Next Article in Journal
Modified Septic Tank: Innovative Onsite Wastewater Treatment System
Next Article in Special Issue
Decision Support for the Design and Operation of Variable Speed Pumps in Water Supply Systems
Previous Article in Journal
Draining Effects on Recent Accumulation Rates of C and N in Zoige Alpine Peatland in the Tibetan Plateau
Previous Article in Special Issue
Groundwater Abstraction through Siphon Wells—Hydraulic Design and Energy Savings
Open AccessArticle

Top-Down and Bottom-Up Approaches for Water-Energy Balance in Portuguese Supply Systems

1
Civil Engineering Research and Innovation for Sustainability (CERIS), Instituto Superior Técnico, Universidade de Lisboa, Lisbon 1049-001, Portugal
2
Hydraulics Department, National Civil Engineering Laboratory, Lisbon 1700-066, Portugal
*
Author to whom correspondence should be addressed.
Water 2018, 10(5), 577; https://doi.org/10.3390/w10050577
Received: 28 March 2018 / Revised: 20 April 2018 / Accepted: 24 April 2018 / Published: 28 April 2018
Water losses are responsible for increased energy consumption in water supply systems (WSS). The energy associated with water losses (EWL) is typically considered to be proportional to the water loss percentage obtained in water balances. However, this hypothesis is yet to be proved since flow does not vary linearly with headlosses in WSS. The aim of this paper is to validate the hypothesis, present real-life values for water-energy balance (WEB) components, and reference values for the key performance indicator that represents the ratio of total energy in excess (E3). This validation is achieved through the application of two approaches—top-down and bottom-up. The first approach requires minimum data, gives an overview of the main WEB components, and provides an effective diagnosis of energy inefficiencies through the calculation of E3 related to pumps, water losses, and networks. The second approach requires calibrated hydraulic models and provides a detailed assessment of the WEB components. Results allow the validation of the stated hypothesis as well as show that the most significant energy inefficiencies are associated with surplus energy, pumping, and water losses, each reaching up to 40% of total input energy. Less significant components are pipe friction and valve headlosses, each reaching up to 15% of total input energy. View Full-Text
Keywords: water losses; energy efficiency; water-energy balance; water-energy nexus; water supply systems water losses; energy efficiency; water-energy balance; water-energy nexus; water supply systems
Show Figures

Figure 1

MDPI and ACS Style

Mamade, A.; Loureiro, D.; Alegre, H.; Covas, D. Top-Down and Bottom-Up Approaches for Water-Energy Balance in Portuguese Supply Systems. Water 2018, 10, 577.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop