This study is devoted to the research of spatial-temporal variation of electricity generation from the kilowatt-peak photovoltaic system made of crystalline silicon solar cells. The research was conducted in the territory of Serbia using the model for estimation photovoltaic performances as a function of incident irradiance and module temperature. Preparation of input data and calculation of the final results was done within the geographical information system. Some of the required raster data, like solar irradiance and wind speed, were already available, while air temperature raster was created from discrete set of observed data using the regression-kriging model. Obtained results were presented in the form of raster maps that enabled further analysis and discussion about new findings. The analysis of seasonal variations reveals that during spring and summer months photovoltaic systems are producing up to 70% of total annual electricity yield. In terms of the spatial distribution, the most promising areas for electricity generation are located in the south part of Serbia and along main river valleys. In addition, discussion part addresses the issue of data imperfection caused by the accuracy of the selected model, as well as quality and availability of data series.