WITHIN hours of the capital's newspapers publishing the load shedding schedule for the city on May 2, panic-stricken Delhiites sent the sales of one product rocketing. The invertor, that ungainly box with its brace of batteries, has suddenly become the chief topic of conversation in offices, homes, buses, everywhere. For, the awful truth is that everyone in the capital is going to spend at least four hours every day this summer without power. The flood of orders has created a waiting list with every invertor supplier in the city: five days to a week between the placing of order and installation. And the Bengali's refrain, that what he thinks today, the rest of India thinks approximately five years hence, is being proved right this time at least.
The invertor helped most of Calcutta survive the intense power cuts in the '70s and '80s, before a superbly efficient power minister, an unshackled Calcutta Electric Supply Corporation, and a fall in industrial power consumption made the City of Joy power-sufficient. Harassed Delhiites are now the big new market. Just ask Rajesh Verma of the Rs 4-crore Hi-tech Power Systems, who has been making invertors for nearly a decade now, and claims to be the first invertor manufacturer in Delhi. While he sold 800 last year, he estimates sales of 2,000 invertors this year. For that matter, you could ask Ajay Bansal of Sharpline Business System, who invested Rs 10 lakh last year and sold 400 invertors. This year he expects to double his sales.
Till last year, petrol or kerosene-powered portable ('take-them-to-the-picnic') generators manufactured by Shriram Honda and Birla Yamaha were outselling invertors by far. But this summer in Delhi is no picnic for the big fish—the local invertor maker is giving them a run for their money. To begin with, invertors are cheaper. A 500 VA (volt-amperes) Birla Yamaha generator costs Rs 17,000 (Rs 2,000 extra for a kerosene model), while an invertor of the same configuration can cost anywhere between Rs 9,000-Rs 16,000, inclusive of installation. Though invertors can vary in capacity from 150 VA to 5,000 VA, the 500 VA model is the most popular as it can run up to four fans and three tubelights.
The invertor switches itself on and off automatically the moment power goes off or comes back on, unlike generators which need to be cranked up and switched off. Generators run on petrol or kerosene which needs to be stored, while invertors run on batteries that get charged by electricity. Thus, generators cause both noise and air pollution. "Invertors are totally silent and cause no air pollution, making them suitable for apartment blocks," says Bansal.
The invertor is connected to the household's electric mains. The invertor batteries suck power from the supply to charge themselves, and the moment there's a power cut, the invertor switches itself on and the batteries begin generating direct current (DC).
The invertor then converts it into alternating current (AC), which is then passed on to the electricity points in the house.
But generators can last for quite a few years while invertors live only three-odd seasons, as the batteries usually give way. Anything more is a rarity. The one-year warranties extend only to the batteries and not the entire invertor. Besides, batteries are half the cost of the invertor, and that's where the customer can get taken for a ride. One manufacturer may give you a 500 VA invertor for Rs 10,000 and another may give you the same configuration for Rs 14,000. The difference lies in the batteries. If they are local and not branded, price can come down by half. Since the vast majority of invertor makers are unorganised sector seasonal outfits, the quality of what you buy could lie in the realms of pure chance. At the very least, the buyer should check whether the components the manufacturer has used are ISI-approved.
The other inherent shortcoming of the invertor is that if utilised at full capacity, it can't run for more than four hours, whereas generators can go on till they run out of fuel, which can be easily replaced. "Besides, after running for four hours, invertors require anywhere between 6-12 hours to recharge," says Verma.
Paradoxically, even if you go powerless half the summer, your electricity bill may still be higher than what it would have been, had there been no power breakdowns. That's because the invertor which charges itself on electricity for 12 hours—running up your electricity bill—can provide you with power for only four hours. So you actually end up using 12 hours of electricity for four hours of comfort. But Delhi families who have begun waking up in a maddening sweat in the middle of the night do not mind. Next stop for the invertor brigade could be Bangalore, which has the chronic power-cut syndrome creeping up on it rapidly.
