Every time a conventional light bulb is replaced with a LED (light-emitting diode) version, half the electricity will be used and therefore greenhouse gases will be cut in half. If you switch to LED lights in your home, your power bill will be lower and you will save money buying replacement bulbs because LEDs can last 25 times longer than a conventional incandescent bulb and 10 times longer than a compact fluorescent light (CFL).

LED lights are still more expensive than the other bulbs,

though the cost of a 60-watt LED has dropped by nearly 40% over the past couple of years. For example, Philips, one of the leading LED companies, brought out a new range of affordable LED warm white and cool daylight lights in Australia late last year with a recommended retail price of between $15 and $29 a bulb, depending on its wattage and lifespan. The Philips LED myVision 9.5-watt bulb, which replaces a 60-watt conventional bulb, lasts for 15,000 hours and costs $19.99, while a six-watt (replacing 40 watts) LED myVision with a 15,000-hour life is $14.99.

LEDs are an improvement on CFLs because they don’t use mercury or take time to warm up to maximum brightness; nor are they affected by being constantly switched on and off. They use a semiconductor to convert electricity into light. Not surprisingly, the world is switching onto LEDs – over 2011 and 2012 global sales of LED bulbs increased by about 22%.

Power savings – and the subsequent cost savings – have prompted some mass replacements of conventional bulbs. For example, the City of Sydney is replacing about 6500 street and park lights with LEDs over the next three years. The $7 million project is expected to save the city nearly $800,000 a year in electricity bills and maintenance costs due to the longer lifespan of LEDs.

People like the quality of light from LEDs too, according to a survey by the City of Sydney about the new LED lights. It found that more than 90% of people described the new lights as “appealing” and 75% said they improved visibility.

The consumer group Choice tested CFLs and LEDs for 1000 hours – the equivalent of seven months – and recommended three LED lights (three other bulbs it recommended were CFLs): the BYD 6.9W LED Globe, the Verbatim LED Classic A Superior and the Philips Master LEDbulb MV 12W dimmable.

In 2012, around 49 million LEDs were installed in the US, according to the US Department of Energy. This cut about $US675 million from annual energy costs. The DOE says switching entirely to LED lights over the next 20 years could save $US250 billion, cut electricity consumption for lighting by nearly 50% and avoid 1800 million tonnes of carbon emissions. Click on their website soli-lite for more information.