On the May 14, 2012, Washington, D.C., Mayor Vincent Gray joined officials from the District Departments of Transportation (DDOT) and Environment (DDOE) to replace the last of approximately 1,360 alleyway lights with new energy-efficient light-emitting diode (LED) lamps. According to Gray, the ceremony brought to a close the first phase of a relighting project that he hopes will be the first steps on the way to what he envisions as a “Sustainable D.C.”

The lamps are expected to save 591,000 kilowatt-hours of electricity per year.

“Already, results show these new light fixtures are saving energy—57 to 60 percent—compared to the old mercury vapor and high pressure sodium lights,” Gray said in a press release. “Imagine how much energy we could save if we expand this program to all 70,000 street and alley lights across the district.”

The lamps are Lighting Science Group’s Prolific series, which have a rated life of up to 60,000 hours. Compared to the shorter rated life of the old lamps, the city will save on maintenance and lamp replacement costs and ensure more alleyways remain illuminated, contributing to safety.

The DDOE supported and funded the LED replacement project, and eventually, DDOT plans to install energy-efficient lighting fixtures throughout the District, including all of its alleys, streets, bridges, tunnels and underpasses, pedestrian walkways, and bike and running trails.