US$3 LED light bulb lasts 60 years, could end battle of the bulbs
By Paul Evans
February 1, 2009
February 2, 2009 Cambridge University researchers have developed cheap, light-emitting diode (LED) bulbs that produce brilliant light but use very little electricity. They will cost just GBP2 (USD2.80) and last up to 60 years. The gallium nitride based bulbs are 12 times more efficient than conventional tungsten incandescent bulbs and three times more efficient than compact fluorescent low-energy bulbs. As well as lasting 100,000 hours, ten times as long as today's eco-bulbs, the LED bulbs do not contain mercury, so disposal is less damaging to the environment, they do not flicker and fully illuminate instantly, unlike the current generation of eco-bulbs.
The 100,000 hour LEDs use gallium nitride, a man-made semiconductor used to make light-emitting diodes. LEDs are currently available as replacement bulbs but they cost $25 - $50 each which makes them too expensive for widespread use. To achieve the price break through the Cambridge scientists have developed a process where they grow Gallium Nitride on silicon wafers instead of the current method, which requires sapphire wafers.
The 10-fold price reduction could slash household lighting bills by three-quarters. A manufacturer has begun work on production prototypes and the first bulbs could be in the shops within two years. The head of the Centre for Gallium Nitride, Professor Colin Humphreys, said: "This could well be the holy grail in terms of providing our lighting needs for the future."
"We are very close to achieving highly efficient, low-cost white LEDs. It is our belief they will render current energy-efficiency bulbs redundant."