This study investigates the impact of selecting an optimal panel-to-inverter capacity ratio on the electricity generation of photovoltaic (PV) power plants. To quantify the influence of this ratio on monthly energy yield across different climatic regions, PVsyst simulation software was employed. The energy output was assessed for five different ratios ranging from 0.90 to 1.14 across 100 locations throughout Iran. The percentage change in electricity production closely mirrors the percentage change in panel capacity, although this relationship varies by month and climate. Generally, for the months of May, June, July, and August, the variability in output across the studied locations is minimal. The predicted ranges of energy output variation due to changes in the panel-to-inverter capacity ratio are as follows: 1) For a ratio of 0.90 , the output change ranges from −11.81% to −11.64% (mean: −11.76%). 2) For a ratio of 0.96, the range is −5.91% to −5.77% (mean: −5.87%). 3) For a ratio of 1.08 , the output increase ranges from +5.32% to +5.90% (mean: +5.77%). 4) For a ratio of 1.14 , the output increase is between +10.12% and +11.78% (mean: +11.27%). Furthermore, if the increase in capital investment per percentage increase in panel capacity remains within the range of 90.5% to 100.3% and 86.1% to 100.2% for ratios of 1.08 and 1.14 respectively, the increase in the panel-to-inverter ratio would be considered economically justified. Among the scenarios analyzed, a ratio of 1.08 demonstrates the highest economic feasibility.