Ever since the EU restricted sales of traditional incandescent light bulbs, homeowners have complained about the shortcomings of their energy-efficient replacements.
The clinical white beam of LEDs and frustrating time-delay of ‘green’ lighting has left many hankering after the instant, bright warm glow of traditional filament bulbs.
But now scientists in the US believe they have come up with a solution which could see a reprieve for incandescent bulbs.
Researchers at MIT have shown that by surrounding the filament with a special crystal structure in the glass they can bounce back the energy which is usually lost in heat, while still allowing the light through.
They refer to the technique as ‘recycling light’ because the energy which would usually escape into the air is redirected back to the filament where it can create new light.
“It recycles the energy that would otherwise be wasted,” said Professor Marin Soljacic.
Usually traditional light bulbs are only about five per cent efficient, with 95 per cent of the energy being lost to the atmosphere. In comparison LED or florescent bulbs manage around 14 per cent efficiency. But the scientists believe that the new bulb could reach efficiency levels of 40 per cent.
And it shows colours far more naturally than modern energy-efficient bulbs. Traditional incandescent bulbs have a ‘colour rendering index’ rating of 100, because they match the hue of objects seen in natural daylight. However even ‘warm’ finish LED or florescent bulbs can only manage an index rating of 80 and most are far less.