Analysis of the effect of an obstacle on the wind energy potential

Abstract

Assessment of the wind energy potential for a given site requires a primitive evaluation of wind speed for a specified period of time. Wind speed distribution depends on the type of air flow in the atmospheric boundary layer and varies as function of the altitude and the site topography. It is also affected by the presence of obstacles, the curvature radius of obstacle, the roughness of the ground and temperature. In this study, circular motion of the atmosphere that is induced by the existence of an obstacle having the form of a hill is investigated by using a 2D model. The hill profile was approximated by a half-ellipse curve. Computational fluid dynamics (CFD) was performed for the turbulent air flow modelled by the Navier-Stokes equations coupled with the K-ϵ turbulence model. To solve the equations, COMSOL software that is based on the finite element method was used. The obtained results were compared to those of a flat ground without obstacles. A noticeable modification of the available wind energy resulted for a wind turbine which is placed downwards of a hill like obstacle.