Why is the SYSWIND network needed?
The International Energy Agency estimates that, in order to meet scientists’ current target for carbon emissions to be halved by 2050, some 17 % of all worldwide electricity generation will need to come from wind. The average annual increase in generated wind energy was about 29% as compared to the annual increase of 3.5% for the total electrical energy consumption (between 1996-2006). Wind energy accounts for approximately 19% of electricity production in Denmark, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland (2007 data). Globally, wind power generation increased more than fivefold between 2000 and 2007. Hence, there is large amount of investment in R&D in this sector in the EU, requiring highly trained human resources. The next generation turbines with capacities as large as 5MW are being constructed consisting of tower heights and rotor diameters of over 80m and 120m respectively. These turbines have the capability of generating approximately 17GWh of power a year. With the 5MW units and even the possibility of higher capacity (7.5 MW) technology in the future, the promise to produce power at competitive prices, particularly at offshore wind farms, becomes a reality.
However, associated with the enormous prospect of development in the generation of wind power, arise certain critical issues. With the increased size and flexibility of the tower and blades, structural vibrations are becoming a limiting factor in the design of even larger and more powerful machines. Blades manufactured with composite materials may experience damage and delamination and thus need critical monitoring. Further, limitation on the tip speed of the blade due to noise generation puts a cap on the energy capture from the available wind energy. In addition, vibration control of the offshore wind turbines poses a serious challenge to further development of such machines including foundation and geotechnical aspects (foundations contribute to 25-30% of the total cost of a wind turbine). Conventional problems related to power generation systems, like gear box vibrations, electro-mechanical coupling and vibration safety of power electronic converters become more critical for wind turbines where instabilities in the response complicate the situation with (i) blade-tower coupling and (ii) aeroelastic effects. These may have an impact on the generation of power and the reliability of the power system with related economic effects.