Cost of Light
Regular incandescent bulbs:
These bulbs, which provide most home lighting, are used in products from nightlights to floodlights. The most common incandescent is a pear-shaped bulb with a medium-sized screw-type base. Incandescent bulbs use electricity to heat a filament until it glows white hot, producing light. About 90 percent of the electricity used by incandescent bulbs is lost as heat. These bulbs typically burn for 750 to 1,000 hours or about three hours a day for a year.
Incandescent spotlights and floodlights:
The reflective coating on these bulbs helps direct and focus the light. Commonly known as spotlights or floodlights, these bulbs often are used in recessed ceiling fixtures or outdoors. They burn for about 2,000 hours.
Halogen bulbs:
Sometimes referred to as “tungsten-halogen filament incandescent bulbs,” these bulbs contain a small capsule filled with halogen gas, which emits a bright white light. Halogen bulbs produce more light, use less energy and last longer than standard incandescent bulbs of the same wattage, but they cost more. They last from 2,000 to 3,000 hours.
General service fluorescent bulbs:
These bulbs are more energy efficient than incandescent bulbs. They’re the thin, long tubes often used in kitchens for under-cabinet lighting, and in garages, workshops and basements. The tubes can last from 10,000 to 20,000 hours 10 to 20 times longer than incandescent bulbs.
Compact fluorescent bulbs:
These bulbs provide as much light as regular incandescent bulbs while using just one-fourth the energy. For example, a 15-watt compact fluorescent bulb yields the same amount of light as a 60-watt incandescent bulb. Compact fluorescent bulbs last about 10,000 hours 10 times longer than incandescent bulbs.
