Hydropower energy recovery in irrigation networks: Validation of a methodology for flow prediction and pump as turbine selection

In recent years, pump-as-turbines (PATs) have been highlighted for their potential benefits as an application of micro-hydropower (MHP) in water distribution networks. However, PATs come with disadvantages of relatively low peak efficiencies, which can be reduced further with large flow fluctuations. MHP and PATs in particular applied in irrigation networks is a relatively new area of research focus for these devices, and one that poses significant opportunities for energy saving as well as significant challenges due to variations in flow rate. This paper discusses the validation of a statistical methodology to estimate the flow and head variability in a network, and to select PATs whose best efficiency point (BEP) returns the lowest payback period. A comparison between the predicted and actual occurrence probabilities for different flow rates was carried out at nine potential points for MHP installation identified within a real network in Southwestern Spain. For the flow occurrence probability, the coefficient of determination (R-2) of 0.804. A total of 281.0MWh were obtained from the flow prediction and PAT selection methodology, in contrast to 230.5MWh using the actual measured data. An overall difference of 0.2% was obtained when both PATs were simulated under actual conditions. (c) 2019 Elsevier Ltd. All rights reserved.