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Editorial

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3 pages, 171 KiB

Open AccessEditorial

Special Issue: Advances in Renewable Energy Systems

by Ferdinando Salata and Virgilio Ciancio

Processes 2024, 12(8), 1583; https://doi.org/10.3390/pr12081583 - 29 Jul 2024

Viewed by 746

Abstract

The greatest challenge that the industrialized world faces today is converting its energy production systems into those that utilize renewable sources, which are more environmentally friendly compared to traditional systems [...] Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

Research

Jump to: Editorial, Review

21 pages, 7381 KiB

Open AccessArticle

Research on Multi-Objective Energy Management of Renewable Energy Power Plant with Electrolytic Hydrogen Production

by Tao Shi, Libo Gu, Zeyan Xu and Jialin Sheng

Processes 2024, 12(3), 541; https://doi.org/10.3390/pr12030541 - 9 Mar 2024

Cited by 2 | Viewed by 1408

Abstract

This study focuses on a renewable energy power plant equipped with electrolytic hydrogen production system, aiming to optimize energy management to smooth renewable energy generation fluctuations, participate in peak shaving auxiliary services, and increase the absorption space for renewable energy. A multi-objective energy [...] Read more.

This study focuses on a renewable energy power plant equipped with electrolytic hydrogen production system, aiming to optimize energy management to smooth renewable energy generation fluctuations, participate in peak shaving auxiliary services, and increase the absorption space for renewable energy. A multi-objective energy management model and corresponding algorithms were developed, incorporating considerations of cost, pricing, and the operational constraints of a renewable energy generating unit and electrolytic hydrogen production system. By introducing uncertain programming, the uncertainty issues associated with renewable energy output were successfully addressed and an improved particle swarm optimization algorithm was employed for solving. A simulation system established on the Matlab platform verified the effectiveness of the model and algorithms, demonstrating that this approach can effectively meet the demands of the electricity market while enhancing the utilization rate of renewable energies. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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21 pages, 12258 KiB

Open AccessArticle

Simulation Experiment Design and Control Strategy Analysis in Teaching of Hydrogen-Electric Coupling System

by Tao Shi, Jialin Sheng, Zhiqiang Chen and Hangyu Zhou

Processes 2024, 12(1), 138; https://doi.org/10.3390/pr12010138 - 5 Jan 2024

Cited by 2 | Viewed by 1451

Abstract

Hydrogen energy, as a clean and green energy medium, is characterized by large capacity, extended lifespan, convenient storage, and seamless transmission. On the one hand, in the power system, hydrogen can be prepared by the electrolysis of water using the surplus power from [...] Read more.

Hydrogen energy, as a clean and green energy medium, is characterized by large capacity, extended lifespan, convenient storage, and seamless transmission. On the one hand, in the power system, hydrogen can be prepared by the electrolysis of water using the surplus power from intermittent new energy generation, such as photovoltaic and wind power, to increase the space for new energy consumption. On the other hand, it can be used to generate electricity from the chemical reaction between hydrogen and oxygen through the fuel cell and be used as a backup power source when there is a shortage of power supply. In this paper, based on the teaching practice, the conversion mechanism and coupling relationship between various forms of energy, such as photovoltaic energy, hydrogen energy, and electric energy, were deeply analyzed. Further, a hydrogen-electricity coupling digital simulation experimental system, including photovoltaic power generation, fuel cell, and electrolysis hydrogen system, was formed. Simultaneously, considering the synergy between hydrogen production and electricity generation businesses, as well as the demand for the efficient utilization and flexible regulation of multiple energy sources, eight sets of simulation experimental scenarios were designed. A cooperative control strategy for the hydrogen-electric coupling system was proposed and validated through simulation on the MATLAB/SIMULINK-R2023a platform. This study shows that the simulation system has rich experimental scenarios and control strategies, and can comprehensively and accurately demonstrate the multi-energy complementary and cooperative control characteristics of the hydrogen-electric coupling system. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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16 pages, 7134 KiB

Open AccessArticle

Fast-Frequency-Response Control Method for Electrode Boilers Supporting New Energy Accommodation

by Tao Shi, Zhiqiang Chen, Shufeng Guo and Dan Li

Processes 2023, 11(11), 3098; https://doi.org/10.3390/pr11113098 - 28 Oct 2023

Cited by 4 | Viewed by 1244

Abstract

With the large-scale integration of new energy generation, represented by wind and photovoltaic power, into the power grid, the intermittency, randomness, and fluctuations of their output pose significant challenges to the safe and stable operation of the power system. Therefore, this paper proposes [...] Read more.

With the large-scale integration of new energy generation, represented by wind and photovoltaic power, into the power grid, the intermittency, randomness, and fluctuations of their output pose significant challenges to the safe and stable operation of the power system. Therefore, this paper proposes a control method for electrode boiler systems participating in rapid grid frequency response based on a fuzzy control strategy. This method improves the traditional electrode boiler control strategy, giving it characteristics similar to those of synchronous generators in terms of active power–frequency droop, allowing it to actively adjust active power based on system frequency disturbances. Furthermore, it optimizes its control performance indicators using fuzzy algorithms. The simulation results on the Matlab/Simulink platform demonstrate that the modified electrode boiler control system, when applying this method, can effectively address power disturbances in the system, reduce system frequency deviations, and contribute to enhancing the grid frequency regulation capability and system stability. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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32 pages, 3393 KiB

Open AccessArticle

Modeling and Multi-Stage Planning of Cement-IIES Considering Carbon-Green Certificate Trading

by Zhaochu Guo and Suyang Zhou

Processes 2023, 11(4), 1219; https://doi.org/10.3390/pr11041219 - 15 Apr 2023

Cited by 4 | Viewed by 2096

Abstract

The cement industry is an important industrial entity responsible for implementing carbon emission reduction targets. Considering the carbon trading and green certificate trading mechanisms, this paper presents a multi-stage planning approach for the constructed Cement-Industrial Integrated Energy System (Cement-IIES). Carbon reduction technologies represented [...] Read more.

The cement industry is an important industrial entity responsible for implementing carbon emission reduction targets. Considering the carbon trading and green certificate trading mechanisms, this paper presents a multi-stage planning approach for the constructed Cement-Industrial Integrated Energy System (Cement-IIES). Carbon reduction technologies represented by low-temperature waste heat recovery, as well as phased changes in economic and technical parameters, are considered in the model. The case study shows that the proposed method not only optimizes the design economy of the Cement-IIES but also achieves a substantial carbon emission reduction in the cement production process and energy supply system. Compared with the traditional single-stage planning, the proposed method improves the system’s economic efficiency by 13.88% and flexibly adapts to changes in policies such as “coal reform”, green certificate trading and carbon quotas. The low-temperature waste heat recovery technology helps the system energy utilization efficiency in the two stages increase by 0.45% and 0.86%, respectively, whilst oxygen-enriched combustion and carbon capture technologies can reduce the total carbon emissions by about 83%. In addition, the negative carbon emission effect of biomass gives the system access to annual benefits of CNY 3.10 × 10⁷ and CNY 7.89 × 10⁷ in the two stages, respectively. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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19 pages, 2472 KiB

Open AccessArticle

Life Cycle Assessment and Cumulative Energy Demand Analyses of a Photovoltaic/Thermal System with MWCNT/Water and GNP/Water Nanofluids

by Gülşah Karaca Dolgun, Meltem Koşan, Muhammet Kayfeci, Aleksandar G. Georgiev and Ali Keçebaş

Processes 2023, 11(3), 832; https://doi.org/10.3390/pr11030832 - 10 Mar 2023

Cited by 9 | Viewed by 2568

Abstract

The global climate crisis has led society toward cleaner energy sources. Another reason is the limited reserves of fossil energy resources. Efforts to increase the efficiency of photovoltaic modules (PVs) have gained momentum. The high temperature is the biggest factor causing a decrease [...] Read more.

The global climate crisis has led society toward cleaner energy sources. Another reason is the limited reserves of fossil energy resources. Efforts to increase the efficiency of photovoltaic modules (PVs) have gained momentum. The high temperature is the biggest factor causing a decrease in the efficiency of PVs. In this study, a commercial PV was cooled with distilled water, a multiwalled carbon nanotubes (MWCNT)/water mixture, and a graphene nanoplatelets (GNP)/water mixture. The environmental impact of electricity, total energetic efficiency, energy payback time, energy return on investment, and embodied energy of the PV/thermal (PV/T) system were compared using life cycle assessment and cumulative energy demand. The electrical efficiency of the PV/T changed between 13.5% and 14.4%. The total efficiency of PV/T changed between 39.5% and 45.7%. The energy returns on investment were 1.76, 1.80, and 1.85 for PV/T-distilled water, the PV/T-MWCNT/water mixture, and the PV/T-GNP/water mixture, respectively. Moreover, the embodied energy evaluation values were 3975.88 MJ for PV/T-distilled water, 4081.06 MJ for the PV/T-MWCNT/water mixture, and 4077.86 MJ for the PV/T-GNP/water mixture. The main objective of this research was to study the energy and environmental performances of PVs cooled with different nanofluids and draw general conclusions about the applicability of these systems. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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28 pages, 21788 KiB

Open AccessFeature PaperArticle

CFD Modeling of an H-Type Darrieus VAWT under High Winds: The Vorticity Index and the Imminent Vortex Separation Condition

by Jansen Gabriel Acosta-López, Alberto Pedro Blasetti, Sandra Lopez-Zamora and Hugo de Lasa

Processes 2023, 11(2), 644; https://doi.org/10.3390/pr11020644 - 20 Feb 2023

Cited by 8 | Viewed by 3477

Abstract

This study introduces a Vorticity Index (VI) and an Imminent Vortex Separation Condition (IVSC), which are considered valuable indicators to quantify the vorticity impact on vertical axis wind turbines (VAWTs) operation. The VI and IVSC are specifically applied to a H-Darrieus vertical axis [...] Read more.

This study introduces a Vorticity Index (VI) and an Imminent Vortex Separation Condition (IVSC), which are considered valuable indicators to quantify the vorticity impact on vertical axis wind turbines (VAWTs) operation. The VI and IVSC are specifically applied to a H-Darrieus vertical axis wind turbine (VAWT). Findings show that these two parameters display a direct relationship with the aerodynamic forces that govern the performance of this type of VAWT. This analysis is accomplished via 2D-CFD simulations of a H-Darrieus with a symmetrical NACA 0018, powered by high winds (8 and 20 m/s), by using a Shear Stress Transport SST k-ω model. The 2D model used is validated for Class II winds (8 m/s), for tip speed ratios (λ) ranging from 0.4 to 0.9. Power coefficients (C_p) predictions are close to those obtained with both 3D simulations and with experimental data, reported in the technical literature. It is found with the numerical simulations developed, that despite the significant increase of the average rotor overall torque values, when the wind speed is augmented from 8 m/s to 20 m/s, the energy extracted by the rotor seems to be moderately lessened by the amplified turbulence and vorticity. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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40 pages, 21057 KiB

Open AccessFeature PaperArticle

Thermal, Lighting and IAQ Control System for Energy Saving and Comfort Management

by Silvia Maria Zanoli and Crescenzo Pepe

Processes 2023, 11(1), 222; https://doi.org/10.3390/pr11010222 - 10 Jan 2023

Cited by 8 | Viewed by 2736

Abstract

The present work proposes a simulation and control framework for home and building automation, focusing on heating, ventilating, and air conditioning processes. Control systems based on different advanced control architectures and different control policies are simulated and compared, highlighting control performances, and energy-saving [...] Read more.

The present work proposes a simulation and control framework for home and building automation, focusing on heating, ventilating, and air conditioning processes. Control systems based on different advanced control architectures and different control policies are simulated and compared, highlighting control performances, and energy-saving results in terms of CO₂ emissions reduction. Heat, lighting, and natural ventilation phenomena were modelized through first-principles and empirical equations, obtaining a reliable and flexible simulation framework. Energy-consuming and green energy-supplying renewable sources were integrated into the framework, e.g., heat pumps, artificial lights, fresh air flow, and natural illuminance. Different control schemes are proposed, based on proportional–integral–derivative advanced control architectures and discrete event dynamic systems-based supervisors; different control specifications are included, resulting in a multi-mode control system. The specifications refer to energy savings and comfort management, while minimizing overall costs. Comfort specifications include thermal comfort, lighting comfort, and a good level of indoor air quality. Simulations on different scenarios considering various control schemes and specifications show the reliability and soundness of the simulation and control framework. The simulated control and energy performances show the potential of the proposed approach, which can provide energy-saving results greater or equal to 6 [%] (in each season) and 19 [%] (in one year) with respect to more standard approaches. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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28 pages, 8477 KiB

Open AccessArticle

Dynamic Performance Assessment of PMSG and DFIG-Based WECS with the Support of Manta Ray Foraging Optimizer Considering MPPT, Pitch Control, and FRT Capability Issues

by Mohamed Metwally Mahmoud, Basiony Shehata Atia, Almoataz Y. Abdelaziz and Noura A. Nour Aldin

Processes 2022, 10(12), 2723; https://doi.org/10.3390/pr10122723 - 16 Dec 2022

Cited by 26 | Viewed by 2865

Abstract

Wind generators have attracted a lot of attention in the realm of renewable energy systems, but they are vulnerable to harsh environmental conditions and grid faults. The influence of the manta ray foraging optimizer (MRFO) on the dynamic performance of the two commonly [...] Read more.

Wind generators have attracted a lot of attention in the realm of renewable energy systems, but they are vulnerable to harsh environmental conditions and grid faults. The influence of the manta ray foraging optimizer (MRFO) on the dynamic performance of the two commonly used variable speed wind generators (VSWGs), called the permanent magnet synchronous generator (PMSG) and doubly-fed induction generator (DFIG), is investigated in this research article. The PMSG and DFIG were exposed to identical wind speed changes depending on their wind turbine characteristics, as well as a dangerous three-phase fault, to evaluate the durability of MRFO-based wind side controllers. To protect VSWGs from hazardous gusts and obtain the optimum power from incoming wind speeds, we utilized a pitch angle controller and optimal torque controller, respectively, in our study. During faults, the commonly utilized industrial approach (crowbar system) was exclusively employed to aid the studied VSWGs in achieving fault ride-through (FRT) capability and control of the DC link voltage. Furthermore, an MRFO-based PI controller was used to develop a crowbar system. The modeling of PMSG, DFIG, and MRFO was performed using the MATLAB/Simulink toolbox. We compared performances of PMSG and DFIG in reference tracking and resilience against changes in system parameters under regular and irregular circumstances. The effectiveness and reliability of the optimized controllers in mitigating the adverse impacts of faults and wind gusts were demonstrated by the simulation results. Without considering the exterior circuit of VSWGs or modifying the original architecture, MRFO-PI controllers in the presence of a crowbar system may help cost-effectively alleviate FRT concerns for both studied VSWGs. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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23 pages, 4187 KiB

Open AccessArticle

How Does Public Sentiment Affect the Socially Responsible Behavior of Construction Enterprises?

by Xiaoxu Dang, Shihui Wang, Xiaopeng Deng, Ziming Zhang, Na Zhang and Hongtao Mao

Processes 2022, 10(11), 2403; https://doi.org/10.3390/pr10112403 - 15 Nov 2022

Cited by 7 | Viewed by 2074

Abstract

The negative environmental impact of the construction sector has garnered global attention, and as the “primary force” in achieving the “double carbon” target, green development is urgent, and social responsibility practices cannot be postponed. An evolutionary game model was constructed by combining the [...] Read more.

The negative environmental impact of the construction sector has garnered global attention, and as the “primary force” in achieving the “double carbon” target, green development is urgent, and social responsibility practices cannot be postponed. An evolutionary game model was constructed by combining the rank-dependent expected utility (RDEU) theory and the evolutionary game theory to understand the interaction mechanism between participants’ emotions and decisions, taking into account the characteristics of construction enterprises and the public regarding irrational decisions under heterogeneous emotional combinations. The study demonstrates that: (1) there is probability in the choice of rational strategies, and emotion is an irrational factor that can affect strategy choice. (2) The evolutionary trend of the strategy choice of the game subjects is altered by emotional intensity and emotional propensity. The optimism of construction enterprises inhibits their socially responsible practice, and the pessimism of the public promotes the probability of their negative strategy choice. Furthermore, moderate optimism is a safety valve for the public’s positive strategy choice. (3) The interaction of emotional states leads to a heterogeneity of strategy choices exhibited under different combinations of emotions, with the emotions of construction companies having a more dominant influence on strategy. Finally, we make some feasible recommendations for improving social responsibility practices and preventing mass incidents by boosting emotional monitoring and guidance for construction businesses and the general public. Overall, this study provides important information about how to be socially responsible, maintain good relationships with the public, and protect the environment. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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22 pages, 7917 KiB

Open AccessArticle

Analysis of Enhanced Heat Transfer Characteristics of Coaxial Borehole Heat Exchanger

by Lin Sun, Biwei Fu, Menghui Wei and Si Zhang

Processes 2022, 10(10), 2057; https://doi.org/10.3390/pr10102057 - 12 Oct 2022

Cited by 6 | Viewed by 3658

Abstract

Coaxial borehole heat exchangers provide a practical method for geothermal energy extraction, but heat transfer efficiency is low. In order to address this problem, three coaxial borehole heat exchangers with vortex generators, based on the enhanced heat transfer theory, are proposed in this [...] Read more.

Coaxial borehole heat exchangers provide a practical method for geothermal energy extraction, but heat transfer efficiency is low. In order to address this problem, three coaxial borehole heat exchangers with vortex generators, based on the enhanced heat transfer theory, are proposed in this paper. The author compared and analyzed the heat transfer performance of three coaxial borehole heat exchangers with vortex generators and those of traditional structures, which explains why the new heat exchanger’s heat transfer mechanism is enhanced. The results demonstrated that the vortex generator can enhance the fluid flow’s turbulent kinetic energy in the coaxial heat exchanger. This generator can also improve the mixing characteristics of the fluid flow and heat transfer. The resultant increase in the inlet flow velocity can decrease the friction coefficient f, increase the Nusselt number and strengthen the coaxial sleeve. As a result, the heat exchange performance of the tubular heat exchanger will also be improved. The thread vortex generator (TVG) heat exchanger outperforms the other three heat exchangers in terms of heat exchange performance, extraction temperature and heat extraction power. The results evidenced that the TVG heat exchanger is better than the smooth tube heat exchanger. The thermal performance coefficient PEC was improved by 1.1 times, and the extraction temperature and heating power were increased by 24.06% and 11.93%, respectively. A solid theoretical foundation is provided by the extracted outcomes for designing and selecting high-efficiency coaxial borehole heat exchangers suitable for geothermal energy extraction. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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13 pages, 2366 KiB

Open AccessArticle

Coordination of Configurations of Technologically Integrated “European Green Deal” Projects

by Anatoliy Tryhuba, Krzysztof Mudryk, Inna Tryhuba, Taras Hutsol, Szymon Glowacki, Oleksandr Faichuk, Nataliia Kovalenko, Alona Shevtsova, Arkadiusz Ratajski, Monika Janaszek-Mankowska and Weronika Tulej

Processes 2022, 10(9), 1768; https://doi.org/10.3390/pr10091768 - 3 Sep 2022

Cited by 8 | Viewed by 1497

Abstract

An analysis of the state of affairs in the theory and practice of implementation of technologically integrated projects in various applied fields was carried out. The peculiarities of the implementation of the technologically integrated projects of the “European Green Deal” for the production [...] Read more.

An analysis of the state of affairs in the theory and practice of implementation of technologically integrated projects in various applied fields was carried out. The peculiarities of the implementation of the technologically integrated projects of the “European Green Deal” for the production of ecologically clean fuel from agricultural waste were analyzed. The expediency of developing a method of coordinating the configurations of technologically integrated “European Green Deal” projects for the production of ecologically clean energy from agricultural waste on the territory of a given region, taking into account their specific project environments, was substantiated. As a result of the conducted research, a method of coordinating configurations of the technologically integrated “European Green Deal” projects for the production of ecologically clean energy from agricultural waste in the territory of a given region, taking into account their specific project environment, was developed. This method involves the implementation of five stages, which ensure consideration of the specific design environment of each region and the type of agricultural raw materials for energy production. This method involves the modeling of individual projects, which makes it possible to increase the accuracy of determining their value indicators, taking into account risk. The balancing of the technologically integrated projects of the “European Green Deal” for the production of clean energy from agricultural waste was carried out on the basis of maximizing value for stakeholders and minimizing risk. On the basis of the proposed method, the computer program “Balancing technologically integrated projects” was developed. The use of this computer program for the given project environment (conditions of LLC “Lutsk Agrarian Company” of the Volyn region, Ukraine) made it possible to forecast the specific value and risk of individual projects involving harvesting raw materials from corn waste. The statistical characteristics of the distribution of the projected specific value of the project of harvesting raw materials from corn waste were established: the estimate of mathematical expectation—EUR 9/ton; dispersion—EUR 25/ton; the estimation of root mean square deviation—EUR 5/ton. The technologically integrated projects of the “European Green Deal” for the production of ecologically clean energy from corn waste with the greatest interconnections in terms of value were identified. The ranking of raw material procurement projects from corn waste was carried out according to their specific values and risks. Among the considered projects, priority was given to project #7 and project #1, which provided the greatest values, 37.6% and 36.6%, respectively, of the total value of the considered projects. The obtained results made it possible to establish priority projects and carry out their balancing by value and risk. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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19 pages, 2428 KiB

Open AccessArticle

Game Analysis of the Evolution of Energy Structure Transition Considering Low-Carbon Sentiment of the Decision-Makers in the Context of Carbon Neutrality

by Xinping Wang, Zhenghao Guo, Ziming Zhang, Boying Li, Chang Su, Linhui Sun and Shihui Wang

Processes 2022, 10(8), 1650; https://doi.org/10.3390/pr10081650 - 19 Aug 2022

Cited by 10 | Viewed by 2261

Abstract

Countries have started to aggressively undertake energy structure transformation strategies in order to reach the objective of carbon neutrality. Both clean and efficient coal energy use and clean energy use will be crucial to the process of changing the energy structure since the [...] Read more.

Countries have started to aggressively undertake energy structure transformation strategies in order to reach the objective of carbon neutrality. Both clean and efficient coal energy use and clean energy use will be crucial to the process of changing the energy structure since the two cannot be totally replaced within a short period of time. In this study, we quantify emotions as an irrational factor, combine them with an evolutionary game using RDEU theory, and build an evolutionary game model between government regulators and energy consumers. We then analyze how low-carbon emotions of decision-makers affect their choice of strategy and the transformation of the energy structure. The findings support that by affecting the relative importance of each strategic choice, emotions have a profound impact on the evolutionary steady state of the system. Appropriate stress and anxiety can increase decision-makers’ feelings of responsibility, while pleasant emotions frequently support strategic conduct. The main countermeasures are as follows: Allow government regulators and energy consumers to properly release positive information, with government regulators forming subsidies and energy consumers actively cooperating and promoting low-carbon activities. This will properly guide the low-carbon sentiment of game subjects to keep them realistically pessimistic. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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25 pages, 1005 KiB

Open AccessFeature PaperArticle

Impact of Electric Vehicles on Energy Efficiency with Energy Boosters in Coordination for Sustainable Energy in Smart Cities

by Pawan Kumar, Srete Nikolovski, Ikbal Ali, Mini S. Thomas and Hemant Ahuja

Processes 2022, 10(8), 1593; https://doi.org/10.3390/pr10081593 - 12 Aug 2022

Cited by 9 | Viewed by 2037

Abstract

The use of electric vehicles (EVs) has recently increased in a smart city environment. With this, the optimal location of the charging station is a great challenge and, hence, the energy efficiency performance (EEP) of an electrical system is important. Ideally, the EEP [...] Read more.

The use of electric vehicles (EVs) has recently increased in a smart city environment. With this, the optimal location of the charging station is a great challenge and, hence, the energy efficiency performance (EEP) of an electrical system is important. Ideally, the EEP is realized through passive energy boosters (PEBs) and active energy boosters (AEBs). PEBs require no external resources, and EEP is achieved through altering the network topology and loading patterns, whereas, in AEBs, integrating external energy resources is a must. The EEP has also become dynamic with the integration of an energy storage system (ESS) in a deregulated environment. Customer energy requirement varies daily, weekly, and seasonally. In this scenario, the frequent change in network topology requires modifying the size and location of AEBs. It alters the customers’ voltage profile, loadability margin, and supply reliability when the EV works differently as a load or source. Therefore, a comprehensive EEP analysis with different probabilistic loading patterns, including ESS, must be performed at the planning stage. This work uses a harmony search algorithm to evaluate EEP for AEBs and PEBs, in coordination, when ESS works as a load or source, at four locations, for customers’ and utilities’ benefits. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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19 pages, 5715 KiB

Open AccessArticle

A Different Approach to Develop a District Heating Grid Based on the Optimization of Building Clusters

by Laura Pompei, Jacob Mannhardt, Fabio Nardecchia, Lorenzo M. Pastore and Livio de Santoli

Processes 2022, 10(8), 1575; https://doi.org/10.3390/pr10081575 - 11 Aug 2022

Cited by 5 | Viewed by 1956

Abstract

Currently, reducing energy consumption and fossil fuel emissions are key factors placed in the first position on the European agenda. District heating technology is an attractive solution, able to satisfy the energy and environmental goals of policymakers and designers. In line with this, [...] Read more.

Currently, reducing energy consumption and fossil fuel emissions are key factors placed in the first position on the European agenda. District heating technology is an attractive solution, able to satisfy the energy and environmental goals of policymakers and designers. In line with this, a different approach to planning a district heating grid based on the optimization of building clusters is presented. The case study is Wilhelmsburg, a district of Hamburg city. This approach also investigates the usage of industrial waste heat as the grid’s heat source, which is CO2-neutral. First, the data acquisition regarding the buildings’ location and heat demand are described in detail. Based on the derived data and the source of the industrial waste heat, the district heating grid is created by clustering the buildings and connecting the obtained nodes. Furthermore, the grid’s efficiency is improved by eliminating nodes, which are too distant from the heat source, or have lower heat demand. Finally, a single building is simulated in Matlab/Simulink, showing the energy-savings and ecological results. The usage of the district heating grid saves 97.32 GWh annually, which results in financial savings of €5.83 million, and avoided CO2 emissions of 19,585 tCO2. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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19 pages, 6237 KiB

Open AccessArticle

Energy and Exergy Analysis of a Modified Absorption Heat Pump (MAHP) to Produce Electrical Energy and Revaluated Heat

by Javier Alejandro Hernández-Magallanes, L. A. Domínguez-Inzunza, Shadai Lugo-Loredo, K. C. Sanal, Andrea Cerdán-Pasarán, Salvador Tututi-Avila and L. I. Morales

Processes 2022, 10(8), 1567; https://doi.org/10.3390/pr10081567 - 10 Aug 2022

Cited by 2 | Viewed by 2075

Abstract

The novel modified absorption heat pump (MAHP) with the H₂O-LiBr working mixture for cogeneration applications is introduced. The MAHP can simultaneously produce electric energy and heat revaluation. The proposed system has the particularity that it can be powered by alternative thermal [...] Read more.

The novel modified absorption heat pump (MAHP) with the H₂O-LiBr working mixture for cogeneration applications is introduced. The MAHP can simultaneously produce electric energy and heat revaluation. The proposed system has the particularity that it can be powered by alternative thermal sources (such as solar energy, biomass, geothermal) or industrial waste heat, thus promoting the production and efficient use of clean energy. The effects of pressure ratio (RP), source or supply temperature (T_GH), and the energy revaluation gradient (GTL) are analyzed. The critical parameters of the proposed system are evaluated, including thermal efficiency (

η_{Th}

), exergetic efficiency (

η_{Ex}

), revaluated heat (

{\dot{Q}}_{A}

), as well as net power produced (

{\underset{W}{˙}}_{net}

). For the MAHP analysis, RP and T_GH operating ranges were chosen at 1.1–15.0 and 100–160 °C, respectively. The results show that

η_{Ex}

of 87% can be obtained, having the maximum performance in T_GH of 120 °C, RP of 1.1, and GTL of 35 °C. The

η_{Th}

varies between 51% and 55%, having a maximum GTL of 45 °C. On the other hand,

{\underset{W}{˙}}_{net}

achieves values between 260 and 582 kW, depending on the defined operating conditions. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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Review

Jump to: Editorial, Research

19 pages, 3848 KiB

Open AccessReview

Desiccant Technologies for Improving Air Quality: An Overview of the Brazilian Scenario and Comparison of Available Design Software for Manufactured Desiccant Wheels

by York Castillo Santiago, Bruno Gomes Nunes, Geovani Souza Fontana, Daiane Busanello, Alexandre Fernandes Santos, Samuel Moreira Duarte Santos, Estefania Neiva de Mello and Leandro A. Sphaier

Processes 2023, 11(7), 2031; https://doi.org/10.3390/pr11072031 - 7 Jul 2023

Cited by 2 | Viewed by 2544

Abstract

A review of desiccant dehumidification technologies for improving air quality is presented, mainly focusing on alternatives for air conditioning systems for minimizing Sick Building Syndrome. The principles and types of desiccant wheels, as well as the existing selection software for these types of [...] Read more.

A review of desiccant dehumidification technologies for improving air quality is presented, mainly focusing on alternatives for air conditioning systems for minimizing Sick Building Syndrome. The principles and types of desiccant wheels, as well as the existing selection software for these types of equipment, were reviewed and comparatively evaluated. The study focused on the Brazilian context; thus, information about this country’s air conditioning systems and laws were evaluated. Possible applications of desiccant wheels, such as their integration into cooling cycles and the sensible heat wheel, were also analyzed. Finally, several examples of commercial desiccant wheel selection software that are useful in many situations were evaluated. Nevertheless, it was evidenced that the available software could not perform an operation analysis for only a specific period. Therefore, creating computational tools to select desiccant wheels is essential when considering the data from the different Brazilian regions for a year. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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30 pages, 5136 KiB

Open AccessFeature PaperReview

Existing Stature and Possible Outlook of Renewable Power in Comprehensive Electricity Market

by Shreya Shree Das, Jayendra Kumar, Subhojit Dawn and Ferdinando Salata

Processes 2023, 11(6), 1849; https://doi.org/10.3390/pr11061849 - 19 Jun 2023

Cited by 6 | Viewed by 1662

Abstract

The massive growth in power demand and the sharp decay in the availability of conventional energy sources forces society to move toward renewable power consumption. The rise in renewable energy utilization is one of the greatest strategies involved in making the environment clean, [...] Read more.

The massive growth in power demand and the sharp decay in the availability of conventional energy sources forces society to move toward renewable power consumption. The rise in renewable energy utilization is one of the greatest strategies involved in making the environment clean, green, and emission-free. The investment cost is slightly high for this kind of resource, but their running costsare very minimal, which encourages power producers to invest in renewable power plants. Power producers always focus on their economic profit and possible feasibilities before the investment in a new power plant setup. Wind, small hydro, and solar photovoltaics have been considered the foremost efficient and feasible renewable sources. In 2021, the worldwide renewable power capacity had grown to 17%, despite supply chain disturbances and surges in prices. The renewable power market set a target of achieving a 95% increment in global power capacity by 2026. Hence, humankind should consider wind, hydro, and solar photovoltaics as the main energy sources, and there is a need to increase use of such sources. This paper highlights the latest developments, enormous technologies, and upcoming aspects of wind power, hydropower, and solar photovoltaics in India, as well as around the globe. The present status of renewable energy can motivate global power producers to spend their money on the installation of a new renewable power plant to obtain more economic benefits and give societal economic and environmental payback to humans. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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23 pages, 5053 KiB

Open AccessReview

Evaluating the Efficacy of Intelligent Methods for Maximum Power Point Tracking in Wind Energy Harvesting Systems

by Dallatu Abbas Umar, Gamal Alkawsi, Nur Liyana Mohd Jailani, Mohammad Ahmed Alomari, Yahia Baashar, Ammar Ahmed Alkahtani, Luiz Fernando Capretz and Sieh Kiong Tiong

Processes 2023, 11(5), 1420; https://doi.org/10.3390/pr11051420 - 8 May 2023

Cited by 12 | Viewed by 2161

Abstract

As wind energy is widely available, an increasing number of individuals, especially in off-grid rural areas, are adopting it as a dependable and sustainable energy source. The energy of the wind is harvested through a device known as a wind energy harvesting system [...] Read more.

As wind energy is widely available, an increasing number of individuals, especially in off-grid rural areas, are adopting it as a dependable and sustainable energy source. The energy of the wind is harvested through a device known as a wind energy harvesting system (WEHS). These systems convert the kinetic energy of wind into electrical energy using wind turbines (WT) and electrical generators. However, the output power of a wind turbine is affected by various factors, such as wind speed, wind direction, and generator design. In order to optimize the performance of a WEHS, it is important to track the maximum power point (MPP) of the system. Various methods of tracking the MPP of the WEHS have been proposed by several research articles, which include traditional techniques such as direct power control (DPC) and indirect power control (IPC). These traditional methods in the standalone form are characterized by some drawbacks which render the method ineffective. The hybrid techniques comprising two different maximum power point tracking (MPPT) algorithms were further proposed to eliminate the shortages. Furtherly, Artificial Intelligence (AI)-based MPPT algorithms were proposed for the WEHS as either standalone or integrated with the traditional MPPT methods. Therefore, this research focused on the review of the AI-based MPPT and their performances as applied to WEHS. Traditional MPPT methods that are studied in the previous articles were discussed briefly. In addition, AI-based MPPT and different hybrid methods were also discussed in detail. Our study highlights the effectiveness of AI-based MPPT techniques in WEHS using an artificial neural network (ANN), fuzzy logic controller (FLC), and particle swarm optimization (PSO). These techniques were applied either as standalone methods or in various hybrid combinations, resulting in a significant increase in the system’s power extraction performance. Our findings suggest that utilizing AI-based MPPT techniques can improve the efficiency and overall performance of WEHS, providing a promising solution for enhancing renewable energy systems. Full article

(This article belongs to the Special Issue Advances in Renewable Energy Systems)

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