Only nine percent of households use compact fluorescent lights, according to the Energy Information Administration Report, Residential Lighting: Use and Potential Savings. A pessimist would say this is a problem. An optimist would say this creates a huge potential for progress.

In the report, EIA estimates that by replacing most incandescent lights with compact fluorescents, American homes would save 31.7 billion kiloWatt-hours of electricity annually. That's enough to light about one-third of all U.S. households for an entire year.

The lights with the greatest potential for savings are those that burn longer. The average household has five lights that burn more than one hour a day and spends about $83 per year on electricity for total household lighting.

Although replacing incandescent bulbs with compact fluorescent lamps produces immediate savings in electricity, dollars savings lag behind because compact fluorescent lights cost substantially more than incandescents. The EIA estimates that in areas with high electricity rates, such as New York City, consumers can recover their investment in as little as 2 years. In areas with lower electric rates, such as the Pacific Northwest, the payback time can be up to four years. (One assumption made by the report was that CFLs cost $22 each. Many retail stores currently carry models as low as $10, which would improve the payback period considerably.)

To see the full report, request a copy from EIA's National Information Center at 202-586-8800.