Comparison and Review of the Application of Deep Learning Models in Forecasting Electrical Energy Generation of Photovoltaic Systems with a Focus on LSTM and Hybrid Models

Document Type : Original Article

Authors
1 School of Energy Engineering and Sustainable Resources, Head of Soft Technologies Institute, College of Interdisciplinary Science and Technology, University of Tehran, Tehran, Iran
2 School of Energy Engineering and Sustainable Resources, College of Interdisciplinary Science and Technology, University of Tehran, Tehran, Iran
Abstract
Accurate solar energy generation forecasting is one of the main challenges in managing renewable energy systems due to the variable nature of solar radiation, dynamic weather conditions, and climate uncertainties. In this study, a comprehensive systematic review of 33 selected studies published between 2019 and 2025 was conducted to investigate the effectiveness of deep learning models in predicting solar energy generation. The main focus was on long-short-term memory (LSTM) networks and hybrid models, which have been widely used in recent years. The models were compared based on error evaluation indices including root mean square error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE). The results showed that hybrid models performed better in short-term forecasts, reducing the error by about 2.9%, while models equipped with attention mechanisms provided greater accuracy in medium- and long-term horizons. In addition, the use of multi-source data including local information, satellite imagery, and meteorological data improved the forecast accuracy by about 30%. Finally, the findings indicate a growing trend of using multi-level approaches, integrating diverse data, and making models smarter to improve reliability and sustainability in solar energy resource management.
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Articles in Press, Accepted Manuscript
Available Online from 02 May 2026

  • Receive Date 26 November 2025
  • Revise Date 07 January 2026
  • Accept Date 02 May 2026
  • First Publish Date 02 May 2026
  • Publish Date 02 May 2026