The Energy Research Centre of the Netherlands (ECN) says its Active Wake Control system is capable of increasing the electricity production of wind farms by 0.5% to 5%. Additionally, ECN expects that maintenance costs could be reduced by 3%.
According to the research center, ECN has tested the technology on five wind turbines at its wind farm test site. The center's Haico van der Heijden says, ‘The next step is a large wind farm, preferably offshore. That is not a place where you want to experiment, which is why we have waited until the technique had proven itself.’
Through optimal positioning of the wind turbines, ECN says the patented system reduces the wake effects of turbulence. In a perfect line position, turbines produce 100% power but also take a 100% load on axes and blades. When placed behind each other, the upstream turbine still produces 100%, but the capacity of the downstream turbines is reduced to 60% or 50%. Further, ECN says wake effects caused by turbulence increase their load to 110% or 115%, and maintenance costs rise proportionally.
By changing the pitch angle and/or the yaw angle of the front turbine a few degrees, ECN says the turbulence is deflected/altered, thus reducing the load and increasing the power production of downstream turbines.