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Light up with leds

Light up with leds
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First Published: Tue, Jun 28 2011. 09 24 PM IST

Light-wise: The range in terms of wattage and design is limited.
Light-wise: The range in terms of wattage and design is limited.
Updated: Tue, Jun 28 2011. 09 24 PM IST
How do you buy a light bulb? No, this is not one of those how-many-engineers-does-it-take-to-change-a-light-bulb jokes; I mean, how do you buy an ordinary light bulb for your home?
Time was we went to the market, asked for a 40-, 60- or 100-watt bulb, plain (meaning see-through) or milky, plugged it into the holder, and that was that. But that was when there was only one type of bulb in the market: the old-fashioned incandescent bulb invented by Thomas Edison, the bulb we’ve used for the last 130 years.
Light-wise: The range in terms of wattage and design is limited.
Those incandescent bulbs are power guzzlers; the bulk of the power they consume is emitted as heat rather than as light. Across the world governments have officially announced plans to phase them out. They are being replaced by CFL (compact fluorescent light) bulbs, which are no doubt more expensive, but last longer and consume less energy to provide the same brightness as an incandescent bulb, and bring down the monthly electricity bill.
The problem with CFL bulbs in India, however, is that they come in so many different shapes and sizes that you have to prepare a list of specs before you set out to the market to buy one. And yet you may not find what you are looking for. I learnt this the hard way recently when I wanted to buy a few CFL bulbs for some new lamps in our house. I had to go to four shops in two different markets. At one point I was worried that we might have to change our beautiful new lamps.
Before you buy a CFL bulb, you first have to calculate the power (or wattage) you require, which is fairly simple: The thumb rule is a 15-watt CFL bulb will give you light equivalent to a 60-watt incandescent bulb—roughly, a ratio of 1:4 (we’re so used to the old incandescent terminology that we still talk in terms of 40, 60 or 100 watts). But that’s not all. Once you have specified the wattage, you also have to tell the salesman whether you want a straight (tubular) or spiral (popularly called jalebi) bulb, white or warm (they call it yellow), and then, depending on the holder (or socket) in your lamp, explain whether you require a screw-type (aka peych-wala) or a hook-type (puraane style-wallah, meaning the old, incandescent bulb type), small or big grooves (chhoti ya badi chudian).
Now, imagine that you want a 15-watt CFL bulb, warm because you find white light rather harsh, spiral in design because straight is too long and may not fit into the lamp, and small grooves because the holder is not a plugin but screw-in type. Chances are you’ll be told, “We have only straight and not spiral.” Or “They make it only in 9 watts.” You then have two choices: Buy 9 watt bulbs and get used to sitting in a dimly lit room, or change your lamps.
But slowly, there’s another option coming into the market: the LED (light emitting diode) bulb. LEDs have been around for a while as tiny lights in gadgets, in torches, and in car headlights; now they are coming into the household sector. An LED bulb consumes even less power than a CFL bulb, and so you save more money: Manufacturers’ websites say you can replace a 13- to 15-watt CFL bulb with just a 6- to 7-watt LED bulb. It warms up—and cools down—instantly. An LED bulb also lasts 100 times longer, and unlike a CFL that has tiny amounts of mercury, it contains no hazardous materials. By all accounts it’s the most energy-efficient bulb to date.
But compared with CFLs, they are very expensive: Depending on the brand, a 5-watt LED light can set you back by around Rs3,000. Replacing every single bulb in your house will cost you a small fortune. The other problem is there isn’t that much choice in the market: The range in terms of wattage and design is very limited.
But I’m sure things will look different in the next two-three years. When they were first introduced, even CFLs were very expensive. Going by the buzz, the future is LED. I only hope they will come in sizes that won’t stick out of lampshades.
Shekhar Bhatia is a former editor, Hindustan Times, a science buff and a geek at heart
Write to Shekhar at thesmartlife@livemint.com
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First Published: Tue, Jun 28 2011. 09 24 PM IST