Tuesday, July 24, 2012


Wind mills are offering a feasible option in the search of sustainable energy sources and already a significant part of global energy produced comes from this sector. However high cost of investment, unbearable noise generation and bird-unfriendly features are still hampering its progress in spite of its pollution free clean credentials. With cheap wind mill systems coming from China considerable boost has been received recently with many countries going ahead in this area aiming to shift a significant part of their energy grid from fossil fuel generation to wind generated energy. It is universally agreed that wind energy can spare the planet pollution to the extent of 1500 tons of CO2, 6.5 tons of SO2, 3.2 tons of NO2 and 27 kg of Mercury spewed out into the atmosphere when fossil fuels are used to generate 1 MW energy. No wonder that more than 65 million MW of energy is produced using wind mills, of which almost 45% is accounted for by Europe though other countries are catching up fast. Though wind mills were known for almost 2000 years, significant development in designing better and more efficient wind power generating systems has taken place after 1970 due to the fossil fuel shock which saw the price of crude oil literally hitting the roof. Most of to day's wind mills are of horizontal axis type but there have been references to vertical axis type also which some how did not seem to have found favor with the energy industry. Now comes the news that commercial scale vertical axis machines are being offered with some superior features. Here is a peep into this new development. 

"Designing and building the new McCamley vertical axis wind turbine took decades, but it may have been well worth it, as the company believes their innovative design could revolutionize urban wind power. The McCamley MT01 Mk2 is designed to be easy to install, without any need for a tower, on urban rooftops, and is claimed to be able to operate with minimal noise and vibration and be able to self-start (no grid power input) at low wind speeds. The McCamley turbine was specifically designed to work in the variable and turbulent winds typically found in the city, and because it can continue to operate in extremely strong winds, may be able to harvest energy from a wider range of wind conditions than other designs.The lightweight turbine is mounted on multiple legs, cutting down on vibration and stress on the roof, and the rotor design is said to be "bird and bat friendly". The Mk2 self-starts in winds as low as 1.8 meters/second, and a self-regulating speed system allows the turbine to continue to operate efficiently in gusting and turbulent winds by keeping the rotor at a consistent speed. The turbine's direct-drive design also eliminates the need for a gear box, simplifying the maintenance or repair of the units". 

One of the good features of the above variant is that it is much less noise polluting and more easy to be installed and maintained. One of the inconveniences of the present generation windmills is the irritating noise generated by the rotating turbine blades which can be extremely annoying to residents nearby. According to the manufacturers of vertical mills the noise generation is not an issue at all with their system. Similarly wind mills are known killers of birds and according to statistics more than 20 to 30 thousand birds are killed every year due to their crossing the path of the turbine blade but vertical wind mills are not as lethal when it comes to bird fatality. If all these claims are true vertical axis wind mills may become very popular especially for small sized power generation with relatively low investment. Countries like India which has thousands of miles of coastal lines, vertical wind mills can make a big difference, especially during summer time when acute power cuts are common due to perennial shortage.  


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