Analysis of Artificial Neural Networks for Forecasting Photovoltaic Energy Generation with Solar Irradiance

HIGHLIGHTS

The input GHI variable increased the prediction accuracy of the ANN models in 10%.

The meteorological variables do not influence the prediction errors statistically.

ANNs with 10 neurons demonstrated lower accuracy than those with 30 and 60 neurons.

ANNs with one hidden layer showed similar or higher accuracy than those with two layers.

Abstract

The growth in the use of solar energy has encouraged the development of techniques for short-term prediction of solar photovoltaic energy generation (PSPEG). Machine learning with Artificial Neural Networks (ANNs) is the most widely used technique to solve this problem. However, comparative studies of these networks with distinct structural configurations, input parameters and prediction horizon, have not been observed in the literature. In this context, the aim of this study is to evaluate the prediction accuracy of the Global Horizontal Irradiance (GHI), which is often used in the PSPEG, generated by ANN models with different construction structures, sets of input meteorological variables and in three short-term prediction horizons, considering a unique database. The analyses were performed with controlled environment and experimental configuration. The results suggest that ANNs using the input GHI variable provide better accuracy (approximately 10%), and their absence increases error variability. No significant difference (p>0.05) was identified in the prediction error models trained with distinct meteorological input data sets. The prediction errors were similar for the same ANN model in the different prediction horizons, and ANNs with 30 and 60 neurons with one hidden layer demonstrated similar or higher accuracy than those with two hidden layers.

Keywords:
forecasting solar power generation; artificial neural network; global horizontal irradiance