A 10 kWp grid connected photovoltaic (PV) system was installed in the framework of the PV Enlargement Project in the Godollo Campus of the Szent Istvan University, Hungary. The main features of the system and the installed data logging system with the type of sensors and the monitored signals are introduced in the paper. During the measurements different meteorological data are measured so the incoming power (energy) to the total system can be determined. As the produced energy is measured by different methods as well, the efficiency can be determined for each used PV technology. Not only the produced DC power, but the AC power is measured continually and from these data the inverter efficiency can be determined. Beside the efficiency analysis the energy production of the system is analyzed, too. For this purpose the comparison between the system operational data and the data of the preliminary modeling are used.