This study proposes general and specific modeling and simulation for Lorentz LA30-12S photovoltaic panel. This panel has monocrystalline cell technology. The panel power parameters are examined under observing different panel temperatures. It is created a special function for this system by Matlab/Simulink programmer. Also, the different solar radiation values are taken into account. The model for the proposed range of irradiance and temperature as model inputs, with the corresponding values of voltages, currents, and power as outputs is presented. Simulation results are compared by doing power calculations. The simulation results show that a photovoltaic panel output power reduces as module temperature increases. This situation is showed with Matlab/Simulink graphics. Ill. 13, bibl. 24, tabl. 1 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.109.3.166