New York City plans to replace its 250,000 street lights with light-emitting diode lamps by 2017, Mayor Michael Bloomberg said Thursday, a move the administration said could ultimately cut power and maintenance costs by $14 million per year.

The changeover to LED lights has already begun, reports Wall Street Journal blogger Ted Mann, with the Department of Transportation testing the new fixtures in areas including Central Park’s walkways, overpasses on the FDR Drive, and on several bridges across the East River.