Light-sensitive switches, motion sensors, energy-efficient bulbs and glare caps are some solutions to common dusk-to-dawn lighting problems. Power usage and intrusion into neighboring homes are the main issues with residential dusk-to-dawn security lights.
Motion sensors trigger lights in the areas where an intruder may be present. The light may be set to remain on for a specified period of time after the switch is tripped. Light-sensitive switches prevent wasted energy without the use of a timer. When the outdoor sunlight drops below a certain threshold, the light switch will turn on.
Energy usage also varies along with the type of light bulb. Fluorescent and incandescent lights are the cheapest and least efficient bulbs. Mercury vapor and metal halide lights generate high-intensity light with low power consumption, but also produce too much heat for many residential settings. Mercury is also toxic and must be disposed of properly to prevent accidental poisoning. High-pressure sodium and LED dusk-to-dawn bulbs produce powerful light with less heat.
Glare caps limit the range of light so neighbors do not get upset with the continual illumination of a typical dusk-to-dawn fixture. This also cuts down on unnecessary light in urban areas where "sky glow" is a problem.