Residential Lighting: Energy Efficient Lighting

Energy-efficient residential lighting products currently on the market present a variety of opportunities for reducing electricity consumption and consumer electricity bills. Fluorescent lamps convert electric power from the electric utility to useful light more efficiently than incandescent lamps. While linear fluorescent lamps are more common in commercial and industrial settings, various types of fluorescent lamps are used in homes in areas such as garages, basements, bathrooms and kitchens. Screw-base compact fluorescent lamps (CFLs) are used for general room lighting and reading light lamps. A small number of highly efficient high intensity discharge (HID) lamps are used in households as well.

Fluorescent lamps use 25%-35% of the energy used by incandescent lamps to provide the same amount of illumination. They also last about 10 times longer (7,000-24,000 hours) than incandescent lamps. According to the US Department of Energy, after accounting for the total cost of buying a CFL and operating it, a 27-watt CFL will save a consumer $62.95 over the life of the CFL compared to the ten incandescent lamps that would be used during the same lifespan. Replace several incandescent lamps with CFLs, and there can be hundreds of dollars in savings in lower utility bills for a single residence. These utility savings also translate into less electricity consumption and a reduction in the emission of carbon dioxide and other gases from coal-fired power plants.

The comparative energy-efficiency of household fluorescent lamps and HID lamps is made possible because an electric arc converts a tiny amount of mercury in the lamp tube to a gas and the mercury atoms give off ultraviolet photons which becomes visible light when the photons hit a phosphor coating on the inside of the tube. Mercury is the only known element that will provide the energy-efficiency experienced by fluorescent lamps. At the end of a fluorescent lamp’s life, there is an even smaller amount of mercury gas left in the tube and mercury atoms that still adhere to the phosphor coating.

To keep the small amount of remaining mercury out of landfills, consumers should dispose of fluorescent lamps separately from regular household waste. Some states mandate that households recycle mercury-added lamps. Local waste disposal and public works authorities should be consulted for lamp recycling requirements and opportunities. Some retail stores now provide opportunities for consumers to return a spent fluorescent lamp for recycling. The homepage on this website provides consumers with an opportunity to find locations for lamp recycling in their area.

Consumers can identify mercury-added fluorescent and HID lamps by the Hg symbol – the chemical symbol for mercury – on the lamp and/or its packaging.