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14 pages, 2190 KiB

Open AccessArticle

A Boussinesq-Type Model for Nonlinear Wave-Heaving Cylinder Interaction

by Theofanis Karambas and Eva Loukogeorgaki

Energies 2022, 15(2), 469; https://doi.org/10.3390/en15020469 - 10 Jan 2022

Cited by 1 | Viewed by 1126

Abstract

In the present work, a Boussinesq-type numerical model is developed for the simulation of nonlinear wave-heaving cylinder interaction. The wave model is able to describe the propagation of fully dispersive and weakly nonlinear waves over any finite water depth. The wave-cylinder interaction is [...] Read more.

In the present work, a Boussinesq-type numerical model is developed for the simulation of nonlinear wave-heaving cylinder interaction. The wave model is able to describe the propagation of fully dispersive and weakly nonlinear waves over any finite water depth. The wave-cylinder interaction is taken into account by solving simultaneously an elliptic equation that determines the pressure exerted by the fluid on the floating body. The heave motion for the partially immersed floating cylinder under the action of waves is obtained by solving numerically the body’s equation of motion in the

z

direction based on Newton’s law. The developed model is applied for the case of a fixed and a free-floating circular cylinder under the action of regular waves, as well as for a free-floating cylinder undergoing a forced motion in heave. Results (heave and surge exciting forces, heave motions, and wave elevation) are compared with those obtained using a frequency domain numerical model, which is based on the boundary integral equation method. Full article

(This article belongs to the Special Issue A New Water-Energy Nexus: The Transition to Sustainable Energy)

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23 pages, 566 KiB

Open AccessArticle

Energy and Water Policies in Chile, Two Different Endings with Implications in the Water-Energy Nexus

by Roxana Bórquez and Rodrigo Fuster

Energies 2021, 14(11), 3286; https://doi.org/10.3390/en14113286 - 4 Jun 2021

Cited by 2 | Viewed by 2132

Abstract

Energy and water have faced important levels of conflicts in the last 20–25 years in Chile. However, the way that they have been politically addressed in the last decade differs. These differences emerge from how these fields have been historically configurated, impacting on [...] Read more.

Energy and water have faced important levels of conflicts in the last 20–25 years in Chile. However, the way that they have been politically addressed in the last decade differs. These differences emerge from how these fields have been historically configurated, impacting on how the policy problems and policy options have been framed. Using thematic analysis of 93 interviews and documentary analysis, this article analyzes by contrasting two participatory processes which nourish the formulation of the energy and water policies in Chile in 2014–2015. It seeks to understand the factors that may influence why the development, impact and inclusion of new voices in public policies related to water and energy have been different, and how that can impact the water–energy nexus. Five factors emerge as determinants in this difference: structure of use, number of actors, governance and institutional framework, elite conformation, and legal framework. These factors impacted the policy processes and the scope of the policy outcomes, generating two different results: a long-term energy policy, and a water policy that did not survive the presidential period. Thus, the water–energy nexus is under pressure as a result of the tension between power structures, social responses to environmental issues and decision-making, environmental limitations, and climate change stressors, creating greater vulnerability and conflicts. Full article

(This article belongs to the Special Issue A New Water-Energy Nexus: The Transition to Sustainable Energy)

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29 pages, 15905 KiB

Open AccessArticle

The Effects of Hydropower Plants on the Physicochemical Parameters of the Bystrzyca River in Poland

by Paweł Tomczyk and Mirosław Wiatkowski

Energies 2021, 14(8), 2075; https://doi.org/10.3390/en14082075 - 8 Apr 2021

Cited by 17 | Viewed by 2352

Abstract

Currently, the literature lacks comprehensive studies on the impact of hydropower plants (HPs) on the environment, including studies focused on the physicochemical parameters of water. The aim of the article is to verify the current state of knowledge on the impact of run-of-river [...] Read more.

Currently, the literature lacks comprehensive studies on the impact of hydropower plants (HPs) on the environment, including studies focused on the physicochemical parameters of water. The aim of the article is to verify the current state of knowledge on the impact of run-of-river HPs on 17 physicochemical parameters of water. The article is in line with the recommendations of the European Union that the member states, under the common energy policy, should increase the share of renewable energy sources in the energy and perform environmental impact assessments of such facilities. As a result of the analysis carried out on three HPs (Sadowice, Skałka and Marszowice) located on the Bystrzyca River (a tributary of the Odra River in Poland), it was found that HPs affect the selected physicochemical parameters of the water, i.e., (p < 0.05): electrolytic conductivity (EC; Skałka, Marszowice HPs), pH (Skałka, Marszowice HPs); nitrate nitrogen (NO₃-N; Marszowice HP), dissolved oxygen (DO; Marszowice HP) and ammonium nitrogen (NH₄-N; Marszowice HP). The largest (>5%), statistically significant mean cumulative effect below Marszowice HP concerned NH₄-N (−27.83%), DO (+14.04%) and NO₃-N (+5.50%). In addition, it was observed that the effect of HPs increases in direct proportion to the damming height, and that run-of-river HPs have a lesser impact on the physicochemical parameters’ values than in storage HPs. Our results were in accordance with those of other scientists in terms of the increase in DO, the decrease in EC, and the decrease in total phosphorus concentrations below HPs. Full article

(This article belongs to the Special Issue A New Water-Energy Nexus: The Transition to Sustainable Energy)

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12 pages, 659 KiB

Open AccessArticle

Environment Management of Hydropower Development: A Case Study

by Yakun Zhang, Wenzhe Tang, Colin F. Duffield, Lihai Zhang and Felix Kin Peng Hui

Energies 2021, 14(7), 2029; https://doi.org/10.3390/en14072029 - 6 Apr 2021

Cited by 5 | Viewed by 3668

Abstract

Environment management is one of the key aspects of hydropower development in acquiring sustainable energy. However, there has been limited research demonstrating the overall aspects of environment management of hydropower development with support of sound empirical evidence. In present study, the status of [...] Read more.

Environment management is one of the key aspects of hydropower development in acquiring sustainable energy. However, there has been limited research demonstrating the overall aspects of environment management of hydropower development with support of sound empirical evidence. In present study, the status of environment management in hydropower development was comprehensively investigated by conducting a case study based on the data collected from a field survey. The results show that, as environment management is largely subject to legal requirements, the environment management system needs to be established by integrating the legal requirements and needs of project implementation. This could potentially reduce the influence of legal restrictions on hydropower development. The main hydropower project environment management processes include identifying key environmental factors, implementation, monitoring, and performance measurement, which deal with environmental issues such as terrestrial and aquatic ecology protection, wastewater treatment, solid waste disposal, and acoustic-environment protection. Project participants should establish partnering relationships to cooperatively deal with environmental impacts of hydropower project development, in which public participation and sufficient resources input into environmental protection are essential for project success. The results of this study provide a sound basis for participants to deal with the key issues of environmental protection such as meeting legal requirements, training for improving environment management process, cost control, and cooperative environment management. The results of this study could help practitioners to tackle the interactions among project delivery, environmental protection, and engagement of local communities in an optimized way with the aim of maximizing effectiveness of the resources of all participants. Full article

(This article belongs to the Special Issue A New Water-Energy Nexus: The Transition to Sustainable Energy)

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23 pages, 5613 KiB

Open AccessArticle

Optimizing Current and Future Hydroelectric Energy Production and Water Uses of the Complex Multi-Reservoir System in the Aliakmon River, Greece

by Panagiotis I. Bakanos and Konstantinos L. Katsifarakis

Energies 2020, 13(24), 6499; https://doi.org/10.3390/en13246499 - 9 Dec 2020

Cited by 6 | Viewed by 2005

Abstract

In this work we study long-term maximization of hydroelectric energy generation from complex multi-purpose reservoir systems, using the reservoir system of the Aliakmon River, Greece, as an application example. This system serves various purposes, like urban water supply, irrigation, hydroelectric energy production, cooling [...] Read more.

In this work we study long-term maximization of hydroelectric energy generation from complex multi-purpose reservoir systems, using the reservoir system of the Aliakmon River, Greece, as an application example. This system serves various purposes, like urban water supply, irrigation, hydroelectric energy production, cooling thermoelectric power plants and flood control, while preserving environmental flow. The system operator uses institutional rules for the annual scheduling of the outflows of the 2 largest reservoirs (Ilarion and Polyfyto) for additional safety and smooth distribution of energy production through the year. In this work, we focus on maximization of energy production. We have considered three different hydrological scenarios (dry, average and wet), both for the current and for anticipated future water demand. The multi-reservoir system’s operation was simulated and then optimized using a rather simple form of genetic algorithms, in order to maximize hydro energy production. All other water uses were taken into account as constraints. Our conceptual and computational approach succeeded to identify and quantify hydro energy production increase and to indicate necessary changes to the operating rule curves of the reservoirs. The methodology can be easily adapted to other large-scale multi reservoir systems. Full article

(This article belongs to the Special Issue A New Water-Energy Nexus: The Transition to Sustainable Energy)

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16 pages, 1248 KiB

Open AccessArticle

Method for Determining the Probability of a Lack of Water Supply to Consumers

by Dawid Szpak

Energies 2020, 13(20), 5361; https://doi.org/10.3390/en13205361 - 14 Oct 2020

Cited by 10 | Viewed by 2276

Abstract

The water distribution subsystem is the most failing subsystem included in the water supply system. One of the main consequences of water supply failures is the lack of water supply to consumers, which is always very onerous. The paper presents a method of [...] Read more.

The water distribution subsystem is the most failing subsystem included in the water supply system. One of the main consequences of water supply failures is the lack of water supply to consumers, which is always very onerous. The paper presents a method of determining the conditional probability that a break in the supply of water to consumers of a certain duration will be caused by a specific type of failure. The result of the work was to identify water supply network failures that result in the longest water supply suspension time. The method was presented on a real water supply system. In order to reduce the incidence of long-term interruptions in water supply, water supply companies should mainly continue replacing gray cast iron pipes with thermoplastic materials. Actions taken to increase the safety of drinking water supply meet the current standards for the safety of drinking water, developed by the World Health Organization and the European Union. Full article

(This article belongs to the Special Issue A New Water-Energy Nexus: The Transition to Sustainable Energy)

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14 pages, 2319 KiB

Open AccessArticle

Water Network-Failure Data Assessment

by Katarzyna Pietrucha-Urbanik, Barbara Tchórzewska-Cieślak and Mohamed Eid

Energies 2020, 13(11), 2990; https://doi.org/10.3390/en13112990 - 10 Jun 2020

Cited by 11 | Viewed by 2196

Abstract

The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their [...] Read more.

The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their degradation mechanisms, criticality, occurrence frequency and intensity. These failure modes have a random nature that impacts on the network disruption indicators, such as disruption frequency, network downtime, network repair time and network back-to-service time, i.e., the network resilience. This paper focuses on the water leakage failure mode. The water leakage failure mode assessment considers the unavoidable annual real water losses and the infrastructure leakage index recommended by the International Water Association’s Water Loss Task Force specialist group. Probabilistic statistical modelling was implemented to assess the seasonal index, the failure rates and the expectation value of the “mean time between failures.” The assessment is based on real operational data of the network. Specific attention is paid to the sensitivity of failures to seasonal variations. The presented methodology of the analysis of the water leakage failure mode is extendable to other failure modes and can help in developing new strategies in the management of the water-supply system in normal operation and crisis situations. Full article

(This article belongs to the Special Issue A New Water-Energy Nexus: The Transition to Sustainable Energy)

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Other

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20 pages, 2787 KiB

Open AccessCase Report

Consumers’ Perceptions of the Supply of Tap Water in Crisis Situations

by Katarzyna Pietrucha-Urbanik and Janusz R. Rak

Energies 2020, 13(14), 3617; https://doi.org/10.3390/en13143617 - 14 Jul 2020

Cited by 43 | Viewed by 2771

Abstract

This paper first presents the results of polling on the subject of potable water in crisis situations, with respondents from south-eastern Poland’s Subcarpathian region asked for their opinions on the level of nuisance associated with water supply interruptions and water quality, levels of [...] Read more.

This paper first presents the results of polling on the subject of potable water in crisis situations, with respondents from south-eastern Poland’s Subcarpathian region asked for their opinions on the level of nuisance associated with water supply interruptions and water quality, levels of consumption and water companies’ quality of service. Among the respondents 53% regard the quality of the water they receive as satisfactory, while a quarter see it as only average. However, respondents are relatively satisfied with the corporate response when supplies are interrupted, as methods and means of notification are judged effective by 60%. Continuing with work to assess possibilities for water companies to improve their performance in crisis situations, the present study generates an Analytical Hierarchy Process allowing recipients to determine importance criteria where quality of service is concerned. This could facilitate management by water companies, providing for centralised control and comparison that help secure services of appropriate quality. The process can also help protect different groups of recipients, as safety is evaluated through analysis of functioning, and of failures and losses. Full article

(This article belongs to the Special Issue A New Water-Energy Nexus: The Transition to Sustainable Energy)

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