Experimental Validation and Performance Benchmarking of a Grid-Connected Rooftop Photovoltaic System Using Measured and Simulated Data

This study presents a performance and techno-economic evaluation of a 24 kWp grid-connected rooftop photovoltaic system in Yeşilova, Burdur, Türkiye, based on measured operational data from 2024. Beyond conventional software comparisons, this research establishes a validated benchmarking protocol for medium-scale rooftop PV systems by quantifying the divergence between measured data and predictive modeling under fluctuating seasonal conditions. Measured results were compared with energy yield predictions from PVsyst and HelioScope. Key performance indicators, including final yield, performance ratio (PR), and capacity factor, were evaluated alongside main loss components. The system produced an annual energy output of 33,977.5 kWh, corresponding to an average PR of 75.7% and a capacity factor of 16.99%. Simulation results show deviations from measured values, with PVsyst moderately overestimating and HelioScope underestimating the annual yield. Thermal effects were identified as the dominant contributor to performance losses, particularly during elevated summer temperatures. A techno-economic assessment indicates a payback period of 8.4 years, a levelized cost of electricity (LCOE) of 0.0485 US$/kWh, and an internal rate of return (IRR) of 15.58%. These findings underline the importance of validating simulation-based assessments with site-specific measurements to improve the reliability of photovoltaic system performance and investment evaluations.