Microhydropower Energy Recovery at Wastewater-Treatment Plants: Turbine Selection and Optimization

Abstract

AbstractRecovering energy using microhydropower turbines on the flow of wastewater into or out of treatment plants has been shown to be a viable method of increasing the sustainability of the process. This paper examines the selection and design optimization of turbines at four wastewater-treatment plants in Ireland. Investigations were conducted to examine the impact of variation in flow rate due to storm events and changes in water demands on the optimal design of turbines. Turbine selection was also investigated in this setting, highlighting the optimum design in terms of power output and cost. Low-cost options for this low-head setting were examined through the use of multiple pump-as-turbines in parallel. The result highlights significant differences between power output estimates, using average flow rates and turbine efficiency, and those conducted using detailed design optimization. Underestimates of up to 12% were shown. The optimized systems efficiencies obtained across the sites ranged from 73 t...