Hydropower plants are today subjected to more frequent transient operating conditions due to the increased use of intermittent energy production sources, such as solar and wind. The changes arise from the need to regulate the power input to the electrical grid, posing questions on the reliability of the self-lubricated bearings used in hydropower applications. Aiming to study the effects of the transient conditions on wear and lifetime of these bearings, modelling and simulation have been employed to systematically investigate how different parameters influence the sliding contact. A simplified model developed using COMSOL Multiphysics 5.3 and LiveLink™ for MATLAB® of polymer composite bearing materials and stainless steel counter surface is presented and evaluated under different tribological conditions in terms of properties such as pressure, sliding speed, temperature and wear. Roughness of real surfaces is measured by white light interferometry and integrated in the model. Experimental results on the influence of important parameters on the behavior of such bearings are also presented, not only to validate the model, but also to provide input data to the simulation. The results of this study show that the simulation model can be used to identify critical operating conditions for self-lubricating bearings used in hydropower applications.