CHARACTERISATION AND ESTIMATION OF THE WIND ENERGY POTENTIAL OF THE TOWN OF MELFI IN CHAD

This study characterised and estimated the wind energy potential of the town of Melfi in the Guera province of central Chad, situated at 11.06° north latitude and 17.93° east longitude at an altitude of 416 m. The data consisted of an hourly time series of wind speed and direction observed at 10 m above ground level over six years, from August 2020 to August 2026, comprising 52,536 valid data points. Monthly wind roses were produced to characterise the distribution of wind directions and intensities throughout the year. The quadratic mean method was chosen to calculate the average wind speed at the site, as it is more representative of the energy content of the wind than the simple arithmetic mean. Three independent methods were compared to extrapolate wind speed to heights of 50, 100 and 150 m: the variable-exponent power law of Justus and Mikhail, the logarithmic roughness law and the fixed-exponent power law of Hellmann. The annual wind speed was 3.50 m/s at 10 m above ground level and ranged from 4.9 to 7.1 m/s at heights of 100 to 150 m, depending on the method used. Of the three methods, that of Justus and Mikhail overestimated wind speed the most. The wind power density, calculated at 10, 50, 100 and 150 m, placed the site in Class 1 (low) at 10 and 50 m and in Class 2 at 100 and 150 m on an annual basis, with more favourable potential during the dry season.