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.
Light-emitting diodes (LEDs) were once used solely for indicator and panel lights in cars and in other electronic equipment, but with the advent of ultra-bright versions, they are being used both individually and in groups as light sources in commercial and domestic settings.
A spotlight lamp made up of multiple LEDs has a life of up to 50,000 hours.
In addition to their longevity, LEDs have several important advantages.
They don’t emit heat.
They consume very little electricity.
And because they remain cool to the touch, they can be safely fitted in rooms where children play, and into floors as uplights without risk to sensitive surfaces, including bare feet.
LV halogen lamps
Low voltage (LV) halogen lamps are a type of incandescent light, but because of the way the tungsten filament interacts with certain chemicals, the bulb lasts longer than an incandescent bulb — although not as long as CFLs and LEDs, about 4000 to 5000 hours.
Halogen bulbs are made of quartz, or from glass with a high melting point.
They emit a beautiful pure light suited to downlights, reading lamps and garden lights.
These lights look great when grouped together but this option is not energy efficient and so best avoided.