Because utility lights and some applications of security lights
are needed only when it is dark and people are present, the
best controller may be a combination of motion sensor to turn
on lights when people are present and photosensor to prevent
lights from operating during daylight hours. Incandescent
flood lights with photosensor and motion detector controls
may actually use less energy than pole-mounted HID or lowpressure
sodium security lights controlled by a photosensor.
Even though HID and low-pressure sodium lights are more
efficient than incandescents, they are turned on for a much
longer period of time than incandescents using these dual
controls.