Hasil untuk "Renewable energy sources"

Mehmet Esen, Tahsin Yuksel

J. Abbas, Li-song Wang, Samira ben Belgacem et al.

The global financial downturn induced by COVID-19 has hampered the effectiveness of renewable energy developments, impeding the accomplishment of the United Nations' sustainable development targets. Green finance is a significant means for promoting renewable energy investment and achieving sustainability. Using data from 2012 to 2021 from fifty energy firms in China, this study highlights the starring part of geopolitical risk, green finance, and environmental tax in investment in renewable energy (IRE) sources. It also investigated how IRE impacts the studied firms' electricity output. The data were analyzed through quantile regression and dynamic analysis techniques. The results indicated that green financing and environmental tax significantly impact IRE sources with 0.137*** and 0.428*** beta values, respectively. However, geopolitical risk significantly impedes such projects. Similarly, IRE significantly increases the electricity output of Chinese energy firms. This research is unique in the sense of studying green financing, geopolitical risk, and environmental tax nexus in renewable energy investments leading to electricity generation, which shows a pivotal role in achieving environmental sustainability and provides valuable insights to environmentalists and policymakers to design and implement ecological strategies leading to achieving sustainable development goals.

Natei Ermias Benti, Mesfin Diro Chaka, A. Semie

This article presents a review of current advances and prospects in the field of forecasting renewable energy generation using machine learning (ML) and deep learning (DL) techniques. With the increasing penetration of renewable energy sources (RES) into the electricity grid, accurate forecasting of their generation becomes crucial for efficient grid operation and energy management. Traditional forecasting methods have limitations, and thus ML and DL algorithms have gained popularity due to their ability to learn complex relationships from data and provide accurate predictions. This paper reviews the different approaches and models that have been used for renewable energy forecasting and discusses their strengths and limitations. It also highlights the challenges and future research directions in the field, such as dealing with uncertainty and variability in renewable energy generation, data availability, and model interpretability. Finally, this paper emphasizes the importance of developing robust and accurate renewable energy forecasting models to enable the integration of RES into the electricity grid and facilitate the transition towards a sustainable energy future.

D. Gayen, R. Chatterjee, S. Roy

Lin Chen, Ying Hu, Ruiyi Wang et al.

The building sector is significantly contributing to climate change, pollution, and energy crises, thus requiring a rapid shift to more sustainable construction practices. Here, we review the emerging practices of integrating renewable energies in the construction sector, with a focus on energy types, policies, innovations, and perspectives. The energy sources include solar, wind, geothermal, and biomass fuels. Case studies in Seattle, USA, and Manama, Bahrain, are presented. Perspectives comprise self-sufficiency, microgrids, carbon neutrality, intelligent buildings, cost reduction, energy storage, policy support, and market recognition. Incorporating wind energy into buildings can fulfill about 15% of a building's energy requirements, while solar energy integration can elevate the renewable contribution to 83%. Financial incentives, such as a 30% subsidy for the adoption of renewable technologies, augment the appeal of these innovations.

Cecilia Naveira-Pazos, María C. Veiga, Christian Kennes

The ability of <i>Rhodotorula toruloides</i> DSM 4444 to metabolize low-cost carbon sources such as fatty acids was comprehensively studied. This organism is shown, for the first time, to simultaneously accumulate microbial oils (biofuel precursors) and carotenoids from acetic acid obtained from CO₂ fermentation. This fatty acid is typically the single end product of acetogenic bioconversion of one-carbon gas pollutants (e.g., CO₂ and CO). In the first set of experiments, different aerobic fermentations were carried out in automated bioreactors, with acetic acid in one case and with glucose, a more conventional carbon source, as a control, in another bioreactor. <i>R. toruloides</i> consumed around 80 g/L substrate under both conditions. Maximum lipid content (27.2% g/g dry weight) was reached from 38 g/L glucose, while carotenoid content was higher with acetic acid (1.4 mg/g cell after 54.1 g/L acetic acid consumed), representing a 40% increase compared to glucose (1.0 mg/g cell after 64.2 g/L glucose consumed). Additionally, in the second set of assays, a fermented broth produced by <i>Acetobacterium woodii</i> from CO₂ fermentation, containing residual nutrients and metabolites, was tested. Despite its complex composition, <i>R. toruloides</i> grew and produced carotenoids (up to 0.141 mg/g), showing potential adaptability. To the best of our knowledge, this is the first report on a greenhouse gas-based biotechnological process as a promising sustainable alternative for the valorization of pollutants, e.g., gas emissions, their bioconversion to VFAs, such as acetic acid, and subsequent fermentation of the carboxylic acid into microbial oils, as a source of renewable energy, as well as carotenoids as a high-value nutraceutical product.

B. Gajdzik, R. Wolniak, R. Nagaj et al.

The article presents an analysis of the statistical relationship between the determinants of and barriers to the development of renewable energy sources (RESs) in the macroeconomic system and the development of renewable energy source consumption in individual European Union countries. The article considers four key categories of RES development barriers in the European Union: political, administrative, grid infrastructural, and socioeconomic. The work is based on publicly available historical data from European Union reports, Eurostat, and the Eclareon RES Policy Monitoring Database. The empirical analysis includes all 27 countries belonging to the European Union. The research aimed to determine the impact of all four types of factors, including socioeconomic, on the development of RESs in European Union countries. The analysis uncovered that describing the European Union as a consistent region regarding the speed of renewable energy advancement and the obstacles to such progress is not accurate. Notably, a significant link exists between a strong degree of societal development and the integration of renewable energy sources. In less prosperous EU nations, economic growth plays a pivotal role in renewable energy development. Barriers of an administrative nature exert a notable influence on renewable energy development, especially in less affluent EU countries, while grid-related obstacles are prevalent in Southern–Central Europe. In nations where the proportion of renewable energy sources in electricity consumption is substantial, an excess of capacity in the renewable energy market significantly affects its growth.

S. Samadi, Andreas Fischer, S. Lechtenböhmer

To combat climate change, it is anticipated that in the coming years countries around the world will adopt more stringent policies to reduce greenhouse gas emissions and increase the use of clean energy sources. These policies will also affect the industry sector, which means that industrial production is likely to progressively shift from CO 2 -emitting fossil fuel sources to renewable energy sources. As a result, a region ’ s renewable energy resources could become an increasingly important factor in determining where energy-intensive industries locate their production. We refer to this pull factor as the “ renewables pull ” effect. Renewables pull could lead to the relocation of some industrial production as a consequence of regional differences in the marginal cost of renewable energy sources. In this paper, we introduce the concept of renewables pull and explain why its importance is likely to increase in the future. Using the examples of direct reduced iron (DRI) and ammonia production, we find that the future costs of climate-neutral production of certain products is likely to vary considerably between regions with different renewable energy resources. However, we also identify the fact that many other factors in addition to energy costs determine the decisions that companies make in term of location, leaving room for further research to better understand the future relevance of renewables pull.

Aashish K Moses, Srinath Ranjan Tripathy, Saroj Sundar Baral

Abstract The existing energy-wastewater nexus may be resolved using metal oxide semiconductor photocatalysts in photocatalytic hydrogen production and pollutant degradation, which is a clean and sustainable process. SnO2 is one such well-researched and proven photocatalyst that is now in use, although it only works with ultraviolet light, which only makes up 4% of the total solar energy received. The present research aims to use iron as a dopant to make SnO2 active under visible light, enhancing reactions like water splitting and dye degradation. The sol-gel method was used to synthesize the photocatalysts. XRD, BET, UV diffuse reflectance spectra, PL spectra, XPS, and SEM micrographs were used to characterize the synthesized photocatalysts. For 7.5 wt% Fe-doped SnO2, a remarkable hydrogen generation rate of 18.81 µmol/hr under sunlight was achieved, nearly three times that of pure SnO2 (5.71 µmol/h). The nanocomposites display excellent photoreactivity towards RhB dye degradation with an optimal concentration of 7.5 wt% Fe-doped SnO2. This optimal composite photocatalyst removes 93% of RhB dye on 0.1 g/L photocatalysts in only 60 min under sunlight. Pristine SnO2 removes 36% of the dye under similar reaction conditions. The photoluminescence spectra of Fe-doped SnO2 had lower peak locations than the pristine SnO2, indicating a decreased rate of charge recombination and increased life duration of the active species. As a result, hydrogen generation rates and dye degradation efficiencies have increased significantly. The photocatalyst’s recyclability study revealed that the photocatalysts can be used efficiently for four cycles without significant reduction in the yield.

Rafał Wyszomierski, Piotr Bórawski, Aneta Bełdycka-Bórawska

Plant biomass is playing a key role in the development of renewable energy sources. The share of biomass in renewable energy sources is about 70% in Poland and more than 40% in the European Union (EU). To assess the competitive position of farms selling plant biomass including straw and wood, including both future opportunities and threats, we conducted research on 185 farms in 2022. The aim of the research was to assess the usage of plant biomass, with the aim of increasing its position compared to other renewable energy sources. We used tabular, graph and descriptive methods to present the research results. Moreover, the Dornik–Hansen test (<i>p</i> = 0.003), Shapiro–Wilk test (<i>p</i> = 0.0017), Lilliefors test (<i>p</i> = 0.000) and Jargue–Berra test (<i>p</i> = 0.008) results show the significance of the research. The most important factors shaping the increased prices of biomass were the availability of raw materials on the market, totaling 41.1%, and calorific value, totaling 17.6%. Looking at the data, it can be seen that the most popular renewable energy technologies in which respondents plan to invest is photovoltaics (57.8%) and biomass (17.6%). According to the respondents, the most profitable renewable energy sources are photovoltaics (38.4%), wind energy (23%) and biogas (16.2%). Farmers also pointed out the most ecologically friendly, renewable energy sources. According to the respondents, the most ecologically friendly, renewable energy sources were wind energy (32.2%), photovoltaics (25.3%) and water energy plants (20.7%). The most frequently indicated limitations of biomass production were the long payback period (19.2%) and high investment costs (18.9%). The most important threat to biomass production was the shortage of arable land (32.5%) and poor farmland (23.5%). These results show that policymakers should adjust laws to encourage farmers to invest in biomass as a renewable energy source. Photovoltaics, which is considered a very clean renewable energy source, faces a big task in cleaning rural areas.

Jayasri Nemala, Devi V.S. Anusuya, Tewari Preeti et al.

This study is concerned with the coordinated charging pattern of plugin electric vehicles (PEVs) by using a simulation and control framework. The first of these is to develop a novel control technique based on a grid structure to manage the charging power of PEVs in reaction to fluctuating renewable energy sources. The grid is assumed to control and communicate instantly and directly through a common control signal the electricity used for PEV charging. Based on the principle of market-based demand modeling, the subsequent theoretical formulation involves a system of partial differential equations for concurrent PEV charging. It is then applied to future real world driving data and compared to a PEV Monte Carlo model. Moreover, the principles of SM control are introduced to synthesize the robust output feedback controller for the system without state error. The fluctuating PEV count is addressed by focusing on the sole observable output: the instantaneous mismatch of supply and demand of renewable electricity by customers. The performance of the controller is evaluated in the present research based on a real wind power state trajectory through numerical simulations of the system.

Mohammed A. Alghassab

The purpose of this study is to explore the architecture and functioning of hybrid solar desalination systems and investigate their potential as a sustainable solution for water purification. The study reveals that solar-powered desalination systems offer a remarkable alternative to traditional methods, as they rely on clean solar energy and produce no noise or sound pollution. In addition, they have demonstrated cost-effectiveness in generating drinking water, especially in desert regions and inaccessible areas. Furthermore, the research highlights the significance of incorporating waste heat energy into the desalination process. Also shows that utilizing waste heat energy can significantly reduce expenses and enhance the overall effectiveness of water desalination. Through an in-depth analysis of the fundamental principles and real-world applications, this study underscores the importance and rationale for implementing hybrid solar desalination systems. By effectively utilizing solar energy, these systems provide a sustainable approach to address water scarcity and ensure the efficient management of water and energy resources. This study emphasizes the fundamental importance of the structure of hybrid solar desalination systems fueled by solar energy in the efficient management of water resources. By combining technological innovations with renewable energy sources, these systems pave the way for a sustainable future. HIGHLIGHTS Hybrid solar desalination systems, which rely on solar energy as their major power source for purifying water.; This review paper explores the architecture and functioning of hybrid solar desalination systems.; This review paper emphasizes the significance and rationale for utilizing hybrid solar desalination systems that rely on solar energy to efficiently handle water and energy resources.;

Ge Sun

The increasing industrial development and energy demand have necessitated the maximization of available energy use and the deployment of renewable resources. Effective energy management, optimal modeling, and efficient planning are essential to transform the power system into a high-efficiency, optimal model. This study focuses on the initial step of modeling smart buildings (SBs) equipped with non-responsive devices and renewable photovoltaic sources. A comprehensive energy management (EM) plan is formulated for these buildings, incorporating the KNX protocol for solar energy system management. Batteries are integrated into the building model to store energy during periods of low consumption and serve as generators during peak load conditions, with the primary goal of minimizing power system losses and related costs. To address the complexity of this model, whale optimization algorithm (WOA) is employed for optimization. Optimal candidate buses are selected for interconnected building management based on a suggested sensitivity analysis to minimize losses. Cost performance is then assessed, considering energy production and sales. The findings indicate that substantial control of operating costs can be achieved through strategic management of battery charging and discharging, as well as the utilization of photovoltaic units. The proposed model is evaluated across various scenarios using a test system comprising 30 modified system, demonstrating its effectiveness in enhancing energy efficiency and management.

Hans H Falk, Stefanie Eckner, Konrad Ritter et al.

The chalcopyrite alloy (Ag,Cu)(In,Ga)Se _2 is a highly efficient thin film solar cell absorber, reaching record efficiencies above 23%. Recently, a peculiar behavior in the bond length dependence of (Ag,Cu)GaSe _2 was experimentally proven. The common cation bond length, namely Ga–Se, decreases with increasing Ag/(Ag + Cu) ratio even though the crystal lattice expands. This is opposite to the behavior observed for Cu(In,Ga)Se _2 , where all bond lengths increase with increasing lattice size. To better understand this peculiar bond length behavior, element-specific bond lengths of (Ag,Cu)InSe _2 and Ag(In,Ga)Se _2 alloys are determined using extended x-ray absorption fine structure spectroscopy. They show that the peculiar bond length dependence occurs only for (Ag,Cu) alloys, independent of the species of common cation (In or Ga). The bond lengths are used to determine the anion displacements and to estimate their contribution to the bandgap bowing. Again, both behaviors differ significantly depending on the type of alloyed cation. A valence force field approach, relaxing bond lengths and bond angles, is used to describe the structural distortion energy for a comprehensive set of I–III–VI _2 and II–IV–V _2 chalcopyrites. The model reveals bond angle distortions as main driving factor for the tetragonal distortion and reproduces the literature values with less than 10% deviation. In contrast, the peculiar bond length dependence is not reproduced, demonstrating that it originates from electronic effects beyond the scope of this structural model. Thus, a fundamental understanding of bond length behavior and tetragonal distortion is achieved for chalcopyrite materials, benefiting their technological applications such as high efficiency thin film photovoltaics.

Jinping Zhao, Ali Arefi, Alberto Borghetti et al.

There is a general concern that the increasing penetration of electric vehicles (EVs) will result in higher aging failure probability of equipment and reduced network reliability. The electricity costs may also increase, due to the exacerbation of peak load led by uncontrolled EV charging. This paper proposes a linear optimization model for the assessment of the benefits of EV smart charging on both network reliability improvement and electricity cost reduction. The objective of the proposed model is the cost minimization, including the loss of load, repair costs due to aging failures, and EV charging expenses. The proposed model incorporates a piecewise linear model representation for the failure probability distributions and utilizes a machine learning approach to represent the EV charging load. Considering two different test systems (a 5-bus network and the IEEE 33-bus network), this paper compares aging failure probabilities, service unavailability, expected energy not supplied, and total costs in various scenarios with and without the implementation of EV smart charging.

Mahdi Dolatabadi, Seyedreza Seyednouri, Albin Hasselström et al.

Abstract This study aims to develop an optimization strategy for determining the optimal type and capacity of batteries in a building‐applied photovoltaic system, taking into account battery degradation, consumption profiles, and regional solar irradiation. Key performance indicators such as peak shaving, savings, net present value, self‐consumption, return on investment, and payback period are examined. The best trade‐off among these indicators is determined using the fuzzy decision‐making method. A study was conducted using real data from Kpenergy Company, focusing on a building with a 50 kW photovoltaic system located in Stockholm. Three cases were examined in MATLAB software, each categorized based on the type of contract between the utility (Vattenfall Company) and the subscriber. The results of these case studies highlight the effectiveness of the proposed optimization approach. Using the proposed approach, optimal batteries are determined, minimizing subscriber costs while maximizing profit.

Christian Rosenberg Petersen, Søren Fæster, Jakob Ilsted Bech et al.

Abstract Leading edge erosion of wind turbine blades is one of the most critical issues in wind energy production, resulting in lower efficiency, as well as increased maintenance costs and downtime. Erosion is initiated by impacts from rain droplets and other atmospheric particles, so to protect the blades, special protective coatings are applied to increase their lifetime without adding significantly to the weight or friction of the blade. These coatings should ideally absorb and distribute the force away from the point of impact; however, microscopic defects, such as bubbles, reduce the mechanical performance of the coating, leading to cracks and eventually erosion. In this work, mid‐infrared (MIR) Optical Coherence Tomography (OCT) is investigated for non‐destructive, contactless inspection of coated glass‐fiber composite samples to identify subsurface coating defects. The samples were tested using rubber projectiles to simulate rain droplet and particle impacts. The samples were subsequently imaged using OCT, optical microscopy, and X‐ray tomography. OCT scanning revealed both bubbles and cracks below the surface, which would not have been detected using ultrasonic or similar non‐destructive methods. In this way, OCT can complement the existing quality control in turbine blade manufacturing, help improve the blade lifetime, and reduce the environmental impact from erosion.

Yu Miao, Alexandre Yokochi, Goran Jovanovic et al.

Non-thermal plasma as a tool in chemical reaction engineering has been studied for many years. The temperature of electrons in non-thermal plasma far exceeds other particles, which leads to its high efficiency. Besides the well-studied destruction of volatile organic compounds (VOCs), the reaction environment generated by non-thermal plasma is also suitable for the activation of many significant gas-phase chemical reactions, e.g., as methane coupling, reduction of carbon dioxide, ammonia synthesis, nitrogen fixation, as well as some liquid phase chemical reactions such as the treatment of contaminated water. Material synthesis is another target field of non-thermal plasma. Plasma in micro scale with several enhanced properties makes it an even more promising tool for plasma-chemical processing. This work summarizes different types of non-thermal plasmas and their performance in commonly studied chemical reactions. The advantages gained by generating non-thermal plasma in micro scale with constricted spaces, reduced timescales, and micro-/nano-structured electrodes are also discussed.

Shamsiev Kh.A., Shamsiev B.Kh., Khamidov Sh.V.

The issues of increasing the reliability of the United Power System of Central Asia in the current conditions of operation and energy transition are analyzed. The issues of integrating renewable energy sources into the energy system are addressed, taking into account the forecasted volumes of their input until 2030.

Sunil Subedi, Bidur Poudel, Pooja Aslami et al.

This research focuses on the evolving dynamics of the power grid, where traditional synchronous generators are being replaced by non-synchronous power electronic converter (PEC)-interfaced renewable energy sources. The non-linear dynamics must be accurately modeled to ensure the stability of future converter-dominated power systems (CDPS). However, obtaining comprehensive dynamic models becomes more complex and computationally intensive as the system grows. This study proposes a scalable and automated data-driven partitioned modeling framework for CDPS dynamics. The method constructs reduced-ordered dynamic linear transfer function models using input-output measurements from a PEC switching model. Validation experiments were conducted on single-house and multi-house scenarios, demonstrating high accuracy (over 97%) and significant computational speed improvements (6.5 times faster) compared to comprehensive models. This framework and modeling approach offer valuable insights for efficient analysis of power system dynamics, aiding in planning, operation, and dispatch.