one of the first cities in the world to pilot a new street lighting technology that uses less than half the energy and lasts more than five times longer than the city’s standard streetlights. Thanks to custom designed Light Emitting Diode (LED) technology, the city may potentially cut its streetlight energy bill in half and significantly reduce light pollution.

In 2006, Ann Arbor paid $1.39 million, nearly 25 percent of its energy budget, on traffic signals and streetlights. In fact, this cost would have been higher had the city not begun replacing incandescent traffic signals and pedestrian crossing signals with LED fixtures back in 2000. LED replacements have saved the city $49,000 annually and have the potential to save the city even more money if LED technology can be utilized for street lighting, which accounts for 92 percent of the city’s $1.39 million annual street lighting costs. This is the result the city is hoping for with its LED pilot program for lighting public spaces and roads.

LED test fixtures were installed in March 2006 in 21 existing light globes in the city for pedestrian lighting. The prototype design, created by Relume Technologies of Oxford, Mich., is the first of its kind in municipal street lighting. The city is also testing numerous types of LED street lights for neighborhoods and parking lots.

What Are LEDs?
LEDs (light-emitting diodes) have been around since the 1960s. You’ve probably seen them used as indicator lights in consumer products. Recently, however, they have become practical for general lighting purposes. Although they cost more upfront than the bulbs they replace, LED lights use half the energy (or less) and last longer than conventional bulbs, resulting in big savings and short payback periods. One specific advantage of LEDs is that they produce directional light. This gives us more control over what we light (i.e. the street) and what we don’t (the night sky), reducing light pollution and wasted energy.

LED Benefits
The LED bulbs for the globe lights require only 40 watts of power to produce the same amount of emitted light as the city’s standard 100-watt metal halide bulbs. In addition to energy savings, the LED lights have a life expectancy of 10 years, compared with the current globe light’s 2-year life span. The LED lights offer more control than their standard counterparts. Unlike the light from the traditional metal halide bulbs, LED light is directional and can be projected downward to the street, reducing skyward light pollution. LED light can also be customized in terms of color temperature and brightness. LED public lighting also could be controlled by motion sensors or timers to brighten when needed most.

“There are many benefits to LED lighting, including decreased maintenance and energy savings that reduces fossil fuel use meaning less air pollution and less global warming impact,” said City of Ann Arbor Energy Coordinator Dave Konkle. “We want public feedback about this new technology and we also want residents to know that Ann Arbor is one of the leading cities in the world in testing this new outdoor lighting technology, which has the potential to save a great deal of energy and maintenance dollars as well as reducing light pollution. We are proud of the fact that lighting experts from across the United States have traveled to Ann Arbor to see examples of LED lights in use,” Konkle said.

For information, contact Mike Bergren, Assistant Field Operations Mgr., 734.994.4918 or email mbergren@a2gov.org.