The City of Ann Arbor paid $1.5 million to operate traffic signals and streetlights in FY2008. The cost would have been higher had the City not begun replacing incandescent traffic signals and pedestrian crossing signals with LEDs back in 2000. The replacements made so far are saving the city $49,000 annually, but the bigger savings opportunities are in street lighting, which accounts for 92 percent of that $1.5 million annual cost. Ann Arbor is currently utilizing LED street lighting in the hopes of cutting our street lighting bill in half.
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.
Where Are We Now?
After successfully piloting LED globe lights on a full block downtown, we are going ahead with full conversion of our over 1,000 downtown streetlights. $630,000 to fund the retrofit project was provided by the Ann Arbor Downtown Development Authority. Five years into the conversion, no LED globe lights have needed replacement.
Ann Arbor is also testing several different varieties of what are called "cobrahead" fixtures on Glendale Dr (below, left and center). To comment on the test installations, send an email to email@example.com.
The LED pilot program has already received considerable recognition, winning ICLEI's first annual Climate Innovation Invitational Award and being featured as part of a video on Ann Arbor that aired at the 2007 International City Managers Association conference.