Special Issue "Renewable Energy and Energy Saving: Worldwide Research Trends"

A special issue of Sustainability (ISSN 2071-1050). This special issue belongs to the section "Energy Sustainability".

Deadline for manuscript submissions: 30 September 2021.

Special Issue Editor

Dr. Alberto-Jesus Perea-Moreno
E-Mail Website
Guest Editor
Department of Applied Physics, University of Cordoba, Campus de Rabanales, 14071 Córdoba, Spain
Interests: renewable energy; energy saving; biomass; sustainability; power quality; smart grids
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

Today, there is an increasing concern for the environment, especially regarding the already evident rise in the planet’s temperature. This circumstance has led to technological progress in the use of natural resources for energy and their availability to all productive sectors.

Faced with the current situation, it is vital to propose actions to put aside production models based on fossil fuels and opt for more sustainable models based on the circular economy, energy saving, and renewable energy.

Energy saving and renewable energy allow us to save our scarce economic resources, postpones the depletion of our scarce fossil resources (on which our energy supply depends for the most part), and finally seems to be one of the best alternatives for reducing CO2 emissions.

This Special Issue aims to advance the contribution of use of renewable energies and energy saving in order to achieve a more sustainable world. This Special Issue seeks contributions spanning a broad range of topics related but not limited to:

  • Solar energy;
  • The use of rooftops for energy generation;
  • Energy conversion from urban biomass or residues;
  • Energy management for water;
  • Bioclimatic architecture and green buildings;
  • Wind energy cogeneration;
  • Next-generation renewable energy technologies;
  • Cogeneration;
  • Public and private energy saving;
  • Policy for urban energy saving;
  • Smart meters;
  • Zero-energy buildings;
  • Legislations, regulations, and standards of energy.

Prof. Alberto-Jesus Perea-Moreno
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sustainability is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Energy saving
  • Renewable energy
  • Zero-energy buildings
  • Biomass
  • Solar energy
  • Wind energy
  • Energy efficiency
  • Sustainability
  • Bioclimatic architecture
  • Sustainable transport
  • PV
  • CSP

Published Papers (6 papers)

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Research

Article
Application of the Multiverse Optimization Method to Solve the Optimal Power Flow Problem in Direct Current Electrical Networks
Sustainability 2021, 13(16), 8703; https://doi.org/10.3390/su13168703 - 04 Aug 2021
Viewed by 273
Abstract
This paper addresses the optimal power flow problem in direct current (DC) networks employing a master–slave solution methodology that combines an optimization algorithm based on the multiverse theory (master stage) and the numerical method of successive approximation (slave stage). The master stage proposes [...] Read more.
This paper addresses the optimal power flow problem in direct current (DC) networks employing a master–slave solution methodology that combines an optimization algorithm based on the multiverse theory (master stage) and the numerical method of successive approximation (slave stage). The master stage proposes power levels to be injected by each distributed generator in the DC network, and the slave stage evaluates the impact of each power configuration (proposed by the master stage) on the objective function and the set of constraints that compose the problem. In this study, the objective function is the reduction of electrical power losses associated with energy transmission. In addition, the constraints are the global power balance, nodal voltage limits, current limits, and a maximum level of penetration of distributed generators. In order to validate the robustness and repeatability of the solution, this study used four other optimization methods that have been reported in the specialized literature to solve the problem addressed here: ant lion optimization, particle swarm optimization, continuous genetic algorithm, and black hole optimization algorithm. All of them employed the method based on successive approximation to solve the load flow problem (slave stage). The 21- and 69-node test systems were used for this purpose, enabling the distributed generators to inject 20%, 40%, and 60% of the power provided by the slack node in a scenario without distributed generation. The results revealed that the multiverse optimizer offers the best solution quality and repeatability in networks of different sizes with several penetration levels of distributed power generation. Full article
(This article belongs to the Special Issue Renewable Energy and Energy Saving: Worldwide Research Trends)
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Article
Value-Based Building Maintenance Practices for Public Hospitals in Malaysia
Sustainability 2021, 13(11), 6200; https://doi.org/10.3390/su13116200 - 31 May 2021
Viewed by 583
Abstract
Public hospital buildings in Malaysia have been facing problems and have become subjects of public criticisms due to poor building maintenance practices. A value-based approach which integrates and assimilates the concepts of value can be applied to mitigate maintenance problems in hospital buildings. [...] Read more.
Public hospital buildings in Malaysia have been facing problems and have become subjects of public criticisms due to poor building maintenance practices. A value-based approach which integrates and assimilates the concepts of value can be applied to mitigate maintenance problems in hospital buildings. This study evaluated the causal relationships between value factors and value outcomes of building maintenance in public hospitals in Malaysia. A total of 66 samples were collected via an online questionnaire survey. Analysis was performed using partial least square structural equation modeling (PLS-SEM). Our results reveal that value-adding practices and value co-creation have a positive influence on value outcomes in hospitals. The findings, however, do not support the relationships between factors of user involvement and value outcomes, which merit further investigation. This study concludes that value-adding practice has the strongest impact on value outcomes. Thus, maintenance service providers should assimilate these practices in their services to enhance performance. In addition, the findings also justify the requirement for collaborative working arrangements for value co-creation of building maintenance. Full article
(This article belongs to the Special Issue Renewable Energy and Energy Saving: Worldwide Research Trends)
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Article
Expert Views on the Future Development of Biogas Business Branch in Germany, The Netherlands, and Finland until 2030
Sustainability 2021, 13(3), 1148; https://doi.org/10.3390/su13031148 - 22 Jan 2021
Cited by 3 | Viewed by 1000
Abstract
To be able to meet the European Union’s energy and climate targets for 2030, all member states need to rethink their energy production and use. One potential renewable energy source is biogas. Its role has been relatively small compared to other energy sources, [...] Read more.
To be able to meet the European Union’s energy and climate targets for 2030, all member states need to rethink their energy production and use. One potential renewable energy source is biogas. Its role has been relatively small compared to other energy sources, but it could have a more central role to solve some specific challenges, e.g., to reduce carbon dioxide (CO2) emissions from traffic, or to act as a buffer to balance electricity production with consumption. This research analyses how the future of the biogas business in three case study countries is developing until 2030. The study is based on experts’ views within the biogas business branch in Germany, The Netherlands, and Finland. Both similarities and differences were found among the experts’ answers, which reflected also the current policies in different countries. The role of biogas was seen much wider than just to provide renewable energy, but also to decrease emissions from agriculture and close loops in a circular economy. However, the future of the biogas branch is much dependent on political decisions. To be able to show the full potential of biogas technology for society, stable and predictable energy policy and cross-sector co-operation are needed. Full article
(This article belongs to the Special Issue Renewable Energy and Energy Saving: Worldwide Research Trends)
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Article
Multi-Objective Stochastic Optimization for Determining Set-Point of Wind Farm System
Sustainability 2021, 13(2), 624; https://doi.org/10.3390/su13020624 - 11 Jan 2021
Cited by 2 | Viewed by 561
Abstract
Due to the uncertainty in output power of wind farm (WF) systems, a certain reserve capacity is often required in the power system to ensure service reliability and thereby increasing the operation and investment costs for the entire system. In order to reduce [...] Read more.
Due to the uncertainty in output power of wind farm (WF) systems, a certain reserve capacity is often required in the power system to ensure service reliability and thereby increasing the operation and investment costs for the entire system. In order to reduce this uncertainty and reserve capacity, this study proposes a multi-objective stochastic optimization model to determine the set-points of the WF system. The first objective is to maximize the set-point of the WF system, while the second objective is to maximize the probability of fulfilling that set-point in the real-time operation. An increase in the probability of satisfying the set-point can reduce the uncertainty in the output power of the WF system. However, if the required probability increases, the set-point of the WF system decreases, which reduces the profitability of the WF system. Using the proposed method helps the WF operator in determining the optimal set-point for the WF system by making a trade-off between maximizing the set-point of WF and increasing the probability of fulfilling this set-point in real-time operation. This ensures that the WF system can offer an optimal set-point with a high probability of satisfying this set-point to the power system and thereby avoids a high penalty for mismatch power. In order to show the effectiveness of the proposed method, several case studies are carried out, and the effects of various parameters on the optimal set-point for the WF system are also analyzed. According to the parameters from the transmission system operator (TSO) and wind speed profile, the WF operator can easily determine the optimal set-point using the proposed strategy. A comparison of the profits that the WF system achieved with and without the proposed method is analyzed in detail, and the set-point of the WF system in different seasons is also presented. Full article
(This article belongs to the Special Issue Renewable Energy and Energy Saving: Worldwide Research Trends)
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Article
Optimal Placement and Sizing of Wind Generators in AC Grids Considering Reactive Power Capability and Wind Speed Curves
Sustainability 2020, 12(7), 2983; https://doi.org/10.3390/su12072983 - 08 Apr 2020
Cited by 8 | Viewed by 880
Abstract
This paper presents an optimization model for the optimal placement and sizing of wind turbines, considering their reactive power capacity, wind speed, and demand curves. The optimization model is nonlinear and is focused on minimizing power losses in AC distribution networks. Also, paired [...] Read more.
This paper presents an optimization model for the optimal placement and sizing of wind turbines, considering their reactive power capacity, wind speed, and demand curves. The optimization model is nonlinear and is focused on minimizing power losses in AC distribution networks. Also, paired wind turbine and power conversion systems are treated via chargeability factor η at the peak hour. This factor represents the percentage of usage of the power conversion system in the nominal wind speed conditions, and allows to support reactive power dynamically during all periods of the day as a function of the distribution system requirements. In addition, an artificial neural network is used for short-term forecasting to deal with uncertainties in wind power generation. We assume that the number of wind power distributed generators could be from zero to three generators integrated into the system, considering unit power factors and reactive power injections to follow up the effect of reactive power compensation in the daily operation. The General Algebraic Modeling System (GAMS) is employed to solve the proposed optimization model. Full article
(This article belongs to the Special Issue Renewable Energy and Energy Saving: Worldwide Research Trends)
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Article
The Optimum Performance of Building Integrated Photovoltaic (BIPV) Windows Under a Semi-Arid Climate in Algerian Office Buildings
Sustainability 2020, 12(4), 1654; https://doi.org/10.3390/su12041654 - 22 Feb 2020
Cited by 10 | Viewed by 1208
Abstract
Recently, Building Integrated Photovoltaic (BIPV) windows have become an alternative energy solution to achieve a zero-energy building (ZEB) and provide visual comfort. In Algeria, some problems arise due to the high energy consumption levels of the building sector. Large amounts of this energy [...] Read more.
Recently, Building Integrated Photovoltaic (BIPV) windows have become an alternative energy solution to achieve a zero-energy building (ZEB) and provide visual comfort. In Algeria, some problems arise due to the high energy consumption levels of the building sector. Large amounts of this energy are lost through the external envelope façade, because of the poorness of the window’s design. Therefore, this research aimed to investigate the optimum BIPV window performance for overall energy consumption (OEC) in terms of energy output, heating and cooling load, and artificial lighting to ensure visual comfort and energy savings in typical office buildings under a semi-arid climate. Field measurements of the tested office were carried out during a critical period. The data have been validated and used to develop a model for an OEC simulation. Extensive simulations using graphical optimization methods are applied to the base-model, as well as nine commercially-available BIPV modules with different Window Wall Ratios (WWRs), cardinal orientations, and tilt angles. The results of the investigation from the site measurements show a significant amount of energy output compared to the energy demand. This study revealed that the optimum BIPV window design includes double-glazing PV modules (A) with medium WWR and 20% VLT in the southern façade and 30% VLT toward the east–west axis. The maximum energy savings that can be achieved are 60% toward the south orientation by double-glazing PV module (D). On the other hand, the PV modules significantly minimize the glare index compared to the base-model. The data extracted from the simulation established that the energy output percentages in a 3D model can be used by architects and designers in early stages. In the end, the adoption of optimum BIPV windows shows a significant enough improvement in their overall energy savings and visual comfort to consider them essential under a semi-arid climate. Full article
(This article belongs to the Special Issue Renewable Energy and Energy Saving: Worldwide Research Trends)
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