Some bright sparks reinvent the light bulb; Update could bring back old version.

Byline: RUKI SAYID Consumer Editor

THE warm glow of traditional light bulbs could return to homes after scientists discovered a way to make them more energy efficient.

The revamped incandescent bulbs will bring back the gentle light of the old models, instead of the harsh white light and slower power-up of the green bulbs that replaced them.

They would cost just 70c a year to run, compared with [euro]2 for a fluorescent eco-bulb and [euro]1.70 for LED, and give off 40% of their energy as light - beating LED's 14%.

The light output is a huge improvement on the old incandescent bulbs banned by the EU seven years ago, which were just 5% energy efficient, meaning 95% of their energy was lost as heat. And the researchers reckon the finished version could be even more efficient.

They had their light bulb moment when they surrounded an incandescent bulb filament with a special crystal that bounced back energy that had previously been lost as heat to create a light that is more efficient than modern bulbs.

Ivan Celanovic, who led the team at the Massachusetts Institute of Technology in the US, said: "This experimental device is a proof-of-concept, at the low end of performance that could be ultimately achieved by this approach."

After an EU ruling in 2009, 100w bulbs were the first to be banned followed by 60w bulbs in 2001 and then a total ban in 2012.

Current energy saving bulbs are 75% efficient.

ruki.sayid@mirror.co.uk

70c Yearly cost of the updated 'banned' bulbs