Polynomial regression approach with ridge regularization for forecasting wind and solar energy in Dhaka City

This study proposes a polynomial regression model with Ridge regularization for forecasting the combined renewable energy generation (solar and wind) in Dhaka City. The model was developed using over a decade of meteorological data (2014–2023), capturing non-linear interactions among key predictors such as temperature, wind speed, and solar irradiance. Data preprocessing included normalization and outlier handling. Model performance was evaluated using standard metrics—mean squared error (MSE), mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination (R 2 )—with 80/20 train-test splitting and 05-fold cross-validation ensuring generalizability. The Ridge-regularized model achieved an R 2 of 0.99 on the test data, with very low normalized error values (MSE ≈ 2.42 × 10 −8 , MAE ≈ 7.59 × 10 −5 ), corresponding to an RMSE of approximately 1.55 × 10 −4 . While these error values are small due to normalization, the R 2 score provides a robust, scale-independent measure of performance. The high accuracy is supported by the strong correlations among features and the model’s ability to generalize effectively across cross-validation folds. By integrating wind and solar forecasting under a unified framework and applying Ridge regularization to manage multicollinearity, this work offers a reliable and interpretable approach for renewable energy planning in rapidly urbanizing regions.