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Wind energy: An alternative source

  1. Wind energy: An alternative source
  2. Pakistan and rain-fed agriculture

wind turbines is a much cheaper, reliable and maintenance-free

By Syed M. Aslam
Apr 24 - 30, 2000

The importance of developing alternative energy source for a power-deficient country like Pakistan can hardly be over-emphasised. The two traditional methods of generating energy, hydel and thermal, involves massive capital costs and to numerous other disadvantages for a developing country like Pakistan.

For instance, hydel generation is heavily dependent on levels of water reservoirs at Mangla and Tarbela, the two major dams built specifically for the purpose of power generation. The silting has further eroded the generation capacity at these dams. Though the thermal power projects costs comparatively less than the hydel projects they use furnace oil the prices of which remains highly volatile in the international market to bleed the national economy in high cost of imports.

Pakistan's recent experience with the Independent Power Producers (IPPs) show that purchasing power from the IPPs can not only be highly unaffordable but could also mean a lot of trouble, as the ongoing litigation between WAPDA (Water and Development Authority) and foreign-financed Hub Power Company shows.

This makes it all the more important to look for home-grown solutions for energy generation. While much has been written about solar energy, another viable, reliable and comparatively less expensive source of energy, the wind energy, has failed to draw the attention which it rightfully deserves. Before highlighting the merit of wind as an alternative energy source we would first trace its history to see it is indeed suitable for Pakistan.

The history of harnessing the wind energy dates back to 17th century when the Dutch started using the wind mills for flour mills and wood cutting. The usage was diversified in the 18th century when wind mills were used for water pumping which also became much popular in America. However, using the wind energy to generate power started in 1940.

At the time, the blades of wind turbines were made of wood which were attached to generator through a gear box. However, it took another 33 years for the wind turbines to become popular in the West in 1973 when the oil-rich Arabs slapped an oil embargo which paralysed the industrial West. The wind turbine today has become so popular in the Western world , particularly the US, that many cities as well villages are getting their electricity.

This has also resulted in induction of latest technology to increase the workings and power of the wind turbines. The technologically advanced wind turbines of today are capable of producing as high as 2 mega watt and everything in between from 50 kilowatt to 500 kilowatt and more. The precision-designed blades are made of corrosion-free fibre to convert even a low wind draft to generate the energy. The small wind turbines ranging from 1 kilowatt to 20 kilowatt are also available for small households is particularly useful to help supply energy to those rural and far-reaching areas which can not be supplied energy through costly network of traditional poll mounted power supply infrastructure. It can also be of immense use for the benefit of people in the urban areas experiencing frequent power-shortage.

Talking to PAGE Azhar Ayub, a wind energy researcher and developer, said that wind turbines is a much cheaper, reliable and maintenance-free source of energy than the solar energy. It costs much less to install wind turbine than a similar power solar panel, the wind energy is more reliable as unlike sun which shines only during the day the wind never stops blowing anytime. Similarly, once installed the maintenance cost on the wind turbine is negligible comprising small oiling every month or so and distilled water for the batteries. No other alternative energy source, including solar energy, matches the inherent advantages of wind energy.

Secondly, he added, the climatical and geographical conditions in Pakistan are ideal for wind energy. An average wind speed of 13 knots across the 560 mile Pakistani coastline across 90 miles inland in the south and the mountainous terrain in the north provides ideal location for the installation of all sizes of wind turbines which can be used for domestic, commercial of small-scale industrial use for the overall benefit of the economy. Viewed in the backdrop of billions of rupee loss in industrial output due to power shortage in a country where the bulk of commercial and industrial activities are in the small and medium sector and where informal sector far exceeds the formal sector, harnessing the wind energy as an alternative cheap source of energy offers numerous benefits, he added.

The small wind turbines of 100 watt to 20 kilowatt is ideal for domestic use, small factory. The power is supplied through the inverter which is connected to the maintenance-free batteries which work for five years. These small wind turbines are ideal for rural and far-flung areas which remain outside the reach of pole-mounted infrastructure. The cost of a 300 watt system inclusive of 4-8 batteries and one kilowatt inverter to generate and store one kilowatt energy translates about Rs 55,000 and is enough to meet the power needs of a small household to run 4 fans, 4 tubelights, a television and a fridge.

The big turbines of 50 kW to 2 mw can be directly connected to an already working grid, such as the ones the WAPDA and Karachi Electric Supply Corporation have. Usually these big turbines are installed in a row in an area where wind is strong and blows continuously. They are commonly used in Holland, Denmark, Germany, Spain, UK and the US. The city of San Francisco, California is supplied power by these big wind turbines, Azhar added.