According to the U.S. Environmental Protection Agency and Department of Energy's Energy Star Web site, http://www.energystar.gov, 20 percent of the electric bill of the average U.S. home is attributable to lighting costs.

One of the easiest ways to lower your home energy costs for lighting is to make good choices when changing light bulbs.

One good choice is an Energy Star-qualified compact fluorescent light bulb.

A CFL can save about $30 over its lifetime and pay for itself in about 6 months, according to the site

The bulb uses about 75 percent less energy and lasts about 10 times longer than an incandescent bulb.

On average, an Energy Star CFL lasts 8,000 hours. This is equivalent to more than seven years based on typical household usage.

According to information at the Web site, if each U.S. home replaced just one incandescent bulb with a qualified CFL bulb, the country could save enough energy to light more than 3 million homes for a year, more than $600 million in annual energy costs.

When getting started, you will save the most money by focusing your replacement efforts on highest use bulbs and fixtures.

Highest-use bulbs are likely to be found in fixtures on the kitchen ceiling, in the living room or family room, and in the outdoor porch or post lamp.

For details on how CFLs work and to view a buyers' guide for selecting CFLs, go to the Web site and under "Products" select "lighting."

Opinions are solely the writer's. Joseph Pellicciotti is a lawyer, professor and vice chancellor at Indiana University Northwest.