Cement, Energy and Environment

• DarWinD, a Dutch company has developed a 5 MW, direct drive turbine having a 15 m rotor diameter and a top head mass (nacelle + rotor) weighing only about 265 tonnes, making it a genuine lightweight in its category. • The American company Clipper Wind power has designed a 7.5-10 MW model featuring a 150 m rotor diameter in the UK. This is currently the largest horizontal axis wind turbine actually under development. • The North American company Pavilion Energy Resources has designed a wind turbine with a wind accelerator, which the company claims would generate "400 per cent more turbine power per dollar of capital that existing technology.'' Vertical axis wind turbines are the latest innovation in the offshore wind sector. These turbines score over conventional turbines since they can cope with higher wind speeds and are more robust due to their inherent design characteristics such as reduced life-cycle costs due to fewer moving parts. Following are some of the latest designs. • The 5-10 MW NOVA (Novel Offshore Vertical Axis) Aerogenerator developed by UK-based Wind Power Ltd is a pioneering venture which is in the feasibility study stage. It comprises a pair of V-shaped fixed angle composite rotor blades rotating around their central (vertical) axis. The company plans to have 1 GW of NOVA turbines, comprising 200 turbines of 5 MW capacity each, installed by 2014. • Another British company VertAx is developing a 10 MW offshore vertical axis turbine. The VertAx machine is based on a permanent magnet 'direct drive' technology which eliminates the need for gearboxes - seen as one of the most common causes of wind turbine downtime. According to the makers of the tu rbine, usage of light weight, low cost materials and fewer slower moving parts will enable the company to produce larger machines which experience less fatigue and a longer life cycle. Floating wind turbine is another novel concept to enter the offshore domain. The world's first floating turbine, the 2.3 MW Hywind, developed by StatoiiHydro of Norway is undergoing testing over a two– year period. It consists of a ballasted steel float, extending 100 m beneath the surface and fastened to the seabed by three anchor wires. The biggest advantage of floating turbines is that they can operate at sea depth between 120 and 700 metres, much deeper than conventional offshore turbines. Since winds are usually much stronger in deeper seas, greater power generation is possible. With innovations happening at such a stupendous pace, the offshore wind sector is poised to create a 'storm' in the future electricity mix. Courtesy: Green Energy, Vol. 5. Nov.- Dec. 2009. P11. 'POWER'FUL WINDS TO BLOW ASHORE THE MALDIVES Maldives plans to set up a massive 75 MW wind farm that would provide 40 per cent of the island nation's electricity needs– an important milestone for a country which aims to become carbon neutral by 2020 through the adoption of renewable energy sources. The 30-turbine wind farm would be located at Gaafaru Island near the capital Male, and will be connected to the capital's electricity grid via underwater cables. The project is expected to go online within the next two years, and would supply enough electricity to meet the needs of Male city, its international airport and 24 resorts. Surplus power will be used to run an energy-intensive desalination plant that will produce bottled water from the sea, while during lean periods, a 50 MW liquefied natural gas plant will supply back-up power. The wind farm would be built at a cost of $200 million and would reduce carbon emissions by 25 per cent. The archipelago is one of the lowest-lying nations in the world and is facing a severe threat of inundation resulting from nstng seas caused by climate change. Maldives recently drew international attention when it staged an underwater cabinet meeting to highlight its plight. Courtesy: Green Energy, Vol. 5, Nov. - Dec. 2009. P12. CLP INDIA TARGETS 450 MW WIND POWER BY 2010 CLP India, the wholly owned subsidiary of Hong Kong based China Light and Power company, is all set to further expand its presence in the wind power sector in the country. The company which at present has established more than 100 MW wind capacity is targeting 450 MW by July 2010, which would make it one of the leading wind power developers in the country. 56