Advantages of split blade design in wind turbines
Europe has set ambitious targets for boosting energy production from renewable energy sources by the year 2010. Unfortunately, adoption of renewable energy solutions has been slow across the continent. Wind farms have been implemented along Europe's northern and Scandinavian coastline with success, but the mountainous regions of Southern Europe remain relatively unexploited. The MEGAWIND project was undertaken in order to address the special requirements for wind turbines in such areas. During MEGAWIND, mechanical engineers from the University of Patras in Greece designed and tested a new 30-meter wind turbine blade. The Greek engineers went beyond conventional blade design and created the first-ever megawatt scale split blade. The advantage of the split blade design is that more energy can be generated, especially in high winds. In order to overcome the additional stresses, the blade was reinforced with carbon fabric in critical areas. During the project an algorithm was invented to optimise blade characteristics, such as blade area and thickness, in order to maximise Annual Energy Capture (AEC). AEC is a measure of the total electricity that can be generated by the system over a period of one year. The algorithm was used to analyse nearly 200 blade types. A full-scale model was tested during MEGAWIND according to international standards defined by the International Electrotechnical Commission (e.g. IEC 61400-23). Measurements on system components like joints provided insight into fatigue and expected lifetime issues. Additional advantages of the new design are that manufacturing time and costs as well as transportation costs are reduced. The modularity of the system makes on-site assembly feasible in remote, mountainous regions and also serves to lower maintenance costs. It is expected that these benefits will help drive the uptake of wind energy in these areas.
