Spatial and Temporal Wind Speed Variability: Case Study of Wolaita Sodo and Areka Area, Ethiopia

Abstract

Study was conducted to assess spatial variability of wind speed for two sites (Areka and Sodo) and short- term wind speed variability for Areka site. The required wind speed data was obtained from Areka agricultural research center Meteorology station and Hawassa Meteorological Service Agency (AMSA.The collected data was analyzed by using MATLAB software. The five months primary data measured during day time at one hour interval was from Areka station for short-term temporal wind speed variability, as a result, short – term wind speed data indicates that increased pressure gradient causes greater wind speeds in the afternoons compared to early morning hours and evenings. Only during the early morning hours and evening, the wind speeds were less than average value and the deviations were lower than the remaining time.  For spatial variability, five year wind speed data were obtained for Areka and Sodo sites and the two were compared. The data were analyzed using statistical analyses. Comparison of daytime measurement of five data points with 12 data points gave identical average wind speed distribution. Accordingly, when it comes to the statistical averaging there is no significant difference between the two since the two values were within statistical error from each other. Therefore; it is fair to assume there is no difference between the two. No significant spatial variability was obtained between Dubbo and Sodo sites. The study revealed that the areas have no abundant wind potential to produce energy. This is partly attributed to the level at which wind speed measurement was taken, 2 m, instead of the recommended 10 m height.  Therefore, these particular sites are not ideal for grid connected applications.

Keywords: Wind speed, Wind data, and pressure gradien