Wind Turbulence Intensity at La Ventosa, Mexico: A Comparative Study with the IEC61400 Standards

C Lopez-Villalobos,Guillermo Hernandez-Cruz,R Campos-Amezcua,O Jaramillo,O Rodriguez-Hernandez,J Mendoza

doi:10.3390/en11113007

Abstract

Wind speed turbulence intensity is a crucial parameter in designing the structure of wind turbines. The IEC61400 considers the Normal Turbulence Model (NTM) as a reference for fatigue load calculations for small and large wind turbines. La Ventosa is a relevant region for the development of the wind power sector in Mexico. However, in the literature, there are no studies on this important parameter in this zone. Therefore, we present an analysis of the turbulence intensity to improve the understanding of local winds and contribute to the development of reliable technical solutions. In this work, we experimentally estimate the turbulence intensity of the region and the wind shear exponent in terms of atmospheric stability to analyze the relation of these design parameters with the recommended standard for large and small wind turbines. The results showed that the atmosphere is strongly convective and stable in most of the eleven months studied. The turbulence intensity analysis showed that for a range of wind speeds between 2 and 24 m/s, some values of the variable measured were greater than those recommended by the standard, which corresponds to 388 hours of turbulence intensity being underestimated. This may lead to fatigue loads and cause structural damage to the technologies installed in the zone if they were not designed to operate in these wind speed conditions.

Highlights

This work presented a characterization of turbulence intensity for small and large wind turbine applications for an open terrain located at La Ventosa, Oaxaca, Mexico, by means of data measured using two ultrasonic anemometers installed at two different heights and Light Detection and Ranging (LIDAR) technology
It was observed that the atmosphere is strongly convective and stable most of the time during the measurement period
The prediction data were in accordance with the data measured with the LIDAR, despite the predicted turbulence intensity being high for lower velocities

Summary

Introduction

In Mexico, the installed wind power generation capacity is close to 4 GW, with wind-generated electricity of 1976 GWh, corresponding to about 4% of the country’s generation [1]. The state of Oaxaca, the Isthmus of Tehuantepec region, has around 63% of the total installed capacity of the country [2]. This region has a wind potential greater than 40 GW, considering only the highest wind potential areas; the wind potential is about 6 GW [3]

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