Even when a wind farm is in operation, there is still something that can be done to improve its productivity: the installation of extensions on the rotor blades of the wind turbines.
Energiekontor has analyzed the production on its own wind farms and realized that some of them were not producing as expected. Thus, in 2009, fk-wind, from the Hochschule Bremerhaven, designed a prototype of a blade extension that consists of a blade tip segment, fixed at the tip of the blade. The system was certified by DEWI / OCC in 2012.
Since November 2009, Energiekontor is operating an extension prototype on a Bonus, Type 54 turbine, in Germany. During the observation period, a 5 to 6% Annual Energy Production (AEP) increase output was observed.
In 2011, Energiekontor requested a new prototype design to fk-wind, for a Bonus type 62 turbine. That prototype was installed in 2014, at wind farm Penedo Ruivo in Portugal. An output improvement of 6 to 7% was observed.
RBE or Rotor Blade Extension applies to wind farms that are not producing as expected on project phase. In that phase, there was an expectation for a certain annual average wind speed which did not occur. The wind turbine was chosen according to initial expectations. That means the WTG (Wind Turbine Generator) has a load reserve that was not being used and can be accessed by installing RBE.
It has been proven that RBE extra loads on the machine are all within the parameters defined for its classification according to IEC, so the lifetime of the modified turbines is not affected.
Regarding the main purpose of these prototypes, Energiekontor had a confirmed result of an improvement of 5 to 6% AEP, for the modified wind turbine type Bonus 54 and an improvement of 6 to 7% for the modified wind turbine type Bonus 62.
For similar turbines and similar sites the method described will be a solution for the improvement of the wind farms. Earlier mistakes in planning and energy prediction can be corrected. More turbines types, in similar wind farms, will be investigated and equipped with an extension in the future. Furthermore the hysteresis of switching between the two modes of operation will be optimized. This can additionally reduce fatigue loads by minimizing the number of switching events.
Learn more about the advantages of Rotor Blade Extension installation in wind farms already in operation at: www.rotorbladeextension.com/advantages-blade-extension.
For the full article and more from RBE: https://goo.gl/JNIjgn