bluuebunny/crossref_metadata_2025 huggingface dataset:
Life Cycle Assessment of a 150 kW Electronic Power Inverter
Authors: Baudais Briac , Ben Ahmed Hamid , Jodin Gurvan , Degrenne Nicolas , Lefebvre Stéphane
Published: February 2023

Based on the consideration of various environmental problems caused by human activities, energy transition solutions are starting to emerge. Power electronics will be central to these transitions. The level of knowledge linking power electronics and sustainability remains very limited today, and the study of the environmental impacts tied to the mass-scale deployment of power electronic systems across all sectors of activity is now essential. This study presents the life cycle assessment of a power electronic inverter capable of delivering a power of 150 kW, operating with an average 450 V DC bus for 15 years with 10,000 operating hours. The main hotspots are investigated to offer recommendations to designers. The most important impact highlighted is the depletion of mineral resources. Manufacturing and use are the two subsections with the highest environmental impact. Manufacturing is dominated by the casing and power module (specifically, the electric contacts, baseplate, and die). These results make it possible to orient an eco-design action with technologies capable of creating an evolution in hotspots. However, they also serve to consider scenarios involving a circular economy by setting up maintenance, recycling, and reuse loops in the inverter, combined with modularity and self-diagnostic functions.
Significance of Harmonic Filters by Computation of Short-Time Fourier Transform-Based Time–Frequency Representation of Supply Voltage
Authors: Priyadarshini M. S. , Krishna D. , Kumar Kurakula Vimala , Amaresh K. , Goud B. Srikanth , Bajaj Mohit , Altameem Torki , El-Shafai Walid , Fouda Mostafa M.
Published: February 2023

The nonlinear characteristics of power electronic-based loads in a power system contribute a major role in the harmonics’ injection and other power quality disturbances. This affects the quality of the power supplied to consumers by distribution systems. Flexible AC transmission system (FACTS) devices at the transmission level and custom power devices at the distribution level are used for an effective power transfer. In addition to these devices, filters play a prominent role in distribution systems. This paper aims to analyze the supply voltage in the time–frequency domain to perceive the variations in signal strength, explaining the role and significance of filters in mitigating or reducing harmonics. This paper presents the significance of harmonic filters in terms of signal-processing terminology. This depicts the prominent role of filters in improving the power quality by harmonic reduction or elimination, depending upon the requirement. The mathematical transform used in this approach is the short-time Fourier transform, which results in transforming the signal into a domain giving information about time and frequency. A MATLAB Simulink environment and ‘spectrogram’ were used to simulate harmonic signals, and we analyzed them using a short-time Fourier transform. Different windows were used with varying window size lengths.
Synthesis of Biobased Composite Heterogeneous Catalyst for Biodiesel Production Using Simplex Lattice Design Mixture: Optimization Process by Taguchi Method
Authors: Oloyede Christopher Tunji , Jekayinfa Simeon Olatayo , Alade Abass Olanrewaju , Ogunkunle Oyetola , Laseinde Opeyeolu Timothy , Adebayo Ademola Oyejide , Abdulkareem Adeola Ibrahim , Smaisim Ghassan Fadhil , Fattah I.M.R.
Published: February 2023

The use of biobased heterogeneous catalysts made from agricultural waste for producing biodiesel has gained attention for its potential to create a sustainable and low-cost process. The blending of two or more biomass residues to create more viable biobased catalysts is still in its early stages. In this study, a Biobased Composite Heterogeneous Catalyst (CHC) was made by blending the shells of periwinkle (PWS), melon seed-husk (MSH), and locust bean pod-husk (LBP) at a mixing ratio of 67:17:17 using Simplex Lattice Design Mixture, that was then calcined for 4 h at 800 °C. The chemical, structural, and morphological components of the CHC were characterized via XRF, XRD, SEM-EDX, BET, TGA/DSC, and FTIR to assess its catalytic potential. The CHC was employed to synthesize biodiesel from palm kernel oil, and the process optimization was conducted using the Taguchi approach. The XRF analysis showed that the catalyst had 69.049 of Calcium (Ca) and 9.472 of potassium (K) in their elemental and oxide states as 61.592% calcium oxide and 7.919% potassium oxide. This was also supported by the EDX result, that showed an appreciable value of 58.00% of Ca and 2.30% of magnesium, that perhaps provided the active site in the transesterification reaction to synthesize biodiesel. The morphological and physisorption isotherms via SEM and BET showed mesoporous structures in the CHC that were made up of nanoparticles. A high maximum biodiesel yield of 90.207 wt.% was attained under the optimized process conditions. The catalyst could be reused for up to four cycles, and the biodiesel produced met both ASTM D6751 and EN 14214 standards for biodiesel. This study demonstrates that blending PWS, MSH, and LBP waste materials can produce high-quality biodiesel without the need for additional catalysts.
Peer-to-Peer Energy Trading Pricing Mechanisms: Towards a Comprehensive Analysis of Energy and Network Service Pricing (NSP) Mechanisms to Get Sustainable Enviro-Economical Energy Sector
Authors: Das Arnob , Peu Susmita Datta , Akanda Md. Abdul Mannan , Islam Abu Reza Md. Towfiqul
Published: February 2023

Peer-to-peer (P2P) energy trading facilitates both consumers and prosumers to exchange energy without depending on an intermediate medium. This system makes the energy market more decentralized than before, which generates new opportunities in energy-trading enhancements. In recent years, P2P energy trading has emerged as a method for managing renewable energy sources in distribution networks. Studies have focused on creating pricing mechanisms for P2P energy trading, but most of them only consider energy prices. This is because of a lack of understanding of the pricing mechanisms in P2P energy trading. This paper provides a comprehensive overview of pricing mechanisms for energy and network service prices in P2P energy trading, based on the recent advancements in P2P. It suggests that pricing methodology can be categorized by trading process in two categories, namely energy pricing and network service pricing (NSP). Within these categories, network service pricing can be used to identify financial conflicts, and the relationship between energy and network service pricing can be determined by examining interactions within the trading process. This review can provide useful insights for creating a P2P energy market in distribution networks. This review work provides suggestions and future directions for further development in P2P pricing mechanisms.
Comparative Analysis of the Overall Efficiency of a Hydraulic Pump Unit with and without a Separate Pre-Charging System
Authors: Banaszek Andrzej , Petrović Radovan , Andjelković Maja , Radosavljević Milan
Published: February 2023

The overall efficiency and energy consumption problem in hydraulic power pack units with and without an additional pre-charging system was analyzed in this paper. A theoretical mathematical model was developed for calculating energy losses in both pump unit structures. To verify the theoretical relationships, a laboratory test stand was built, upon which the results of calculating the overall efficiency were compared with the results of the laboratory tests. Universal diagrams of the overall efficiency dependence as a function of pressure load and geometric adjustment of the main pump’s working volume were created for the case of a particular hydraulic pump unit without and with a pre-charging system. Based on this, discussions were carried out on whether and the way in which the additionally pre-charging system affects the parameters of the overall efficiency characteristics of the researched pump unit. Additionally, the dependence of the optimal pressure load and the maximum overall efficiency of the pump unit on the geometric adjustment of the main pump’s working volume was analyzed. It was shown that the pre-charging system affects the increase in the optimal pressure load at which the most favorable operating conditions, in terms of energy consumption, are obtained for the researched hydraulic pump unit.
Design of a Dynamic Hybrid Compensator for Current Sharing Control of Parallel Phase-Shifted Full-Bridge Converter
Authors: Gong Baihui , Liu Kan , Luan Haozhe , Wu Jiaming , Zhou Jing , Tan Shilin , Huang Chao , Wu Huajiang
Published: February 2023

The phase-shifted full-bridge (PSFB) converter has been widely used in power supply modules due to its simple control and high output power. However, with the market’s increasing demand for higher power sources, the PSFB converter needs to face challenges in increasing its output power level. Compared to redesigning a larger power module or a larger single converter, it will be more cost-effective to achieve a higher power output by paralleling the existing converters. However, due to the manufacturing differences in circuit components, the output imbalance in parallel PSFB converter systems may damage the power modules. Thus, the influence of differences in circuit components is analyzed in this paper, and it is found that the leakage inductance and transformer ratio are the main factors resulting in errors in current sharing control. Consequently, a dynamic hybrid compensator (DHC) is proposed in this paper, that can significantly reduce the error in current sharing control via the compensation of the duty cycle of a slave module. Furthermore, the DHC is verified on an 800 W two-phase PSFB converter, which shows that even when the difference in components is as large as 20%, the proposed method can still reduce the error in current sharing control to less than 2% under both half and full load conditions.
Experimental Comparison of Functionality between the Main Types of Methane Measurement Sensors in Mines
Authors: Lorenzo-Bayona José Luis , León David , Amez Isabel , Castells Blanca , Medic Ljiljana
Published: February 2023

In recent years, coal mine methane measurement techniques in mines have been gaining importance as poor firedamp control in work can cause the interruption of production and even fatal accidents. Since there is currently a variety of methane measurement equipment with different functional characteristics and measurement principles, a study is needed to indicate which type of equipment has the highest degree of confidence. This research presents the results of a study carried out by the Official Laboratory J. M. Madariaga (LOM) of the Polytechnic University of Madrid that aims to analyze the reliability of methane detection systems used in underground mining. Therefore, a series of portable and non-portable methane detectors with different measurement principles have been selected to subject them to laboratory tests following the methods described in the applicable regulations, such as time of response, dust effect, temperature, pressure, etc. The test equipment is usually the one used in the certification and calibration of these devices, subject to the LOM quality system. The results of these tests allowed for defining a marking system that led to a ranking of the tested methane detectors in order to find the advantages and disadvantages of each type. From the performed tests, a summary of the main sources of sensor inaccuracy was reported. It was found that catalytic sensors might present significant deviations when testing high concentrations in short periods of time or low concentrations during long periods of time. On the other hand, devices with an interferometric sensor can be unreliable as the measures are very sensitive to changes in environmental conditions, and optical sensors present longer response times than catalytic sensors.
The Impact of Windows Replacement on Airtightness and Energy Consumption of a Single Apartment in a Multi-Family Residential Building in Montenegro: A Case Study
Authors: Tombarević Esad , Vušanović Igor , Šekularac Milan
Published: February 2023

One of the important factors influencing the thermal performance of buildings is the leakage of the envelope. When it comes to Montenegro, although there is a formal airtightness requirement, air permeability tests are not mandatory and therefore there is a lack of data in this regard. This paper reports the results of fan pressurization tests on a single apartment in a multi-family residential building before and after replacing the windows. The replacement of old wooden windows with new UPVC ones, provided that the installation is carefully supervised, proved to be an effective air tightening measure, as it resulted in a reduction of air change rate at the reference building pressure from 6.25 h−1 to 0.77 h−1, or by nearly 90%. The energy impact of air leakage was evaluated using the national software for calculating the energy performance of buildings based on the DIN V 18599 methodology. Calculations showed that by reducing infiltration, significant energy savings for heating can be achieved, while savings for cooling are practically negligible. Savings in relative terms were greater when the façade walls were thermally insulated and when the building was located in a colder climate zone. Savings in delivered energy ranged from 13 to 25 kWh/m2·year, depending on the climate zone.
An Extensive Review and Comparison of Modern Biomass Reactors Torrefaction vs. Biomass Pyrolizers—Part 2
Authors: Slezak Radoslaw , Unyay Hilal , Szufa Szymon , Ledakowicz Stanislaw
Published: February 2023

The depletion of fossil fuels has led to a search for new methods of fuel and chemical production from biomass. One of the methods of converting biomass into valuable products is the process of pyrolysis. This process has been extensively researched in recent years due to the rising prices of energy and chemicals. This work contains basic information on the pyrolysis process concerning the individual components present in the biomass and the types of biomass used in the pyrolysis process. Particular attention was paid to sewage sludge, the management of which is a big challenge. The influence of the most important process parameters (temperature, heating rate, residence time of the solid and vapor, reaction atmosphere) on the pyrolysis products (char, oil, and gas) was presented. The paper presents an overview of the reactors used in the pyrolysis process, from slow to fast pyrolysis, together with their efficiency, advantages, and disadvantages. The analysis of the application of other thermochemical processes for producing the energy used in the process of pyrolysis and in the drying of the biomass was carried out. Two industrial-scale installations for the pyrolysis of sewage sludge were presented.
The Role of Fiscal Policy in G20 Countries in the Context of the Environmental Kuznets Curve Hypothesis
Authors: Mar’I Muhammad , Seraj Mehdi , Tursoy Turgut
Published: February 2023

Fiscal policy is an essential tool that policymakers use for guiding the economy. Thus, the effects of fiscal policy may affect many aspects of our lives, including the impact of carbon dioxide (CO2) emissions. This article investigates the role of fiscal policy, in addition to gross domestic product (GDP), innovation, and financial development, in mitigating CO2 emissions in the context of the Environmental Kuznets Curve theory in the Group of Twenty (G20) countries from 1995 to 2019. The study implied the autoregressive distributed lag of pooled mean group (ARDL-PMG) approach to analyze the suggested model. The results revealed the validity of the model for the G20 countries, as well as a long-run cointegration between the study variables. The results also showed that fiscal policy is associated positively with CO2 emissions. Hence, we recommend reconsidering the applied financial policy, redirecting it to support clean energy projects, provide incentives for projects combating environmental degradation, and relying on environmentally friendly energy.
Diagenetic Evolution and Its Impact on Reservoir Quality of Tight Sandstones: A Case Study of the Triassic Chang-7 Member, Ordos Basin, Northwest China
Authors: Yu Wei , Wang Feng , Liu Xianyang , Tian Jingchun , Yang Tian , Ren Zhaocai , Gong Li
Published: February 2023

The Upper Triassic Chang-7 Member of the Ordos Basin contains typical tight sandstone reservoirs. Reservoir quality is affected by diagenesis, which is a critical factor in tight oil exploration. In this study, the Chang-7 Member tight sandstones were studied by a variety of experimental methods, including thin sections, scanning electron microscopy (SEM), and X-ray diffraction (XRD), to determine the reservoir characteristics and diagenesis and discuss their influences on the reservoir quality. The Chang-7 Member sandstones are mainly lithic arkose and feldspathic litharenite with an average porosity and permeability of 7.17% and 0.13 mD, respectively. The pore type is mainly primary intergranular pores, and the secondary pores are feldspar dissolved pores, which are relatively developed, with pore radii of 2–20 µm. Diagenesis of Chang-7 Member tight reservoirs mainly includes compaction, quartz cementation, carbonate cementation, clay mineral cementation, and dissolution. The diagenetic stage develops into Mesodiagenesis A. The average porosity loss from compaction and cementation of sandstone in the Chang-7 Member is 15.93% and 18.67%, respectively. With the increase in burial depth, the porosity and permeability of the reservoir gradually decrease. In mesodiagenesis, the authigenic illite and carbonate cementation compacts the reservoir. The acid fluid carried by the two stages of oil and gas filling during diagenesis dissolved feldspar and carbonate cement, which plays a certain role in transforming the tight reservoir.
Hybrid System of Photovoltaic and Solar Thermal Technologies for Industrial Process Heat
Authors: Rosales-Pérez Josué F. , Villarruel-Jaramillo Andrés , Romero-Ramos José A. , Pérez-García Manuel , Cardemil José M. , Escobar Rodrigo
Published: February 2023

Process heating is the activity with the most energy consumption in the industrial sector. Solar heating (SH) systems are a promising alternative to provide renewable thermal energy to industrial processes. However, factors such as high investment costs and area limitations in industrial facilities hinder their utilization; therefore, hybrid systems that combine two different solar thermal or photovoltaic technologies where each technology operates under conditions that allow a higher overall performance than conventional configurations have been proposed. In this review, we discuss the limitations of conventional SH systems and the potential of hybrid configurations to overcome them. First, the current literature about conventional and hybrid systems is presented. Then, the application of common performance indicators to evaluate hybrid configurations is analyzed. Finally, the limitation, advantages, and potential applications of conventional and hybrid systems are discussed. This work shows that conventional systems are the most promising alternatives in low and high-temperature industrial applications. At the same time, in medium and processes, hybrid configurations have great potential to increase the performance of SH systems and help to boost their adoption in the industrial sector. There are few studies about hybrid systems in industrial applications, and further research is required to determine their potential.
Technology Trend Analysis of Japanese Green Vehicle Powertrains Technology Using Patent Citation Data
Authors: Jiang Jiaming , Zhao Yu
Published: February 2023

As automobiles are major contributors to greenhouse gas emissions, the technological shift towards vehicle powertrain systems is an attempt to lower problems such as emissions of carbon dioxide and nitrogen oxides. Patent data are the most reliable measure of business performance for applied research and development activities when investigating knowledge domains or technology evolution. This is the first study on Japanese patent citation data of the green vehicle powertrains technology industry, using the social network analysis method, which emphasizes centrality estimates and community detection. This study not only elucidates the knowledge by visualizing flow patterns but also provides a precious and congregative method for verifying important patents under the International Patent Classification system and grasping the trend of the new technology industry. This study detects leading companies, not only in terms of the number of patents but also the importance of the patents. The empirical result shows that the International Patent Classification (IPC) class that starts with “B60K”, which includes hybrid electric vehicle (HEV) and battery electric vehicle (BEV), is more likely to be the technology trend in the green vehicle powertrains industry.
Fatigue Reliability Based on Predicted Posterior Stress Ranges Determined from Strain Measurements of Wind Turbine Support Structures
Authors: Kinne Marko , Thöns Sebastian
Published: February 2023

In the present paper, an approach for updating the continuous stress range distribution of a welded connection of a wind turbine support structure with predicted information from strain measurements is presented. Environmental conditions, such as wind or, in offshore fields, waves and currents, in combination with rotor excitations generate cyclic stresses affecting the reliability of welded joints of the support structure over the service life. Using strain measurements, these conditions can be monitored, and the resulting stress ranges, under consideration of measurement, mechanical and material uncertainties, can be reconstructed. These stress ranges can be used as an input for updating the prior probability density function (PDF) of the stress ranges predicted by the overall dynamics and a detailed design analysis. Applying Bayesian probability theory and decision theoretical implications, the predicted posterior probability density of the stress ranges is calculated based on the design information and uncertainties. This approach is exemplified, and it is shown how the predicted stress ranges and the design stress ranges are distributed. The prior and the predicted posterior stress ranges are used for a reliability calculation for potentially entering a pre-posterior decision analysis.
PSOα: A Fragmented Swarm Optimisation for Improved Load Frequency Control of a Hybrid Power System Using FOPID
Authors: Appasani Bhargav , Jha Amitkumar V. , Gupta Deepak Kumar , Bizon Nicu , Thounthong Phatiphat
Published: February 2023

Particle swarm optimisation (PSO) is one of the widely adopted meta-heuristic methods for solving real-life problems. Its practical utility can be further enhanced by improving its performance. In order to acheive this, academics have presented several variants of the original PSO over the past few years, including the quantum PSO (QPSO), bare-bones PSO (BB-PSO), hybrid PSO, fuzzy PSO, etc. In this paper, the performance of PSO is improved by proposing a fragmented swarm optimisation approach known as the PSOα. The PSOα is tested and compared with PSOs over 14 different benchmarking cost functions to validate its efficacy. The analysis is also carried out to see the impact of α on its performance. It is observed that the average value of the cost function over 50 simulations obtained using the fragmented swarm approach is lower than that obtained using the standard PSO in 12 out of 14 benchmark functions. Similarly, the fragmented approach outperforms the standard PSO in 13 out of 14 benchmark functions when compared with the best fitness value achieved out of 50 simulations. Finally, the proposed approach is applied to solve the well-known real-life optimisation problem of load frequency control (LFC) in power systems. A test system comprising both renewable and traditional power sources is considered to evaluate the efficacy of the proposed technique. A fractional order proportional-integral-differential (FOPID) controller is used, whose parameters are optimised using the proposed PSO for achieving the LFC. The proposed fragmentation approach can be applied with other optimisation techniques to improve their performance.
Study on Atmospheric Stability and Wake Attenuation Constant of Large Offshore Wind Farm in Yellow Sea
Authors: Liu Hao , Chen Jixing , Zhang Jing , Chen Yining , Wen Yafeng , Zhang Xiaoyang , Yan Zhongjie , Li Qingan
Published: February 2023

Power generation estimation is one of the key steps in wind farm micro-sitting, and its accuracy is related to the wake decay constant in the wake model. Considering the influence of wind resource distribution in different regions, this study carried out interval optimization for the wake decay constant of offshore wind farms in the Yellow Sea region of China. Given the very small length of the sea surface roughness, atmospheric stability is a critical factor influencing the wake extent and recovery speed of offshore wind farms. WAsP 10 (Wind Atlas Analysis and Application software) simulates the wake of various scenarios, and the selection range of wake attenuation constant is investigated by combining the cases of two offshore wind farms in the Yellow Sea region. The study found that the higher the atmospheric stability, the larger the wake and the lower the wake attenuation coefficient. The Yellow Sea wind farm’s wake error system is between 0.03 and 0.04, and the forecast error can be controlled to within 3%. When simulating the wind farm at Yellow Sea offshore for improving power generation and economic evaluation, it is critical to select the correct value range of wake decay constant.
Editorial for the Special Issue “Heat Transfer Enhancement and Fluid Flow Features Due to the Addition of Nanoparticles in Engineering Applications”
Authors: Souayeh Basma , Ali Abro Kashif , Bhattacharyya Suvanjan
Published: February 2023

This Special Issue titled “Heat Transfer Enhancement and Fluid Flow Features Due to the Addition of Nanoparticles in Engineering Applications” comprises nine original research articles devoted to recent advances, as well as up-to-date progress, in all areas of heat transfer due to the addition of different types of nanoparticles in engineering and its influence on emerging technologies [...]
Integrated Power and Economic Analysis of Austria’s Renewable Electricity Transformation
Authors: Gaugl Robert , Sommer Mark , Kettner Claudia , Bachhiesl Udo , Klatzer Thomas , Gruber Lia , Böheim Michael , Kratena Kurt , Wogrin Sonja
Published: February 2023

Austria has set the goal to transform its electricity sector to 100% renewable energy sources by 2030. The transition to highly renewable power systems is not only a technical challenge but also has economic implications due to high investment needs. Furthermore, electricity price and demand are interlaced and influence each other, which requires both technical and economic analyses. In order to provide these comprehensive integrated analyses, we present a novel approach of linking the technical model of the continental European electricity system ATLANTIS with the macroeconomic model DYNK. This allows us, inter alia, to analyze the effects of increasing shares of renewables on wholesale electricity prices and demand, and to perform a sensitivity analysis with respect to CO2 prices. Our results show that increasing CO2 prices greatly affect coal-fired generation abroad, which in turn promotes the role of gas-fired generation, at least until 2030. For Austria, this results in increased national gas-fired generation and electricity exports. Therefore, gas-fired power plants still determine the Austrian market price for electricity in the merit order, which leads to higher electricity prices due to CO2 pricing. In turn, however, higher electricity prices only cause a marginal reduction in the electricity demand in Austria.
In Situ Combustion of Heavy Oil within a Vuggy Carbonate Reservoir: Part I—Feasibility Study
Authors: Fazlyeva Rita , Ursenbach Matthew , Mallory Donald , Mehta Sudarshan (Raj) , Cheremisin Alexey , Moore Gordon , Spasennykh Mikhail
Published: February 2023

Worldwide, the known recoverable heavy oil and bitumen reserves make up more than 64% of the total reserves, of which more than 60% are trapped in carbonates. Air injection has immense potential for hydrocarbon recovery from various reservoirs. While most of the successful air-based techniques are performed within carbonate reservoirs containing light oil, theoretically, in situ combustion (ISC) has also shown great potential for recovering heavy oil and bitumen. Carbonates are complex in terms of geology and are often associated with fractures and vugs that affect the fluid flow, pressure propagation and progression of the ISC reactions. This paper describes the first experiment in which the triple-porosity concept was applied to simulate heterogeneity through artificially induced vugs, core matrix and fractures. This approach was used to study the feasibility of the ISC recovery technique for heavy oil (14° API) within a dolomite reservoir using a combustion tube (CT) in an experiment performed at 1740 psig. The combustion front advanced through 78% of the core length prior to the termination of air injection, producing 80% of the initial oil. To differentiate between the various sources of the CO2 gas (a product of carbonate decomposition vs. the combustion reaction) the atomic ratios of (CO2 + CO)/CO = 6 and (CO2 + CO)/N2 = 0.21 were applied. Additionally, partial upgrading of the produced heavy oil was observed.
Design of an Energy Policy for the Decarbonisation of Residential and Service Buildings in Northern Portugal
Authors: Capelo Sara , Soares Tiago , Azevedo Isabel , Fonseca Wellington , Matos Manuel A.
Published: February 2023

The decarbonisation of the building sector is crucial for Portugal’s goal of achieving economy-wide carbon neutrality by 2050. To mobilize communities towards energy efficiency measures, it is important to understand the primary drivers and barriers that must be overcome through policymaking. This paper aims to review existing Energy Policies and Actions (EPA) in Portugal and assess their effectiveness in improving Energy Efficiency (EE) and reducing CO2 emissions in the building sector. The Local Energy Planning Assistant (LEPA) tool was used to model, test, validate and compare the implementation of current and alternative EPAs in the North of Portugal, including the national EE plan. The results indicate that electrification of heating and cooling, EE measures, and the proliferation of Renewable Energy Sources (RES) are crucial for achieving climate neutrality. The study found that the modelling of alternative EPAs can be improved to reduce investment costs and increase Greenhouse Gas (GHG) emissions reduction. Among the alternatives assessed, the proposed one (Alternative 4) presents the best returns on investment in terms of cost savings and emissions reduction. It allows for 52% investment cost savings in the residential sector and 13% in the service sector when compared to the current national roadmap to carbon neutrality (Alternative 2). The estimated emission reduction in 2050 for Alternative 4 is 0.64% for the residential sector and 3.2% for the service sector when compared to Alternative 2.
Application of Quantum Computing in Power Systems
Authors: Gao Fang , Wu Guojian
Published: February 2023

Due to continuous expansion, the current interconnected power system is the largest and most complex man-made dynamic system on the planet [...]
Performance Analysis Using Multi-Year Parameters for a Grid-Connected Wind Power System
Authors: Z. Alharthi Yahya
Published: February 2023

One of the most crucial solutions to the issues of climate change and global warming is clean energy. However, creating intelligent, resilient, and sustainable systems is a worldwide problem, particularly for grid-connected Renewable Energy Systems (RES). Therefore, it is important to investigate how prospective changes in electricity pricing, renewable energy sources, and load demand could affect system performance during the projects. This paper presents a techno-economic analysis of a grid-connected wind energy system located in the Al-Jouf region in Saudi Arabia. To this end, the potential of renewable energy sources was assessed using Hybrid Optimization of Multiple Electric Renewables (HOMER) software, that also carried out the technical and economic study utilizing multi-year parameters. The novelty of this study is that it is the first-ever investigation of a grid-connected wind farm system in Saudi Arabia that considers the impact of multi-year parameters such as the grid price, system fixed operation, maintenance cost, and the AC electric load. The results showed that the proposed system in the chosen area recorded a very low Levelized Cost of Energy (LCOE) of around 0.06 USD/kWh compared to other systems. Also, running a multi-year model showed that the considered parameters have an impact on the system’s performance, and this reflects the importance of considering these parameters in any such system that will increase the study’s accuracy.
Real-Time Fuzzy Logic Based Energy Management System for Microgrid Using Hardware in the Loop
Authors: El Zerk Abdallah , Ouassaid Mohammed
Published: February 2023

This research presents a hierarchical energy management strategy for isolated microgrids (MG). The strategy’s objectives are achieved through a master-slave topology where local controllers are managed and controlled through a central controller. This can provide many technical advantages, particularly regarding the microgrid’s performance and the supply of energy. The local controller is designed to meet the local objectives of the microgrid, such as stabilization of DC voltage and maximization of sources’ extracted power. The objectives of the central controller are achieved through a centralized approach based on fuzzy logic to preserve battery life and manage the energy balance between generation and consumption. The microgrid’s performances were investigated under a steady-state and faulty regime. A Hardware in the Loop (HIL) test based on the Simulink platform is established by RT-LAB real-time simulator. Results are presented to validate the proposed hierarchical control. The OP1400 test bench, based on the OP4150 digital simulator, is utilized to test and validate the proposed hierarchical control strategy. The results are compared to international standards IEEE 1547 and IEC 61727, which demonstrate excellent consistency.
Artificial Intelligence for Electric Vehicle Infrastructure: Demand Profiling, Data Augmentation, Demand Forecasting, Demand Explainability and Charge Optimisation
Authors: Sumanasena Vidura , Gunasekara Lakshitha , Kahawala Sachin , Mills Nishan , De Silva Daswin , Jalili Mahdi , Sierla Seppo , Jennings Andrew
Published: February 2023

Electric vehicles (EVs) are advancing the transport sector towards a robust and reliable carbon-neutral future. Given this increasing uptake of EVs, electrical grids and power networks are faced with the challenges of distributed energy resources, specifically the charge and discharge requirements of the electric vehicle infrastructure (EVI). Simultaneously, the rapid digitalisation of electrical grids and EVs has led to the generation of large volumes of data on the supply, distribution and consumption of energy. Artificial intelligence (AI) algorithms can be leveraged to draw insights and decisions from these datasets. Despite several recent work in this space, a comprehensive study of the practical value of AI in charge-demand profiling, data augmentation, demand forecasting, demand explainability and charge optimisation of the EVI has not been formally investigated. The objective of this study was to design, develop and evaluate a comprehensive AI framework that addresses this gap in EVI. Results from the empirical evaluation of this AI framework on a real-world EVI case study confirm its contribution towards addressing the emerging challenges of distributed energy resources in EV adoption.
Design of an Algorithm for Modeling Multiple Thermal Zones Using a Lumped-Parameter Model
Authors: Fernández de Córdoba Pedro , Montes Frank Florez , Martínez Miguel E. Iglesias , Carmenate Jose Guerra , Selvas Romeo , Taborda John
Published: February 2023

The generation of mathematical models for the analysis of buildings with multiple thermal zones is a large and complex task. Furthermore, the order and complexity of the dynamical model are increased by the number of included thermal zones. To overcome this problem, this paper presents an algorithm to define the mathematical model automatically, using the geometric and physics parameters as inputs. Additionally, the spatial position of each thermal zone must be recorded in an arrangement called a contact matrix. The algorithm for modeling systems with multiple thermal zones is the main contribution of this work. This algorithm is presented in pseudocode format and as an annex, an implementation in MATLAB software. One of the advantages of this methodology is that it allows us to work with parallelepipeds and not necessarily cubic thermal zones. The algorithm allows us to generate mathematical models with symbolic variables, starting from the knowledge of how many thermal zones compose the system and its geometric organization. This information must be organized in a matrix arrangement called a contact matrix. Different arrays of thermal zones were constructed with wooden boxes to verify the functionality of the models generated with the algorithm. Each case provided information that allowed us to adjust the mathematical models and their simulations, obtaining a range of errors between experimental and simulated temperatures from 2.08 to 5.6, depending on the number of thermal zones studied.
Spatial-Temporal Evolution Characteristics of Industrial Carbon Emissions in China’s Most Developed Provinces from 1998–2013: The Case of Guangdong
Authors: Wang Ran , Ci Hui , Zhang Ting , Tang Yuxin , Wei Jinyuan , Yang Hui , Feng Gefei , Yan Zhaojin
Published: February 2023

Industry is widely valued as an important contributor to carbon emissions. Therefore, it is of great significance to analyze the industrial carbon emissions (ICE) in Guangdong, the strongest industrial province in China. We have adopted the carbon emission accounting model and standard deviational ellipse analysis model to analyze the temporal and spatial characteristics and evolution trends of the industry carbon emission amount and intensity in Guangdong from 1998 to 2013. The study results include: (1) Due to the rapid development of industry, Guangdong’s ICE showed a steady growth trend; (2) The distribution characteristics of ICE were characterized by the trend of taking the Pearl River Delta (PRD) region as the center and gradually spreading to the surrounding areas. From the perspective of industrial sectors, it can be divided into steady growth type, fluctuant growth type, basically stable type, and decrease type; (3) The spatial pattern of the ICE in Guangdong is basically the same as that of the total industrial output value, that is, the southwest-northeast pattern. This work is helpful for China’s carbon peak, especially for the formulation of industrial carbon peak policy and the sustainable development of the environment.
Modular and Transferable Machine Learning for Heat Management and Reuse in Edge Data Centers
Authors: Brännvall Rickard , Gustafsson Jonas , Sandin Fredrik
Published: February 2023

This study investigates the use of transfer learning and modular design for adapting a pretrained model to optimize energy efficiency and heat reuse in edge data centers while meeting local conditions, such as alternative heat management and hardware configurations. A Physics-Informed Data-Driven Recurrent Neural Network (PIDD RNN) is trained on a small scale-model experiment of a six-server data center to control cooling fans and maintain the exhaust chamber temperature within safe limits. The model features a hierarchical regularizing structure that reduces the degrees of freedom by connecting parameters for related modules in the system. With a RMSE value of 1.69, the PIDD RNN outperforms both a conventional RNN (RMSE: 3.18), and a State Space Model (RMSE: 2.66). We investigate how this design facilitates transfer learning when the model is fine-tuned over a few epochs to small dataset from a second set-up with a server located in a wind tunnel. The transferred model outperforms a model trained from scratch over hundreds of epochs.
Physicochemical Characterization and Thermal Behavior of Different Wood Species from the Amazon Biome
Authors: Bimestre Thiago Averaldo , Silva Fellipe Sartori , Tuna Celso Eduardo , dos Santos José Carlos , de Carvalho João Andrade , Canettieri Eliana Vieira
Published: February 2023

The Brazilian Amazon is one of the main tropical wood-producing regions in the world, where exploration and industrial processing are among its main economic activities. Wood is characterized as a material consisting mainly of compounds with a high degree of polymerization and molecular weight such as cellulose, hemicellulose and lignin, in addition to other compounds such as ash and extractives. This chemical complexity of wood brings with it a wide possibility of chemical and thermochemical processing aiming at the production of bioproducts and biofuels. In this context, it is essential to know the physicochemical properties and thermal behavior of wood species from the Amazon biome to add value to the product, reducing waste and maximizing the species used. This work presents an investigation into the physicochemical and thermogravimetric characteristics of 21 species of wood from the Amazon, in addition to the determination of the higher heating value (HHV) of each one of them, focusing on the energy use of the biomass under analysis. The samples showed a high lignin content, varying between 26.8% and 33.9%, with a standard deviation of 1.7% and an average of 30.0%. The Trattinnickia sp. had the highest lignin content (33.86 ± 0.13%). The cellulose content varied from 31.3% to 55.9%, with a standard deviation of 7.3% and an average of 41.74%. The Ruizterania albiflora had the highest cellulose content (55.90 ± 1.20%). For the hemicellulose content, the variation ranged from 8.6% to 17.0%, with a standard deviation of 2.6% and an average of 12.38%. The samples that showed the highest HHVs were Ocotea sp. (18.588 ± 0.082 MJ kg−1) followed by Ferreiraa spectabilis (18.052 ± 0.157 MJ kg−1).
Integrated Policies to Reduce Australia’s Electricity Sector Greenhouse Gas Emissions to Net Zero by 2050
Authors: Byrom Steph , Bongers Geoff , Dargusch Paul , Garnett Andrew
Published: February 2023

Recent events within the Australian National Electricity Market have demonstrated that the system of an energy-only market (a market that only compensates power that has been produced) is no longer fit for purpose. The rate of change in installed capacity and generation requires better planning to ensure reliability is maintained at the lowest total system cost during the transition to net zero. Australian National Electricity Market participants will need sufficient incentives and confidence to invest in new capacity. This paper assesses a “no constraints” scenario and recommends a range of policy and market mechanisms that could be utilized to achieve a net zero National Electricity Market in Australia by 2050. This paper adopts the perspective of total system cost, which allows multiple factors relating to decision-making to be incorporated. In the absence of a carbon price, this paper seeks to put forward technology-based policy and market mechanisms to incentivise the changes required. The “Modelling Energy and Grid Services” model used in this study has shown that this “no constraints” future grid will need to contain approximately 100 GW of variable renewable energy, almost 20 GW of firm, low-emissions generation, such as carbon capture, utilisation and storage, bioenergy with carbon capture and storage, hydroelectric power, or nuclear power. It will also require more than 10 GW of storage, including pumped hydro energy storage and other energy storage technologies, and over 30 GW of firm, dispatchable peaking plants, including thermal power generation.
Machine Learning in Renewable Energy
Authors: Gogas Periklis , Papadimitriou Theophilos
Published: February 2023

The volume of energy produced and consumed from renewable sources increases by a significant rate both in absolute value and also as a proportion of the total energy produced and consumed [...]
The Facies Analysis, Evolution, and Coal-Bearing Source Rock Features of the Middle–Late Triassic Shallow-Water Delta in the North Carnarvon Basin, Northwest Shelf of Australia
Authors: Zeng Zhiwei , Wang Wei , Zhu Hongtao , Yang Xianghua , Li Dan
Published: February 2023

The sedimentary facies, architecture, and depositional mechanism of deltaic systems have been one of the global research hotspots in recent decades; however, the detailed distribution, sedimentary evolution, source rock potential, and major control factors of the coal-bearing shallow-water delta are still unclear. A typical shallow-water braided delta with coal-bearing source rocks developed in the Middle–Late Triassic Mungaroo Formation of the North Carnarvon Basin, which can be a good study area for an analysis of coal-bearing source rocks. In this study, the sedimentary facies, distribution and evolution, and coal-bearing source rock features of the Triassic strata were analyzed based on the integrated study of wireline logs, drilled cores, thin sections, seismic facies and attributes, and geochemical data. A range of shallow-water delta sedimentary facies was identified, including the proximal delta plain channel/interdistributary bay, distal delta plain channel/interdistributary bay, and the delta front. The coal-bearing shallow-water delta system of the Middle–Late Triassic Mungaroo Formation was characterized by the largest scale delta system with relatively broad proximal and distal delta plains and relatively narrow delta front subfacies. The scale of the delta system showed a trend of increasing from the Early Triassic Locker Shale to the Middle–Late Triassic Mungaroo Formation and then decreasing to the Late Triassic Brigadier Formation. The distal delta plain subfacies of the Mungaroo Formation should have the highest potential coal-bearing source rock, and the proximal delta plain also can be a favorable target for source rock evaluation. The major control factors of the coal-bearing source rocks of the Mungaroo shallow-water delta mainly included the Triassic megamonsoon climate, the topographic features, eustatic changes, and provenance supply. The proximal and distal delta plains of the shallow-water delta system with thin coal seams, carbonaceous mudstone, and dark mudstone lithologies’ association could be a favorable source rock exploration facies for the next stage of natural gas field exploration.
Manufacturing Energy Efficiency and Industry 4.0
Authors: Salonitis Konstantinos
Published: February 2023

This Special Issue of Energies was devoted to the topic of “Manufacturing Energy Efficiency and Industry 4.0”. To a great extent, this issue follows the successful previous Special Issue on “Energy Efficiency of Manufacturing Processes and Systems”, which attracted some significant attention from scholars, practitioners, and policy-makers from all over the world. In total, six papers were published. The main topics included energy efficiency improvement in both the manufacturing process and system levels, as well as how this can be facilitated through the use of Industry 4.0.