Solar radiation in Serbia is for about a third higher than in Middle Europe, which represents a very favorable energy potential. Southeast Serbia is a leading area in this aspect, since the annual average of daily global radiation on a horizontal surface exceeds 4.2 kWh/m2. This paper compares four photovoltaic power plants installed in southeastern Serbia. Analyzes are done based on results from two years of power plant exploitation. The power plants are not located in the same area – there are differences between topography and altitude of their locations, which is also taken into account during analyzes. Photovoltaic modules have different orientation and inclination toward horizontal surface, and their capacity varies from 30-40 kW. The conclusion provides recommendations for improvement of production where it is actually possible.