German wind start-up Evoblade has developed a retrofittable spoiler for rotor blades, working with Deutsche Windtechnik and Wirtschaftsforderung Bremen.
The results of a side-by-side study of testing and optimising the EvoFlap have confirmed that installing the spoiler can improve the aerodynamic flow in the area of the blade root, resulting in improved efficiency and performance of wind turbine rotor blades.
The results of the side-by-side study confirmed a 6% increase in annual energy production that had been predicted using simulated data, with an average annual wind speed of seven metres per second.
Evoblade CEO and founder Frank Kortenstedde said: “Rotor blades have a significant impact on the technical and economic performance of a wind turbine.
“By developing and optimising a retrofittable flow element, we wanted to achieve a technical and economic improvement in the properties of existing systems that leverages the advances in technical understanding.”
The EvoFlap can be adapted to different rotor blade types.
The NEG Micon NM 82 turbine type with a rated output of 1.5MW and a rotor blade length of 40 metres was selected as the basic system for the testing and optimisation.
Kortenstedde added: “The blade does not have to be removed from the hub to allow EvoFlap to be installed, and this reduces the amount of work and costs.
“Also, the blade structure is not damaged by gluing the segments onto it, and the EvoFlap blends harmoniously with the blade design.”
“Depending on the useful life of the EvoFlap, a possible extension of 1.2 to 2.6 years beyond the maximum service life of 20 years can be achieved,” Kortenstedde said.