DEATH OF THE LIGHT BULB
Daily Mirror
Nov 15 2003
By Pete Samson

WHEN scientist Thomas Edison discovered it in 1878, it changed our lives for ever. All of a sudden, thanks to a small filament heated by an electric current until it glows, the world could see in the dark. And it stands next to the wheel as one of those inventions that made our lives a whole lot better... But now, after 125 years, the light bulb is beginning to dim, with another electronic device set to steal its glowing crown. The LED, or light-emitting diode, is on the verge of consigning the light bulb to the history books. They've been around for years, but only in red, yellow and green. Now, the recent development of white and blue diodes is bringing them into the living room. LEDs are smaller, last longer, and are better for the environment. They could save tens of billions of pounds a year in electricity bills alone. Professor Colin Humphreys, part of a team researching the subject at Cambridge University, believes LEDs will be widely used to light homes by 2008. And in 10 years, he says the light bulb could be switched off forever. Prof Humphreys says: "The LED will spell the end for the light bulb as we know it. And I won't shed any tears. "We'll soon be taking our children to museums to show them what we once used to light our homes." LEDs come with a glowing report from energy experts. They can be left on for 100,000 hours - that's 11 years - without running out. AND if switched on for only four hours a day - the average for a household light - they will last for over 60 years. Imagine, the light in your living room could outlive its owner... The benefits don't end there. The current light bulb wastes much of its energy omitting heat. In LEDs, however, nearly all the energy goes on creating the light. In short, LEDs last 100 times longer than normal light bulbs and use only 10 per cent of their energy. That means huge savings on electricity bills, and as they run on as little as four volts, there is no danger of electric shocks. Prof Humphreys says: "The light bulb hasn't changed much in its 100 years. But LEDs will soon take over. "They could last for more than 60 years, save electricity, and would be far cheaper. "Several power stations would be able to close, cutting carbon dioxide omissions dramatically." Prof Humphreys says LEDs are already popping up in more places than you realise. He says: "Red LEDs are used on new cars to light up the bumpers. And they're now being used in brake lights - and eventually in traffic lights - as well. "That could save lives as they come on instantly, while light bulbs take quarter of a second to respond. "They are even beginning to be utilised on airport runways. A runway has to be closed every time a bulb needs changing. "LEDs last so long that would hardly ever have to happen." LEDs were invented in the 1960s. First came red, then orange, yellow and a yellowish green, but to compete with the light bulb they had to produce a white light. In 1993 the elusive blue LED was finally unveiled - and that meant that they had all the colours they needed to make a white light. More recently gallium nitride, hailed as the most important new material for electronics since silicon, has also been used to create white light and even ultra-violet light to run in LEDs Along with his research team Prof Humphreys is now ironing out the final problems with the technology. He says: "Currently the light output is not very high, so clusters of LEDs have to be used to light a room. "And they are not quite affordable yet. But within five years the output will rise and the cost will come down. "An LED which will last for 60 years will cost you £1." ENVIRONMENTAL groups have welcomed the news of the rise of the LED. They say that the old-fashioned light bulbs should be phased out, and the sooner the better. Bryony Worthington, of Friends of the Earth, says: "We fully support new technology that would reduce our demand for energy. "LEDs would help to combat climate change and other environmental problems by helping to get rid of power stations. "The government should find a way to help phase out the existing inefficient light bulbs." The government encouraged a move to LEDs in their energy white paper this spring. And Ray Molony, editor of Lighting Equipment News, believes current light bulb manufacturers will not suffer. He says: "LEDs are the future. They promise much and the light bulb companies know it. "The light bulb is a living antique. It's 91 per cent inefficient. The government is encouraging the transition because they see light as an easy way to meet Kyoto agreement targets. "Current companies who deal in light bulbs are all involved in ventures to make LEDs, so they'll be OK." In London, a flat which uses nothing but LEDs has already been unveiled. More than 500 tiny lights are used in the trendy Vos Pad - designed by Marcel Jean Vos - to illuminate the Chelsea Harbour apartment. And by using red, green and blue LEDs the one-bedroom apartment can be lit by any colour in the spectrum. The walls become a blank canvas, and the colour can be changed to suit your mood. While the lighting in Vos Pad cost £30,000, this is a particularly elaborate example. And the designer believes it added around £90,000 to its value. So once the price of LEDs price plummet, as it will over the next five years, changing a light bulb will be consigned to the history books. So, unfortunately, will all the jokes that go with it.