Seasonal quality factor; 60 kWp PV system at north Mexico City

In the Research Center (CINVESTAV), located north Mexico City was evaluated 60 kWp photovoltaic (PV) system. The PV system energy performance ratio, so called “quality factor” are reported together with the measured solar irradiation, ambient and PV module temperatures. Quality factor defines the overall system performance with respect to the energy production, solar resource, and total effect of system losses. The electric grid-tied PV system consists of 240 PV modules of 250 Wp each, which are connected to 5 inverters to produce three phase AC. We describe the general PV system quality factor in a month basis for 2013. In spite of the different seasonal weather conditions and some inverter trouble, the calculated average quality factor was 91.75%. The averaged daily PV generated energy throughout the year was 258.9 kWh/day. The accumulated total generated energy during the year was 94,427.7 kWh. However, instead of using solar irradiance sensor at the array tilt angle, and taking in consideration the horizontal global irradiation, the quality factor reduces drastically to 83.56%.