This Master Thesis deals with the topic Energy Efficiency in Underground Gas Storage Facilities in three ways. •Finding facilities or processes where energy is not used in the most efficient way. •Finding possibilities to produce energy within the UGS facility. •Finding applications of the ideas developed in this thesis also outside the underground gas storage application. The first part is done by questioning the need of pressures and temperatures used in the processes and facilities during injection, withdrawal and facility stop. This results in various options to safe energy in all forms. These options are audited on their economical and engineering feasibilities. The second part is done by analysing various options of energy production in theory, concerning practical issues and finally economically. These options are expansion, photovoltaic, and the usage of exhaust heat. The third part is done by finding aspects with simular or related surroundings outside the underground gas storage facility and comparing it with the possible application within the storage facility. Furthermore it is analysed how the energy gained could be used within and outside the facility and how the ideas of this Master Thesis can be integrated in future UGS projects and projects of production processes in general. Additionally to ideas which could be realized immediately, some ideas will become interesting in the future, when energy prices will rise and the awareness of environmental problems and the room for approvement will increase. For promising processes the economical sense was proved. This was done by the net present value method.