Enhancement of water and energy efficiency in water supply systems

Aisha Zulquifal Mamade

Key information

Authors:

Aisha Zulquifal Mamade (Aisha Zulquifal Mamade)

Supervisors:

Dídia Isabel Cameira Covas (Dídia Isabel Cameira Covas); Dália Susana dos Santos da Cruz Loureiro (Dália Susana dos Santos da Cruz Loureiro)

Published in

December 10, 2019

Abstract

This research aims to enhance water and energy efficiency in water supply systems through a systemic and objective-oriented framework, robust and well-tested energy balances and energy efficiency metrics. These provide guidance on the type of water-energy inefficiencies, allowing comparison of different improvement solutions and fostering continuous improvement. The research approach encompasses relevant scientific developments applied in a living lab of water utilities with different system configurations and maturity levels. The scientific development involves: the mathematical formulation of an energy balance, flexible in terms of data requirements, compactible with the water balance and calculated, in detail, through the system hydraulic simulation; the development of energy efficiency metrics that highlight the nature of inefficiencies in water supply systems (i.e., related to equipment, water losses or system configuration); and the systematization of the previous developments in a framework that follows the Plan-Do-Check-Act principles. The application in a large dataset of water utilities is carried out in three steps. The first step consists of the application of the energy balance and energy efficiency metrics in a top-down approach to identify sources of inefficiency at a macro level. The second step consists of applying a bottom-up energy balance in calibrated mathematical models of the water distribution systems, for an in-depth analysis of energy consumption; this allows a comprehensive discussion of the different mathematical formulations of the energy balance and related energy efficiency metrics. The third step focuses on a more detailed application to illustrate the framework, with a particular emphasis on the analysis of unconventional energy improvement solutions. The main outcomes of this research are: i) an integrated framework for the energy efficiency diagnosis, the prioritisation of subsystems and the comparison of energy efficiency improvement solutions; ii) a novel energy balance for water supply systems with different implementation formulations; iii) real-life values for energy balance components and energy efficiency metrics in 110 systems; iv) tools for computing the different energy balance formulations and calculating performance metrics; and v) examples of unconventional solutions resulting from the application of the framework that may lead considerable water-energy efficiency improvements.