The amount of power used by a night light is listed by the wattage the light uses. In addition, some night lights automatically shut off when room light increases during the day. The wattage times the amount of time the light is used determines how much electricity a night light uses.
Night lights come in a variety of types including incandescent, neon, electroluminescent and LED (light-emitting diode). The light should have a UL (Underwriters Laboratories) listing for rated wattage. This is how much electricity the night light will use when it is on. Typical incandescent or neon night lights use about 1.5 to 7.5 watts of energy. LED and electroluminescent night lights can use less than a single watt.
The wattage of the night light in combination with how long the lamp is burning determines how much electricity it uses. Manual switch night lights run when you turn them on and stop when you turn them off. Automatic night lights have light sensors that turn them off when room light reaches a certain level. The wattage times the number of hours you run the light determines the amount of electricity the night light uses. For instance, a 1.5 watt light used for 12 hours will use 18 watt hours. That is equivalent to using a single 60-watt light for only 20 minutes.
Average Electricity Use
American residential dwellings use an average of about 920 kilowatt hours per month. That works out to about 30 kilowatt hours per day. About 15 percent of that is used for lighting, coming out to about 4.5 kilowatt hours used for lighting every day.
Electricity Used for Night Lights
A single 1.5-watt night light used for 12 hours each day uses about 0.4 percent of the total electricity used for lighting an average U.S. residence. A 7.5-watt night light burning for 12 hours uses about 2 percent of the total electricity used for lighting.
Some specialty night lights are rated at less than a single watt. The wattage does not determine the light output for a light. Modern designs are more efficient than incandescent lights and can produce more light with less wattage. Other factors to consider are the initial cost of a night light, and how long the night light is likely to last. While night lights consume much less power than typical lights, they are used for longer periods of time.