A computational software tool for the minimization of costs and greenhouse gas emissions associated with water distribution systems

Lost in Optimisation of Water Distribution Systems? A Literature Review of System Design

“…Possible options to consider are, for example, to predetermine a limited number of potential pump locations [93,120], to evaluate network nodes as potential pump locations (yes/no) via binary variables [52] or to upgrade the current pump stations where new pumps are to be installed in parallel to existing ones [99]. Secondly, a pump size, which can be included as a pump capacity [14,121], pump type [75,76], pumping power [17], pump head/height [52,122], pump operation curve/head-flow [93] or pump size in a combination with the number of pumps [26]. Thirdly, a pump schedule, which describes when the pump is on and off during a scheduling period (e.g., 24 h).…”

“…Thirdly, a pump schedule, which describes when the pump is on and off during a scheduling period (e.g., 24 h). It can be specified by a pumping power [53,54] or pump head [123] at each time step, the number of pumps in operation during 24 h [97], binary pump statuses [29], continuous options representing on/off times with a limit imposed on the number of pump switches [76], discrete options representing the time at which a pump is turned on/off using a predefined time step (e.g., 30 min) [75]. All of these decisions impact on the size of the search space and eventually on the computational efficiency of the optimisation algorithm used.…”

“…A multi-objective optimisation approach was possibly first applied in the late 1990s (Figure 1), maximising the network benefit on one hand and minimising the system cost (of network rehabilitation) on the other hand [63]. In studies of newly designed WDSs, in addition to the economic measure, the other objectives considered were the pressure deficit [30,62,[64][65][66][67] or excess [68,69] at network nodes, the penalty cost for violating the pressure constraint [70], greenhouse gas (GHG) emissions [71][72][73][74][75][76] or emission cost [77], water discolouration risk [68] and water quality [78]. A multiobjective optimisation approach is considered "very appealing for engineers as it provides a tool to investigate interesting trade-offs", for example, a marginal pressure deficit can be outweighed by a considerable cost reduction [67].…”

Comparison of Pumping Regimes for Water Distribution Systems to Minimize Cost and Greenhouse Gases

“…Objectives of pumping electricity cost and GHG emissions are considered separately and the characteristics of the optimal operating strategies for the objectives are compared. Multi-objective optimization of cost and GHG emissions for WDSs has been extensively covered in Wu et al (2010a); Wu et al (2010b); Wu et al (2011); Stokes et al (2012b); Stokes et al (2012c); Wu et al (2012a); Wu et al (2012b); Wu et al, (2013);and Stokes et al (2014). This research is different in that it considers the effect of the different pump operating regimes on each objective individually.…”

PEPSO: Reducing Electricity Usage and Associated Pollution Emissions of Water Pumps

“…Wu et al included the effect of variable emission rates and electricity tariffs in their WDS design optimization study [14]. Stokes et al also suggested a framework for the modeling and optimization of Greenhouse Gases (GHG) emissions associated with energy usage and pump operation [15]. In most of these efforts, the emission rate of energy usage was considered as a constant value and was linearly related to the amount of consumed energy.…”