A novel solar radiation forecasting model based on time series imaging and bidirectional long short-term memory network

The instability of solar energy is the biggest challenge to its successful integration with modern power grids, and accurate prediction of long-term solar radiation can effectively solve this problem. In this study, we proposed a novel long-term solar radiation prediction model based on time series imaging and bidirectional long short-term memory network. First, inspired by the computer vision algorithm, the recursive graph algorithm is used to transform the one-dimensional time series into two-dimensional images, and then convolutional neural network is used to extract the features from the images, thus, the deeper features in the original solar radiation data can be mined. Second, to solve the problem of low accuracy of long-term solar radiation prediction, a hybrid model BiLSTM-Transformer is used to predict long-term solar radiation. The hybrid prediction model can capture the long-term dependencies, thereby further improving the accuracy of the prediction model. The experimental results show that the hybrid model proposed in this study is superior to other single models and hybrid models in long-term solar radiation prediction accuracy. The accuracy and stability of the hybrid model are verified by many tests.