Performance Evaluation of Grid-Connected Photovoltaic System Under Climatic Conditions of Isthmus of Tehuantepec

This article assesses the use of solar photovoltaic radiation as a renewable resource for a region of the Isthmus of Tehuantepec in Mexico, where a 163.2 kW grid-connected photovoltaic system is located. The study aims to understand the system’s performance under the specific location conditions and to demonstrate the feasibility of installing photovoltaic systems in the Isthmus region. System monitoring was conducted for one year, with monthly and daily averages of normalized performance parameters determined. A three-month study of the power quality was conducted to assess compliance with interconnection and power quality requirements for power plants with a rated power Pn ≤ 500 kW. Results show higher energy production in the spring–summer months (138.946 MWh) than in autumn–winter (136.500 MWh), while the best overall performance occurred in autumn–winter (PR = 85% vs. 79.5% in spring–summer), probably due to cooler photovoltaic module temperatures. The final yield and PR indicate stable and predictable operation, even without maintenance, with PR = 82.3%. This supports the feasibility of photovoltaic installations in the southwestern region of Mexico. The present work is particularly relevant as it advances understanding of photovoltaic performance in understudied regions with substantial solar potential, such as the Isthmus of Tehuantepec, where policy prioritizes wind resource exploitation over solar energy.