Design of Interacting Small Hydropower Systems in Water Distribution Networks under the Consideration of Demand Uncertainties and Rehabilitation Measures

In this work, interacting small hydro power systems (SHPS) within a water distribution system with over capacities are investigated. Therefore, an excess water turbine (Pelton turbine–PT) is installed at the end of a supply zone, downstream of a pump as a turbine (PAT) which reduces the pressure for that supply zone. Different sizes of PT cause different flows and therefore also impact the energy production of the PAT. In addition, upcoming rehabilitation measure of the pipe feeding the PAT provides the chance to consider different rehabilitation strategies. The savings and additional costs for smaller or bigger pipe diameters also in combination with the consequential different feasible SHPS device sizes are analyzed. It was found that considering the interactions of the SHPS leads to an efficient overall solution, while the savings due to installing smaller diameter are more beneficial than less friction losses in a larger but more expensive pipe. Further, it is found that the impact of future demand scenarios (increase and decrease) is in relation to the sensitivities from costs assumptions insignificant.