Evaluation of the wind shear at a site in the north-west of the Yucatan peninsula, Mexico

Extrapolations from 10m above the ground up to the wind turbine hub height are frequently made to the data available for wind power assessments. Because of its simplicity, the power law profile has been one of the most popular mathematical formulations to predict the vertical wind shear. This paper presents an analysis of wind speed and wind shear in terms of the directional, diurnal and seasonal patterns for a site at the Autonomous University of Yucatan which experiences the tropical conditions of the Yucatan Peninsula in Mexico. This analysis takes a detailed look at frequency distributions to facilitate a comprehensive understanding of the local climatic conditions. Diurnal wind speed variations are shown to be affected in particular by the differing wind conditions associated with fetches over two distinct offshore regions. Seasonal behaviour suggests some departure from the oscillations expected from temperature variation. In addition, the use of rate of change of temperature at one height is proposed as an alternative to vertical temperature gradient inferred from two heights as an indicator of atmospheric stability which will affect the wind shear. The work presented is part of a regionally funded research program to evaluate the onshore and offshore wind potential in the north of the Yucatan Peninsula.