Energy Recovery in Water Networks: Numerical Decision Support Tool for Optimal Site and Selection of Micro Turbines

A Bi-Objective Approach for Optimizing the Installation of PATs in Systems of Transmission Mains

“…Another meaningful postprocessing variable is the payback period, i.e., the amount of time T b (years) it takes to recover the cost of the investment. While authors in [23,24] used a simplified calculation of T b , which did not consider the decrease in the net present value as a function of the selling year, T b was calculated here iteratively, by searching for the lowest value of T for which C p is larger than 0 in Equation (4).…”

“…Additionally, the subsequent works by Corcoran et al [22], Coelho and Andrade-Campos [23], and Fernández García and McNabola [24] use the number of devices as a surrogate for their total cost in the optimization phase, although removing the simplifying assumption of unitary efficiency made in [21]. Notably, Corcoran et al [22] compared the effectiveness of three different kinds of algorithms, namely nonlinear programming, mixed integer nonlinear programming, and evolutionary optimization, in the maximization of produced hydropower.…”

“…Notably, Corcoran et al [22] compared the effectiveness of three different kinds of algorithms, namely nonlinear programming, mixed integer nonlinear programming, and evolutionary optimization, in the maximization of produced hydropower. Coelho and Andrade-Campos [23] proposed a two-step optimization, which was carried out in a decoupled way. The first step concerned identification of site locations, which was performed using an optimization algorithm tailored to identifying the best locations of pressure reducing valves.…”

“…A financial analysis was also carried out by the two authors to evaluate installation cost, annual income associated with PAT operation, and investment payback period. Unlike the works in [21][22][23][24], the works of Fecarotta and McNabola [25] and Tricarico et al [26] proposed considering the installation cost in the context of the optimization, rather than the number of energy recovery devices. In fact, Fecarotta and McNabola [25] proposed an objective function combining installation costs and annual net income associated with device operation to be used inside a nonlinear mixed integer programming algorithm.…”

Coupled Electric and Hydraulic Control of a PRS Turbine in a Real Transport Water Network

“…An alternative to the use of valves is the use of pumps as turbines (PATs), or small hydraulic turbines [9] to convert hydraulic energy into electricity as an alternative to dissipation. Nowadays many studies can be found in the literature about the use of turbines with free outlet discharge [10][11][12][13][14] or positive outlet pressure [15]. However, the use of these turbines is limited by their high cost compared to the gross power usually available in the pipelines.…”