||Our aim is to show a complex picture of energy system modelling with a focus on partial equilibrium energy models and on specific conditions in the Czech Republic. We describe the basic characteristics of the Czech electric system. Then we discuss the advantages and drawbacks of partial model and introduce a few energy models used in Europe and in the world. Furthermore we discuss the key parameters of partial equilibrium models and energy system development. In the end, we construct a model of the Czech electric system in the MESSAGE model and analyze the possible future development of the Czech electric system on four scenarios.