Compact Fluorescent Lamps (CFLs) reduce energy consumption but carry with it the sting of mercury that is potentially hazardous to humans. With no immediate means of recycling, CFLs may undo more than envisaged. Light Emitting Diodes (LEDs) on the other hand, seems to be better positioned and may allow countries such as India to phase out mercury laced substances without getting into the trouble of setting up disposal facilities—subverting the complications therein. With a 10 to 100-year life the LED prototypes claim a much longer life span than CFLs and also use 40 percent lower energy. The primary advantages of an LED are thus better light quality and higher efficiency for lower energy consumption apart from its robust nature and ability to interface with the digital world. At present LED technology is expensive and demand for such lamps being low, the cost remains high varying between Rs 500 and Rs 900; only a few LED emergency lamps are priced below Rs. 300. BEE sources inform us that, despite all odds the sale of LEDs has grown from Rs. 300 crores in 2009 to Rs 1200 crore in 2012-13.
The Bureau of Energy Efficiency (BEE) encourages individuals and bulk users such as railways, defense and others for large scale adoption of LED usage through its outreach activities. However, their efforts have borne no fruit officials inform G’nY, and there has been no confirmation from the users. BEE further adds that the Department of Electronics and Information Technology (DeitY) under its Modified Special Incentive Package Scheme (M-SIPS) provides capex subsidy for expenditure incurred on plants, machinery, and equipment etc. towards the establishment of LED manufacturing facilities in India. Also, excise duty on LED lamps is reduced to 6 per cent. The Preferential Market Access (PMA) policy provides assured market share for domestic manufacturers in government procurements. The government also plans to distribute 25-27 million LED lamps to BPL families through the ongoing Rajiv Gandhi Vidyut Vitaran Yojana.
On the downside, LED lamps emit a focused, intense light which can be damaging to the eye. The BIS has developed the Indian Standard 16108 for photobiological safety, while its subcommittee is studying the effects of LED lamps on eyes. Despite this drawback LED lamps are being seen as a better replacement for incandescent lamps by both manufacturers and government officials.
How does an LED work?
The LED lamp is basically a semiconductor device which is available in a wide range of colours. LED lamps emit light in a specific direction whereas incandescent and fluorescent lamp emits light in all directions. When a voltage is applied to the LED, light is emitted as a side-effect of the movement of electrons in the semiconductor. When an electron from a higher orbital moves to a lower orbital, it releases energy in the form of a photon, which is the most basic unit of light. An LED is usually made by combining two or more inorganic materials such as aluminium gallium arsenide, silicon carbide, zinc selenide etc. Depending on the material used LEDs can be made to shine in colours from the infrared to ultraviolet, and all the other visible spectra.