Search Results (534)

Multi-use of sea space is increasingly seen as a tool for efficient marine resource management, renewable energy utilisation, and sustainable food production. Multi-use Offshore Installations combine two or more production technologies on a single platform at sea. However, achieving commercial viability faces several challenges: social, technical, environmental, and economic. This research focuses on the social aspect, investigating community perceptions of a multi-use offshore installations over three years from 2019 to 2021. Our research was conducted in Reggio Calabria, Italy, where a prototype was deployed in 2021, and Islay, Scotland, suitable for a full-scale multi-use offshore installation but with no deployment, using community surveys. We used the theories of Social License to Operate and Institutional Analysis and Development to frame our analysis. Our findings indicate that coastal communities prefer wind turbines over fish farming, have low trust in public officials to regulate environmental impacts of a multi-use offshore installation, and that short-term deployment of a prototype does not significantly change opinions. We reflect on the challenges of understanding societal opinions of a multi-use offshore installation, given complex boundary conditions, and that multi-use offshore installations combine familiar technologies into a new and unknown form. We suggest that future research should explore the scale of deployment needed to crystallise community opinions, and the role of regulators in developing social license to operate for multi-use offshore installations. Full article

The global transition towards sustainable energy has accelerated the development and deployment of offshore wind turbines. Jacket foundations, commonly installed in intermediate to deep water depths to access available space and higher load capacities, are built to withstand intensified hydrodynamic loads. Due to their structural complexity near the seabed, however, they are prone to local and global scour, which can compromise stability and increase maintenance costs. While extensive research has addressed scour protections around monopiles, limited attention has been given to complex foundation geometries or even hybrid configurations that combine energy-harvesting devices with structural support. These hybrid systems introduce highly unsteady flow fields and amplified turbulence effects that current design frameworks appear to be unable to capture. This study provides an experimental characterisation of scour damage in riprap-protected jackets as well as additional tests for a hybrid jacket foundation. A novel adaptation of a high-resolution overlapping sub-area methodology was employed. For the first time, it was successfully applied to quantify the damage to riprap protections for a complex offshore foundation. Results revealed that, although hybrid jackets showed the capacity to attenuate incident waves, the scour protection experienced damage numbers (S_3D) two to six times higher than conventional jackets due to flow amplifications. The findings highlight the need for revised design guidelines that can account for the complex hydrodynamic-structural interactions of next-generation marine harvesting technologies integrated into complex foundations. Full article

The reliability of an offshore wind farm (OWF) depends strongly on the export and inter-array cable installations. AC export cables (EXCs) are typically up to 120 km long and operate at voltages ranging from 220 to 275 kV. The newest inter-array cables (IACs) operate at 66 kV and can be up to 20 km long. They connect individual wind turbines to the offshore substation. This paper discusses current failure statistics and costs, as well as the technical challenges associated with different site acceptance testing (SAT) methods for offshore wind farm export and inter-array cables. The technical benchmark analysis for both EXCs and IACs shows the most reliable solutions for SAT. Moreover, practical applications based on 13 international OWF installations show that damped AC (DAC) supports quality control of newly installed EXC and IAC cable systems and provides a solid basis for in-service condition-based maintenance. Full article

Using the geologically complex Wanning (Hainan) site as context, this study applies finite-element analyses to quantify how three construction-induced conditions—foundation out-of-level, directional misalignment, and seabed scour—affect the bearing performance of deep-water pile-anchor foundations for floating offshore wind. For the Wanning case, typical installation and loading deviations reduce the characteristic resistance by a clearly measurable amount: changing the loading inclination from 30° to 45° and superimposing a 5° out-of-level installation leads to reductions in R_c of approximately 7–10%. A 3 m scour pit around the pile has a more severe impact, decreasing R_c by about 18% for 30° loading and up to 28% for 45° loading. Under accidental-limit-state loading, the maximum pile-head displacement increases from about 0.247 m (ULS) to 0.396 m (ALS), i.e., by roughly 60%. These quantitative results demonstrate that construction-induced deviations and scour can significantly erode safety margins, highlighting the need to control installation accuracy and to explicitly incorporate scour allowances and protection in design. Full article

With the rapid development of offshore photovoltaic (PV) systems, PV support structures have become a critical component in offshore PV installations. The material properties of these structures significantly influence the safety and reliability of the entire system. 3D printing technology, leveraging its advantages such as rapid prototyping, complex structure manufacturing, and high material utilization, holds broad application prospects in the field of offshore PV. However, the infill pattern of 3D printing materials can significantly affect their mechanical properties. Marine PV systems require extremely high resistance to wave action, tensile strength, and torsional performance, while offshore PV support structures need sufficient compressive capacity. Therefore, this study aims to investigate how different infill patterns affect the compressive properties of 3D printed materials, thereby optimizing material selection and printing processes for offshore PV applications. Through experimental design, a variety of common infill patterns were selected. Universal testing machines and torsion testing machines were used to conduct systematic tests on compressive strength, elastic modulus, and compressive fracture strain. The results showed that different infill patterns have a significant impact on compressive properties, among which the honeycomb infill exhibited the best overall mechanical performance, effectively enhancing load-bearing capacity and stability. Based on the experimental results, appropriate infill configurations and material combinations for different components of offshore PV systems were proposed. The feasibility of optimizing 3D printing processes to improve the overall performance of offshore PV structures was further explored. The findings of this study not only provide a theoretical basis for material selection and process optimization in 3D printing for offshore PV systems but also offer important references for promoting the application of 3D printing technology in this field. Full article

This Vertical-axis wind turbines (VAWTs) are emerging as promising alternatives to conventional horizontal-axis wind turbines (HAWTs) for renewable energy generation, particularly in urban and offshore environments. Despite increasing interest, a comprehensive evaluation of their technical, economic, and environmental performance remains limited. This review, based on a targeted literature search, critically evaluates and compares the performance, economic viability, environmental impact, technological advancements, and adoption barriers of VAWTs and HAWTs. VAWTs demonstrate lower aerodynamic efficiency (20–35%) and capacity factors (20–35%) compared to HAWTs (efficiency 40–50%, capacity factors 30–45%), yet offer advantages such as omnidirectional wind capture, simpler ground-level maintenance, lower noise emissions, reduced avian impact, and greater feasibility for space-constrained urban settings. Economic analyses indicate that VAWTs typically have higher levelized costs of energy (60–80 EUR/MWh) than HAWTs (40–60 EUR/MWh), although these are partially offset by reduced operational costs. Environmental assessments favor VAWTs in terms of land use, biodiversity impact, and water consumption. Technological progress, including AI-based aerodynamic optimization, hybrid rotor designs, advanced composite materials, and Maglev bearings, has enhanced the competitiveness of VAWTs. The main adoption challenges are lower power output, scalability constraints, and lack of support from policymakers. While HAWTs remain dominant in large-scale wind energy production due to superior aerodynamic performance and economies of scale, VAWTs offer significant benefits for decentralized, urban, and offshore applications where installation flexibility, noise, and environmental considerations are critical. Continued innovation and more policy support could increase VAWT market penetration and contribute to more diversified, sustainable energy portfolios. Full article

Floating offshore wind is now receiving much attention as an expansion to bottom-fixed, especially in deep waters with large wind resources. In this regard, improving the performance and efficiency of floating offshore wind farms (FOWFs) is currently a highly addressed topic. The inter-array (IA) cable connection is a key aspect to be optimised. Due to floating offshore wind (FOW) particularities such as dynamic cable designs, higher power capacities, and challenging installation, IA cabling is expected to be a primary cost driver for commercial-scale FOWFs. Therefore, IA cabling optimisation can lead to large cost reductions. In this work, an optimisation with an adaptive particle swarm optimisation (PSO) algorithm for such wind farms is proposed, considering the floating substructures’ horizontal translations and its impact on the dynamic cable length. The method provides an optimised IA connection, reducing acquisition costs and power losses by using a clustered minimum spanning tree (MST) as an initial solution and improving it with the PSO algorithm. The PSO achieves a reduction in the levelised cost of energy (LCOE) between 0.018% (0.022 EUR/MWh) and 0.10% (0.12 EUR/MWh) and a reduction in cable acquisition costs between 0.18% (0.3 M EUR) and 1.34% (3.8 M EUR) compared to the initial solution, showing great potential for future commercial-sized FOWFs. Full article

Aiming at the limited applicability of traditional empirical formulas in roll prediction for offshore wind turbine installation vessels (WTIVs), this study proposes a collaborative verification method that integrates model tests with Computational Fluid Dynamics (CFD) simulations. This approach reveals the influence mechanism of the fluid trapped in the leg-spudcan well region on the roll period and damping, facilitating high-precision prediction. A numerical model of the WTIV in a jack-up operating condition was established, and a CFD method based on the RANS equations was employed alongside experimental data for synergistic analysis. The results demonstrate that the fluid in the leg-spudcan well generates a significant additional moment of inertia, which reduces the natural roll period by approximately 7% and increases the damping coefficient by approximately 58%. Furthermore, an increase in leg length leads to a linear increase in damping and a linear decrease in the roll period. The motion response transfer functions derived from tests and the motion response errors of key structures in irregular waves are generally less than 10%. On this basis, a motion response conversion method applicable to any location on the entire ship is derived, providing a reliable numerical analysis tool for WTIV seakeeping evaluation and operational window assessment. Full article

With the growing global need for climate change mitigation and the transition to renewable energy, the development and adoption of photovoltaic (PV) power generation technologies have accelerated significantly. However, land-based PV systems face increasing limitations due to land scarcity, high costs, and environmental constraints. Consequently, floating offshore PV systems that utilize marine environments have emerged as promising alternatives. This study introduces a novel structural redesign specifically developed to enable full containerization of floating PV platforms, adapting the PV–bos model by Spain’s BlueNewables for standardized offshore deployment. The research focuses on the standardization and modularization of floating structures to allow repetitive factory production and efficient container-based logistics. The methodology includes modular segmentation, and transportation simulation, which together establish standardized unit configurations that minimize uncertainty during manufacturing, assembly, and installation. By applying containerization principles to structural design, the study proposes standardized component dimensions and optimized container loading strategies to enhance productivity, constructability, and scalability. The novelty of this research lies in establishing a quantitative framework that integrates modular segmentation and standardized container logistics into floating PV structural design—a topic that has not been previously addressed in offshore solar studies. The results demonstrate substantial improvements in logistics efficiency and cost reduction, achieving over 80% savings in transportation CAPEX for a 0.5 MW floating PV system using 40 HC (High Cube) and 45 HC containers. Future research will complement these strategies through finite element and hydrodynamic simulations to validate the structural and environmental performance of modular joints under real marine conditions, further strengthening the technological robustness and sustainability of standardized offshore PV deployment. Full article

Installing energy storage devices can improve the frequency modulation ability of offshore wind farms to participate in the grid. The lifecycle and wear of energy storage devices are significantly influenced by ambient temperature, charge and discharge rates, cycle depths, and operating environments. To extend the lifecycle and reduce the replacement frequency of these devices, their operation mode must be carefully considered. However, existing energy storage optimization configurations rarely consider these factors, particularly when addressing the frequency stability of offshore wind power systems. To address this gap, an optimization method is proposed for energy storage allocation that incorporates system frequency support, energy storage cost, and the devices’ lifecycle and degradation. This approach ensures a reasonable and efficient allocation of energy storage. Full article

Approximately 27.6% of Italian beaches are currently affected by erosion, despite the widespread implementation of coastal defence structures. Around 10,500 installations—mainly groins and detached breakwaters—occupy nearly 24.6% of the national shoreline. Although primarily designed to protect tourist beaches, these hard-engineered structures often degrade coastal landscapes, alter nearshore circulation, and pose risks to swimmers. Nevertheless, beaches remain a fundamental asset for the “3S” (Sun, Sea, Sand) tourism sector, which contributes approximately 2.2% to Italy’s GDP, accounting for over 175 million tourists’ overnight stays in 2024, frequently concentrated near protected coastal zones. In this study, drowning incidents along the Italian coastline were analyzed using press reports complemented by official statistics. Between 2016 and 2021, an average of 145 fatalities occurred per bathing season. Sudden drownings following medical emergencies accounted for 41% of cases, non-swimmers for 18%, accidental falls into the water for 3%, and water sports activities for an additional 3%. Rip currents on natural beaches were responsible for 22% of drownings, whereas those generated by coastal defence structures accounted for 12%. A further 12% of non-swimmer fatalities are suspected to have resulted from falls into depressions or channels formed in proximity to these structures. Evidence from previous studies and seabed morphology analyses indicates that coastal defence structures can generate rip currents through two main mechanisms: (1) hydraulic pressure exerted against groins, which drives offshore flow, and (2) water outflow between pairs of breakwaters resulting from wave setup behind them. Both processes, though often less intense, are also observed near submerged structures. The erosional channels formed by these currents may persist well beyond storm events, maintaining dangerous conditions for bathers. As Italy continues to rely predominantly on hard coastal protection measures, improving the understanding of drowning dynamics associated with these structures is crucial. This should be accompanied by regulatory updates requiring designers and coastal managers to systematically assess related hazards and to propose effective mitigation and safety strategies. Full article

Floating and offshore photovoltaic (FPV) installations present a promising solution for addressing land-use conflicts while enhancing renewable energy production. With an estimated global offshore PV potential of 4000 GW, FPV systems offer unique advantages, such as increased efficiency due to water cooling effects and synergy with other offshore technologies. However, challenges related to installation costs, durability, environmental impacts, and regulatory gaps remain. This review provides a comprehensive and critical analysis of FPV advancements, focusing on inland, nearshore, and offshore applications. A systematic evaluation of recent studies is conducted to assess technological innovations, including material improvements, mooring strategies, and integration with hybrid energy systems. Furthermore, the economic feasibility of FPVs is analysed, highlighting cost–benefit trade-offs, financing strategies, and policy frameworks necessary for large-scale deployment. Environmental concerns, such as biofouling, wave-induced stress, and impacts on aquatic ecosystems, are also examined. The findings indicate that while FPV technology has demonstrated significant potential in enhancing solar energy yield and water conservation, its scalability is hindered by high capital costs and the absence of standardised regulations. Future research should focus on developing robust offshore floating photovoltaic (OFPV) designs, optimising material durability, and establishing regulatory guidelines to facilitate widespread adoption. By addressing these challenges, FPVs can play a critical role in achieving global climate goals and accelerating the transition to sustainable energy systems. Full article

In this paper, 15-min production data from renewable energy sources (RES), aggregated by technology (onshore wind, offshore wind, solar) and by country (Germany, Austria, Hungary), are analyzed. The concept of a confidence interval is introduced as a parameter for practical use in power-system management. In probabilistic dimensioning of the FRR (Frequency Restoration Reserve; sometimes also called “secondary reserve”), it is necessary to ensure reserve sufficiency for a high percentage of time p, in the order of 99.9%. The confidence interval is specified by upper and lower deviation limits, expressed as percentages of the total installed capacity of the observed RES system, not to be exceeded with a probability greater than $1-p$. The concept of the “regulation multiplier” is also considered, which essentially indicates how many additional megawatts of RES capacity can be installed for each added megawatt of FRR capacity, ceteris paribus. Finally, a previously experimentally developed regulation-multiplier model is verified by replicating the original research on a new dataset used in this paper. Full article

Monitoring bottom-hole pressure (BHP) is critical for reservoir management and flow assurance, especially in offshore fields where challenging conditions and production losses are more impactful. However, reliability issues and high installation costs of Permanent Downhole Gauges (PDGs) often limit access to this vital data. Soft sensors offer a cost-effective and reliable alternative, serving as backups or replacements for physical sensors. This study proposes a novel data-driven methodology for estimating flowing BHP using wellhead and topside measurements from plant monitoring systems. The framework employs ensemble methods combined with clustering techniques to partition datasets, enabling tailored supervised training for diverse production conditions. Aggregating results from sub-models enhances performance, even with simpler machine learning algorithms. We evaluated Linear Regression, Neural Networks, and Gradient Boosting (XGBoost and LightGBM) as base models. A case study of a Brazilian Pre-Salt offshore oilfield, using data from 60 wells across nine platforms, demonstrated the methodology’s effectiveness. Error metrics remained consistently below 2% across varying production conditions and reservoir lifecycle stages, confirming its reliability. This solution provides a practical, economical alternative for studies and monitoring in wells lacking PDG data, improving operational efficiency and supporting reservoir management decisions. Full article

The urgent pursuit of net-zero emissions presents a critical challenge for modern societies, necessitating a speedup of transformative shifts across sectors to mitigate climate change. Predicting trends and drivers in the integration of energy technologies is essential to addressing this challenge, as it informs policy decisions, strategic investments, and the deployment of innovative solutions crucial for transitioning to a sustainable energy future. Despite the importance of accurate forecasting, current methods remain limited, especially in leveraging the vast, unlabelled energy literature available. However, with the advent of large language models (LLMs), the ability to interpret and extract insights from extensive textual data has significantly advanced. Sentiment analysis, in particular, has just emerged as a vital tool for detecting scientific opinions from the energy literature, which can be harnessed to forecast energy trends. This study introduces a novel multi-agent framework, EnergyEval, to evaluate the sentiment and factuality of the energy literature. The core novelty of the multi-agent framework is found to be the use of heterogeneous energy-specialised roles with different LLMs. This investigation, using both multiple persona agents and different LLMs, provides a bespoke collaboration mechanism for multi-agent debate (MAD). In addition, we believe our approach can extend across the energy industry, where deep application of MAD is yet to be exploited. We apply EnergyEval to the case of UK offshore wind literature, assessing its predictive performance. Our findings indicate that the sentiment predicted by the EnergyEval effectively aligns with observed trends in increasing the installed capacity and reductions in Levelised Cost of Energy (LCOE). It also helps us to identify key drivers in offshore wind development. The advantage of employing a multi-agent LLM debate team allows us to achieve competitive accuracy compared to single-LLM-based methods, while significantly reducing computational costs. Overall, the results highlight the potential of EnergyEval as a robust tool for forecasting technology developments in the pursuit of net-zero emissions. Full article