Tired of sky-high energy bills? Swap out 20 old bulbs in your home for compact fluorescent bulbs (or CFLs) and you’re looking at a savings of roughly $100 a year.

Here are five things you should know about CFLs:

¢ They’re good for the environment. Because they require less energy than normal bulbs, CFLs put less of a strain on power plants, thus reducing production of greenhouse gas carbon dioxide and nitrogen oxides that cause smog. CFLs can last 3,000 hours or longer, about three times longer than normal bulbs.

¢ They take a little longer to power up. CFLs can take anywhere from 25 seconds to 3 minutes to reach full brightness, Consumer Reports found.

¢ They should be recycled. CFLs contain small amounts of mercury and should be recycled. Lawrence’s household hazardous waste program accepts CFLs for disposal. For more information, visit www .lawrencerecycles.org or call 832-3030.

¢ Their quality varies. After testing five major brands, Consumer Reports recommends opting for Energy Star-qualified CFLs.