This research presents a seasonal classification of the operational parameters of a real network connection system of nominal power 3.0 kWp, installed at 3828 meters above sea level, in the renewable energy laboratory (EPIER-UNAJ) - Puno, whose objective is the HSP, the efficiency indicators, to visualize the influence of losses on the performance of the SFcR with string inverter. To achieve this objective, the data obtained from March 2019 to February 2020 is processed using the IEC 61724 approach, and then classified by seasons of the year. Likewise, a comparison is made with the manufacturer's reference data. With the results obtained, the proposed approach is validated to demonstrate that the SFcR with string inverter has been successfully supervised. The maximum HSP appeared in spring with 6.4kWh/m ^ 2 and an annual average value of 6.0kWh/m ^ 2, the maximum PR is 81.85% at the spring equinox which indicates that the system works well. There are average net output losses of 18.86%, Lc represents the operating losses of the array, the losses in the string inverter amount to 12% on average, and due to inclination and orientation are below 10%, the CF is 20.26%, which shows the great potential of solar radiation to take advantage of photovoltaic solar generation.