The article discusses the principle of operation of a combined heat and power plant. Aspects of diversifi cation are commented. The principle of operation of heat exchangers used in combined heat and power plants is discussed, as well as a daily analysis of changes taking place in the exchangers. The paper presents the method of analysis based on parametric models. In the discussed research, the ARX model was used with the use of MATLAB tools. The entered data allowed to obtain comparative ARX models presented in the charts. Paper starts from the exemplary data set description, through the other suitable data set, then the formulation of resulting simulation function, and it fi nalizes in the presentation of real data graph in the comparison to simulating function graph. Conclusions are described in the aspect of diff erent levels of energy generation diversifi cation. An increase in energy demand in the evening and night hours has been noticed. The obtained models are adequate with each other, which confi rms that the data has been correctly entered into the application. Through this simulation better energy safety can be provided and positive social impact with ecological goals can be reached.