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Records with Keyword: Renewable and Sustainable Energy
Showing records 912 to 936 of 1087. [First] Page: 1 34 35 36 37 38 39 40 41 42 Last
Analysis of the Implementation of Functional Hydrogen Assumptions in Poland and Germany
Tomasz Jałowiec, Dariusz Grala, Piotr Maśloch, Henryk Wojtaszek, Grzegorz Maśloch, Agnieszka Wójcik-Czerniawska
February 24, 2023 (v1)
Keywords: decarbonization, enterprises, Germany, green energy, Hydrogen, individuals, Poland, Renewable and Sustainable Energy, transport
The use of hydrogen exists in various sectors in Poland and Germany. Hydrogen can be used in industry, transport, decarbonisation of the Polish steel industry and as one of the low-emission alternatives to the existing coal applications in this sector. Limiting climate change requires efforts on a global scale from all countries of the world. Significant economic benefits will be realized by stimulating the development of new technologies to deal with climate change. The scenarios show an increasing demand for industrial hydrogen in the future. The key is to replace gray hydrogen with green, and to convert industrial processes, which will create additional hydrogen demand. The condition for the development of a green hydrogen economy is access to adequate installed capacity in renewable energy. Germany will become the leading market in the era of energy transformation in the coming years. The implementation of the hydrogen assumptions in Poland is possible, to a greater extent, by the... [more]
R&D Human Capital, Renewable Energy and CO2 Emissions: Evidence from 26 Countries
Grzegorz Mentel, Waldemar Tarczyński, Hossein Azadi, Kalandar Abdurakmanov, Elina Zakirova, Raufhon Salahodjaev
February 24, 2023 (v1)
Keywords: CO2 emission, human capital, Renewable and Sustainable Energy
This study examines the long-term relationship between carbon emissions and a number of researchers engaged in Research and Development (R&D), economic development, foreign capital inflows, renewable energy and population growth in 26 countries between 1995 and 2015. Pedroni’s panel cointegration test confirms the cointegrating relationship between the variables. Long-term elasticities are derived from FMOLS regression. Researchers in R&D and renewable energy are negatively and significantly related to carbon emissions. There is a positive and significant long-term relationship between GDPs per capita and CO2 and between the FDI and CO2. Dumitrescu and Hurlin’s panel causality test revealed unidirectional causality running from economic development to carbon emissions and feedback hypotheses between the FDI and CO2 and between renewable energy and CO2.
Wind Energy on the High Seas: Regulatory Challenges for a Science Fiction Future
Ignacio Herrera Anchustegui, Violeta S. Radovich
February 24, 2023 (v1)
Keywords: climate change, high seas, public international law, Renewable and Sustainable Energy, spatial planning, wind energy
This paper aims to study the current regulation and governance of wind energy turbines on the high seas and detect regulatory challenges. We focus on the existing regulatory framework to develop marine wind farms in areas beyond national jurisdiction (ABNJ), the nature of wind farms and wind turbines in said areas, and which governance schemes and institutions ought to coordinate and regulate any future marine wind energy development. Our research shows that under public international law, the deployment of wind turbines on (most parts of) the high seas for all States is possible, but many issues still remain, either thinly regulated or unanswered. We inquire where, by whom, and how can marine wind parks be built on the high seas according to public international law and the United Nations Convention on the Law of the Sea (the LOSC). Lastly, we evaluate the possible role of marine spatial planning (MSP) in developing wind energy on the high seas.
Experimental and Numerical Investigation of the Effect of Blades Number on the Dynamic Response of a Small Horizontal-Axis Wind Turbine
Matteo Vedovelli, Abdelgalil Eltayesh, Francesco Natili, Francesco Castellani
February 24, 2023 (v1)
Keywords: dynamic response, number of blades, Renewable and Sustainable Energy, small wind turbine, solidity, vibrations, wind tunnel test
The new energy scenario is rising a strong interest towards the distributed production from renewable sources; among them, wind seems to be one of the most interesting and at the same time critical due to the challenges of the conversion technology. Operation of small wind energy conversion systems is generally very complex due the extremely variable regime of operation and the high turbulent wind, so that a deep knowledge of the dynamic response of such devices is crucial not only for optimising their performances but also to make them comfortable to be used in residential areas. For these reasons, the present work is focused on analysing the effect in changing the number of blades on a small horizontal axis wind turbine through an experimental campaign in the wind tunnel. The turbine dynamics has been characterised running some “wind ramp” tests and analysing the rotor capability in following the wind as well the vibrations transmitted by the turbine during the operation. Results dem... [more]
Analysis of the Influence of Selected Factors on Heating Costs and Pollutant Emissions in a Cold Climate Based on the Example of a Service Building Located in Bialystok
Agata Ołtarzewska, Dorota Anna Krawczyk
February 24, 2023 (v1)
Keywords: environmental pollution, heat pumps, heating costs, operating schedule, operating temperatures, Renewable and Sustainable Energy
In recent years, due to the rapidly growing global energy crisis and the ever-increasing prices of energy carriers, more attention has been paid to the energy efficiency of existing buildings, especially in the context of reducing harmful emissions and lowering heating costs. The purpose of this study was to analyse the influence of selected factors on heating costs and air pollution in a cold climate based on the example of a service building located in Bialystok, Poland. The following scenarios were assumed: the implementation of a heating schedule, improvement of the thermal insulation of the building envelope, lowering of the indoor temperature in all rooms, and moving away from a traditional heat source (gas boiler) to renewable energy (heat pump). The results showed that improvements in heat transfer coefficients had the greatest impact on reducing heating costs and that emissions from renewable energy sources depend largely on the national energy mix.
The Energy Transition as a Super Wicked Problem: The Energy Sector in the Era of Prosumer Capitalism
Aleksander Jakimowicz
February 24, 2023 (v1)
Subject: Energy Policy
Keywords: change management, climate change, complexity catastrophe, complexity management, energy policy, energy prosumerism, energy transition, prosumer capitalism, Renewable and Sustainable Energy, super wicked problem
The main objective of this paper is to demonstrate that the energy transition as part of prosumer capitalism is a socio-economic process whose complexity increases over time, which makes it an example of a super wicked problem. It comprises many new phenomena emerging spontaneously, and often unpredictably, in the energy markets. The main contemporary challenge involves such an energy sector transformation which will prevent climate change and will ensure the sustainable development of the global economy. However, this requires solving a large number of sub-problems in areas such as legislation, energy distribution, democracy, and cybersecurity. Therefore, this is a multidisciplinary issue. Moreover, the situation is complicated by the frequently omitted fact that energy transition is not part of the standard capitalism model, extensively described in handbooks and scientific literature, but it is conducted as part of a new economic system—prosumer capitalism, which has not been proper... [more]
Novel Nanomaterials for Hydrogen Production and Storage: Evaluating the Futurity of Graphene/Graphene Composites in Hydrogen Energy
Ahmed Hussain Jawhari
February 24, 2023 (v1)
Subject: Materials
Keywords: graphene, hydrogen energy, nanocomposites, nanomaterials, Renewable and Sustainable Energy, storage
Using hydrogen energy as an alternative renewable source of fuel is no longer an unrealized dream, it now has real-world application. The influence of nanomaterials on various aspects of hydrogen energy, such as hydrogen production, storage, and safety, is considerable. In this review, we present a brief overview of the nanomaterials that have been used as photocatalysts during hydrogen production. The use of nanomaterials and nanomaterial composites for hydrogen storage is also reviewed. The specific use of graphene and its associated nanocomposites, as well as the milestones reached through its application are elaborated. The need to widen the applicability of graphene and its allied forms for hydrogen energy applications is stressed in the future perspectives. Hydrogen energy is our future hope as an alternative renewable fuel, and graphene has the potential to become the future of hydrogen energy generation.
A Fractional Order Super Twisting Sliding Mode Controller for Energy Management in Smart Microgrid Using Dynamic Pricing Approach
Taimoor Ahmad Khan, Amjad Ullah, Ghulam Hafeez, Imran Khan, Sadia Murawwat, Faheem Ali, Sajjad Ali, Sheraz Khan, Khalid Rehman
February 24, 2023 (v1)
Keywords: demand response programs, energy management, fractional order super twisting sliding mode controller, Renewable and Sustainable Energy, smart grid
A real-time energy management strategy using dynamic pricing mechanism by deploying a fractional order super twisting sliding mode controller (FOSTSMC) is proposed for correspondence between energy users and providers. This framework, which controls the energy demand of the smart grid’s users is managed by the pricing signal provided by the FOSTSMC, issued to the smart meters, and adjusts the users’ demand to remove the difference between energy demand and generation. For the implementation purpose, a scenario based in MATLAB/Simulink is constructed where a sample renewable energy−integrated smart microgrid is considered. For the validation of the framework, the results of FOSTSMC are compared with the benchmark PI controller’s response. The results of the benchmark PI controller are firstly compared in step response analysis, which is followed by the comparison in deploying in renewable energy−integrated smart grid scenario with multiple users. The results indicate that the FOSTSMC-ba... [more]
Aerodynamic Performance Analysis of Trailing Edge Serrations on a Wells Turbine
Abdullah Saad Alkhalifa, Mohammad Nasim Uddin, Michael Atkinson
February 24, 2023 (v1)
The primary objective of this investigation was to explore the aerodynamic impact of adding trailing edge serrations to a Wells turbine. The baseline turbine consists of eight NACA 0015 blades. The blade chord length was 0.125 m and the span was 0.100 m. Two modified serrated blade configurations were studied: (1) full-span, and (2) partial-span covering 0.288c of the trailing edge. The numerical simulations were carried out by solving the three-dimensional, incompressible steady-state Reynolds Averaged Navier-Stokes (RANS) equations using the k-ω SST turbulence model in ANSYS™ (CFX). The aerodynamic performance of the modified Wells turbine was compared to the baseline by calculating non-dimensional parameters (i.e., torque coefficient, pressure drop coefficient, and turbine efficiency). A comparison of the streamlines was performed to analyze the flow topology around the turbine blades for a flow coefficient range of 0.075 ≤ ϕ ≤ 0.275, representing an angle of attack range of 4.29° ≤... [more]
Technological Advancements and Challenges of Geothermal Energy Systems: A Comprehensive Review
Laveet Kumar, Md. Shouquat Hossain, Mamdouh El Haj Assad, Mansoor Urf Manoo
February 24, 2023 (v1)
Keywords: challenges, cooling technology, geothermal system, Renewable and Sustainable Energy, technological advancements
Geothermal is a renewable energy source, but this is not as often seen as other renewable energy sources, such as solar, wind, hydro, etc. Several applications could be implemented through geothermal energy, and heating & cooling systems are one of them. Because of the limits of technology, it is hard to improve cooling systems as an application. To address long-term sustainable space heating and cooling, it is imperative to develop geothermal technology. It is known as the oldest, most flexible, most adaptable, and most prevalent approach toward using renewable energy. Therefore, this review has reviewed the global development and challenges of geothermal energy for cooling systems. There are large reserves of geothermal energy available around the world, and numerous scholars have emphasized its importance, but due to a lack of knowledge, no operational work has been done in using these systems for cooling up to this point. This review paper examines globally available geothermal ene... [more]
Grid-Forming Virtual Power Plants: Concepts, Technologies and Advantages
Khalil Gholami, Behnaz Behi, Ali Arefi, Philip Jennings
February 24, 2023 (v1)
Keywords: Energy Storage, grid-forming inverters, Renewable and Sustainable Energy, review, virtual power plant
Virtual Power Plants (VPPs) are efficient structures for attracting private investment, increasing the penetration of renewable energy and reducing the cost of electricity for consumers. It is expected that the number of VPPs will increase rapidly as their financial return is attractive to investors. VPPs will provide added value to consumers, to power systems and to electricity markets by contributing to different services such as the energy and load-following services. One of the capabilities that will become critical in the near future, when large power plants are retired, is grid-forming capability. This review paper introduces the concept of grid-forming VPPs along with their corresponding technologies and their advantages for the new generation of power systems with many connected VPPs.
Optimal Design of Hybrid Renewable Energy Systems Considering Weather Forecasting Using Recurrent Neural Networks
Alfonso Angel Medina-Santana, Leopoldo Eduardo Cárdenas-Barrón
February 24, 2023 (v1)
Keywords: deep learning, GHI, long-term forecasting, LSTM, non-linear optimization, optimal sizing, Renewable and Sustainable Energy, RNN, solar energy, time-series forecasting
Lack of electricity in rural communities implies inequality of access to information and opportunities among the world’s population. Hybrid renewable energy systems (HRESs) represent a promising solution to address this situation given their portability and their potential contribution to avoiding carbon emissions. However, the sizing methodologies for these systems deal with some issues, such as the uncertainty of renewable resources. In this work, we propose a sizing methodology that includes long short-term memory (LSTM) cells to predict weather conditions in the long term, multivariate clustering to generate different weather scenarios, and a nonlinear mathematical formulation to find the optimal sizing of an HRES. Numerical experiments are performed using open-source data from a rural community in the Pacific Coast of Mexico as well as open-source programming frameworks to allow their reproducibility. We achieved an improvement of 0.1% in loss of load probability in comparison to... [more]
Potential of Producing Green Hydrogen in Jordan
Mustafa Jaradat, Omar Alsotary, Adel Juaidi, Aiman Albatayneh, Asem Alzoubi, Shiva Gorjian
February 24, 2023 (v1)
Keywords: ALK, CO2 emissions, electrolyzer, green hydrogen, LCOH, PEM, photovoltaic, Renewable and Sustainable Energy, techno-economic
Green hydrogen is becoming an increasingly important energy supply source worldwide. The great potential for the use of hydrogen as a sustainable energy source makes it an attractive energy carrier. In this paper, we discuss the potential of producing green hydrogen in Jordan. Aqaba, located in the south of Jordan, was selected to study the potential for producing green hydrogen, due to its proximity to a water source (i.e., the Red Sea). Two models were created for two electrolyzer types using MATLAB. The investigated electrolyzers were alkaline water (ALK) and polymeric electrolyte membrane (PEM) electrolyzers. The first model was used to compare the required capacity of the PV solar system using ALK and PEM from 2022 to 2025, depending on the learning curves for the development of these technologies. In addition, this model was used to predict the total investment costs for the investigated electrolyzers. Then, a techno-economic model was constructed to predict the feasibility of us... [more]
Multi-Objective Optimal Scheduling of a Microgrid Using Oppositional Gradient-Based Grey Wolf Optimizer
Arul Rajagopalan, Karthik Nagarajan, Oscar Danilo Montoya, Seshathiri Dhanasekaran, Inayathullah Abdul Kareem, Angalaeswari Sendraya Perumal, Natrayan Lakshmaiya, Prabhu Paramasivam
February 24, 2023 (v1)
Keywords: gradient-based grey wolf optimizer, microgrid, multi-objective optimization, optimal scheduling, Renewable and Sustainable Energy
Optimal energy management has become a challenging task to accomplish in today’s advanced energy systems. If energy is managed in the most optimal manner, tremendous societal benefits can be achieved such as improved economy and less environmental pollution. It is possible to operate the microgrids under grid-connected, as well as isolated modes. The authors presented a new optimization algorithm, i.e., Oppositional Gradient-based Grey Wolf Optimizer (OGGWO) in the current study to elucidate the optimal operation in microgrids that is loaded with sustainable, as well as unsustainable energy sources. With the integration of non-Renewable Energy Sources (RES) with microgrids, environmental pollution is reduced. The current study proposes this hybrid algorithm to avoid stagnation and achieve premature convergence. Having been strategized as a bi-objective optimization problem, the ultimate aim of this model’s optimal operation is to cut the costs incurred upon operations and reduce the em... [more]
Assessing Wind Energy Projects Potential in Pakistan: Challenges and Way Forward
Jamshid Ali Turi, Joanna Rosak-Szyrocka, Maryam Mansoor, Hira Asif, Ahad Nazir, Daniel Balsalobre-Lorente
February 24, 2023 (v1)
Keywords: Pakistan, Renewable and Sustainable Energy, Sustainability, wind energy potential
Energy is the driver of the socioeconomic growth and development of a country. In the pursuit of available and affordable sources of energy, nations around the world have forgotten the sustainability angle and are facing an energy crisis. The developing world has initiated development plans in an unsustainable way, causing a demand−supply gap and leading to very high energy prices. Renewable energy gives us a solution to this circular crisis. The recent world has seen significant investment in renewables, particularly in the wind energy sector. The investment was initiated as a government spending program, but is now taken up by the private sector. The current study presents a thorough analysis of the prospects for wind energy and the means and measures required to fully capacitate the sector in Pakistan. In Pakistan’s three largest provinces, there is tremendous potential for wind energy, which requires proper utilization and exploration for sustained socioeconomic development. This s... [more]
Challenges and Opportunities for Integrating RE Systems in Egyptian Building Stocks
Ahmad I. Elshamy, Engy Elshazly, Olugbenga Timo Oladinrin, Muhammad Qasim Rana, Rasha Said Abd el-Lateef, Seif Tarek El-Badry, Mahmoud Elthakaby, Ahmed M. R. Elbaz, Khaled Dewidar, Iman El-Mahallawi
February 24, 2023 (v1)
Subject: Environment
Keywords: Egyptian built environment, green buildings, Renewable and Sustainable Energy, renewable energy systems, small-scale wind turbines, solar-thermal cooling
The twentieth century started with engineers’ new concepts and ideas to develop the built environment, with ideas ranging from reducing weight to automated industrialisation, enhancing energy efficiency, etc. However, they failed to predict the negative impact of automation on the environment and its resources. Therefore, future technologies proposed by engineers should consider the adverse effects on nature and the surrounding ecosystem. Using the science of ecology and integrating it into building typology can help avoid unwanted scenarios. Such technologies prioritise the performance of buildings and cities by using simulation tools to explore more ideas for designing and testing their performance. This work explores the obstacles and challenges opposing the plan to successfully supply Egypt with clean, renewable energy that reaches 42% of its total electricity. Furthermore, some solutions are proposed to tackle those barriers, such as installing thermal cooling systems and ball win... [more]
Agricultural Biomass-Based Power Generation Potential in Sri Lanka: A Techno-Economic Analysis
W. A. M. A. N. Illankoon, Chiara Milanese, Alessandro Girella, Puhulwella G. Rathnasiri, K. H. M. Sudesh, Maria Medina Llamas, Maria Cristina Collivignarelli, Sabrina Sorlini
February 24, 2023 (v1)
Keywords: agricultural residues, alternative energy, biomass energy production, decarbonization, green economy, green technologies, Renewable and Sustainable Energy, rice straw, rick husk, Sri Lanka
Worldwide energy costs have grown in recent years due to the dwindling global fossil fuel resources and the increased reliance on them for global energy production. This is a common scenario in many nations, including Sri Lanka. As a developing country, Sri Lanka should encourage the diversification of its renewable energy supplies using locally available resources. In this regard, Sri Lanka can promote the use of agricultural residues for energy generation. The present work explores the energy potential of the solid waste generated by the rice industry: rice straw (RS) and rice husk (RH). A new approach was developed using statistical data on rice production and paddy cultivation in each district of the island. The obtained data were integrated into a geographic information system (GIS) to provide geo-referenced results. A physico-chemical characterization of the RS and RH was conducted to correlate the properties of raw materials to their potential energy generation. As an energy gen... [more]
A Review: Existing Methods for Solving Spatial Planning Problems for Wind Turbines in Poland
Artur Amsharuk, Grażyna Łaska
February 24, 2023 (v1)
Keywords: localisation, multi-criteria decision analysis, Poland, Renewable and Sustainable Energy, wind farm
The article presents the most commonly used multi-criteria analysis methods for choosing the optimal location for future wind parks. The article makes a comparison of the criteria and restrictions of localisation and an overview of the main legal constraints and prospects in the development of renewable energy sources (RES). Financial assistance from the EU to accelerate the achievement of the required indicators was described. Moreover, restrictions considering environmental, social and noise factors that affect the life of the local population and the perception of the landscape visually are important. Additionally, it includes an option for developing wind energy in the absence of the necessary space for construction. In a new approach for the location of the wind farm, to the investors and another researcher related to the topic of wind turbine foundations, we indicate the most important aspects of wind energy control that should be taken into account in wind farm location proceedi... [more]
A Comprehensive Review of Photovoltaic Modules Models and Algorithms Used in Parameter Extraction
Samuel R. Fahim, Hany M. Hasanien, Rania A. Turky, Shady H. E. Abdel Aleem, Martin Ćalasan
February 24, 2023 (v1)
Keywords: double diode model, objective functions, Optimization, photovoltaic, Renewable and Sustainable Energy, single diode model, soft computing algorithms, statistical evaluation, triple diode model
Currently, solar energy is one of the leading renewable energy sources that help support energy transition into decarbonized energy systems for a safer future. This work provides a comprehensive review of mathematical modeling used to simulate the performance of photovoltaic (PV) modules. The meteorological parameters that influence the performance of PV modules are also presented. Various deterministic and probabilistic mathematical modeling methodologies have been investigated. Moreover, the metaheuristic methods used in the parameter extraction of diode models of the PV equivalent circuits are addressed in this article to encourage the adoption of algorithms that can predict the parameters with the highest precision possible. With the significant increase in the computational power of workstations and personal computers, soft computing algorithms are expected to attract more attention and dominate other algorithms. The different error expressions used in formulating objective functi... [more]
Forecasting Hydrogen Production from Wind Energy in a Suburban Environment Using Machine Learning
Ali Javaid, Umer Javaid, Muhammad Sajid, Muhammad Rashid, Emad Uddin, Yasar Ayaz, Adeel Waqas
February 24, 2023 (v1)
Subject: Environment
The environment is seriously threatened by the rising energy demand and the use of conventional energy sources. Renewable energy sources including hydro, solar, and wind have been the focus of extensive research due to the proliferation of energy demands and technological advancement. Wind energy is mostly harvested in coastal areas, and little work has been done on energy extraction from winds in a suburban environment. The fickle behavior of wind makes it a less attractive renewable energy source. However, an energy storage method may be added to store harvested wind energy. The purpose of this study is to evaluate the feasibility of extracting wind energy in terms of hydrogen energy in a suburban environment incorporating artificial intelligence techniques. To this end, a site was selected latitude 33.64° N, longitude 72.98° N, and elevation 500 m above mean sea level in proximity to hills. One year of wind data consisting of wind speed, wind direction, and wind gust was collected a... [more]
Flexible Loads Scheduling Algorithms for Renewable Energy Communities
Tiago Fonseca, Luis Lino Ferreira, Jorge Landeck, Lurian Klein, Paulo Sousa, Fayaz Ahmed
February 24, 2023 (v1)
Keywords: Algorithms, energy community, flex-offers, Renewable and Sustainable Energy, Scheduling
Renewable Energy Communities (RECs) are emerging as an effective concept and model to empower the active participation of citizens in the energy transition, not only as energy consumers but also as promoters of environmentally friendly energy generation solutions, particularly through the use of photovoltaic panels. This paper aims to contribute to the management and optimization of individual and community Distributed Energy Resources (DER). The solution follows a price and source-based REC management program, in which consumers’ day-ahead flexible loads (Flex Offers) are shifted according to electricity generation availability, prices, and personal preferences, to balance the grid and incentivize user participation. The heuristic approach used in the proposed algorithms allows for the optimization of energy resources in a distributed edge-and-fog approach with a low computational overhead. The simulations performed using real-world energy consumption and flexibility data of a REC wit... [more]
Green and Blue Hydrogen Production: An Overview in Colombia
Sebastián Mantilla, Diogo M. F. Santos
February 24, 2023 (v1)
Keywords: blue hydrogen, Colombia, green hydrogen, Renewable and Sustainable Energy
Colombia, a privileged country in terms of diversity, availability of natural resources, and geographical location, has set a roadmap for hydrogen as part of the energy transition plan proposed in 2021. To reduce its emissions in the mid-term and foster its economy, hydrogen production should be green and blue, with specific targets set for 2030 for the hydrogen costs and produced quantities. This work compares the state-of-the-art production of blue and green hydrogen and how Colombia is doing in each pathway. A deeper analysis considers the advantages of Colombia’s natural resources, the possible paths the government could follow, and the feedstock’s geographical location for hydrogen production and transportation. Then, one discusses what may be the next steps in terms of policies and developments to succeed in implementing the plan. Overall, it is concluded that green hydrogen could be the faster, more sustainable, and more efficient method to implement in Colombia. However, blue h... [more]
Purification of Residual Glycerol from Biodiesel Production as a Value-Added Raw Material for Glycerolysis of Free Fatty Acids in Waste Cooking Oil
K. A. Viraj Miyuranga, Udara S. P. R. Arachchige, Randika A. Jayasinghe, Gamunu Samarakoon
February 24, 2023 (v1)
Subject: Materials
Keywords: biodiesel, biofuel, free fatty acid, glycerol, glycerolysis, purification, Renewable and Sustainable Energy, Sustainability, value-added, waste cooking oil
The crude glycerol produced as a byproduct of transesterification synthesis has very few applications because it comprises of significant amounts of methanol, catalyst, and soap. On the other hand, transesterifications of highly acidic oil in the presence of an alkaline catalyst are problematic due to the presence of high amounts of free fatty acids. In this study, the free fatty acid level of high acid oil, which was initially determined to be 19.25%, was decreased to permit the direct production of biodiesel via glycerolysis with pure glycerol, making direct transesterification feasible. Through a process of purification, crude glycerol was refined to 92.5% purity. It was revealed that the physiochemical parameters of density, moisture content, ash content, matter organic non-glycerol content, pH, and Na/K concentrations of generated purified glycerol are equal to those of commercially available glycerol. In contrast, glycerolysis treatment successfully decreased the free fatty acid... [more]
Robust Dynamic Control of Constant-Current-Source-Based Dual-Active-Bridge DC/DC Converter Used for Off-Board EV Charging
Muhammad Husnain Ashfaq, Zulfiqar Ali Memon, Muhammad Akmal Chaudhary, Muhammad Talha, Jeyraj Selvaraj, Nasrudin Abd Rahim, Muhammad Majid Hussain
February 24, 2023 (v1)
Keywords: bidirectional DAB–DC/DC converter, constant-current control, fast dynamic performance, off-board EV charging, Renewable and Sustainable Energy
Due to the high power density, inherent zero-voltage-switching (ZVS), and high voltage-conversation ratio, the current source-based isolated dual-active-bridge DAB−DC/DC converters are extensively used for charging EVs under constant-current mode. However, the fast dynamic response of an output current is a crucial requirement for dual-active-bridge DC/DC converters operating as a constant-current source. This study proposes a fast current controller (FCC) for tracking the desired output current under various input/output parameter disturbances/variations. The proposed control strategy can ensure a fast transient response with negligible overshoot/undershoot for output current during start-up and when there are variations in the load or input voltage. Furthermore, the dynamic behavior of the current control against change in the reference current value has also been improved. A constant-current-based DAB−DC/DC converter is modeled and simulated in MATLAB/Simulink software and a scaled-... [more]
Cross-Cultural Study on OSH Risk Perception of Solar PV Workers of Saudi Arabia and India: Risk Mitigation through PtD
Abhijit Sen, Abdulrahman Khamaj, Majed Moosa, Sougata Karmakar
February 24, 2023 (v1)
Subject: Environment
Keywords: design, occupational health and safety, Renewable and Sustainable Energy, solar photovoltaics, sustainable development goals
A large number of workers are entering the rapidly growing solar photovoltaic industry. The emerging occupational safety and health risks faced by the workers have rarely been measured and aptly addressed. Moreover, there is a lack of cross-cultural studies on solar photovoltaic workers engaged across different countries. This study was planned to measure the occupational safety and health risks, socio-demographic parameters, study the cross-cultural aspects and develop design concepts for risk mitigation. Field studies were conducted in solar installations in Saudi Arabia and India. Socio-demographic data and risk perception scores for eighteen different occupational safety and health risks were obtained from the workers (n = 135). In addition, discomfort glare was also measured. Design concepts were developed following the hierarchy of controls matrix and the bow-tie analysis method using the prevention through design approach. Heat stress, electrocution, solar radiation, and fire/el... [more]
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