Ridge regression ensemble of machine learning models applied to solar and wind forecasting in Brazil and Spain

•Use of four machine learning models to forecast wind and solar resources.•Implementation of ensemble learning method based on ridge regression.•Application and validation in two locations (Brazil and Spain).•Proposed method achieved significant reduction in errors compared to individual predictors. In recent years, with the rapid development of wind and solar power generation, some problems arise gradually and are often inherent to intermittency. Currently, one of the essential methods to solve these problems is the application of forecasting methodologies. Our article proposes an ensemble learning method based on crest regression (penalized L2) which integrates consolidated wind and solar forecasting methodologies applied to two locations with different latitudes and climatic profiles. From the simulations carried out, the methodology is efficient to improve the predictions performance of isolated methods and applicable to different locations around the world. For solar data from Brazil and Spain, the ensemble model achieves MAPE values of 14.191% and 11.261%, respectively; for the same data, the best model applied individually (CFBP) shows a higher MAPE of 24.207% and 12.465%, respectively. For wind data from Brazil and Spain, the ensemble model has a MAPE of 3.927% and 5.491%, respectively. The best model applied individually to Brazilian wind data is CFBP, with MAPE of 9.345%. For the Spanish data, the best individual model is MLP, with MAPE of 7.186%. The ensemble modeling reduces the forecast errors and can be useful in optimizing the planning for the use of intermittent solar and wind resources in the electrical matrices.