Compact fluorescent lights (CFLs)

Compact fluorescent lights (CFLs) use one-quarter to one-third the electricity of common incandescent bulbs and screw into standard light sockets. CFLs can save 60% to 75% on lighting costs. They're available in a wide range of light output and in a pleasing range of colors.

A CFL will cost several times the price of an incandescent bulb, but it will last 6 to 10 times longer. This makes the long-term cost of the CFL less. The savings on your electric bill will begin immediately. 

Start by installing CFLs in the rooms you use the most, such as your kitchen, bathroom, and living room. Choose CFLs with a much lower wattage than the incandescent bulbs they replace. For example, replace 100-watt incandescents with 26–30-watt CFLs to get the same light output, replace 75-watt incandescents with 20–23-watt CFLs, and replace 60-watt incandescents with 15–20-watt CFLs.

Standard CFLs are slightly larger than incandescent light bulbs and may not fit in all fixtures. The smallest CFLs, called sub-compact fluorescent, may work in these cases. Check your fixtures before purchasing CFLs.

You can buy fluorescent fixtures for every home application. Tubular fluorescent fixtures work well for garages, kitchens, work rooms, and recreation areas. For other areas CFL fixtures come in a variety of attractive styles and types.

If you're building a home, or plan to replace existing built-in fixtures, look for fixtures that are designed especially for CFLs. Airtight recessed CFL fixtures – those that fit into the ceiling – are an especially good replacement for the recessed incandescent fixtures that allow large amounts of air to leak into the home.

One of the best sources of information about compact fluorescent lights is the Better Bulbs web site.

For more information on lighting, see Residential Energy: Cost Savings and Comfort for Existing Buildings Chapter 7.

CFLs & Mercury

Compact fluorescent lamps (CFLs) contain the poisonous heavy metal: mercury. Each compact fluorescent lamp (CFL) contains around 4 milligrams (mg) of mercury. However, CFLs reduce mercury emissions significantly in regions electrified by coal-fired generators because CFLs use one-quarter of the electricity as incandescent bulbs and last up to 10 times longer. 

The amount of mercury saved by replacing an incandescent bulb with a CFL is around 8 mg due to the reduced mercury emissions from coal-fired power plants. Nevertheless, CFLs should be recycled to avoid polluting the environment with even the small amount mercury contained in the CFL. Chain stores like Home Depot, Ace Hardware, and others have initiated recycling programs for CFLs.

One of the best sources of information about compact fluorescent lights is the Better Bulbs web site.

For more information on lighting, seeResidential Energy: Cost Savings and Comfort for Existing Buildings Chapter 7.