Evaluation of actual PV modules performance at low insolation conditions

In the paper the results of analysis of some data gathered by three independent Data Acquisition Systems, during prolonged outdoor testing of several commercial photovoltaic modules (PV modules) working in Solar Lab of Wroclaw University of Technology and University of Opole, are presented and discussed. The effects of solar radiation intensity, ambient temperature, and even wind rate and direction on the actual performance of standard silicon solar cells based PV modules. are shown. Special emphasis has been put on potentially cumulated electric charge and energy generated by the modules in different ambient conditions rather than on standard parameters measured. Effect of single-axis sun-tracking is demonstrated showing that in poor insolation conditions using of such systems may be nonbeneficial.