## 5 Conclusions  
From the presented results it is a clear well-known fact that the tilt angle and azimuth angle have significant influence on the total energy balance of the PV system. The research also confirmed that is very important to know the optimal tilt angle and azimuth angle orientation for the area in which the PV system is installed. The first benefit of presented research is a simplified mathematical model for energy production expressed through the time relations for tilt angle and azimuth angle which contains a very small number of input parameters which are easily identifiable to ordinary users of PV system. The results of the  
Figure 16: Flowchart of the prepared application for smart devices.  
research presented in the manuscript are localized to the area of Southern Slovakia, but the general forms of model equations are applicable to the area of Central Europe respectively for areas with similar climatic conditions. For a detailed prediction of energy production in certain areas, a modification of regression equation coefficients and differential equations can be applied. The second benefit is that the model can be described by the simple polynomial function of the second degree. Since the model equations were created on the basis of data processing from long-term monitoring of the operating parameters of the PV system, the resulting model, although not based on data obtained by satellite measurements, gives results better corresponding to the real energy production of the PV system at the site. The third benefit is that the mentioned mathematical model gives about 4% more accurate results than models used so far for the locality of southern Slovakia. Experimental methods, numerical simulation, and data analysis find that the effect of PV module tilt angle on the amount of electricity generated by the PV power plant is about 18%. The ideal tilt angle for southern Slovakia region is 34.5\({}^{\circ}\). The effect of azimuth angle changes on the PV system energy production is 24.19% during the year. Maximum energy production was achieved in the selected locality at azimuth angle from the range (\(-\)20-15\({}^{\circ}\)). All obtained results are a part of final mathematical model for simulation of PV system power and energy balance. This model created the platform for development of application for smart devices. Presented results allow a simple prediction of the energy production of a PV power plant installed in real operating conditions and they can be used in practice for the design, dimensioning, and optimization of PV power plants in the southern Slovakia.  
Conceptualization, M.B. ([PERSON]) and M.B. ([PERSON]); methodology, M.B. ([PERSON]) and M.B. ([PERSON]); software, M.B. ([PERSON]) and V.M.; validation, M.B. ([PERSON]), M.B. ([PERSON]) and V.M.; formal analysis, M.B. ([PERSON]) and V.M.; investigation, M.B. ([PERSON]), M.B. ([PERSON]) and I.K.; resources, M.B. ([PERSON]) and T.S.; data curation, M.B. ([PERSON]), M.B. ([PERSON]), I.K., V.M., and V.C.; writing--original draft preparation, M.B. ([PERSON]) and M.B. ([PERSON]), V.C. and V.M.; writing--review and editing, L.K. and V.C.; visualization, M.B. ([PERSON]) and V.M.; supervision, M.B. ([PERSON]), V.C., I.K. and J.L.; project administration, M.B. ([PERSON]) and T.S.; funding acquisition, M.B. ([PERSON]) and T.S. All authors have read and agreed to the published version of the manuscript. This publication was funded by the Grant Agency Slovak University of Agriculture (GA SPU), grant number No 03-GASPU-2021. No applicable. No applicable. The data presented in this study are available in the main text of this document. The authors declare no conflict of interest.