’Natural’ Sunlight In Offices 24 Hours A Day, Scientists Predict

New technology which can create ’natural’ sunlight in offices and homes and save billions on energy bills will soon be in everyday use, scientists will announce this week.

Researchers from the University of Bath will give details of work which will help change fundamentally the way that mobile phones, TVs, cars and buildings use lighting.

The new technology, called Solid State Lighting, will save billions of pounds by reducing the amount of electricity needed to light homes and offices.The researchers estimate that in the next 20 years 90 per cent of the world’s lighting will be provided by this technology, saving billions of pounds in energy costs.

Until recently light emitting diodes (LEDs) – devices that turn electricity into light – only produced red light and so were unsuitable for illuminating rooms. But recent research by scientists has allowed LEDs to emit high-quality green and blue light as well, allowing the full spectrum to be produced for the first time artificially.

This means that offices which now use conventional light bulbs which emit yellow light can now be lit by LEDs that produce light that is the same as the sun’s. It also means that at the turn of a dial, the light can be changed to any colour of the spectrum. In addition, the improved quality of blue and green light from LEDs will make images on TV, cinema screens and mobile phones much clearer.

LEDs last 20 times as long as ordinary light bulbs, and the new technology could cut the cost of lighting homes and offices by half by 2025, which could, for example, save the USA over one hundred billion dollar each year, the equivalent output of 133 power stations. Savings in the UK are expected to be similar, proportionally.

Light from LEDs can also be used more flexibly. For instance, car headlights can be programmed to emit a stronger beam when the vehicle goes faster, so that more of the road ahead can be seen to allow the driver to brake easily before obstacles.

At the moment the LEDs are more expensive than conventional lighting, but their cost is falling and new research being done at the University of Bath will play a major role in bringing making the devices cheap enough for people to use them to light their homes and offices.

The research will be outlined by Professor Wang-Nang Wang of the Physics Department at the University of Bath at his free inaugural lecture entitled “Future Trends in Lighting and Data Storage”at Lecture Theatre 2 in the 3East building on campus on Wednesday April 28 at 6.15pm. Those interested should obtain the free tickets by calling 01225 386631 or e-mailing S.D.Willmott@bath.ac.uk

Professor Wang has been among the leading researchers into Solid State Lighting for five years. Although several universities and companies in the world are working on the new technology, his team at the University of Bath has developed a new way of making the LEDs more cheaplyand efficiently. They were given a £400,000 grant from the Engineering and Physical Sciences Research Council and the Department of Trade and Industry for their work.

His team have developed a LED using a compound called gallium nitride, which is half the cost of conventional LEDs, which use sapphire. He is also working on a LED structure called resonance tunnelling which will improve efficiency by a further 20 per cent.

Already, some 30 million LEDs based on the resonance tunnelling structure by Professor Wang’s team are being produced commercially each month by a company called Arima Optoelectronics Co., in Taiwan. These have specialist uses such as in traffic lights, large panel full colour displays and the backlighting for mobile phones, but as their cost falls so their application could spread.

Professor Wang will also outline his team’s role in producing a new generation of “Blu-ray” DVDs that will appear in shops in the next few years and which store five times as much information as existing ones.

Professor Wang said: “Our work is another step on the road to making Solid State Lighting cheap enough to be used across the world.

“We believe that in the next 20 years 90 per cent of our lighting will be provided by this technology, saving the world billions of pounds in energy costs.

“The new technology is not only cheaper, but can give more flexible lighting and a better quality of picture on screens.

“My lecture will explain some of the work we have been doing and how it will affect all our lives over the next 20 years.”