The topic of the dissertation is the evaluation of Enhanced Geothermal Systems (EGS). The focus is on the development of a concept, a methodology and finally the evaluation model that aims to promote a greater penetration of geothermal energy as one of the renewable energy sources by supporting various interested parties in this field. As a prerequisite for the development of methodology and model, this thesis identifies and describes in detail the most important influencing factors that should be considered when analysing and evaluating geothermal projects. These factors are divided into several categories: technical, economic, social and environmental factors. In addition, the methodology presented in this thesis incorporates the concept of multi-criteria decision making (MCDM), which accurately reflects the possibility of supporting interested investors in comparing different locations and ways of exploiting geothermal energy and ultimately making the optimal investment decision. In the last part of the dissertation, this methodology was implemented in an evaluation model, which was also the basis for the developed decision support tool in MATLAB software. With the help of this evaluation model, it is possible to choose the best location and the best method for the utilization of geothermal energy on the one hand and the best integration of the EGS project into the electricity system and/or the district heating system on the other hand. The achieved scientific contributions of the research presented in this dissertation are: 1. Method for standardized evaluation of influencing criteria related to investments in enhanced geothermal system energy projects, 2. An integrated weighting and ranking multi-criteria decision-making methodology for the evaluation and comparison of different options for the transformation of geothermal energy into electricity and heat and 3. Model for the evaluation and comparison of different geothermal sites, regarding electricity and heat production, based on multi-criteria decision-making.