A crew from the 319th Civil Engineer Squadron replace streetlight fixtures on Grand Forks Air Force Base, N.D., March 19, 2015. Old high-pressure sodium bulbs such as the one being lowered are being replaced with energy-saving LED fixtures. (U.S. Air Force photo/Staff Sgt. David Dobrydney)
Airman 1st Class Ryan McClure, 319th Civil Engineer Squadron electrical systems apprentice, installs a new LED fixture on a streetlight on Grand Forks Air Force Base, N.D., March 19, 2015. The new fixtures are expected to use far less electricity than the previous high-pressure sodium bulbs. (U.S. Air Force photo/Staff Sgt. David Dobrydney)