N K Bansal, of Centre for Energy Studies, Indian Institute of Technology, New Delhi talks to TV Jayan on energy efficiency
Indian buildings are said to be very energy inefficient and a substantial part of our electricity shortage can be addressed, if we have improved energy efficiency....
Compared to developed countries, buildings in India consume more energy for lighting as well as heating and airconditioning. It is estimated that electricity demand in buildings -- both commercial and residential -- in India has been growing at the rate of 13 per cent per annum. Of the total peak load demand of 30,000 mw, 50 per cent is used for lighting, 15 per cent for airconditioners and coolers and the rest 35 per cent is for other purposes.
Nearly 89 per cent of lighting devices used in the country are incandescent bulbs, which lose about 90 per cent electricity as heat. Replacing them by compact fluorescent lamps (cfl) and tube lights will reduce the lighting load by 30 to 40 per cent. But the problem is that good quality cfl costs about 20 times more than an incandescent lamp. It is here where a major push from policy makers is needed. When electricity boards sanction a new load, it can be made mandatory that the new consumer has to use cfls and tube lights. One way of ensuring this could be electricity boards themselves supplying 4-5 cfls, the cost of which could be included in the initial connection charges. For customers, who have already been given connections, a serious campaign should be carried out highlighting how cfls can reduce the electricity bills.
But what about those who steal electricity?
In such cases the government has to be innovative. It should supply at least one cfl to houses in slum areas free of cost. The resultant energy savings will more than compensate for the cost incurred in giving them free. A ballpark calculation shows that if one incandescent lamp of 60 Watts is replaced by a cfl by each of the nearly 3 million users in the capital, the savings could be about 120 mw -- quite substantial, considering that the peak load deficit in the city is about 900 mw. Similarly, replacing geysers with solar water heaters can reduce peak load by as much as 60 to 70 per cent.
What about airconditioners? They are said to be energy guzzlers....
All our airconditioned buildings and heated building are very energy expensive. Their annual energy consumption comes to around 400 Kilowatt/hr/per metre square per annum. In western countries this figure has been brought down to about 50 or 70 kw att-hr/m2. At present there is no policy mechanism in India that stipulates a maximum load for airconditioned buildings.
Some codes are enough to take care of these things?
It is a mixture of code and policy making. A lot can be achieved by effective information. For instance people can be informed that their electricity bills can be reduced, by using good quality windows, some sort of air cavity in the walls, some sort of insulation in buildings, and good doors. This can motivate many to use less airconditioning. On the other hand, architects and building designers should abide by a code that the overall heat transfer efficiency value of a building should not be more than one. At present it is two.
Can retrofitting improve matters?
Wattage cannot be improved in existing plants, what can be achieved is reduction in running energy. For instance, proper insulation can reduce airconditioning requirements of a building by 50 percent. So there is a need to educate people that if proper insulation is provided in the existing buildings, they will save on electricity bills. To begin with, these measures must be made mandatory for government buildings and public buildings managed by various government and public bodies.
Haven't they been carrying out such campaigns?
Yes, but it is certainly not enough. The middle class and rich sections of society and the government can do much more. It is also true that such campaigns bypass the poor sections of the society. A look at the electricity consumption patterns of the poor reveals that maximum load is being used for lighting. Also they use cheap and high energy inefficient incandescent lamps. The government has to take a conscious decision that a substantial portion of these would be replaced by cfls.
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