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TECHNOLOGY Scope of small wind turbines in India With proper study and appropriate technology that suits the Indian conditions, small wind turbines can make a difference in how we use energy in the future Wind power has emerged as the biggest renewable energy source in the world. So far wind turbines of total combined capacity of 25,000 MW have been installed in the world. Germany is the largest and India the 4th largest producer of wind power in the world. Government of India has estimated the potential of 45,000 MW of wind power throughout the country. So far about 2,500 MW capacity of wind power has been installed. All this power is obtained through big wind turbines from 250 kWh to 1,250 kWh capacity. The modern trend to make bigger wind turbines and 2 MW wind turbine has become very common in Europe and soon 5 MW capacity wind turbines are likely to be produced. Government of India also promotes big wind turbines and does not seem to recognize the potential of small wind turbines. In fact, there is a huge potential for small wind turbines in India. As per my own estimate, roughly 100,000 MW power can be produced in India from only small wind turbines of up to 10 kWh. There are bright prospects to establish about 50 million small wind turbines from 500W to 10 kWh capacity. Though such a huge possibility exists, but unfortunately small wind turbines are neglected by Government of India. Land holdings are small and there are about 100 million small farmers in India. A lot of manufacturing is also through tiny and small industries consuming less than 10 kWh power. So there is a possibility of installing small wind turbine in every farm and every small factory where ever there is sufficient wind. Therefore, millions of small wind turbines can be installed in small farms of India making farmers self reliant in electricity for their own use. If small wind turbines are promoted in India, every farmer can supply excess power to the grid and thus power shortage can be avoided. Such excess power may even be sent to the cities and big thermal power stations may not be required. Government of India spends about 6 crores (60 million) rupees for installing 1 MW capacity of electricity generator. This is equivalent to Rs. 60,000 per kWh or roughly 1,100 Euro per kWh. Big wind turbines are available at the cost of Euro 1,000 per kWh of installed capacity. But in Europe, small wind turbines are installed at the cost of Euro 2,000 per kWh. This cost can be substantially decreased in India. As per my estimate, small wind turbines can be cheaper than big wind turbines on the basis of per kWh cost. If systematic efforts are made, it is possible to reduce the cost of small wind turbines up to Euro 500 per kWh i.e. half of big wind turbines. As per my estimate, it is possible to reduce it up to Euro 300 (Rs. 16,000 to 18,000 per kWh). This means that investment in small wind turbines on per kWh basis will be only 1/3 of investment of big wind turbines. Thus, small wind turbines may be viable and India can become biggest supplier of small wind turbines in the world. Unfortunately, there is total vacuum of wind turbine technology in India. There is little awareness about the advantages of wind energy. There is no course in India for wind energy at any university, engineering college and polytechnic or even at ITI level. If Government recognizes the importance of small wind turbines, there should be degree and diploma courses and also short term certificate courses on wind energy technology in every university to every ITI. The Government should encourage for publication of technology books relating to wind energy in all the regional languages. Then technology can spread to grass root level and technicians will start understanding and manufacturing small wind turbines. Government has already passed Electricity Act 2003 in favor of renewable energy and distributed generation. But it is not implemented in practice so far. It is essential to give permission to connect small wind turbines with grid power. If this is done at the government level, in one or two decades, India will become number one in the world in wind energy production and that also only through small wind turbines producing roughly 100,000 MW of electricity. If Government permits grid connection to small wind turbines, then simple induction motors can be used as generators. Thus, small wind turbine will become extremely cheap and strongly viable compared to big wind turbines. In addition the electricity cost will be far cheaper than those of thermal power stations. So it is evident that small wind turbines have so much potential that they may replace big thermal power stations. Even if the Government does not encourage this activity of small wind turbines, above possibility can be realized through peoples’ initiative alone. Technology of small wind turbine is not very difficult. Stand alone wind turbine is rather complicated than grid connected system. But electronics can help.
Highly developed industrial infrastructure to manufacture towers, blades, wind rotors and also electronic controllers already exists in India. In few years, various types of electronic controllers will be devised to control all the parameters of stand alone small wind turbines. The generators for wind energy are basically of 3 different types. Radial flux permanent magnet generator is converted from induction motors which are cheaply available in India. Technology of axial flux permanent magnet generator is completely unknown in India at present. But it is very simple technology and a complete manual is available to produce axial flux permanent magnet generator. However, both these types of generators require neodymium magnets, which are not manufactured in India and have to be imported and thus are costlier. But if tiny electro magnet generators are developed, it will become very cheap. Similarly, small auto alternator technology is going to play vital role in drastically cutting the cost of small wind turbine. As India is a developing country, small and simple technology will better suit the conditions. Cloth sails wind rotors and tube and wire type blades are more suitable to Indian condition to reduce the cost of wind turbines. Most scientific air foil sections of blades are made from wood in Europe which last up to 20 years. Scientific wooden blades can be made in India at the least cost. Similarly wooden towers also will be cheaper and suitable for small wind turbines. I feel that very cheap small wind turbines can be a reality in India in few years. The only constraint is lack of knowledge. Hugh Piggott’s small book Windpower Workshop is one of the best practical books to understand wind turbine technology in short. But many such cheap books should be written and published in Hindi and regional languages. Then only this technology can spread up to village technicians. It may not be too presumptuous to conclude that after about 20 years, electricity could flow in grid lines in reverse direction i.e. from villages to city through distributed generation only by solar, by wind, by bio mass and such renewable means. Small wind turbines up to 10 kWh capacity may become cheap and hence strongly viable. Solar cells could be produced on screen printing technology by women in every home in 20 years time. Solar thermal electricity generation may become a feasible option and could be produced in every village. So it is my basic conviction that electricity will be surplus in India in 20 years time and it will be cheapest in the world.
Courtesy: V.K. Desai, Managing Director |
