Search Results (1,778)

This paper proposes novel designs of dual-layer flower-shaped heave plates, featuring both aligned and staggered configurations with three, six, and nine petals. Numerical simulations were conducted to study the hydrodynamic effects of these various heave plate designs integrated with the OC4 DeepCwind semisubmersible floating offshore wind turbine platform under prescribed heave oscillations. The overset mesh technique was employed to treat the floating platform’s motions. Comprehensive assessments of vertical force, radiated wave patterns, vorticity fields, added mass, and damping coefficients were conducted. The results revealed that the novel flower-shaped staggered heave plates significantly outperformed conventional circular plates in terms of damping coefficients. Specifically, the damping coefficient of flower-shaped staggered heave plates was greater than that of circular heave plates, while the aligned configuration exhibited a lower damping coefficient. The damping coefficient increased with a reduction in the number of petals for the staggered heave plates. Among the evaluated designs, the dual-layer flower-shaped staggered heave plates with three petals demonstrated the highest effectiveness in attenuating heave motion of the floating platform. The utilization of novel dual-layer flower-shaped staggered heave plates is therefore a promising practice aimed at damping the heave motion of platforms in rough seas. Full article

Beneath the promise of clean energy, the rapid rise of wind energy farms has stirred mounting concern for pollinator-dependent livelihoods—particularly in beekeeping. This study investigates the effect of wind energy farms on honey-related income using data from six provinces in Turkiye’s Aegean region and the propensity score matching method. Results show that beekeepers operating near wind energy farms experience significantly higher incomes—an average treatment gain of 45,107 TL, with treated groups earning 56,515 TL more—backed by several robust statistical evidence such as placebo and bootstrap techniques. Certain groups—such as younger, nomadic, and family-trained beekeepers, and those receiving financial support—exhibit greater resilience. The findings highlight the need for land-use strategies that balance renewable energy development with ecological and economic concerns. Introducing bee-friendly vegetation around turbines is proposed as a practical solution. This approach can foster a mutually beneficial relationship between wind energy farms and beekeeping, supporting both rural livelihoods and the broader goals of sustainable development. Full article

As a novel energy storage technology, seawater batteries exhibit significant application potential across various domains, including marine exploration, underwater communication, and island power supply. However, the deep-sea low-temperature environment adversely affects the performance of seawater battery systems. This paper proposes a seawater metal–air battery system equipped with a preheater (SMAB-P). This innovative system establishes stable natural circulation and utilizes the high-temperature seawater within the system to preheat the incoming low-temperature seawater, thereby effectively enhancing battery performance. It was found that, compared with the SMAB system without a preheater, when achieving a heat recovery rate of 100% the average temperature of seawater in the electrode plate area of the SMAB-P system can be increased by 54%. Consequently, the electrical conductivity of seawater within the system can be increased by approximately 20%, leading to a significant reduction in ohmic losses and an enhancement in the load voltage of the battery. Furthermore, increasing either the height or width of the electrode plate can enhance self-driven force and circulation flow rate, as well as both average and maximum temperatures of seawater in the electrode plate area to some extent. Reducing the annular space of the preheater can significantly increase the seawater temperature within the system, but excessive reduction may hinder the effective replacement of fresh seawater in the system. It is also noted that seawater velocity in the electrode plate channels remains relatively low and evenly distributed while exhibiting very small temperature variation. Full article

Wave energy converters (WECs) that are installed in nearshore environments offer several practical advantages, including easier access, lower maintenance, reduced transmission costs, and potential integration with the existing coastal infrastructure, leading to cost savings and improved commercial viability. This study presents a techno-economic analysis and power take-off (PTO) optimization for a vertical cylindrical WEC positioned adjacent to a vertical seawall under irregular wave conditions. The PTO system is connected via frames and hinges, with one end connected to the vertical seawall and the other end to the arm extending to the oscillating WEC. Hydrodynamic parameters were obtained from WAMIT, incorporating the seawall effect via the image method using linear potential theory. This analysis considers variations in WEC diameter, the lengths of frame segments supporting the PTO system, and the PTO damping. First, the geometric configuration is optimized. The results show that placing the WEC closer to the seawall and positioning the hinge joint of the PTO frame at the midpoint of the actuating arm significantly enhances power extraction, due to intensified hydrodynamic interactions near the seawall. A techno-economic analysis is then conducted using two techno-economic metrics, with one representing device cost and the other a newly introduced metric for PTO cost, combined through the weighted sum model (WSM) within a multi-criteria decision analysis (MCDA) framework. Our findings indicate that a smaller-diameter WEC is more cost-effective within a narrow range of PTO damping, while larger WECs, although requiring higher PTO damping capacity, become more cost-effective at higher PTO damping values, due to increased power absorption. Optimal PTO damping values were identified for each diameter of the WEC, demonstrating the trade-off between power output and system cost. These findings provide practical guidance for optimizing nearshore WEC designs to achieve a balance between performance and cost. Full article

Accurate and efficient next-event prediction in wind-turbine maintenance processes (WTMPs) is crucial for proactive resource planning and early fault detection. However, existing deep-learning-based prediction approaches often encounter performance challenges during the training phase, particularly when dealing with large-scale datasets. To address this challenge, this paper proposes a Sampling-based Next-event Prediction (SaNeP) approach for WTMPs. More specifically, a novel event log sampling technique is proposed to extract a representative sample from the original WTMP training log by quantifying the importance of individual traces. The trace prefixes of the sampled logs are then encoded using one-hot encoding and fed into six deep-learning models designed for next-event prediction. To demonstrate the effectiveness and applicability of the proposed approach, a real-life WTMP event log collected from the HuangYi wind farm in Hebei Province, China, is used to evaluate the prediction performance of various sampling techniques and ratios across six predictive models. Experimental results demonstrate that, at a 30% sampling ratio, SaNeP combined with the LSTM model achieves a 3.631-fold improvement in prediction efficiency and a 6.896% increase in prediction accuracy compared to other techniques. Full article

Accurate and uncertainty-aware wind power forecasting is essential for reliable and cost-effective power system operations. This paper presents a novel probabilistic forecasting framework based on diffusion probabilistic models. We adopted a two-stage modeling strategy—a deterministic predictor first generates baseline forecasts, and a conditional diffusion model then learns the distribution of residual errors. Such a two-stage decoupling strategy improves learning efficiency and sharpens uncertainty estimation. We employed the elucidated diffusion model (EDM) to enable flexible noise control and enhance calibration, stability, and expressiveness. For the generative backbone, we introduced a time-series-specific diffusion Transformer (TimeDiT) that incorporates modular conditioning to separately fuse numerical weather prediction (NWP) inputs, noise, and temporal features. The proposed method was evaluated using the public database from ten wind farms in the Global Energy Forecasting Competition 2014 (GEFCom2014). We further compared our approach with two popular baseline models, i.e., a distribution parameter regression model and a generative adversarial network (GAN)-based model. Results showed that our method consistently achieves superior performance in both deterministic metrics and probabilistic accuracy, offering better forecast calibration and sharper distributions. Full article

The United States has emerged as a global leader in wind energy deployment, yet the industry faces evolving challenges linked to policy uncertainty, infrastructure constraints, and supply chain disruptions. This review aims to analyze selected aspects of the U.S. wind energy market in light of recent economic, regulatory, and environmental developments. Drawing upon the academic literature, policy documents, and industry reports, the paper outlines key trends in both onshore and offshore wind sectors, evaluates technological and economic progress, and identifies structural barriers that may hinder further growth. Special attention is given to the role of federal incentives, such as the Inflation Reduction Act, and to the regional differentiation in wind capacity expansion. Additionally, the potential of small-scale wind systems for individual- and community-level energy resilience is explored as an underrepresented area in current research. The findings suggest that while the U.S. wind market holds significant untapped potential, strategic improvements in grid modernization, permitting processes, and public engagement are essential. The review highlights the need for more inclusive and regionally sensitive policy approaches to unlock future development pathways in the U.S. wind energy sector. Full article

With countries around the world required to change their energy systems to mitigate climate change, offshore wind power has become one of the most important renewable energy sources. This study aims to analyze the potential for offshore wind power generation based on the water depth and annual average wind speed in the Akita region, Japan. A geographical information system was used not only for a conventional square mesh but also for a rectangular mesh when there is a prevailing wind, and a greater water depth was also considered. The results obtained indicate that the use of a rectangular mesh reduces the potential for implantable offshore wind turbines compared to a square mesh. It was also found that the potential for offshore wind power generation is significant up to a water depth of 500 m. Full article

The objective of this study is to create an integrated and sustainability-centered framework to identify optimal locations for wind energy projects in Indonesia. This research employs a novel two-phase multi-criteria decision-making (MCDM) framework that combines the strengths of Data Envelopment Analysis (DEA), Fuzzy Analytic Hierarchy Process (FAHP), and Fuzzy Combined Compromise Solution (F-CoCoSo). Initially, DEA is utilized to pinpoint the most promising sites based on a variety of quantitative factors. Subsequently, these sites are evaluated against qualitative criteria such as technical, economic, environmental, and socio-political considerations using FAHP for criteria weighting and F-CoCoSo for ranking the sites. Comprehensive sensitivity analysis of the criteria weights and a comparative assessment of methodologies substantiate the robustness of the proposed framework. The results converge on consistent rankings across methods, highlighting the effectiveness of the integrated approach. Notably, the results consistently identify Lampung, Aceh, and Riau as the top-ranked provinces, showcasing their strategic suitability for wind plant development. This framework provides a systematic approach for enhancing resource efficiency and strategic planning in Indonesia’s renewable energy sector. Full article

A hybrid wave energy conversion (WEC) system, integrating a backward bent duct buoy (BBDB) with an oscillating buoy (OB) via a flexible mooring chain, is introduced in this study. Unlike existing hybrid WECs, the proposed system dispenses with rigid mechanical linkages and enables flexible offshore deployment. Flared BBDB and buoy models with spherical, cylindrical, and semi-capsule shapes are designed and tested experimentally in a wave flume using both regular and irregular wave conditions. The effects of nozzle ratio (NR), coupling distance, buoy draft, and buoy geometry are systematically examined to investigate the hydrodynamic performance and energy conversion characteristics. It is found that NR at 110 under unidirectional airflow produces an optimal balance between pressure response, free surface displacement, and energy conversion efficiency. Energy extraction is significantly influenced by the coupling distance, with the hybrid system achieving maximum performance at a specific normalized spacing. The semi-capsule buoy improves power extraction ability and expands effective bandwidth due to asymmetric shape and coupled motion. These findings provide valuable insights into the coupling mechanism and geometric optimization for hybrid WECs. Full article

The growing global demand for electricity, driven by the development of electromobility, data centers, and smart technologies, necessitates innovative approaches to energy generation. Wind power, as a clean and renewable energy source, plays a pivotal role in the global transition towards low-carbon power systems. This paper presents a comprehensive review of generator technologies used in wind turbine applications, ranging from conventional synchronous and asynchronous machines to advanced concepts such as low-speed direct-drive (DD) generators, axial-flux topologies, and superconducting generators utilizing low-temperature superconductors (LTS) and high-temperature superconductors (HTS). The advantages and limitations of each design are discussed in the context of efficiency, weight, reliability, scalability, and suitability for offshore deployment. Special attention is given to HTS-based generator systems, which offer superior power density and reduced losses, along with challenges related to cryogenic cooling and materials engineering. Furthermore, the paper analyzes selected modern generator designs to provide references for enhancing the performance of grid-synchronized hybrid microgrids integrating solar PV, wind, battery energy storage, and HTS-enhanced generators. This review serves as a valuable resource for researchers and engineers developing next-generation wind energy technologies with improved efficiency and integration potential. Full article

Reliable wave prediction plays a significant role in wave energy converter (WEC) research, but there are still prediction errors that would increase the uncertainty for the power grid and reduce the power quality. The efficiency and stability of the power take-off (PTO) system are also important research topics in WEC applications. In order to solve the above-mentioned problems, this paper presents a model predictive control (MPC) method composed of a prediction error compensation controller and a PTO optimization controller. This work aims to address the limitations of existing wave prediction methods and improve the efficiency and stability of hydraulic PTO systems in WECs. By controlling the charging and discharging of the accumulator, the power quality is enhanced by reducing grid frequency fluctuations and voltage flicker through prediction error compensation. In addition, an efficient and stable hydraulic PTO system can be obtained by keeping the operation pressure of the hydraulic motor at the optimal range. Thus, smoother power output minimizes grid-balancing penalties and storage wear, and stable hydraulic pressure extends PTO component lifespan. Finally, comparative numerical simulation studies are provided to show the efficacy of the proposed method. The results validate that the dual-controller MPC framework reduces power deviations by 74.3% and increases average power generation by 31% compared to the traditional method. Full article

This paper addresses the challenge of maximizing power extraction in offshore wind energy systems through the development of an enhanced maximum power point tracking (MPPT) control strategy. Offshore wind energy is inherently intermittent, leading to discrepancies between power generation and electricity demand. To address this issue, we propose three advanced control algorithms to perform a comparative analysis: sliding mode control (SMC), the Integral Backstepping-Based Real-Twisting Algorithm (IBRTA), and Feed-Back Linearization (FBL). These algorithms are designed to handle the nonlinear dynamics and aerodynamic uncertainties associated with offshore wind turbines. Given the practical limitations in acquiring accurate nonlinear terms and aerodynamic forces, our approach focuses on ensuring the adaptability and robustness of the control algorithms under varying operational conditions. The proposed strategies are rigorously evaluated through MATLAB/Simulink 2024 A simulations across multiple wind speed scenarios. Our comparative analysis demonstrates the superior performance of the proposed methods in optimizing power extraction under diverse conditions, contributing to the advancement of MPPT techniques for offshore wind energy systems. Full article

Simulations are conducted using a microscale model framework to quantify differences in projected Annual Energy Production (AEP), Capacity Factor (CF) and wake losses for large offshore wind farms that arise due to different input datasets, installed capacity density (ICD) and/or wake parameterizations. Differences in CF (and AEP) and wake losses that arise due to the selection of the wake parameterization have the same magnitude as varying the ICD within the likely range of 2–9 MW km⁻². CF simulated with most wake parameterizations have a near-linear relationship with ICD in this range, and the slope of the dependency on ICD is similar to that in mesoscale simulations with the Weather Research and Forecasting (WRF) model. Microscale simulations show that remotely generated wakes can double AEP losses in individual lease areas (LA) within a large LA cluster. Finally, simulations with the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) model are shown to differ in terms of wake-induced AEP reduction from those with the WRF model by up to 5%, but this difference is smaller than differences in CF caused by the wind farm parameterization used in the mesoscale modeling. Enhanced evaluation of mesoscale and microscale wake parameterizations against observations of climatological representative AEP and time-varying power production from wind farm Supervisory Control and Data Acquisition (SCADA) data remains critical to improving the accuracy of predictive AEP modeling for large offshore wind farms. Full article

The concept of the circular economy aims to develop systems for reusing, recovering, and recycling products and services, pursuing both economic growth and sustainability. In many countries, legislation has been enacted to create frameworks ensuring environmental protection and fostering initiatives to implement the circular economy across various sectors. The wind energy industry is no exception, with industries and institutions adopting strategies to address the forthcoming challenge of repowering or dismantling a significant quantity of wind turbines in the coming years reaching a total of global wind power capacity by 2024. This also involves managing the resulting waste, which includes materials with high economic value as well as others that have considerable environmental impacts but that can be reused, recycled, or converted. In parallel, the research activity in this field has increased significantly in response to this challenge, leading to a vast body of work in the literature, especially in the last three years. The aim of this paper is to conduct a bibliometric study to provide a global perspective on the current literature in the field, covering the period from 2009 to 2024. A total of 670 publications were retrieved from Web of Science and Scopus, with 57% of them published in the last three years, highlighting the growing interest in the field. This study analyzes the research product, the most relevant journal, the most cited authors and institutions, their collaborative patterns, emerging trends, and gaps in the literature. This contribution will provide an up-to-date analysis of the field, fostering better understanding of the direction of the research and establishing a solid foundation for future studies Full article