The diploma thesis deals with the possibilities of reducing energy consumption or the use of energy generated during the wastewater treatment process in the Waste Water Treatment Plant in Liptovský Mikuláš. The aim is to design efficient energy solutions for the use of sludge gas, waste heat and stabilized dewatered sludge. The thesis describes the process of wastewater treatment and technology, which can effectively increase the utilization of individual types of energy. The practical part of the thesis consists of an overview of the current state of energy use and the possibility of reducing the consumption of electricity. It discusses ways of using biogas with the main focus on electricity generation or heat production for drying dewatered sludge. At the same time it deals with the use of waste heat from the wastewater treatment process. Part of the thesis are proposals for the installation of technologies that would make the operation of the wastewater treatment plant in Liptovský Mikuláš more efficient from the energy point of view.