Photo of Fluorescent bulbsCompact Fluorescent lights

When these new designs were introduced in the early 1980s, they revolutionized lighting. A variation on the fluorescent tube, compact fluorescents work the same way, only the tube has been made smaller and folded over in a way to make them fit into spaces designed for incandescent bulbs. With a screw base that fits a normal light bulb socket, they operate on a quarter of the energy used by incandescents, and last ten times longer.

Your lighting energy bill can be cut nearly in half if you replace 25 percent of your lights in high-use areas with fluorescents. That will save you money, but you should consider the environmental benefits, too.

A single 20-watt compact fluorescent lamp used in place of a 75-watt incandescent will save about 550 kilowatt-hours over its lifetime. If your electricity is produced in a coal-fired power plant (like 20 percent of California's electricity is), that savings represents nearly 500 pounds of coal not burned, which means that 1,300 pounds of carbon dioxide and 20 pounds of sulfur dioxide will not get into the atmosphere.

A compact fluorescent lamp will initially cost more that an incandescent bulb, but because it lasts longer and costs so much less to run, it will prove to be a better bargain over time. Just keep in mind that light bulbs cost much more to run than to buy in the first place. A 75-cent, 100-watt light bulb will cost you about six dollars in electricity over its 750-hour lifespan.

Here's a rough comparison of the long-term costs of the two types of light bulbs:

Bulb Type 100W Incandescent 23W Compact Fluorescent
Purchase Price $0.75 $11.00
Life of the Bulb 750 hours 10,000 hours
Number of Hours Burned per Day 4 hours 4 hours
Number of Bulbs Needed About 6 over 3 years 1 over 6.8 years
Total Cost of Bulbs $4.50 $11.00
Lumens Produced 1,690 1,500
Total Cost of Electricity
(8 cents/kilowatt-hour)
$35.04 $8.06
Your Total Cost over 3 years $39.54 $19.06
Total Savings over three years with the Compact Fluorescent: $20.50
Source: U.S. Department of Energy, Energy Information Administration

Some utilities offer rebates on compact fluorescent lamps. Be sure to look for them - you'll save even more. Also use compact fluorescents for lights you use often. The more a light is used, the faster a compact fluorescent will pay for itself.