N. Ramakrishnan

Among the non-conventional sources of power, wind seems to be the best bet, and is the biggest success story in renewable energy. Though still an insignificant contributor to the overall power demand, wind may soon become the fastest growing source in India, as is happening elsewhere in the world. N. Ramakrishnan surveys the Indian scene.

FROM his first floor office on Chennai's Old Mahabalipuram Road, the city's information technology highway, Mr Ramesh Kymal, Managing Director, NEG-Micon (India) Pvt Ltd, points to a windsock flapping in the wind on a building across the road. "It is always horizontal," he says to make his point about the wind potential in Chennai. "We have got a wind mast up there (on the terrace). We are studying the wind," he replies when one wonders if it would be possible to put up a wind turbine in his factory at Sholinganallur, about 20 km from the city-centre.

It is this potential in what would appear an unlikely place like Chennai and the advances in wind turbine technology that give Mr Kymal and his company, which is a major manufacturer of wind turbines, the confidence that the country's wind power capacity can be as high as 100,000 MW, more than double the accepted estimate of45,000 MW.

With better turbines, the plant load factor has also improved to 30-35 per cent now (from 12 per cent a few years ago), with some machines even managing 44 per cent. That is, for an installed capacity of 45,000 MW the generation would be 9000 MW, at an average PLF of even 20 per cent.

There are, he admits, no studies to substantiate his statement, but Mr Kymal is confident that advances in technology have made it possible to generate more electricity from the same wind speeds than earlier.

Differing estimates

But the Planning Commission is not quite so optimistic. In its recent Mid-Term Appraisal of the Tenth Plan, the Planning Commission notes: "There is a lack of clarity on the economically exploitable wind resource potential for wind power generation.

The earlier estimated potential of 20,000 MW has been scaled up to 45,000 MW. The Ministry of Non-Conventional Energy Sources (MNES) has estimated that the exploitable technical potential is limited at only 13,000 MW due to limited power evacuation capacity of the grid... ."

Elsewhere too, opinions are divided on wind power potential. Mr U. B. Reddy, General Manager (Business Development), Enercon India Ltd, another leading wind turbine manufacturer, thinks that 100,000 MW is an over-estimation, but does not agree with the MNES figure of 13,000 MW either. He puts the technical potential closer to 45,000 MW. His argument is that all Grade-A sites — where the full potential of wind can be harvested to generate electricity — have already been exploited.

Officials of Suzlon Energy Ltd, on the other hand, think that the potential can be 15-20 per cent more than the MNES estimates (See Graphic: Wind Power Potential).

Mr Sarvesh Kumar, Chief Operating Officer, Vestas RRB India Ltd, shares Mr Kymal's confidence that the gross potential is definitely higher than the Ministry's figure, but tempers his estimate at 65,000 MW.

NEG-Micon, Suzlon and Vestas RRB as also Mr K. Kasturi Rangaian, Vice-Chairman, Indian Wind Power Association, a representative body of those who have installed wind turbines, all emphasise that the turbines available now are far more efficient than those made even three-four years ago. They also embed a lot more electronics that enable the blades to adjust to the wind speeds and generate more electricity. Also, new sites are coming up.

Improving technology

Mr Kymal, who is also chairman of the Indian Wind Turbine Manufacturers Association, points out that the installed capacity in Tamil Nadu alone will be about 3,000 MW by the end of this financial year, whereas its technical potential has been estimated at 1,750 MW.

Technology is improving, and what were once second and third grade sites, are becoming first grade sites now because manufacturers have tweaked the machines to operate at those levels of wind speeds. There have indeed been considerable developments in the turbines. Almost all leading global manufacturers and some home-grown manufacturers too offer turbines with capacities ranging from 250 kW to 2 MW, with Suzlon Energy installing the first 2 MW turbine in Tirunelveli last year.

While NEG-Micon and Suzlon offer turbines of 1.65 MW and 2 MW capacities respectively, the others are in the sub-1 MW capacity. Internationally, manufacturers have gone up to 5 MW capacity turbines and are also erecting them in the sea. Mr Kymal feels that the situation in India does not warrant manufacturers going offshore. According to him, the ocean bed is far too deep to lay the foundation for the turbine towers.

In Europe, the depth ranges from 25metres to 30 metres. Also, he says, the country is yet to tap many of the on-shore sites. More important, the best winds are east of the Western Ghats, through the Aralvoimozhi and Palakkad passes, between Tamil Nadu and Kerala.

Most parts of the country experience good winds from May to October. In the Tirunelveli region alone, there are two wind seasons — May to October and November to March, with the wind speeds higher during the first period. In Muppandal in south Tamil Nadu, the wind speeds exceed 12-13 metres a second (43.2-46.8 km an hour) during the peak period, while the annual average is 6-7 metres a second (21.6-25.2 km an hour). Thanks to advances in technology, India now occupies the fifth place — behind Germany, the US, Spain and Denmark — in total installed capacity.

Evacuation problem

Yet, the share of wind energy in India's total power generation capacity is minuscule, at slightly over 2 per cent. This is mainly a problem of the grid infrastructure. Every one is agreed that the major constraint to harnessing the full wind potential is the inability of the grid to evacuate the power generated by the turbines.

This is a problem because wind farms — large tracts of land on which stand colonies of turbines with a total capacity of, say, 300 MW — are as of now located in remote areas, with limited local power demand. Thus, the electricity generated has to be transmitted over long distances to load centres, which are typically in urban and semi-urban areas. Transmission over long distances at low voltages will result in higher technical losses.

This problem threatens to discourage wind turbine installation. For instance, in some parts of Tamil Nadu, wind turbines have been asked to shut 8-10 hours a day because of the utility's inability to evacuate power. And this is happening during the peak wind generating season. But to overcome this problem, the Tamil Nadu Electricity Board, has been encouraging the turbine manufacturers to set up sub-stations.

A part of the evacuation problem can also be traced to a rapid rise in the installed capacity — by about 1,100 MW, a 45 per cent growth, in 2004-05 to 3,595 MW from 2,483 MW a year earlier (See Table: State-wise wind power installed capacity). This was largely because of more States tweaking policies to facilitate capacity addition (See Table: States' policies on wind power in bottom story).

Indeed, the returns are so attractive that a number of companies have invested in wind power not just for their captive requirement but also as an investment.

Some high net worth individuals too have done this . But most often it is the power-intensive industries, such as textiles (which also get the benefit of an interest subsidy under the Textile Upgradation Fund Scheme) and cement that have invested in wind power (See Story: A back-up and an investment).

Policy support

The Electricity Act, 2003 says specifically that the State Electricity Regulatory Commissions must promote the renewable energy sector by, among other measures, stipulating that a distribution licencee should purchase a percentage of the total requirement of electricity from renewable sources. Three State regulatory commissions — of Andhra Pradesh, Madhya Pradesh and Maharashtra — have set a minimum percentage required to be procured by the utility.

In Tamil Nadu, the purchase price of Rs 2.70 a unit for wind power has not been revised for more than five years. The industry wants around Rs 3.20 which, it says, will help raise capacity addition. Andhra Pradesh, according to industry experts, has only set the price at which the utility will buy wind power, but not the minimum percentage. Even this price, effective from 2004, is valid for five years, whereas it takes at least seven years to recover the investment.

As the regulatory commission has not specified the minimum percentage of power that has to be purchased from renewable sources, APTRANSCO, the transmission utility, is not signing power purchase agreements, according to the experts.

A criticism against wind power is its high capital cost and its limited reliability in effective grid management. The capital cost of setting up one MW of wind power capacity ranges from Rs 4.5 crore to Rs 5 crore (including the price of the land, the turbine, installation, evacuation and the sub-station ) against Rs 4-4.5 crore for a MW of thermal power. While the cost may not appear substantially different, the amount of power generated is significantly so; an average PLF of 20-25 per cent for wind against 75-80 per cent for thermal.

But what wind power has going for it is that it is fuel-cost free, whereas for conventional modes, this component keeps rising continuously. Then there is the cost of tackling pollution; again, wind power scores here.

The cost factor

Mr Kymal argues that when talking of wind power, it is not quite appropriate to look at the per MW cost. Instead, he suggests the per unit cost of electricity generated (see interview). According to him, taking the life-cycle cost of a wind turbine, the cost over its 20-year life-cycle will work out to Rs 1.10-1.15 a kWh. In the initial years, when the loans have to be repaid, the cost per unit will be higher.

With most State electricity boards allowing owners of wind turbines to bank the electricity generated, they can use an equivalent quantity of power from the grid within the financial year — utilities find it tough to manage the grid. That is, in lean months, the grid will have to buy costlier power to meet the requirement of all those who have banked their wind power. A point against wind power is the fall in the number of units fed into the grid in 2004-05 when the installed capacity rose. But Mr Kymal says that drop — about 20 per cent — was unusual; the normal is a 5-6 per cent variation.

Those associated with the sector feel that a lot more needs to be done. Says Mr M. K. Deb, Managing Director of the Bhopal-based Consolidated Energy Consultants Ltd, involved in renewable energy sources and mainly wind power: "Electricity regulatory commissions should declare the purchase price which would ensure both bankability and profitability of the project."

Apart from viewing wind power as an infrastructure sector, Mr Deb says that setting up a central body to facilitate validation, approval and trading carbon credit on behalf of small investors also needs to be looked into.

How much is one MW?

AT AN average plant load factor of 30 per cent, 1 MW of wind power generates 26.28 lakh units of electricity in a year. This is enough to meet the power requirements of about 6,410 persons at a per capita energy consumption rate of 410 units. In contrast, a 1 MW thermal plant generates, at the national average PLF of 72 per cent, 63.07 lakh units which can meet the requirements of 15,380 persons.

Graphics by K. Balakrishnan

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