A lighting revolution is on the way that could end at the flick of a switch the battle between supporters of conventional bulbs and the eco-friendly variety.
Cambridge University researchers have developed cheap, light-emitting diode (LED) bulbs that produce brilliant light but use very little electricity. They will cost £2 and last up to 60 years.
Despite being smaller than a penny, they are 12 times more efficient than conventional tungsten bulbs and three times more efficient than the unpopular fluorescent low-energy versions.
Even better, the bulbs fully illuminate instantly, unlike the current generation of eco-bulbs.
It is reckoned the bulbs, which were unveiled yesterday, could slash household lighting bills by three-quarters.
If installed in every home and office, they could cut the proportion of electricity used for lights from 20 per cent to 5 per cent a year. 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, and they do not flicker - a problem that has been blamed for migraines and epileptic fits.
The Daily Mail revealed earlier this month that in the switchover to eco-bulbs, shops had stopped replenishing stocks of the traditional 100-watt incandescent version.
The move prompted panic buying among consumers. Whitehall claims the switch will reduce emissions of carbon dioxide by five million tons a year - the amount produced by a typical one gigawatt power station.
The new bulbs could cut emissions by eight times that amount.
They use gallium nitride, a man-made semiconductor used to make light-emitting diodes. LEDs are already in use in bicycle lights, mobile phones, camera flashes and Christmas lights because they are relatively cheap due to their size and brightness compared to normal bulbs.
But until now the production costs have been too expensive for widespread use because the material had to be 'grown' on sapphire wafers, meaning a single household bulb would have cost £20.
Scientists at the Cambridge University-based Centre for Gallium Nitride solved that problem by growing it on silicon wafers.
A manufacturer, RFMD in County Durham, has begun work on production prototypes and the first bulbs could be in the shops within two years.
The head of the centre, 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.
'That won't just be good news for the environment. It will also benefit consumers by cutting their electricity bills.
'It is our belief they will render current energy-efficiency bulbs redundant.'
