In this paper, a model has been developed for determining the heat characteristics of a solar thermal collector made of polymers as part of optimization and prototype making. Work has been carried out in several phases. At the beginning, a review of literature related to the current development of polymer collectors is presented. In the first stage, an analytical model of a classic plate solar collector was developed. For the verification of the analytical model, the test results used by the Laboratory for Heat and Heat Equipment were used. As part of the first phase, the impact of structural, operating and optical properties on the efficiency of the collector is also shown. The analytical model was developed using the Matlab program package. In the second phase, a numerical model was developed for determining the thermal characteristics of a classical plate solar collector. The numerical model is verified by means of analytical model and experimental data. The Fluent software package was used for the simulation of heat transfer inside the collector. Based on the experience gained from the first and second phases, in a third phase model has been developed to determine the thermal characteristics of a solar thermal collector made of polymers. Based on the results obtained by the numerical simulations of the polymer collector, guidelines have been provided for further improvement of the numerical model itself and hence the improvement of the thermal characteristics of the polymer collector.