A Study of Energy Optimisation of Urban Water Distribution Systems Using Potential Elements

Abstract

Energy use in water supply systems represents a significant portion of the global energy consumption. The electricity consumption due to the water pumping represents the highest proportion of the energy costs in these systems. This paper presents several comparative studies of energy efficiency in water distribution systems considering distinct configurations of the networks and also considers implementation of the variable-speed pumps. The main objective of this study is the energy optimisation of urban systems using optimal network configurations that reduce energy consumption and improve energy efficiency. The paper describes in detail four strategies for improving energy efficiency of water pumping: control systems to vary pump speed drive according to water demand, pumped storage tanks, intermediary pumping stations integrated in the network, and elevated storage tanks floating on the system. The improving energy efficiency of water pumping is briefly reviewed providing a representative real case study. In addition, a different approach for the hydraulic analysis of the networks and the determination of the optimal location of a pumped storage tank is provided. Finally, this study compares the results of the application of four water supply strategies to a real case in Romania. The results indicate high potential operating costs savings.

Standalone Photovoltaic Direct Pumping in Urban Water Pressurized Networks with Energy Storage in Tanks or Batteries

“…Nowadays, the utility manager does not know which is the best choice between two common alternatives: batteries or a compensation tank as energy storage. Water pressurized networks were designed without considering tanks in the optimization process, but researchers and practitioners have made an effort to integrate them and optimize their size [45][46][47][48] in real-world operation projects. Tanks are of paramount importance in WPNs [45] because of their use as water storage (filled during the day while it empties, releasing the volume at night) for daily use and in emergencies, but they present inconveniences regarding higher water age and higher energy consumption [49], and some approaches have considered the effect of tanks in the indirect water supply [50].…”

Energy Savings Potential for Pumping Water in District Heating Stations

“…There are two methods to vary the water discharge in a pipe network with an FSP: -Bypassing part of the water discharge (the pump operates at the same pump head, water flow rate increases and the absorbed power also increases). -Introducing a supplementary pressure loss using a control valve (the operating point is heading towards the left on the H-Q curve) [19,20].…”

Equipamento de baixo custo para monitoramento de pressões em sistemas de abastecimento de água

“…As pressões e as vazões são grandezas que variam com grande frequência no sistema de abastecimento de água, principalmente em função das oscilações de sua demanda durante o dia, do perfil socioeconômico, da localização, do clima, entre outros fatores (DIAS; MARTINEZ; LIBÂNIO, 2010), inferindo em dificuldades na determinação dessas variáveis. Diversos estudos abordam a importância do acompanhamento e do controle das pressões no sistema de abastecimento de água, apresentando-se como uma das principais opções técnicas para incremento da eficiência hidráulica e energética, além da criação de um banco de dados para possíveis modelagens em relação às pressões e aos vazamentos (SOARES et al, 2004;FORMIGA;CHAUDHRY, 2008;CAMPISANO;MODICA;VETRANO, 2012;FECAROTTA et al, 2015;SARBU, 2016;MOURA et al, 2018).…”