The effects of blade pitch angle on the performance of small-scale wind turbine in urban environments

Abstract

Due to the growing importance of wind power as a clean and renewable energy source, the use of small-scale wind turbines in urban environments has increased lately. The blade pitch control is an effective method to improve the aerodynamic response of a wind turbine, usually applied to large-scale wind turbines. This study presents the effects of varied blade pitch on the aerodynamic performance of a small-size wind turbine. The blades were sketched out according to the Blade Element Moment (BEM) theory, applying the aerodynamic profile NREL-S809 and designed for a tip speed ratio of eight. To analyze the influence of the blade pitch angle on the energy conversion, a comparative study was carried out varying the pitch angle to five different values. Using the analysis of variance (ANOVA), it was possible to demonstrate that blade pitch control could be an effective method also for small-sized wind turbines. A performance chart from the results of blade pitch experiments shows that the power coefficient varies significantly when the angle changes. As conclusion, it is highlighted that an enhanced behavior could be attained by the use of a pitch angle controller resulting in a better recovery of the energy available in the wind.