Guide To Green Lighting
Compact fluorescents (CFLs) give off the same amount of light as incandescent bulbs, but use 20 per cent or less electricity and last about 10 times longer.
They work by passing an electric current through a gas that emits ultraviolet light, causing a coating of phosphorous on the inside of the tube to glow.
However, CFLs are not all positive for the environment.
They contain a small amount of mercury, so take care to dispose of old bulbs carefully by using a chemical collection service.
For advice and information, contact your local council.