Empirical Performance Comparison of PV System With and Without Optimizer

This study aims to empirically analyze the impact of optimizer application on photovoltaic (PV) energy yield under identical environmental conditions. The analysis was conducted using a 400kW Phase 2 demonstration facility installed at the Renewable Energy-Linked ESS Safety Evaluation Center. Comparative experiments were performed by configuring optimizer-applied systems (6-1, 7-1) and non-applied systems (6-2, 7-2) using the same module manufacturers (Manufacturer A and B). The test systems were based on four 50kW inverters, with series-parallel configurations reflecting real-world installations. Energy yield was compared based on the cumulative MPPT-level output under equivalent irradiance conditions. In addition, time-series current data and string-level mismatch characteristics were examined. The findings of this study provide empirical evidence on the effectiveness of optimizers, serving as a foundational reference for PV system designers considering their application.