Improving Performance
Improving the performance of wind turbines is a key topic for the industry. When the performance is improved the cost of energy decreases and makes wind energy obviously more viable. In this issue of Windtech International we have several articles focusing on this topic from different perspectives.
{access view=!registered}Only logged in users can view the full text of the article.{/access}{access view=registered}Numerous studies have shown that wind turbine generator failure rates are unacceptably high, particularly given the long downtime incurred per failure. However, generator failures have, to date, received relatively little attention in the wind industry, with the focus mostly having been on the blades and the gearbox. There is evidence that the bearings are the most important source of generator failures; one important root cause of bearing failure is misalignment. In the article on page 7, Matthew Whittle gives an overview of publicly available wind turbine reliability data and describes the importance of drive train misalignment.
The article on page 20 written by Thomas Hahm from F2E Fluid & Energy Engineering focuses on optimisation of wind turbine spacing to improve the performance. When placing wind turbines too close together turbulence generated by the wakes of the wind turbines may seriously affect their structural integrity and so becomes a limiting factor in wind farm layouts. The article explains how and why turbulence intensity must be borne in mind during the design stage of creating a wind farm layout and gives an overview of the factors that must be considered in this process, the influencing parameters and the uncertainties.
Wind power engineering has tended to be a fairly conservative area of industry. Most current changes in the design and construction of rotor blades are brought about by new technologies and materials with higher strength characteristics. This ensures higher reliability and extends service life. Such things as the amount of energy that can be extracted from the wind flow as it moves through a defined swept area have remained more or less unchanged for many years. However, the Latvian company SIA Latekols claims to have found a way to substantially improve wind turbine performance with its ‘LEK’ vertical axis wind turbine (VAWT). On page 35 the author describes the design and development of this turbine.
Introducing large amounts of wind energy into the grid also requires new solutions to improve the reliability. Many governments are looking into the development of smart grids. A smart grid is a form of electricity network using digital technology. A smart grid delivers electricity from suppliers to consumers using two-way digital communications to control appliances at consumers’ homes; this could save energy, reduce costs and increase reliability. The ‘Smart Grid’ is envisioned to overlay the ordinary electrical grid with an information and net metering system, including smart meters. Korea has launched a national Smart Grid project to achieve green growth in a transparent, comprehensive, effective and efficient way. With these plans in mind, Korea has started building a Smart Grid Test-bed on Jeju Island to prove its determination to make the low-carbon, green-growth strategy succeed. On page 28 you can read about the ambitious goals of the Korean government.
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Floris Siteur
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