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Energies, Volume 15, Issue 2 (January-2 2022) – 279 articles

Cover Story (view full-size image): The current power production capacity is being replaced by renewable energy sources, and it is vital that this new capacity is located rationally. The positioning of this capacity can be affected by energy market policies and pricing schemes. Synthetic networks and graph theory provide tools to assess how these policies can affect power production positioning and power system performance. For example, windy coasts can be an attractive location for wind turbines due to weather conditions, but socioeconomic costs might increase if transmission distances get too long. View this paper
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18 pages, 4587 KiB  
Article
Analysis of Available Conditions for InSAR Surface Deformation Monitoring in CCS Projects
by Tian Zhang, Wanchang Zhang, Ruizhao Yang, Huiran Gao and Dan Cao
Energies 2022, 15(2), 672; https://doi.org/10.3390/en15020672 - 17 Jan 2022
Cited by 9 | Viewed by 2758
Abstract
Carbon neutrality is a goal the world is striving to achieve in the context of global warming. Carbon capture and storage (CCS) has received extensive attention as an effective method to reduce carbon dioxide (CO2) in the atmosphere. What follows is [...] Read more.
Carbon neutrality is a goal the world is striving to achieve in the context of global warming. Carbon capture and storage (CCS) has received extensive attention as an effective method to reduce carbon dioxide (CO2) in the atmosphere. What follows is the migration pathway and leakage monitoring after CO2 injection. Interferometric synthetic aperture radar (InSAR) technology, with its advantages of extensive coverage in surface deformation monitoring and all-weather traceability of the injection processes, has become one of the promising technologies frequently adopted in worldwide CCS projects. However, there is no mature evaluation system to determine whether InSAR technology is suitable for each CO2 sequestration area. In this study, a new evaluation model is proposed based on the eight factors that are selected from the principle of the InSAR technique and the unique characteristics of the CO2 sequestration area. According to the proposed model, the feasibility of InSAR monitoring is evaluated for the existing typical sequestration areas in the world. Finally, the challenges and prospects of InSAR in the CCS project are discussed. Full article
(This article belongs to the Special Issue Advances in Methane Production from Coal, Shale and Other Tight Rocks)
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15 pages, 1943 KiB  
Article
An Improved Charge-Based Method Extended to Estimating Appropriate Dead Time for Zero-Voltage-Switching Analysis in Dual-Active-Bridge Converter
by Haoyu Zhang and Takanori Isobe
Energies 2022, 15(2), 671; https://doi.org/10.3390/en15020671 - 17 Jan 2022
Cited by 4 | Viewed by 1644
Abstract
This paper presents a comprehensive analysis of zero-voltage-switching (ZVS) realization with an improved charge-based method by considering both voltage dependency parasitic capacitance and dead time in dual-active-bridge (DAB) converters, when the voltage ratio between the primary and secondary sides does not match the [...] Read more.
This paper presents a comprehensive analysis of zero-voltage-switching (ZVS) realization with an improved charge-based method by considering both voltage dependency parasitic capacitance and dead time in dual-active-bridge (DAB) converters, when the voltage ratio between the primary and secondary sides does not match the turn ratio of the transformer. For this purpose, a unified equivalent circuit is proposed to represent the switching motions at all possible switching instances under the condition of one-leg manipulation. The combinations of switching cases can be presented in a table to build the corresponding equivalent circuit for ZVS analysis. Combined with the improved charge-based method, the common solutions of the minimum required switching current and the appropriate dead-time range for each equivalent circuit to realize ZVS are deduced. The allowable range of the dead time for ZVS as a function of the switching current is analyzed to determine the appropriate dead time. Once the switching current and dead-time range are derived, the model-based lowest switching current control method can be used to achieve ZVS by using the appropriate amount of both factors. Experiments using a 4 kW DAB prototype were conducted to verify the theoretical analyses. Full article
(This article belongs to the Special Issue Power Converters: Modeling, Design and Applications)
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16 pages, 6549 KiB  
Article
Modal Analysis of Tubing Considering the Effect of Fluid–Structure Interaction
by Jiehao Duan, Changjun Li and Jin Jin
Energies 2022, 15(2), 670; https://doi.org/10.3390/en15020670 - 17 Jan 2022
Cited by 9 | Viewed by 2258
Abstract
When tubing is in a high-temperature and high-pressure environment, it will be affected by the impact of non-constant fluid and other dynamic loads, which will easily cause the tubing to vibrate or even resonate, affecting the integrity of the wellbore and safe production. [...] Read more.
When tubing is in a high-temperature and high-pressure environment, it will be affected by the impact of non-constant fluid and other dynamic loads, which will easily cause the tubing to vibrate or even resonate, affecting the integrity of the wellbore and safe production. In the structural modal analysis of the tubing, the coupling effect of the fluid and the tubing needs to be considered at the same time. In this paper, a single tubing is taken as an example to simulate and analyze the modal changes of the tubing under dry mode and wet mode respectively, and the effects of fluid solid coupling effect, inlet pressure, and ambient temperature on the modal of the tubing are discussed. After considering the fluid–structure interaction effect, the natural frequency of tubing decreases, but the displacement is slightly larger. The greater the pressure in the tubing, the greater the equivalent stress on the tubing body, so the natural frequency is lower. Furthermore, after considering the fluid–solid coupling effect, the pressure in the tubing is the true pulsating pressure of the fluid. The prestress applied to the tubing wall changes with time, and the pressures at different parts are different. At this time, the tubing is changed at different frequencies. Vibration is prone to occur, that is, the natural frequency is smaller than the dry mode. The higher the temperature, the lower the rigidity of the tubing and the faster the strength attenuation, so the natural frequency is lower, and tubing is more prone to vibration. Both the stress intensity and the elastic strain increase with the increase of temperature, so the displacement of the tubing also increases. Full article
(This article belongs to the Collection State of the Art Geo-Energy Technology in China)
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16 pages, 1772 KiB  
Article
Analysis and Evaluation of the Photovoltaic Market in Poland and the Baltic States
by Ewa Chomać-Pierzecka, Andrzej Kokiel, Joanna Rogozińska-Mitrut, Anna Sobczak, Dariusz Soboń and Jacek Stasiak
Energies 2022, 15(2), 669; https://doi.org/10.3390/en15020669 - 17 Jan 2022
Cited by 37 | Viewed by 2983
Abstract
The household, industrial, and service sectors in Poland and the Baltic States have been facing ever-higher bills for their electricity consumption at a time when a number of them have been hit hard financially by the pandemic. Rising inflation, the border crisis—with its [...] Read more.
The household, industrial, and service sectors in Poland and the Baltic States have been facing ever-higher bills for their electricity consumption at a time when a number of them have been hit hard financially by the pandemic. Rising inflation, the border crisis—with its set of restrictions, or the spread of the fourth wave of the COVID-19 coronavirus pandemic, is causing strong concerns in the social and economic sphere, with significant increases in electricity prices. Many countries are implementing measures to reduce the adverse effects of rising electricity prices in response to this complex situation. The main orientation is towards obtaining energy from renewable sources, such as the sun. The current situation in the energy market determines the price per 1 KW. Among the countries under study, the price of electricity has increased the most in Poland. On the other hand, the development of the photovoltaic segment in Poland is undergoing a strong, upward trend. The above inspired the authors to explore the energy market situation in Poland and the Baltic States in the current economic conditions, along with an analysis of its development potential in light of the coronavirus pandemic. The main research problem of this study is an attempt to answer the question of what should be changed in the development of the renewable energy market in Poland, with particular emphasis on photovoltaics, to accelerate the process of reducing CO2 emissions, leading to a reduction in dramatically rising electricity prices. Which solutions implemented in the Baltic countries can inspire strengthening Poland’s energy market development? Full article
(This article belongs to the Special Issue The Effect of COVID-19 Pandemic on the Energy Economics and Markets in Central and Eastern Europe)
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21 pages, 6651 KiB  
Article
Elliptical-Shaped Fresnel Lens Design through Gaussian Source Distribution
by Dário Garcia, Dawei Liang, Joana Almeida, Bruno D. Tibúrcio, Hugo Costa, Miguel Catela and Cláudia R. Vistas
Energies 2022, 15(2), 668; https://doi.org/10.3390/en15020668 - 17 Jan 2022
Cited by 2 | Viewed by 2895
Abstract
A novel three-dimensional elliptical-shaped Fresnel lens (ESFL) analytical model is presented to evaluate and maximize the solar energy concentration of Fresnel-lens-based solar concentrators. AutoCAD, Zemax and Ansys software were used for the ESFL design, performance evaluation and temperature calculation, respectively. Contrary to the [...] Read more.
A novel three-dimensional elliptical-shaped Fresnel lens (ESFL) analytical model is presented to evaluate and maximize the solar energy concentration of Fresnel-lens-based solar concentrators. AutoCAD, Zemax and Ansys software were used for the ESFL design, performance evaluation and temperature calculation, respectively. Contrary to the previous modeling processes, based on the edge-ray principle with an acceptance half-angle of ±0.27° as the key defining parameter, the present model uses, instead, a Gaussian distribution to define the solar source in Zemax. The results were validated through the numerical analysis of published experimental data from a flat Fresnel lens. An in-depth study of the influence of several ESFL factors, such as focal length, arch height and aspect ratio, on its output performance is carried out. Moreover, the evaluation of the ESFL output performance as a function of the number/size of the grooves is also analyzed. Compared to the typical 1–16 grooves per millimeter reported in the previous literature, this mathematical parametric modeling allowed a substantial reduction in grooves/mm to 0.3–0.4, which may enable an easy mass production of ESFL. The concentrated solar distribution of the optimal ESFL configuration was then compared to that of the best flat Fresnel lens configuration, under the same focusing conditions. Due to the elliptical shape of the lens, the chromatic aberration effect was largely reduced, resulting in higher concentrated solar flux and temperature. Over 2360 K and 1360 K maximum temperatures were found for ESFL and flat Fresnel lenses, respectively, demonstrating the great potential of the three-dimensional curved-shaped Fresnel lens on renewable solar energy applications that require high concentrations of solar fluxes and temperatures. Full article
(This article belongs to the Special Issue Challenge and Research Trends of Solar Concentrators)
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20 pages, 17197 KiB  
Article
A Transformerless AC-AC Converter with Improved Power Quality Employed to Step-Down Power Frequency at Output
by Naveed Ashraf, Ghulam Abbas, Nasim Ullah, Ahmad Aziz Al-Ahmadi, Abdul Rehman Yasin, Ahmed Bilal Awan and Mohsin Jamil
Energies 2022, 15(2), 667; https://doi.org/10.3390/en15020667 - 17 Jan 2022
Cited by 6 | Viewed by 2777
Abstract
Variable voltage and frequency are required to govern the torque-speed characteristics of many industrial drive systems. Traditionally, this is achieved with a power converting system implemented with multistage converters. This technology is based on rectifying AC power into DC and then DC into [...] Read more.
Variable voltage and frequency are required to govern the torque-speed characteristics of many industrial drive systems. Traditionally, this is achieved with a power converting system implemented with multistage converters. This technology is based on rectifying AC power into DC and then DC into AC with an inverter circuit. The power quality concerns of both conversion stages are tackled by selecting high switching frequency PWM control and harmonics mitigation filters. Also, using a bulky DC-link capacitor is one of the big sources of low system reliability, so this approach increases the conversion losses, circuit, and control complications. The frequency step-down conversion is very attractive with direct AC-AC converters as it has a simple control and circuit structure, but these converters face poor power quality challenges once the output frequency is decreased with respect to an input. In these converters, the total harmonic distortion (THD) of the output voltage becomes very poor once the output frequency is reduced. The problem of high THD of the output is addressed in the power converting circuits implemented with line frequency multi-winding transformers. The required number of output winding and switching devices (diodes and thyristors) increases once the value of the output frequency is decreased. This will increase the overall volume, cost, and losses. The use of a bulky and costly line frequency transformer may be eliminated if AC voltage controllers have non-inverted and inverted voltage buck capabilities, such existing topologies either have complex control schemes or require a large number of operating devices. Therefore, in this research article, a new transformerless frequency step-down converter employing fewer devices is proposed. This approach is realized with a high-frequency controlled rectifier for the required voltage stabilization and a low-frequency inverter bridge for frequency control. Its validation is supported by the results attained from Simulink and practical-based prototypes. Full article
(This article belongs to the Special Issue Design and Investigation of Power Electronics Converters and Its Control)
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22 pages, 1336 KiB  
Article
An Analysis-Supported Design of a Single Active Bridge (SAB) Converter
by Rupesh Jha, Mattia Forato, Satya Prakash, Hemant Dashora and Giuseppe Buja
Energies 2022, 15(2), 666; https://doi.org/10.3390/en15020666 - 17 Jan 2022
Cited by 5 | Viewed by 2791
Abstract
Currently, due to its various applications, the high-performance isolated dc-dc converter is in demand. In applications where unidirectional power transfer is required, the single active bridge (SAB) is the most suitable one due to its simplicity and ease of control. The general schematic [...] Read more.
Currently, due to its various applications, the high-performance isolated dc-dc converter is in demand. In applications where unidirectional power transfer is required, the single active bridge (SAB) is the most suitable one due to its simplicity and ease of control. The general schematic of the SAB converter consists of an active bridge and a passive bridge, which are connected through a high-frequency transformer thus isolated. The paper summarizes the behavior of this converter in its three operation modes, namely the continuous, discontinuous, and boundary modes. Later, the features of this converter, such as its input-to-output and external characteristics are discussed. Input-to-output characteristics include the variation of converter output power, voltage, and current with an input control variable i.e., phase-shift angle, whereas the external characteristic is the variation of the output voltage as a function of output current. In this discussion, the behavior of this converter in its extreme operating conditions is also examined. The features of the characteristics are elucidated with the help of suitable plots obtained in the MATLAB environment. Afterward, the specifications of a SAB converter are given and, based on the results of the analysis, a detailed design of its electrical elements is carried out. To validate the features and the design procedures presented in this paper, a prototype is developed. An element-wise loss estimation is also carried out and the efficiency of the converter has been found to be approximately equal to 93%. Lastly, the test was executed on this prototype, confirming the theoretical findings concerning this converter. Full article
(This article belongs to the Collection Electrical Power and Energy System: From Professors to Students)
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18 pages, 8477 KiB  
Article
Reliability-as-a-Service Usage of Electric Vehicles: Suitability Analysis for Different Types of Buildings
by Akhtar Hussain and Petr Musilek
Energies 2022, 15(2), 665; https://doi.org/10.3390/en15020665 - 17 Jan 2022
Cited by 4 | Viewed by 1579
Abstract
The use of electric vehicles (EVs) to provide different grid services is becoming possible due to the increased penetration levels, mileage efficiencies, and useable battery sizes of EVs. One such application is providing reliability-as-a-service (RaaS) during short-term power outages. Instead of using a [...] Read more.
The use of electric vehicles (EVs) to provide different grid services is becoming possible due to the increased penetration levels, mileage efficiencies, and useable battery sizes of EVs. One such application is providing reliability-as-a-service (RaaS) during short-term power outages. Instead of using a dedicated backup power source, EVs can be contracted to provide RaaS, which is an environmentally friendly solution with benefits for both building owners and EV owners. However, the presence of EVs at a particular location during different hours of the day and the availability of energy from EVs is uncertain. Therefore, in this study, a suitability analysis is performed concerning the use of EVs to provide RaaS for different types of buildings. First, the National Household Travel Survey (NHTS) survey data are used to estimate driver behavior, such as arrival/departure times, daily mileage, and traveling duration. Then, the usable battery size and mileage efficiency of EVs is extracted from the database of commercially available EVs. Based on these parameters, the daily energy consumption and available energy of EVs to provide RaaS are estimated. A suitability analysis is conducted for residential, commercial/industrial, and mixed buildings for both weekdays and holidays. The participation ratio of EV owners is varied between 10 and 90%, and nine cases are simulated for commercial/industrial buildings and multi-unit residential buildings. Similarly, the ratio of home-based EVs is varied between 5 and 50%, and 10 cases are tested for mixed buildings. The analysis shows that mixed buildings are the most suitable, while commercial/industrial buildings are the least suitable for using EVs to provide RaaS. To this end, an index is proposed to analyze and determine the desired ratio of EVs to be contracted from homes and workplaces for mixed buildings. Finally, the impact of EV fleet size on the available energy for RaaS is also analyzed. Full article
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14 pages, 1049 KiB  
Article
Structural Model of Power Grid Stabilization in the Green Hydrogen Supply Chain System—Conceptual Assumptions
by Marzena Frankowska, Marta Mańkowska, Marcin Rabe, Andrzej Rzeczycki and Elżbieta Szaruga
Energies 2022, 15(2), 664; https://doi.org/10.3390/en15020664 - 17 Jan 2022
Cited by 10 | Viewed by 2966
Abstract
The paper presents the conceptual assumptions of research concerning the design of a theoretical multi-criteria model of a system architecture to stabilize the operation of power distribution networks based on a hydrogen energy buffer, taking into account the utility application of hydrogen. The [...] Read more.
The paper presents the conceptual assumptions of research concerning the design of a theoretical multi-criteria model of a system architecture to stabilize the operation of power distribution networks based on a hydrogen energy buffer, taking into account the utility application of hydrogen. The basis of the research process was a systematic literature review using the technique of in-depth analysis of full-text articles and expert consultations. The structural model concept was described in two dimensions in which the identified variables were embedded. The first dimension includes the supply chain phases: procurement and production with warehousing and distribution. The second dimension takes into account a comprehensive and interdisciplinary approach and includes the following factors: technical, economic–logistical, locational, and formal–legal. Full article
(This article belongs to the Special Issue Financial Development and Energy Consumption Nexus)
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20 pages, 4681 KiB  
Article
A Quantile Regression Random Forest-Based Short-Term Load Probabilistic Forecasting Method
by Sanlei Dang, Long Peng, Jingming Zhao, Jiajie Li and Zhengmin Kong
Energies 2022, 15(2), 663; https://doi.org/10.3390/en15020663 - 17 Jan 2022
Cited by 16 | Viewed by 2542
Abstract
In this paper, a novel short-term load forecasting method amalgamated with quantile regression random forest is proposed. Comprised with point forecasting, it is capable of quantifying the uncertainty of power load. Firstly, a bespoke 2D data preprocessing taking advantage of empirical mode decomposition [...] Read more.
In this paper, a novel short-term load forecasting method amalgamated with quantile regression random forest is proposed. Comprised with point forecasting, it is capable of quantifying the uncertainty of power load. Firstly, a bespoke 2D data preprocessing taking advantage of empirical mode decomposition (EMD) is presented. It can effectively assist subsequent point forecasting models to extract spatial features hidden in the 2D load matrix. Secondly, by exploiting multimodal deep neural networks (DNN), three short-term load point forecasting models are conceived. Furthermore, a tailor-made multimodal spatial–temporal feature extraction is proposed, which integrates spatial features, time information, load, and electricity price to obtain more covert features. Thirdly, relying on quantile regression random forest, the probabilistic forecasting method is proposed, which exploits the results from the above three short-term load point forecasting models. Lastly, the experimental results demonstrate that the proposed method outperforms its conventional counterparts. Full article
(This article belongs to the Special Issue Modeling, Analysis and Control of Power System Distribution Networks)
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23 pages, 7794 KiB  
Article
Development of Photovoltaic Energy in EU Countries as an Alternative to Fossil Fuels
by Radosław Wolniak and Bożena Skotnicka-Zasadzień
Energies 2022, 15(2), 662; https://doi.org/10.3390/en15020662 - 17 Jan 2022
Cited by 30 | Viewed by 3545
Abstract
The aim of the article is to present the development of photovoltaic energy in the EU countries as one of the alternatives to fossil fuels. The article was prepared on the basis of secondary information and statistical data on the photovoltaic energy market [...] Read more.
The aim of the article is to present the development of photovoltaic energy in the EU countries as one of the alternatives to fossil fuels. The article was prepared on the basis of secondary information and statistical data on the photovoltaic energy market in EU countries, and three hypotheses were formulated: H1—There is a statistically significant correlation between a country’s long-term orientation and its use of photovoltaic energy in European Union countries; H2—There is a statistically significant correlation between GDP per capita and photovoltaic energy use in European Union countries; and H3—There is a relationship between climate and photovoltaic energy use in European Union countries. Correlation coefficients and the Guilford classification were used to analyse the data. Data analysis has shown that photovoltaic energy is the second fastest-growing energy source in the EU, after wind energy. In 2020, 134 TWh of solar energy was produced in the EU countries. Based on the analysis, it can be concluded that there is a statistically significant correlation between the production of photovoltaic energy per person and the level of GDP per capita in the EU countries (Hypothesis 2). Germany and the Netherlands produce the most solar energy. The studies did not confirm Hypothesis 3; however, it can be seen that countries such as Germany, Belgium and the Netherlands have the highest PV energy efficiency compared to average temperature values. A data analysis showed statistically significant correlations between the country’s long-term orientation in the use of photovoltaic energy (Hypothesis 1). In the case of Germany and Belgium, the long-term orientation indicator is very high above 80, while Portugal, Poland and Finland have the lowest indicator, from 30 to 40. Full article
(This article belongs to the Special Issue Economics and Management in Extractive and Energy Industry)
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23 pages, 2274 KiB  
Article
Assessment of the Feasibility of Energy Transformation Processes in European Union Member States
by Michał Bernard Pietrzak, Magdalena Olczyk and Marta Ewa Kuc-Czarnecka
Energies 2022, 15(2), 661; https://doi.org/10.3390/en15020661 - 17 Jan 2022
Cited by 15 | Viewed by 2295
Abstract
The energy transition is now treated in most countries as a necessary condition for their long-term development. The process of energy transformation assumes the simultaneous implementation of the Sustainable Development Goals, which are a major challenge for modern economies and introduce significant restrictions [...] Read more.
The energy transition is now treated in most countries as a necessary condition for their long-term development. The process of energy transformation assumes the simultaneous implementation of the Sustainable Development Goals, which are a major challenge for modern economies and introduce significant restrictions in their functioning. Our study aims to group EU member states according to their ability to achieve energy transition over time. The novelty of our approach is the assessment of energy transformation in the European Union through two aspects. The first one, “smart and efficient energy systems”, assess the current, widely understood energy consumption in economy, and the second one, “macroeconomic heterogeneity”, refers to the economic potential of a country. In our analysis, we included indicators from the 7th, 8th, 10th, 11th, and 12th Sustainable Development Goals. Using taxonomic methods, we created clusters of countries according to the emissivity of their economies and the socio-economic potential for the energy transition. The analysis results revealed that countries vary more due to their emissivity than economic potential. Full article
(This article belongs to the Special Issue Transformation of Energy Markets: Description, Modeling of Functioning Mechanisms and Determining Development Trends)
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35 pages, 15120 KiB  
Article
Optimising High-Rise Buildings for Self-Sufficiency in Energy Consumption and Food Production Using Artificial Intelligence: Case of Europoint Complex in Rotterdam
by Berk Ekici, Okan F. S. F. Turkcan, Michela Turrin, Ikbal Sevil Sariyildiz and Mehmet Fatih Tasgetiren
Energies 2022, 15(2), 660; https://doi.org/10.3390/en15020660 - 17 Jan 2022
Cited by 14 | Viewed by 3087
Abstract
The increase in global population, which negatively affects energy consumption, CO2 emissions, and arable land, necessitates designing sustainable habitation alternatives. Self-sufficient high-rise buildings, which integrate (electricity) generation and efficient usage of resources with dense habitation, can be a sustainable solution for future [...] Read more.
The increase in global population, which negatively affects energy consumption, CO2 emissions, and arable land, necessitates designing sustainable habitation alternatives. Self-sufficient high-rise buildings, which integrate (electricity) generation and efficient usage of resources with dense habitation, can be a sustainable solution for future urbanisation. This paper focuses on transforming Europoint Towers in Rotterdam into self-sufficient buildings considering energy consumption and food production (lettuce crops) using artificial intelligence. Design parameters consist of the number of farming floors, shape, and the properties of the proposed façade skin that includes shading devices. Nine thousand samples are collected from various floor levels to predict self-sufficiency criteria using artificial neural networks (ANN). Optimisation problems with 117 decision variables are formulated using 45 ANN models that have very high prediction accuracies. 13 optimisation algorithms are used for an in-detail investigation of self-sufficiency at the building scale, and potential sufficiency at the neighbourhood scale. Results indicate that 100% and 43.7% self-sufficiencies could be reached for lettuce crops and electricity, respectively, for three buildings with 1800 residents. At the neighbourhood scale, lettuce production could be sufficient for 27,000 people with a decrease of self-sufficiency in terms of energy use of up to 11.6%. Consequently, this paper discusses the potentials and the improvements for self-sufficient high-rise buildings. Full article
(This article belongs to the Special Issue Research Innovations for Advanced Analysis and Multi-Performance Driven Design in the Built Environment)
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14 pages, 30212 KiB  
Article
Alternative Fuel Generation from Dangerous Solid Waste in a Protected Environmental Area
by Pedro Mora, Daniel Barettino, Antonio Ponce, Laura Sánchez-Martín and Bernardo Llamas
Energies 2022, 15(2), 659; https://doi.org/10.3390/en15020659 - 17 Jan 2022
Viewed by 1332
Abstract
The present investigation project aims to evaluate the extraction of contaminant material from two settling ponds to be used as alternative fuel in two cement plants. The extraction is carried out through mechanical means, and after that extraction, two options are compared: energy [...] Read more.
The present investigation project aims to evaluate the extraction of contaminant material from two settling ponds to be used as alternative fuel in two cement plants. The extraction is carried out through mechanical means, and after that extraction, two options are compared: energy recovery and incineration. Through energy recovery, a potentially contaminated area is decontaminated and its waste is used; its high calorific value makes this option a viable one. The waste extraction is carried out through mechanical means due to the high density and viscosity of the waste. Because of these characteristics, the waste undergoes an on-site security adaptation to stabilize it, reduce declivity risk and make it suitable to be handled and moved. The second treatment is carried out in external installations where the final product is obtained (alternative fuel), which is to be used at industrial kilns. The entire described process shows a difference on the consumed energy of 6060.42 kWh/twaste between the two options under study: waste incineration and energy recovery. In addition, it also reduces CO2 emissions on 2.178 tCO2/twaste. Full article
(This article belongs to the Special Issue Circular Economy and Environmental Protection in the Upstream Petroleum Industry)
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29 pages, 4224 KiB  
Article
The Place of Energy Security in the National Security Framework: An Assessment Approach
by Daniel Mara, Silviu Nate, Andriy Stavytskyy and Ganna Kharlamova
Energies 2022, 15(2), 658; https://doi.org/10.3390/en15020658 - 17 Jan 2022
Cited by 28 | Viewed by 4284
Abstract
The term “energy security” is used almost everywhere in economic and political discussions related to energy supply. However, different authors use different meanings to express the concept of energy security. Quite often, this term is used to give more importance or relevance to [...] Read more.
The term “energy security” is used almost everywhere in economic and political discussions related to energy supply. However, different authors use different meanings to express the concept of energy security. Quite often, this term is used to give more importance or relevance to issues that are often not inherently related to energy security. Attempts to define the essence of the concept of “energy security” have hitherto not been systematic and are characterized by a variety of approaches, and some insufficient justification especially in the aspect of state national security is notable. Our contribution to the discourse development is the consideration of energy security as part of internationally recognized indices that are developed to assess the temperature of world security. A regression modeling approach to test the crucial factors of social-economic development that impact the energy security indicators is presented. The literature analysis and review of the world’s existing national security indices show that the link between energy security and national security is in fact hardly considered. Mostly, energy security is considered in the dichotomy concerning economic security at the international, as well as national levels. The calculative regression modeling revealed that the significant correlation of economic and energy security is just for the U.S.A., the rest of the analyzed countires display the weak or non-significant correlations of the indices of economic/energy/security threats. That pushes the discussion on whether energy security is indeed so impactful a factor for geo-policy and geo-economy, or whether it is mostly the well-rolled media-supported megatrend. However, the present study notes a great shortage of long-term cross-state indices to reflect energy, economic, and national security to allow for valuable modeling. Full article
(This article belongs to the Special Issue Policy and Economic Analysis of Sustainable Energy Transition and Mobility)
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39 pages, 10884 KiB  
Article
Different Fuzzy Control Configurations Tuned by the Bees Algorithm for LFC of Two-Area Power System
by Mokhtar Shouran, Fatih Anayi, Michael Packianather and Monier Habil
Energies 2022, 15(2), 657; https://doi.org/10.3390/en15020657 - 17 Jan 2022
Cited by 11 | Viewed by 2051
Abstract
This study develops and implements a design of the Fuzzy Proportional Integral Derivative with filtered derivative mode (Fuzzy PIDF) for Load Frequency Control (LFC) of a two-area interconnected power system. To attain the optimal values of the proposed structure’s parameters which guarantee the [...] Read more.
This study develops and implements a design of the Fuzzy Proportional Integral Derivative with filtered derivative mode (Fuzzy PIDF) for Load Frequency Control (LFC) of a two-area interconnected power system. To attain the optimal values of the proposed structure’s parameters which guarantee the best possible performance, the Bees Algorithm (BA) and other optimisation tools are used to accomplish this task. A Step Load Perturbation (SLP) of 0.2 pu is applied in area one to examine the dynamic performance of the system with the proposed controller employed as the LFC system. The supremacy of Fuzzy PIDF is proven by comparing the results with those of previous studies for the same power system. As the designed controller is required to provide reliable performance, this study is further extended to propose three different fuzzy control configurations that offer higher reliability, namely Fuzzy Cascade PI − PD, Fuzzy PI plus Fuzzy PD, and Fuzzy (PI + PD), optimized by the BA for the LFC for the same dual-area power system. Moreover, an extensive examination of the robustness of these structures towards the parametric uncertainties of the investigated power system, considering thirteen cases, is carried out. The simulation results indicate that the contribution of the BA tuned the proposed fuzzy control structures in alleviating the overshoot, undershoot, and the settling time of the frequency in both areas and the tie-line power oscillations. Based on the obtained results, it is revealed that the lowest drop of the frequency in area one is −0.0414 Hz, which is achieved by the proposed Fuzzy PIDF tuned by the BA. It is also divulged that the proposed techniques, as was evidenced by their performance, offer a good transient response, a considerable capability for disturbance rejection, and an insensitivity towards the parametric uncertainty of the controlled system. Full article
(This article belongs to the Special Issue Powering Net Zero Emissions—Selected Papers from 56th International Universities Power Engineering Conference (UPEC 2021))
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35 pages, 5213 KiB  
Article
Prediction of Oil Recovery Factor in Stratified Reservoirs after Immiscible Water-Alternating Gas Injection Based on PSO-, GSA-, GWO-, and GA-LSSVM
by Pål Østebø Andersen, Jan Inge Nygård and Aizhan Kengessova
Energies 2022, 15(2), 656; https://doi.org/10.3390/en15020656 - 17 Jan 2022
Cited by 6 | Viewed by 1716
Abstract
In this study, we solve the challenge of predicting oil recovery factor (RF) in layered heterogeneous reservoirs after 1.5 pore volumes of water-, gas- or water-alternating-gas (WAG) injection. A dataset of ~2500 reservoir simulations is analyzed based on a Black Oil [...] Read more.
In this study, we solve the challenge of predicting oil recovery factor (RF) in layered heterogeneous reservoirs after 1.5 pore volumes of water-, gas- or water-alternating-gas (WAG) injection. A dataset of ~2500 reservoir simulations is analyzed based on a Black Oil 2D Model with different combinations of reservoir heterogeneity, WAG hysteresis, gravity influence, mobility ratios and WAG ratios. In the first model MOD1, RF is correlated with one input (an effective WAG mobility ratio M*). Good correlation (Pearson coefficient −0.94), but with scatter, motivated a second model MOD2 using eight input parameters: water–oil and gas–oil mobility ratios, water–oil and gas–oil gravity numbers, a reservoir heterogeneity factor, two hysteresis parameters and water fraction. The two mobility ratios exhibited the strongest correlation with RF (Pearson coefficient −0.57 for gas-oil and −0.48 for water-oil). LSSVM was applied in MOD2 and trained using different optimizers: PSO, GA, GWO and GSA. A physics-based adaptation of the dataset was proposed to properly handle the single-phase injection. A total of 70% of the data was used for training, 15% for validation and 15% for testing. GWO and PSO optimized the model equally well (R2 = 0.9965 on the validation set), slightly better than GA and GSA (R2 = 0.9963). The performance metrics for MOD1 in the total dataset were: RMSE = 0.050 and R2 = 0.889; MOD2: RMSE = 0.0080 and R2 = 0.998. WAG outperformed single-phase injection, in some cases with 0.3 units higher RF. The benefits of WAG increased with stronger hysteresis. The LSSVM model could be trained to be less dependent on hysteresis and the non-injected phase during single-phase injection. Full article
(This article belongs to the Special Issue Management of High Water Cut and Mature Petroleum Reservoirs)
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12 pages, 3221 KiB  
Article
Effects of Cofiring Coal and Biomass Fuel on the Pulverized Coal Injection Combustion Zone in Blast Furnaces
by Gyeong-Min Kim, Jae Hyung Choi, Chung-Hwan Jeon and Dong-Ha Lim
Energies 2022, 15(2), 655; https://doi.org/10.3390/en15020655 - 17 Jan 2022
Cited by 4 | Viewed by 1932
Abstract
CO2 emissions are a major contributor to global warming. Biomass combustion is one approach to tackling this issue. Biomass is used with coal combustion in thermal power plants or with blast furnaces (BFs) because it is a carbon-neutral fuel; therefore, biomass provides [...] Read more.
CO2 emissions are a major contributor to global warming. Biomass combustion is one approach to tackling this issue. Biomass is used with coal combustion in thermal power plants or with blast furnaces (BFs) because it is a carbon-neutral fuel; therefore, biomass provides the advantage of reduced CO2 emissions. To examine the effect of co-firing on pulverized coal injection (PCI) in BFs, two coals of different ranks were blended with the biomass in different proportions, and then their combustion behaviors were examined using a laminar flow reactor (LFR). The PCI combustion primarily functions as a source of heat and CO to supply the upper part of the BF. To create a similar PCI combustion environment, the LFR burner forms a diffusion flat flame with an oxygen concentration of 26% with a flame temperature of ~2000–2250 K at a heating rate of 105 K/s. The combustion characteristics, such as the flame structure, burning coal particle temperature, unburned carbon (UBC), and CO and CO2 emissions were measured to evaluate their effect on PCI combustion. With the increase in the biomass blending ratio, the brightness of the volatile cloud significantly increased, and the particle temperature tended to decrease. The fragmentation phenomenon, which was observed for certain coal samples, decreased with the increase in the biomass blending ratio. In particular, with an increase in the biomass blending ratio, the optimum combustion point occurred, caused by the fragmentation of coal and volatile gas combustion of biomass. Full article
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29 pages, 46865 KiB  
Article
Study on Behavioral Decision Making by Power Generation Companies Regarding Energy Transitions under Uncertainty
by Ryosuke Gotoh, Tetsuo Tezuka and Benjamin C. McLellan
Energies 2022, 15(2), 654; https://doi.org/10.3390/en15020654 - 17 Jan 2022
Cited by 2 | Viewed by 1828
Abstract
With respect to decision making by companies, normative approaches such as the net present value (NPV) method are widely applied, even though it is known that investors may make non-normative decisions. This study aimed to obtain new information on the decision-making behavior of [...] Read more.
With respect to decision making by companies, normative approaches such as the net present value (NPV) method are widely applied, even though it is known that investors may make non-normative decisions. This study aimed to obtain new information on the decision-making behavior of renewable energy (RE) companies under uncertainty in the energy market, which is not provided by the conventional normative approach. In this study, we designed a novel framework that expressed both normative and non-normative perspectives of decision making, and developed a behavioral decision-making model of a power generation company investing in large-scale RE (RE company). We also examined the decisions of the RE company under uncertainty in the energy market using the developed model, considering the Kansai region in Japan as an example study area. As a result, compared to the conventional NPV method, we obtained the following information: (i) heavy investments in either photovoltaics (PV) or wind resulted in decreased variable renewable energy (VRE) capacity, even though financial support was sufficient; (ii) balanced investments in both PV and wind yielded a larger VRE capacity in cases where financial support was sufficient; and (iii) co-worker’s suggestions that lowered the decision-makers’ reference point (RFP) encouraged VRE investments despite insufficient financial support. Full article
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12 pages, 938 KiB  
Article
Experimental Lognormal Modeling of Harmonics Power of Switched-Mode Power Supplies
by Dima Bykhovsky
Energies 2022, 15(2), 653; https://doi.org/10.3390/en15020653 - 17 Jan 2022
Cited by 4 | Viewed by 1391
Abstract
Switched-mode power supplies (SMPSs) are an important component in many electrical systems. As a highly non-linear device, an unavoidable side-effect of SMPS operation is its high harmonics power. One of the ways to model the harmonic power consumption profile is in terms of [...] Read more.
Switched-mode power supplies (SMPSs) are an important component in many electrical systems. As a highly non-linear device, an unavoidable side-effect of SMPS operation is its high harmonics power. One of the ways to model the harmonic power consumption profile is in terms of a random process. This paper addresses random process modeling with a corresponding probability density function (PDF), auto-covariance function (ACF) and spectral coherence. The consumed harmonics power was evaluated under different load conditions and is based on experimental results of current consumption from SMPSs. The analysis shows that harmonics power may be modeled by a lognormal distribution that is time-domain uncorrelated, and that has spectral-domain correlation modeled by a Gaussian radial basis function. Extensive discussion on the modeling results is also provided. Moreover, random simulation approach based on the modeling results was proposed. Full article
(This article belongs to the Special Issue New Challenges in Harmonics and Power Quality Research)
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23 pages, 2107 KiB  
Article
Standing Wave Pattern and Distribution of Currents in Resonator Arrays for Wireless Power Transfer
by Mattia Simonazzi, Ugo Reggiani and Leonardo Sandrolini
Energies 2022, 15(2), 652; https://doi.org/10.3390/en15020652 - 17 Jan 2022
Cited by 7 | Viewed by 1757
Abstract
The possibility of increasing the transmission efficiency in mid-range wireless power transfer (WPT) applications can be achieved by inserting resonant relay coils between the transmitting and receiving sides of the device, forming an array of magnetically coupled resonant circuits, over which a receiver [...] Read more.
The possibility of increasing the transmission efficiency in mid-range wireless power transfer (WPT) applications can be achieved by inserting resonant relay coils between the transmitting and receiving sides of the device, forming an array of magnetically coupled resonant circuits, over which a receiver can be placed. This is a very cheap solution for improving the performance of the WPT apparatus, even if the complexity of the system increases, requiring a complete and detailed investigation for a smart design and control of the apparatus. The presented study investigates the current distribution in the coils of the array, which revealed strong peaks in magnitude depending on the load and receiver position. The analysis is carried out with the transmission line (TL) theory and it is performed for different positions of the receiver, as well as for different load conditions. Furthermore, a real application is considered and discussed, which includes the presence of a power converter as power supply and a battery charging system as load. Each resonant circuit resonates at 150 kHz and the whole apparatus is capable to transmit power up to 1 kW with an efficiency around 70%. The theoretical results have been validated with experimental measurements. Full article
(This article belongs to the Special Issue Intelligent Wireless Power Transfer System and Its Application 2021)
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8 pages, 1264 KiB  
Article
The Comparison of Microwave Reflectance of Graphite and Reduced Graphene Oxide Used for Electronic Devices Protection
by Roman Kubacki, Ludwika Lipińska, Rafał Przesmycki and Dariusz Laskowski
Energies 2022, 15(2), 651; https://doi.org/10.3390/en15020651 - 17 Jan 2022
Cited by 2 | Viewed by 1848
Abstract
This work presents the investigation of graphite and reduced graphene oxide (RGO) reflectance as an important parameter for electronic devices’ protection. These materials should protect electronic circuits against external as well as internal reflected radiation. The investigation was focused on comparing the reflectance [...] Read more.
This work presents the investigation of graphite and reduced graphene oxide (RGO) reflectance as an important parameter for electronic devices’ protection. These materials should protect electronic circuits against external as well as internal reflected radiation. The investigation was focused on comparing the reflectance of both materials on the metal layers. The measurements of constant electromagnetic parameters, such as permittivity and permeability, were carried out on pure materials without any additives, such as polystyrene foam, resin, wax, etc. The measurements were implemented in a coaxial line within the microwave frequency range from 100 MHz to 10 GHz. The measurements show a high value of reflected power, over 90% for graphite while RGO reflects only 80% of incident power. In addition, due to the half-wavelength effect in reduced graphene oxide, the reflection coefficient is reduced to 70%. Full article
(This article belongs to the Special Issue Engineering and Medical Aspects of the Use of Electromagnetic Field Energy 2021)
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20 pages, 2698 KiB  
Article
Designing the Business Ecosystem of a Decentralised Energy Datahub
by Sinan Küfeoğlu, Eray Açıkgöz, Yunus Emre Taşcı, Taha Yasin Arslan, Jan Priesmann and Aaron Praktiknjo
Energies 2022, 15(2), 650; https://doi.org/10.3390/en15020650 - 17 Jan 2022
Cited by 4 | Viewed by 2745
Abstract
Datahubs step forth as convenient test beds for innovative solutions to create value from the energy data. There are numerous pilots and early trials for establishing energy Datahubs, especially in northern Europe. These are all centralised models, and the centralisation of data control [...] Read more.
Datahubs step forth as convenient test beds for innovative solutions to create value from the energy data. There are numerous pilots and early trials for establishing energy Datahubs, especially in northern Europe. These are all centralised models, and the centralisation of data control and value creation can be regarded as contradictory to the decentralisation trend in the energy sector. This paper attempts to design the first decentralised energy Datahub ecosystem’s business ecosystem, with the name DenHub, using Blockchain technology. This model enables easy access to transparent and flexible energy data and new business models that will emerge upon its use. All data produced, distributed, used, and curated will help researchers and entrepreneurs study this field and propose new business models to make the energy ecosystem more efficient, clean, and inclusive. The paper also presents the differences between centralised and decentralised methods by underlining the advantages and disadvantages of both approaches. Full article
(This article belongs to the Special Issue State-of-the-Art Energy Related Technologies and New Business Models in UK)
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18 pages, 3552 KiB  
Review
Performance-Based Analysis in Evaluation of Safety in Car Parks under Electric Vehicle Fire Conditions
by Dorota Brzezinska and Paul Bryant
Energies 2022, 15(2), 649; https://doi.org/10.3390/en15020649 - 17 Jan 2022
Cited by 21 | Viewed by 6965
Abstract
Even though electric vehicles (EV) were invented over a century ago, their popularity has grown significantly within the last 10 years due to the development of Li-ion battery technology. This evolution created an increase in the fire risk and hazards associated with this [...] Read more.
Even though electric vehicles (EV) were invented over a century ago, their popularity has grown significantly within the last 10 years due to the development of Li-ion battery technology. This evolution created an increase in the fire risk and hazards associated with this type of high-energy battery. This review focuses on lessons learned from electric vehicle fires and fire risk mitigation measures for passenger road vehicles partially or fully powered by Li-ion batteries. The paper presents EV fire risks, as well as historical car fires, published large-scale fire tests, and some proposed fire protection strategies in the aspect of electromobility safety for the future. Technical solutions for EV fire hazard mitigation are discussed, and methods of performance-based analysis and simulations for fire safety in car park evaluation are demonstrated. The Fire Dynamic Simulator (FDS) was used for the CFD simulations for the prediction of smoke dispersion and temperature distribution during an EV fire. The presented case study demonstrates how fire simulations could predict conditions for the safe evacuation of people and Fire Brigade intervention conditions in the case of an EV fire in a car park. Full article
(This article belongs to the Special Issue Performance Analysis and Simulation of Electric Vehicles)
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23 pages, 18069 KiB  
Article
A Thermohydraulic Performance of Internal Spiral Finned Tube Based on the Inner Tube Secondary Flow
by Yicong Li, Zuoqin Qian and Qiang Wang
Energies 2022, 15(2), 648; https://doi.org/10.3390/en15020648 - 17 Jan 2022
Cited by 1 | Viewed by 1474
Abstract
In this article, the BSL k-ω model was chosen as the turbulence model to simulate the heat transfer and flow characteristics of the proposed tubes inserted with internal spiral fins when the Re was set as 3000 to 17,000. The numerical results agreed [...] Read more.
In this article, the BSL k-ω model was chosen as the turbulence model to simulate the heat transfer and flow characteristics of the proposed tubes inserted with internal spiral fins when the Re was set as 3000 to 17,000. The numerical results agreed well with the empirical formula. The average deviations of Nu and f between the simulation results and empirical formula results were 5.11% and 8.45%, respectively. By means of numerical simulation, the impact of three configurational parameters on the thermal performance was studied, namely the pitch P, the height H, and the number N of the internal spiral fins. The results showed that the Nu and f of the internal spiral finned tube were 1.77–3.74 and 3.04–10.62 times higher than those of smooth tube, respectively. PEC was also taken into account, ranging from 1.038 to 1.652. When the Re was set as 3000, the PEC achieved the peak value of 1.652 under the height H of the fins at 5 mm, the number N was 8, and the pitch P was 75 mm. However, with the increase of Re, the effect of pressure drop on the comprehensive performance in the tube was stronger than that of thermal enhancement. However, the PEC gradually decreased as the Re increased from 3000 to 17,000. In addition, the velocity and temperature fields were obtained to investigate the mechanisms of heat transfer enhancement. Full article
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33 pages, 2320 KiB  
Review
Review of Carnot Battery Technology Commercial Development
by Vaclav Novotny, Vit Basta, Petr Smola and Jan Spale
Energies 2022, 15(2), 647; https://doi.org/10.3390/en15020647 - 17 Jan 2022
Cited by 42 | Viewed by 7656
Abstract
Carnot batteries are a quickly developing group of technologies for medium and long duration electricity storage. It covers a large range of concepts which share processes of a conversion of power to heat, thermal energy storage (i.e., storing thermal exergy) and in times [...] Read more.
Carnot batteries are a quickly developing group of technologies for medium and long duration electricity storage. It covers a large range of concepts which share processes of a conversion of power to heat, thermal energy storage (i.e., storing thermal exergy) and in times of need conversion of the heat back to (electric) power. Even though these systems were already proposed in the 19th century, it is only in the recent years that this field experiences a rapid development, which is associated mostly with the increasing penetration of intermittent cheap renewables in power grids and the requirement of electricity storage in unprecedented capacities. Compared to the more established storage options, such as pumped hydro and electrochemical batteries, the efficiency is generally much lower, but the low cost of thermal energy storage in large scale and long lifespans comparable with thermal power plants make this technology especially feasible for storing surpluses of cheap renewable electricity over typically dozens of hours and up to days. Within the increasingly extensive scientific research of the Carnot Battery technologies, commercial development plays the major role in technology implementation. This review addresses the gap between academia and industry in the mapping of the technologies under commercial development and puts them in the perspective of related scientific works. Technologies ranging from kW to hundreds of MW scale are at various levels of development. Some are still in the stage of concepts, whilst others are in the experimental and pilot operations, up to a few commercial installations. As a comprehensive technology review, this paper addresses the needs of both academics and industry practitioners. Full article
(This article belongs to the Topic Energy Storage and Conversion Systems)
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28 pages, 13437 KiB  
Article
Towards a Powerful Hardware-in-the-Loop System for Virtual Calibration of an Off-Road Diesel Engine
by Antonio Riccio, Filippo Monzani and Maurizio Landi
Energies 2022, 15(2), 646; https://doi.org/10.3390/en15020646 - 17 Jan 2022
Cited by 8 | Viewed by 2629
Abstract
A common challenge among internal combustion engine (ICE) manufacturers is shortening the development time while facing requirements and specifications that are becoming more complex and border in scope. Virtual simulation and calibration are effective instruments in the face of these demands. This article [...] Read more.
A common challenge among internal combustion engine (ICE) manufacturers is shortening the development time while facing requirements and specifications that are becoming more complex and border in scope. Virtual simulation and calibration are effective instruments in the face of these demands. This article presents the development of zero-dimensional (0D)—real-time engine and exhaust after-treatment system (EAS) models and their deployment on a Virtual test bench (VTB). The models are created using a series of measurements acquired in a real test bench, carefully performed in view of ensuring the highest reliability of the models themselves. A zero-dimensional approach was chosen to guarantee that models could be run in real-time and interfaced to the real engine Electronic Control Unit (ECU). Being physically based models, they react to changes in the ECU calibration parameters. Once the models are validated, they are then integrated into a Simulink® based architecture with all the Inputs/Outputs connections to the ECU. This Simulink® model is then deployed on a Hardware in the Loop (HiL) machine for ECU testing and calibration. The results for engine and EAS performance and emissions align with both steady-state and transient measurements. Finally, two different applications of the HiL system are presented to explain the opportunities and advantages of this tool integrated within the standard engine development. Examples cited refer to altitude calibration activities and soot loading investigation on vehicle duty cycles. The cases described in this work are part of the actual development of one of the latest engines developed by Kohler Engines: the KDI 1903 TCR Stage V. The application of this methodology reveals a great potential for engine development and may become an essential tool for calibration engineers. Full article
(This article belongs to the Special Issue Advanced Calibration Methodologies for a New Generation of Engines and Powertrains)
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20 pages, 2048 KiB  
Article
Linking the National Energy and Climate Plan with Municipal Spatial Planning and Supporting Sustainable Investment in Renewable Energy Sources in Austria
by Susanne Geissler, Abraham Arevalo-Arizaga, David Radlbauer and Peter Wallisch
Energies 2022, 15(2), 645; https://doi.org/10.3390/en15020645 - 17 Jan 2022
Cited by 12 | Viewed by 2462
Abstract
The Austrian National Energy and Climate Plan (NECP) refers to spatial planning as an important instrument to achieve 2030 targets because the technical potential of renewable energy sources (RES) are closely related to the types of land use. In Austria, land use is [...] Read more.
The Austrian National Energy and Climate Plan (NECP) refers to spatial planning as an important instrument to achieve 2030 targets because the technical potential of renewable energy sources (RES) are closely related to the types of land use. In Austria, land use is regulated by the spatial planning laws of the nine provinces, whereby the municipalities play an important role. It was the objective of the transFORMAT project to understand the scope for action of the municipalities with regard to promoting renewable energy use, and to understand the practical implications for renewable energy projects. To this end, the consolidated versions of spatial planning laws were analyzed and supported by a software tool (transFORMAT-Analyzer) that was developed to facilitate this process and the resulting follow-up activities. Responsible administrative departments were approached for supplementary information when deemed necessary. As a conclusion, the legal instrument (municipal ordinance), called a municipal development plan or concept, represents a long-term plan for the development of the municipality with the obligation or the option for revision under specific conditions. In theory, these revision intervals could be used to better align municipal plans with the NECP. In practice, however, significant barriers exist and opportunities for improvement have been identified, leading to recommendations on how investments in renewable energy systems can be planned more realistically and, thus, more sustainably. Full article
(This article belongs to the Special Issue The Role of Spatial Policy Tools in Renewable Energy Investment)
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13 pages, 3205 KiB  
Article
Optimization of Operating Conditions of a Solid Oxide Fuel Cell System with Anode Off-Gas Recirculation Using the Model-Based Sensitivity Analysis
by Eun-Jung Choi, Sangseok Yu and Sang-Min Lee
Energies 2022, 15(2), 644; https://doi.org/10.3390/en15020644 - 17 Jan 2022
Cited by 4 | Viewed by 1683
Abstract
Designing a configuration of an efficient solid oxide fuel cell (SOFC) system and operating it under appropriate conditions are important for achieving a highly efficient SOFC system. In our previous research, the system layout of a SOFC system with anode off-gas recirculation was [...] Read more.
Designing a configuration of an efficient solid oxide fuel cell (SOFC) system and operating it under appropriate conditions are important for achieving a highly efficient SOFC system. In our previous research, the system layout of a SOFC system with anode off-gas recirculation was suggested, and the system performance was examined using a numerical model. In the present study, the system operating conditions were optimized based on the system configuration and numerical model developed in the previous paper. First, a parametric sensitivity analysis of the system performance was investigated to demonstrate the main operating parameters. Consequently, the fuel flow rate and recirculation ratio were selected. Then, the available operating conditions, which keep the system below the operating limits and satisfy the desired system performance (Ufuel > 0.7 and ηelec > 45%) were discovered. Finally, optimized operating conditions were suggested for three operating modes: optimized electrical efficiency, peak power, and heat generation. Depending on the situation, the demand for electricity and heat can be different, so different proper operating points are suggested for each mode. Additionally, using the developed model and the conducted process of this study, various optimized operating conditions can be derived for diverse cases. Full article
(This article belongs to the Special Issue Fuel Cell-Based and Hybrid Power Generation Systems Modeling)
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17 pages, 2724 KiB  
Article
Energy Efficiency of Transport Tasks Performed by the Air SAR System in the Baltic Sea: Case Study
by Jerzy Fiuk, Norbert Chamier-Gliszczynski, Marianna Jacyna and Mariusz Izdebski
Energies 2022, 15(2), 643; https://doi.org/10.3390/en15020643 - 17 Jan 2022
Cited by 3 | Viewed by 1483
Abstract
The issues discussed in this article concern the energy efficiency of transport tasks carried out by the air SAR system in the Baltic Sea. Search and rescue (SAR) are rescue operations consisting of finding people in danger, providing them with help, and delivering [...] Read more.
The issues discussed in this article concern the energy efficiency of transport tasks carried out by the air SAR system in the Baltic Sea. Search and rescue (SAR) are rescue operations consisting of finding people in danger, providing them with help, and delivering them to a safe place. The transport task is an element of the rescue operations carried out in the open water area. It is carried out by a given type of helicopter from a strictly defined rescue base. The aim of the article is to develop a method of selecting the base and means of transport for the transport task carried out by the air SAR system, based on the assessment of energy efficiency of a given transport task. The article proposes a selection model; parameterization of the model was carried out, indicators of energy efficiency evaluation were determined, and limitations were indicated. In practical terms, the authors’ model of selection is presented on the example of transport tasks carried out by the air SAR system in the Polish zone of responsibility in the Baltic Sea. Full article
(This article belongs to the Special Issue Energy Intensity of Transport and Environmentally Friendly Mobility)
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