At the parking structure of the U.S. Department of Labor headquarters in Washington, D.C., LED luminaires were installed in place of the incumbent high-pressure sodium (HPS) luminaires and evaluated for relative light quantity and performance. Results showed energy savings of 52% from the initial conversion of HPS to LED—which increased to 88% by using occupancy sensor controls—and simple payback periods of 6.5 and 4.9 years for retrofit and new construction scenarios, respectively. Read more.