Day-ahead seasonal solar radiation prediction, combining VMD and STACK algorithms

Abstract

Abstract This article proposes a method for accurately predicting solar irradiance over a 24-hour horizon to forecast photovoltaic energy generation in a positive-energy building. In order to make this prediction, the input data are divided into seasons and preprocessed using the variational mode decomposition (seasonal-VMD) method. The VMD method is used for extracting high-bandwidth features from the input data, decomposing them into a finite number of smooth modes and focusing on specific frequency ranges. Hence, the accuracy of signal extraction using the VMD method can be improved by selecting particular parameters judiciously, which impacts the smoothing and frequency concentration of the extracted signal. In this regard, the salp swarm algorithm (SSA) is employed to identify the optimal VMD parameters that can be used to enhance extraction accuracy. In addition, the obtained residual between the observed solar irradiation data and their decomposed modes is treated to enhance the prediction process. A stacking algorithm (STACK) is used to predict the following 24-hour solar irradiance modes and the residual, which are finally summed to reconstruct the desired signal. The performances of the proposed prediction method are evaluated using two quantitative evaluation indices: the normalized root mean square percentage error (NRMSPE) and normalized mean absolute percentage error (NMAPE). The proposed model is trained on data collected for three years in Rabat (2019–22). The performance of the proposed model is evaluated by predicting the 24-hour solar irradiance for a different season. The proposed approach seasonal-VMD-STACK is compared with two other methods in the case of using VMD-based STACK without season partition and STACK method only. Moreover, the proposed method has exhibited stability and proven good results with an NRMSPE of 3.87% and an NMAPE of 1.58% for cloudy days during the test phase. The results demonstrate that residual preprocessing, seasonal input data partition and appropriate selection of VMD parameters improve the performance and accuracy of the prediction.