MADISON, Wis. -- Compact Fluorescent Light bulbs, or CFLs, are a very common and easy way for people to go green.

But one viewer asked WISC-TV to look into whether the long-life claims for these bulbs are really as advertised.

During a recent remodel, Harold McAllister, of Fitchburg, replaced most of the light bulbs in his home with the more energy-efficient CFLs. But after many of them went dark within the first year, he questioned whether or not they were worth what he paid.

"Some of them (failed) in a matter of months -- some of them in a matter of weeks," McAllister said. "It came to seven of them (failed) out of the first batch of 12 that we bought in December of 2007."

McAllister documented every one that failed early -- very early, considering how long the CFL bulbs are supposed to last.

"If it's used under optimum circumstances, it should last approximately 10 times longer (than standard incandescent bulbs)," said Jim Lawler, a University of Wisconsin-Madison physics professor.

Lawler studies light bulbs and lighting technology. He said that many of the CFL bulbs in retail stores don't last as long as they should.

"Not all of these compact fluorescents are made with the same quality," Lawler said. "And if you buy the very cheapest ones, they may not hold up as well."

Lawler said the bulbs also can fail if they're turned on and off too much. In addition, they are affected by extreme conditions, like excessive heat or being out in the cold.

"The cold is a killer," Lawler said.

McAllister said the bulbs he bought might not have been the best quality and that he bought them on sale.

"I support their use," McAllister said. "But something has to be done about the reliability."

Lawler recommended that consumers stick with name-brands, like Sylvania, GE and Phillips. He said the brand name bulbs are generally made better and are more reliable.

Many of the CFL bulbs are guaranteed to last a certain amount of time. If people do have trouble, they should hold on to their receipt and return them.