It is shown that converting your plant lighting to high- pressure sodium-now-pays dollar dividends. This is true even if your plant went on-stream last year. Lighting systems that depart from the usual are shown to save energy and therefore help profits. Treating lighting as the plant stepchild wastes your money and our energy. Planning a sound maintenance program, starting when the plant is designed, yields 1) fewer fixtures, 2) better lighting, 3) lower electric bills, and 4) less total maintenance.