Cambridge University researchers have developed cheap, light-emitting diode (LED) bulbs that produce brilliant light but use very little electricity.
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.
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. Also LED bulbs do not contain mercury, so disposal is less damaging to the environment
