Optimization of the tilt angle was performed for various locations in European countries including Turkey [18; 19], Romania [20], Austria and Germany [21], Italy [22], Greece [16], Cyprus [23], Spain [24]. For Middle Eastern countries such as Oman [25], United Arab Emirates [8], Saudi Arabia [26; 27], Egypt [28], Jordan [29; 30], and Syria [31]. For Asian Countries, such as Pakistan [32], Thailand [33], Indonesia [34], China [35; 36], Taiwan [37], India [38; 39], Japan [40], and Bangladesh [41]. For the American continent, such as in Canada [11; 42] and the United States of America [43; 44; 45], all mentioned studies point to the fact that the tilt angle and azimuth angle change has significant influence on the amount of solar energy absorbed by the surface of the PV modules and so on PV system energy balance. Location of the PV system is very important because of different external operating conditions at the various points on the earth's surface. From the theoretical point of view there exist mathematical models and methods of calculation for comparison of the best tilt angles of solar modules through monthly diffused radiation and actual monthly diffused radiations [46]. The operational parameters of PV module were modeled and discussed in literature [47]. The key formula for getting the PV system energy production is described in [48]. The connection between the energy production and energy consumption in irrigation networks was investigated by [49]. Very important for prediction of PV system energy production is knowledge about the reasons of power losses, which were described in the article [50]. From the practical point of view, the optimal technique to enhance the tilt angle and orientation is solar trackers [51; 52]. The active sun trackers follow the path of the Sun, and they optimize the position of the solar module. Tracking systems are used to maximize daily solar energy received by photovoltaic modules [53]. Solar trackers consist of mechanical components that ensure the rotation of the solar module and therefore one of the solar tracker disadvantages is the failure of their mechanical parts and more demanding maintenance than in the case of static solar panels. Trackers are slightly more expensive, need energy for operation, and they are not always applicable because of specific installation conditions. The information provided above was the reason for further focusing on the research and formulating its goal. The main aim of this research was the creation of the simplified mathematical model. The basis for creating the model was experimental data. The simplified model contains a minimum number of input parameters. It allows the calculation of the energy amount produced by the photovoltaic system in the region of South Slovakia during the calendar year. The model should be easy to use in practice. Due to the applicability of the model equations, it contains only parameters that are easily identifiable in practice for the users. Within the results, the influence of the azimuth angle and the tilt angle on the electrical output of PV system per month was assessed. The created model will be also a part of the application for smart devices which can be used for photovoltaic systems dimensioning. The results of implemented study are valid for Nitra region.