Cost-Benefit Analysis for Hydropower Production in Water Distribution Networks by a Pump as Turbine

The use of microhydroelectric plants in urban pipe networks, based on the combination of a pump as turbine (PAT), two regulating valves, and two pressure meters, is proposed along with simple automation rules. Its economic benefit is tested on a small pipe network, where the network geometry as well as the demand coefficient variation in time and space have been inferred from previously collected data and existing analysis. A similar analysis has been also carried out for different scenarios in which the reduction of pipe installation cost due to a diameter reduction is compared with the increased benefit in energy production. The case study shows that a small increment of the pipe installation cost, with respect to the minimum required by the nodes minimum pressure, can lead to a larger benefit for energy production. (C) 2014 American Society of Civil Engineers.