NAGPUR: Keeping up with the philosophy of 'a penny saved is a penny earned', a Nagpur University teacher has been doing research on development of eco-friendly Light Emitting Diodes (LEDs) which will save up to 80-90% power.

Taking inspiration from three Japanese scientists - Isamu Akasaki, Hiroshi Amano and Shuji Nakamura - who won the Noble prize for their innovation of blue LEDs last year, associate professor at NU's Physics Department JL Dhoble is working on developing a mercury-free lighting with high luminous output and low power consumption to pave way for the fourth generation lighting based on the LEDs.

His project titled 'Development of eco-friendly LED with a view to boost the new generation lighting' has been selected for funding by Board of Research in Nuclear Sciences ( BRNS), an advisory body of the Department of Atomic Energy (DAE). Recently, his work was showcased at Indian Science Congress (ISC) in Mumbai and was well appreciated.

"LEDs have high luminous efficiency compared to conventional sources. Importantly, they are mercury-free, don't pose threat to the environment, free from any type of hazardous emission and extremely eco-friendly. LED lamps have a lifespan of about one lakh hours, which is staggering as compared to the 1,000 hours and 10,000 hours of tungsten filament bulbs and CFL lamps respectively," Dhoble explains.

Japanese physicists' discovery of blue LED and its contributions to develop energy-efficient white light sources was a big breakthrough in the white LEDs production. Until then, it was not possible to directly obtain white light from single material of LEDs. NU teacher's work on LEDs was also published in different international journals explaining its usability in several applications such as house and street lighting, indicator lamps and displays.

"LEDs require a low operating voltage from three to nine volts. Therefore, it could be powered by solar energy or batteries in areas where there is shortage. Even the rural areas which suffer from heavy load-shedding could get power through this technology at extremely cheap rates," Dhoble says.

Stressing on the need to boost the LED market globally, he said it would require development of more efficient and advanced materials. "Usage of this revolutionary technology significantly reduces the power generation expenditure. Subsequently, the load on power stations also reduces and saved energy could be utilized for productive purposes such as agriculture to boost the economy," he said.

Dhoble's research also has a mention of history and how LEDs form the fourth generation of lighting. "The first generation included kerosene/oil lamps that emitted pollutants and were hazardous. Besides, there were possibilities of properties catching fire and humans receiving injuries. Then there was an era of incandescent (tungsten filament) lamps, which gave low luminous output. It converts only 10% of electricity into light with remaining 90% as heat emission. The third generation started with compact fluorescence lamp (CFL) which consumed four times less electricity, but suffered from the hazards of mercury. CFL contains 2.5 mg of mercury and are not eco-friendly for domestic use due to its disposal problem," he pointed out.

How LEDs can change the lives

* LEDs have high luminous efficiency which saves 80-90% of power

* They're mercury-free, don't pose threat to the environment

* Free from any type of hazardous emission and extremely eco-friendly

* LED lamps have a lifespan of about one lakh hours

* Require a low operating voltage from three to nine volts

* Could be powered by solar energy or batteries in areas where power is scarce