Assessment of Hydropower Potential in Wastewater Systems and Application in a Lowland Country, Lithuania

This paper focuses on possible power generation by micro-hydro turbines integrated into lowland wastewater systems, which convert the potential energy of effluents in pipes into electric power. While other European countries have widely invested in this technology, Lithuania and other Baltic countries are still behind with their potential development rate. A search for potential micro-hydro sites was carried out, and a methodology for assessing water resources for an ungauged wastewater network is proposed herein. Particularities of wastewater flow patterns are briefly reviewed, and turbine operational constraints are analyzed. The hydro turbines available on the market to be installed in wastewater systems that meet lowland conditions are discussed. Available tools on the hydropower market to conduct a preliminary assessment of potential sites for urban water networks are considered. Multicriteria analysis is performed to select optimal projects by assessing the relevant economic, technical, and environmental criteria in water networks. The outcomes of this study can be used for unlocking the hydropower potential of wastewater systems in low-lying areas