Field Of Renewable Energy Research Articles

Forest biomass and bioenergy supply chain resilience: A conceptual decision-making model

In recent years, with the increasing concerns about the global warming, limited non-renewable energy sources, and uncertainty in renewable energy sources accessibility, how to continuously supply clean sources of energy in form of a resilient system structure has become a topic of intense scholarly interest. Based on the milestone literature on the research field of renewable and non-renewable energies, forest biomass and bioenergy have significant compatibility with both industry and nature. Through this, our proposal contributes to supply one of the most available clean energy sources and direct this type of energy needed in an optimal way. The essential resilience components are determined and classified according to the theoretical and practical concepts. Then, this research is made use of a conceptual decision-making model based on third order confirmatory factor analysis to explore the interactions among the components in form of a network. The results reveal that the proposed model has sufficient validity and reliability levels. Finally, key interactions among the elements of model that contributed to most of the impacts on the forest biomass and bioenergy supply chain resilience were found to be optimized constantly within the network.

Modelling Li-ion batteries using equivalent circuits for renewable energy applications

During the last decades, environmental policies have advanced the promotion of renewable energy sources, opening a market for smart-grids both connected and disconnected from the main electrical grid. In the field of renewable energies, such as solar or wind ones, batteries are an essential component since they allow to easily store the energy excess that can be dispensed during periods of scarcity of these sources. This paper presents a dynamic Li-ion battery model for renewable purposes based on an electrical equivalent circuit model. This model takes into account both charge and discharge processes using the same equation, while most models found in the literature only contemplate the discharge process. Several tests were carried out in an experimental micro-grid bench at different state of charge to adjust the model parameters including the non-linear relation between the state of charge and the open circuit voltage. Finally, different experiments were performed to experimentally validate the model. The model predicts, with a low error, the battery voltage as well as the state of charge.

Desain dan Simulasi Konverter Tiga Fasa AC – DC pada Pico Hydro

Pico hydropower plant is a generator engaged in the field of renewable energy, in general, the power system uses a 3-phase synchronous generator with AC voltage, in its development it can be used as a converter, by converting AC voltage to DC voltage. One of the uses of DC voltage is as so that it can be used as a battery charger or battery discharger. An AC-DC converter, also known as a rectifier, is a device for converting alternating current (AC) to direct current (DC). In general, many technologies in the industrial world utilize converters. In this paper, a simulation design of an AC-DC converter system will be made with a 230 Volt AC input with a DC voltage output. The manufacture of the converter is carried out with different gate values on the thyristors which are simulated using Simulink in MATLAB. The results of this study are in the form of analysis and mathematical calculations of the output of the AC-DC converter where from the simulation results that AC voltage can be converted to DC voltage with the working principle of the thyristor, thus the converter output results can be used in battery chargers and battery dischargers

Biochemical Characterization of an Endoglucanase GH7 from Thermophile Thermothielavioides terrestris Expressed on Aspergillus nidulans

Endoglucanases (EC 3.2.1.4) are important enzymes involved in the hydrolysis of cellulose, acting randomly in the β-1,4-glycosidic bonds present in the amorphous regions of the polysaccharide chain. These biocatalysts have been classified into 14 glycosyl hydrolase (GH) families. The GH7 family is of particular interest since it may act on a broad range of substrates, including cellulose, β-glucan, and xylan, an attractive feature for biotechnological applications, especially in the renewable energy field. In the current work, a gene from the thermophilic fungus Thermothielavioides terrestris, encoding an endoglucanase GH7 (TtCel7B), was cloned in the secretion vector pEXPYR and transformed into the high-protein-producing strain Aspergillus nidulans A773. Purified TtCel7B has a molecular weight of approximately 66 kDa, evidenced by SDS-PAGE. Circular dichroism confirmed the high β-strand content consistent with the canonical GH7 family β-jellyroll fold, also observed in the 3D homology model of TtCel7B. Biochemical characterization assays showed that TtCel7B was active over a wide range of pH values (3.5–7.0) and temperatures (45–70 °C), with the highest activity at pH 4.0 and 65 °C. TtCel7B also was stable over a wide range of pH values (3.5–9.0), maintaining more than 80% of its activity after 24 h. The KM and Vmax values in low-viscosity carboxymethylcellulose were 9.3 mg mL−1 and 2.5 × 104 U mg−1, respectively. The results obtained in this work provide a basis for the development of applications of recombinant TtCel7B in the renewable energy field.

On the State-of-the-Art of Solar, Wind, and Other Green Energy Resources and Their Respective Storage Systems

In this article, we provide a brief overview of solar photovoltaic and thermal energy, wind turbines with vertical and horizontal axes, and other sustainable energy production systems as well as energy storage systems. In some remote areas away from easy access to electricity and fresh water, a self-contained and self-sustainable off-grid energy production and storage farm is very much needed. In this so-called sustainable energy farm, solar photovoltaic and solar thermal energies along with wind energy can be harvested and stored in a secured battery warehouse with mobile wireless surveillance systems with unpredictable coherent motions. In this battery-based energy storage system, special fire protection measures must also be employed with heat sensors and early detection and alarm systems. The alarm system will be connected to both local fire stations and automated fire extinguishing systems. A subsequent paper will present the details of this wireless fireproof alarm powered by sustainable energy resources. The main purpose of this paper is to document, provide references, and inform about the state-of-the-art achievements in the field of renewable energies, particularly, solar, wind, and other green energy resources.

Unsteady and three-dimensional computational fluid dynamics modelling of scroll expander for low-grade waste heat recovery transcritical carbon dioxide micro-scale power system

Recent developments in the field of renewable energy have led to a renewed interest in low-grade heat (< 500 K). The low-grade heat is widely wasted by the lack of efficient heat recovery technologies. It is also limited by the system size, which defines as the micro to small-scale (< 50 kW). Although ORC based unit has been implemented in this field, the CO2 based waste heat recovery units can be more capable in the size construction. The performance of the expander plays a vital role in the system’s efficiency. Thus, the current paper provides thermodynamic and CFD analysis of a scroll expander regarding a micro-scale T-CO2 recovery system (< 10 kW) with a 400 K low-grade heat source. In the current CFD model, all the fluid domains were constructed by structural mesh. It also successfully integrated with the thermodynamic table to simulate two-phase T-CO2. This model can be the first scroll expander model for T-CO2 power system and gap the bridge of utilising the scroll machinery in this field. The CFD methodology was successfully validated by the new-built testing platform and previous data. The energy performance of T-CO2 and ORC (R123) based scroll expanders are compared by isentropic and exergy efficiency. The results showed that isentropic and exergy efficiencies of T-CO2 were 7% and 14% higher than the R123. It also identified higher irreversibilities of T-CO2 by the exergy of the working fluids. The pressure and temperature distributions identified the over-expansion and reversed flow characteristics, and the pressure imbalance of the initial expansion chambers denoted the reversed flow.

Study on the Optimal Reaction Parameters of C4 Olefin Prepared by Ethanol Catalyzed Reaction Based on XGBoost Regression Prediction Algorithm

The production of C4 olefin by ethanol coupling catalytic reaction has a broad development prospect in the field of renewable energy. In this paper, the influencing factors of C4 olefin preparation process were studied, the influence of temperature and catalyst type on the reaction was analyzed, and the multivariate nonlinear regression fitting model was established under the assumption of ignoring the small probability of experimental error. Then, based on the grey correlation analysis model, the correlation degree between each variable and ethanol conversion rate and C4 olefin selection rate was studied.Then, using the catalyst parameter variables considered above, the relationship equations between four catalyst parameter variables, temperature and C4 olefin yield were calculated, and the overall constructor model of C4 olefin yield under the joint action of five variables was established by using the constructor method. Finally, using MPai data science platform software based on XGBoost regression prediction algorithm, the established constructor was cross-validated by 50% fold, and the optimal solution of reaction parameters was finally obtained.Finally, five experiments were selected to improve the experimental control group data and verify the accuracy of the theoretical value of the optimal solution. By changing the catalyst parameters and temperature, a relative control group was added to the experimental group, and the conclusion of the theoretical parameter optimal solution under unrestricted and temperature restrictions was experimentally verified.

High Precision IGBT Health Evaluation Method: Extreme Learning Machine Optimized by Improved Krill Herd Algorithm

The insulated gate bipolar transformer (IGBT) is widely used in industry, aerospace, renewable energy and other fields, which requires high reliability. However, in the research field of IGBT health evaluation, there are still problems that the accuracy is not high enough and the reliability manager of IGBT cannot accurately grasp. In this study, an IGBT health status evaluation model based on improved krill herd optimized extreme learning machine (IKH-ELM) is proposed to accurately evaluate the health status of IGBT, provide guidance for timely replacement of components, thus reducing the failure probability and maintenance cost, and improving the system reliability. Firstly, the power cycle accelerated aging test, short pulse-high amplitude current test and thermal resistance measurement test are carried out to obtain the failure predictor parameters data of IGBT. Then, an IGBT health status classification method based on cloud model is proposed to make the health status assessment results more scientific. In addition, since the random selection of weights and thresholds of ELM affects the performance of the model, the krill herd algorithm is improved to optimize ELM for obtaining better prediction ability. Based on this, a prediction model based on IKH-ELM is established. Finally, the proposed model is proved to be more accurate and effective under the same experimental environment and the same index.

Prevention of the Spread of the COVID-19 Virus with an Online to Offline Shopping System with an Independent Self-Service Concept using a Miniature Solar-Powered Mobile Market

The participation of universities is highly expected in assisting economic recovery, so that economic turnover activities can continue without increasing the number of Covid-19 sufferers. In this case, universities provide solutions in the field of renewable energy as a source of electricity to support the efficiency of the prototypes produced. This activity was carried out by students and lecturers as a form of community service. Where the concept offered is online to offline to maintain shopping loyalty. Consumers can make transactions by selecting product quality, tasting the product, and tasting the product first and they do it in front of their house in the form of a solar-powered mobile market. The method used in the data collection process: the Preparation Stage, the Group Discussion Stage, the Capacity Building Implementation Stage: the Research Stage, the Data Analysis Stage. The conclusion from this study is that the community is enthusiastic, especially those living in housing because of the online to offline system (online ordering system, goods come offline, consumers can choose). For vehicles, it can save fuel because it uses a solar power engine.

Profiles of Two JOMAE Associate Editors (The Fifth in a Continuing Series)

Profiles of Two JOMAE Associate Editors (The Fifth in a Continuing Series)

Implementasi Kendali Tegangan Lup Tertutup Buck Converter dengan ArduinoMega

One type of power converter that is widely applied in the field of renewable energy is DC-DC Converter. In variousapplication cases, voltage control features are often required. One of the challenges is how to build a closed loop controller to control the output voltage of the DC-DC Converter. In this journal, an Arduino Mega based output voltage controller will be implemented. The type of voltage controller implemented is the PI controller with the consideration that the controller has been well-known tested and mathematically proven. The PI controller is set based on closed loop block diagram calculations with the Buck Converter as the main plant. The implementation of the PI controller on the Arduino Mega is based on the expected transient response settings. PI controller was successfully implemented in this study. The experimental results show that, the controller can maintain its voltage along with changes, both source and load voltage. Thus, it can be concluded that the Arduino Mega board can work well in closed loop applications for power converter control.

Forecast and Analysis of Renewable Energy Technology Development Trend Based on Knowledge Graph and Patent Data

The development and utilization of renewable energy is an important part of national strategy. In this study, Cite Space was used to analyze the Knowledge Graph of relevant research literature and define the research hotspots and the key technologies in the field of renewable energy. Then, the domestic and foreign related patent data in the field of renewable energy were retrieved through the database of Wanfang, and Logistic model was used to make a comparative analysis of the life cycle of relevant technologies in this field, so as to predict the current development stage and future development trend of China's renewable energy technology.

Forecast and Analysis of Renewable Energy Technology Development Trend Based on Knowledge Graph and Patent Data

The development and utilization of renewable energy is an important part of national strategy. In this study, Cite Space was used to analyze the Knowledge Graph of relevant research literature and define the research hotspots and the key technologies in the field of renewable energy. Then, the domestic and foreign related patent data in the field of renewable energy were retrieved through the database of Wanfang, and Logistic model was used to make a comparative analysis of the life cycle of relevant technologies in this field, so as to predict the current development stage and future development trend of China's renewable energy technology.

Study on Standardization of Renewable Energy Asset Transaction

With the rapid development of the renewable energy industry, the traditional renewable energy asset transaction mode is facing great challenges in terms of the transaction cycle, security, work efficiency, and so on. This report analyzes the current situation of renewable energy asset transactions and system platforms. The purpose of this paper is to show the study of renewable energy asset transaction standard framework and standard content. Furthermore, this paper presents the concept of market-oriented renewable energy asset transaction, explains the basic framework of renewable energy asset transaction standards, and proposes a series of renewable energy asset transaction standards. Finally, it analyses the elements that need to be paid attention to promote the standardization of renewable energy asset transactions. The work pushes forward the coordinated development of science and technology, industry and finance of the renewable energy industry chain, and provides standardized support for convenient circulation and high-quality development in the renewable energy field.

Green and Renewable Energy Innovations: A Comprehensive Bibliometric Analysis

Taking into account factors such as unfavorable climate changes, shrinking fossil fuel resources, low energy efficiency, and the pace of population growth, the transformation towards green and renewable energy is one of the most important goals and challenges facing the world. The energy sector is the source of about 75% of global greenhouse gas emissions and energy-related emissions are reaching new record levels. For the energy transition to succeed, innovation at the level of technology, business processes and policies (local, national, and international) are necessary. Therefore, the aim of this article is to analyze the size, structure, and dynamics of research on innovations in the field of green and renewable energy in the last decade in order to identify the main topics and research trends in this field. The authors conducted a bibliometric review based on the PRISMA guidance together with visualization analysis based on the VOSviewer software. For this purpose, the Web of Science Core Collection (WoS CC) database was used, and based on defined inclusion criteria, the authors selected 1144 records for bibliographic analysis. The database was subjected to a performance analysis from the perspective of the number of publications per year, dominant countries, and journals. Further, science mapping was employed to analyze such features of the publications as co-citations, co-occurrences, and bibliometric coupling. Based on the results, gaps in green and renewable energy innovations were identified and issues for future research were defined and recommended.

Bioethanol and biomethane production from watermelon waste: A circular economy strategy

In the present study, bioethanol and biogas were produced from watermelon waste aiming at the integral use of residual biomass in a circular economy context. Watermelon pulp was processed and used as the culture medium for ethanol production with the yeast Wickerhamomyces sp. UFFS-CE-3.1.2 and watermelon rinds were used for biochemical biogas production (BBP) assays. For the ethanol production step from watermelon pulp, the results demonstrate that there was no requirement to supplement the medium with nitrogen sources to achieve satisfactory yields and cell viability. With this, a sequential batch configuration with cell recycling was conducted for thirty cycles, with fermentation yields of around 90% during all recycling, high cell density and viability, and reduced fermentation time from 9 h to 3 h. The results of the biogas production step from watermelon rinds indicate that the biomass performed well, with biogas and methane production of 581 ± 11 mLN·gVS and 290.63 ± 5.63 mLCH4·gVS, respectively, and energetic potential of 15,461.54 kJ·kgbiomass−1. Our data provide a perspective on using watermelon waste for biofuel production to reduce the environmental impacts of this biomass disposal, thus contributing to the circular economy and the advances in the field of renewable energy.

Regulation of Incentives for Use of Renewable Energy at the Level of Regional Legislation in Federal States, Using the Russian Federation as an Example

Effective use of renewable energy requires a system of energy legislation that meets modern challenges. Although, in large countries, climate and socioeconomic factors in different regions can significantly vary and can affect the regional legislation regulating renewable energy sources, careful reproduction of good practices and successful experiences of other regions are a good basis for the development of legislation. The comparative method of legal research was the main method used to achieve the objectives set in this study. Based on the results, a number of recommendations were developed to consolidate and expand the powers of regional regulators in the field of renewable energy, to include an economic assessment of the effectiveness of state programs, to use tax incentives for renewable energy projects, and to introduce restrictions on the use of petroleum products. Recommendations were also made to improve regional legislation on renewable energy sources in terms of legal techniques. Further development of this study would contribute to the improvement of regional legal regulation and would accelerate the transition to “green” energy.

Renewable Energies and Sustainable Development: A Bibliometric Overview

Sustainable development has positioned itself as a fundamental element of a transversal nature, being linked to the energy transition. In this sense, it must be included as a mainstream objective of all actions and strategies developed at the social, academic, business, and political levels. However, to the best of our knowledge, no bibliometric work has been carried out to date to analyze the main contributions to the literature focused on the concepts of renewable energy and sustainable development. The main aim of this paper is to establish the key trends and academic contributions made in the field of renewable energies and sustainable development. For this purpose, a bibliometric and co-citation analysis has been carried out using the Bibliometrix® tool, an open-source R package. The results show that this is a field of study that has significantly increased its importance in recent years, which is illustrated using different indicators. We conclude that research trends seem to be directed towards managing the transition to a new, more sustainable energy model composed of renewable energy production systems, in addition to the adoption of new technologies to increase the efficiency of products and power transmission systems. In this respect, the transition towards a new, more sustainable energy model seems to be a fundamental step to guarantee the sustainability of human action.

Impact of the EPBD on Changes in the Energy Performance of Multi-Apartment Buildings in Lithuania

As per general provisions of European Directive 2010/31/EU on the energy efficiency of buildings (recast), the Lithuanian government transposed the Directive into Lithuanian national law. In the process, the Lithuanian government prepared strategic documents in the field of energy performance and renewable energy that were integrated together through the National Energy and Climate Plan for 2021–2030 (NECP). To better understand the current situation vis-à-vis energy performance, the main characteristics of buildings pertaining to the Lithuanian multi-apartment building stock, classified according to their energy performance class, are analysed and discussed in this paper. Through the exploitation of data from the national Energy Performance Certificate (EPC) register, an overview of the energy performance of the existing Lithuanian residential building stock is presented along with an analysis of the unused potential energy savings pertinent to this building category. The results obtained from the analysed data of energy consumption in buildings shows that the policies adopted over the years were successful in improving the building stock, promoting the move towards the specifications required by a Class A++ (nearly zero energy buildings—NZEB) by 2021. The results show that this was primarily achieved by a significant reduction in the thermal energy used for space heating.

Effect of Edaravone (An Antioxidant) on the Performance of Organic Perovskite Solar Cells

Perovskite solar cells (PSCs) have broad application prospects in the field of renewable energy. The photovoltaic performance and long‐term stability of PSCs are important factors for the industrialization of PSCs. Passivation of perovskite films by antioxidants is an effective approach to not only reduce the density of defect states but also improve the environmental stability of the device. Herein, edaravone (EDA) is added to the perovskite precursor solution to passivate the defects and also scavenge ultraviolet(UV)‐induced free radicals during photoaging. The EDA‐optimized device achieves a champion power conversion efficiency (PCE) of 20.81%, and after 1000 h of exposure to the environment, the efficiency can maintain 72% of the original value.