On 1 January 2015 the Federal Energy Efficiency Act came into force and Austria has set itself the objective to reduce the consumption of end-use energy, cut greenhouse gas emissions as well as increase the share of renewable energy sources in the energy mix. The growing integration of renewables poses new challenges to present energy systems. The supply of volatile regenerative energies, like wind and solar power, is subject to considerable temporal fluctuation. This causes major differences between energy supply and demand at certain time periods, which require the inclusion of compensation technologies like storages or load transfer methods. The storage capacity of the electrical grid, in which renewables primarily feed in, is limited. The connection of energy networks of different energy carriers can increase the storage capacity of the overall system. In order to achieve a better integration and efficient use of the available energy, considering exergy is important. Exergy is the part of the energy that can be transformed in any other form of energy. Hence, exergy is a quality feature which can be used to compare energy carriers. This is important, as the demand for energy has various levels of quality and a proper usage of exergy can reduce energy losses. The aim of this master’s thesis is to add an exergetic evaluation to an existing optimization tool for multi-energy systems to determine the exergetic optimum of the system. An essential part of this thesis is the integration of non-dispatchable renewable energy sources and the exergetic usage of excess energy. First of all, existing modelling and optimization frameworks, with a freely accessible source code, get investigated and validated. Appropriate optimization models consist of consumers, regenerative and conventional energy sources, storages and conversion technologies, which connect the different grids. After the selection of a suitable software tool, different supply scenarios are defined and the operation of the exergetic optimization is analyzed. By using real data for energy demand and supply different supply systems of the city Leoben are compared. On the one hand, the actual photovoltaic performance is considered and, on the other hand, the change in the system when utilizing the full pv-potential.