Have wind turbines stopped maturing?

With all the work done so far on the design of wind generators and their widespread use throughout the world, it could be assumed that the technology has matured and all of the engineering decisions have been made. However, this is not the case. As knowledge has increased, more questions have been raised and complications are realized. Biggest determinant factor of wind turbine industry is the need in the market. The worlds cumulative installed capacity at the end of 1995 was approximately 5GW. This increased to 120GW in 2008. It is anticipated that this exponential growth will continue and be 287GW by the end of 2012. Back in 1995, the only challenges of wind were varying speed and intensity. The prefered wind turbine concept used for this task was the Squirrel cage induction generator (SCIG). Installations were typically dispersed single, small, and with the alternator working at fixed speed. Their popularity came from being robust, simple and low cost. The penetration of wind turbines in power systems at that time was not as significant, so the turbines could be switched off without detrimental effect to grid. Currently, the main trend of modern wind turbine design is clearly the use of variable speed operation. However, main design drivers for current wind technologies is machine capacity. As the demand for renewable resources ramps up wind farms come into the equation. These farms have different profiles throughout.Performance and site specific optimizations start to play an essential part. As the penetration grows grid compability and grid integration problems arises. Top turbine manufacturers are working on different technologies and concepts. Concepts which are borrowed from other fields or other applications have been merged into wind turbines current state of art concepts. Looking to the future according to the developments made by these top companies, it is expected that future concepts are based on more optimized and cost effective designs. Prices of power electronics will continue to play vital role on rate of growth of turbine capacity and size. Different companies are adressing the challange of conversion of varying speed into constant speed without use of power electronics and achieving it by means of total mechanical conversion. This is providing the opportunity to use of synchronous generators rather than DFIGs. Other companies are sticking and reinforcing to their DFIG concepts. As with all technologies, the future is diffucult to predict. However, one thing is for sure, the demand of renewable energy resources are growing exponentially and wind is an important element in any energy portfolio. Innovations will pursue market needs. Many concepts will be considered and even applied but the only ones that fulfill market expectations and demonstrate significant performance will survive.