Comparative Study of Energy Yield in PV Systems Using Different Module Technologies and Inverter Configurations

The rapid development of photovoltaic (PV) technology has led to a broad variety of products in both the module and inverter markets, raising questions about long-term reliability and real-world performance. While new cell technologies such as TOPCon, SHJ, and IBC promise higher efficiency, recent field reports indicate higher degradation rates than expected, which could impact warranty stability and market confidence. Likewise, inverter configurations ranging from classical string inverters to optimizers and microinverters introduce trade-offs between compliance with grid regulations, system scalability, and final energy yield. Within the Horizon 2020 project Aurora, five new PV power plants were installed within the renewable energy community at the Faculty of Electrical Engineering, University of Ljubljana, to evaluate performance of different inverter types and cell technologies under real operating conditions. Five new systems consist mostly of TOPCon modules alongside smaller strings of PERC, SHJ, and IBC technologies. Energy production data from February to August 2025 were analysed with a digital twin approach, combining pyranometer and temperature measurements with pvlib Python library based irradiance and thermal modelling. Performance evaluation relied on temperature-corrected AC performance ratio and energy yield for PV power plants, and on DC performance ratio for PV modules. Shading was identified and removed from the dataset to ensure comparability. Results show that the new PV plants achieve shading and temperature corrected power ratio values between 0.85 and 0.9, while the 15-year-old reference power plant displayed expected degradation. String inverters performed best under unshaded conditions, optimizers were ~1% lower, and microinverters ~3% lower. Module-level comparison revealed similar performance across technologies, with IBC showing slightly reduced summer values. Initial degradation trends were not yet evident. Overall, the study highlights the importance of shading correction, accurate thermal modelling, and multi-technology benchmarking for objective PV system evaluation.