Wind Resource and Energy Potential Assessment in Ten Nigerian Cities Based on a Modified Bimodal Mixture Weibull Probability Density Function

The potential for wind resources in Nigeria is spatially heterogeneous and strongly controlled by seasonal circulation, terrain exposure, surface roughness, elevation, and coastal and inland atmospheric forcing. This study assessed wind speed distributions and energy potential in Bauchi, Calabar, Ilorin, Jos, Kaduna, Kano, Maiduguri, Nsukka, Owerri, and Uyo using the Modified Bimodal Mixture Weibull probability density function. Twenty-one years of average monthly wind speed data measured at 10 m above ground level were obtained, cleaned for missing values, negative and non-numeric entries, and fitted independently for each site. The model couples two Weibull components via a logistic transition function, allowing a smooth representation of low and high-speed regimes, skewness, bimodality, and energy-relevant upper and tail behaviour. Parameters were estimated using maximum likelihood, while model adequacy was evaluated using AIC, BIC, RMSE, the Chi-square test, the Kolmogorov-Smirnov test, and Monte Carlo validation. Results revealed substantial inter-site variability. Calabar recorded the highest mean wind speed of 5.8906 m/s, followed by Kaduna, Maiduguri, Uyo, and Kano, whereas Jos had the weakest mean speed of 3.3269 m/s. The fitted model reproduced empirical PDF and CDF structures with generally low RMSE and K-S values. Kaduna showed the strongest fit. Energy estimates projected Kaduna as the leading site, with an annual energy density of 1218.0897 kWh m−2 yr−1 and wind power density of 139.3836 W/m2, followed by Calabar, Maiduguri, and Uyo. The findings indicate that the Modified Bimodal Mixture Weibull PDF provides a reliable framework for city-level wind resource classification and renewable energy planning in Nigeria.