Abstract In this work, the study, modeling and simulation of custom designed geothermal power plant production processes are presented. A model based on the thermodynamical steam power cycles theory is developed using directed graphs, in order to consider different types of geothermal power plant structural models to be studied. The model includes steady state forms of the thermodynamical mass and energy conservation laws for each one of the considered equipments, in order to study the mass and energy interactions among them. A computational implementation of the IAPWS-IF97 formulation for the calculation, also by steady state forms, of the physical properties of the water is also presented, thus providing a reliable and accurate method to calculate them in execution time. The analysis of both topological and thermodynamical feasibility of the proposed input models is also presented, as well as the analysis of the efficiency in terms of both generated and invested heat and power. The results are compared against reference results in the literature; these are presented in relation to the proposed models, by reporting the variations of the mentioned water properties and by stating the results of the production processes in terms of both mechanical power generation, and efficiency of the proposed structural models.