Search Results (213)

Floating solar technology has gained significant attention as part of the global expansion of renewable energy due to its potential for installation in underutilized water bodies. Several countries, including the Netherlands, have initiated efforts to extend this technology from inland freshwater applications to open offshore environments, particularly within offshore wind farm areas. This development is motivated by the synergistic benefits of increasing site energy density and leveraging the existing offshore grid infrastructure. The deployment of offshore floating photovoltaic (OFPV) systems involves assembling multiple modular units in a marine environment, introducing operational risks that may give rise to safety concerns. To mitigate these risks, weather windows must be considered prior to the task execution to ensure continuity between weather-sensitive activities, which can also lead to additional time delays and increased costs. Consequently, optimizing marine logistics becomes crucial to achieving the cost reductions necessary for making OFPV technology economically viable. This study employs a simulation-based approach to estimate the installation duration of a 5 MWp OFPV plant at a Dutch offshore wind farm site, started in different months and under three distinct risk management scenarios. Based on 20 years of hindcast wave data, the results reveal the impacts of campaign start months and risk management policies on installation duration. Across all the scenarios, the installation duration during the autumn and winter period is 160% longer than the one in the spring and summer period. The average installation durations, based on results from 12 campaign start months, are 70, 80, and 130 days for the three risk management policies analyzed. The result variation highlights the additional time required to mitigate operational risks arising from potential discontinuity between highly interdependent tasks (e.g., offshore platform assembly and mooring). Additionally, it is found that the weather-induced delays are mainly associated with the campaigns of pre-laying anchors and platform and mooring line installation compared with the other campaigns. In conclusion, this study presents a logistics modeling methodology for OFPV systems, demonstrated through a representative case study based on a state-of-the-art truss-type design. The primary contribution lies in providing a framework to quantify the performance of OFPV installation strategies at an early design stage. The findings of this case study further highlight that marine installation logistics are highly sensitive to local marine conditions and the chosen installation strategy, and should be integrated early in the OFPV design process to help reduce the levelized cost of electricity. Full article

Our regression analysis documents that energy policies to promote renewable energy development, as well as hydroelectric imports from Canada, lead to short-run reductions in average electricity prices (also known as merit-order effects) throughout the Northeast United States. Changes in the reliance upon renewable energy in one of the Northeast’s three interconnected electricity markets will impact wholesale prices in the other two. The retirement of a 1000 MW nuclear plant can increase prices by about 9% in the Independent System Operator of New England market and 7% in the New York Independent System Operator market in the short run at reference hubs, while also raising prices in neighboring markets. Some proposed large-scale off-shore wind farms would not only lower prices in local markets at the reference hubs modeled but would also lower prices in neighboring markets. Full article

This study identifies the optimal location for an offshore energy island to supply sustainable power to desalination plants along the Red Sea coast. As demand for clean energy in water production grows, integrating renewables into desalination systems becomes increasingly essential. A decision-making framework was developed to assess site feasibility based on renewable energy potential (solar, wind, and wave), marine traffic, site suitability, planned developments, and proximity to desalination facilities. Data was sourced from platforms such as Windguru and RETScreen, and spatial analysis was conducted using Inverse Distance Weighting (IDW) and Multi-Criteria Decision Analysis (MCDA). Results indicate that the central Red Sea region offers the most favorable conditions, combining high renewable resource availability with existing infrastructure. The estimated regional desalination energy demand of 2.1 million kW can be met using available renewable sources. Integrating these sources is expected to reduce local CO₂ emissions by up to 43.17% and global desalination-related emissions by 9.5%. Spatial constraints for offshore installations were also identified, with land-based solar energy proposed as a complementary solution. The study underscores the need for further research into wave energy potential in the Red Sea, due to limited real-time data and the absence of a dedicated wave energy atlas. Full article

Offshore synthetic fuel production and marine carbon dioxide removal can be enabled by direct ocean capture, which extracts carbon dioxide from the ocean that then can be used as a feedstock for fuel production or sequestered underground. To maximize carbon capture, plants require a variety of low-carbon energy sources to operate, such as variable renewable energy. However, the impacts of variable power on direct ocean capture have not yet been thoroughly investigated. To facilitate future deployments, a generalizable model for electrodialysis-based direct ocean capture plants is created to evaluate plant performance and electricity costs under intermittent power availability. This open-source Python-based model captures key aspects of the electrochemistry, ocean chemistry, post-processing, and operation scenarios under various conditions. To incorporate realistic energy supply dynamics and cost estimates, the model is coupled with the National Renewable Energy Laboratory’s H2Integrate tool, which simulates hybrid energy system performance profiles and costs. This integrated framework is designed to provide system-level insights while maintaining computational efficiency and flexibility for scenario exploration. Initial evaluations show similar results to those predicted by the industry, and demonstrate how a given plant could function with variable power in different deployment locations, such as with wind energy off the coast of Texas and with wind and wave energy off the coast of Oregon. The results suggest that electrochemical systems with greater tolerances for power variability and low minimum power requirements may offer operational advantages in variable-energy contexts. However, further research is needed to quantify these benefits and evaluate their implications across different deployment scenarios. Full article

316L stainless steel is widely employed in various industrial sectors, including shipbuilding, offshore plants, high-temperature/high-pressure (HTHP) piping systems, and hydrogen infrastructure, due to its excellent mechanical stability, superior corrosion resistance, and robust resistance to hydrogen embrittlement. This study presents 316L stainless steel alloys fabricated via hot isostatic pressing (HIP), conducted at 1300 °C and 100 MPa for 2 h, incorporating Cr₂N powder and an optimized Ni/Mn ratio based on the nickel equivalent (Ni_eq). During HIP, Cr₂N decomposition yielded a uniformly refined, dense austenitic microstructure, with enhanced corrosion resistance and mechanical performance. Corrosion resistance was evaluated by potentiodynamic polarization in 3.5 wt.% NaCl after 1 h of OCP stabilization, using a scan range of −0.25 V to +1.5 V (Ag/AgCl) at 1 mV/s. Optimization of the Ni/Mn ratio effectively improved the pitting corrosion resistance and mechanical strength. It is cost-effective to partially substitute Ni with Mn. Of the various alloys, C13Ni-N exhibited significantly enhanced hardness (~30% increase from 158.3 to 206.2 HV) attributable to nitrogen-induced solid solution strengthening. E11Ni-HM exhibited the highest pitting corrosion resistance given the superior PREN value (31.36). In summary, the incorporation of Cr₂N and adjustment of the Ni/Mn ratio effectively improved the performance of 316L stainless steel alloys. Notably, alloy E11Ni-HM demonstrated a low corrosion current density of 0.131 μA/cm², indicating superior corrosion resistance. These findings offer valuable insights for developing cost-efficient, mechanically robust corrosion-resistant materials for hydrogen-related applications. Further research will evaluate alloy resistance to hydrogen embrittlement and investigate long-term material stability. Full article

In the Chengdao–Zhuanghai area, there are few core samples of Mesozoic clastic rocks but abundant logging data. It is difficult to establish a fracture model of clastic rocks directly based on core samples and relevant tests. In this study, triaxial compression tests are conducted on Mesozoic clastic rock samples to reveal the failure mechanism of clastic rocks. A statistical model based on logging data is utilized to calculate dynamic rock mechanical parameters, and theoretical relationships between static and dynamic mechanical parameters are derived. A failure model for clastic rocks is established using logging data and the minimum energy consumption principle by applying the principle of minimum energy consumption and adopting the unified energy yield criterion of rocks as the energy consumption constraint. This research study shows that a linear relationship exists between the static and dynamic mechanical parameters of Mesozoic clastic rocks, and the correlation coefficient can reach 85%. The core aspect of clastic rock failure is energy dissipation. As confining pressure increases, more energy must be dissipated during the failure of clastic rocks. Upon failure, the releasable elastic energy accumulated within the clastic rocks clearly reflects the confining pressure effect. A higher initial confining pressure leads to a greater release of elastic energy and results in a more severe failure degree. The developed rock failure model effectively represents the nonlinear mechanical behavior of Mesozoic clastic rocks in the Chengdao–Zhuanghai area under complex stress conditions. It is suitable for investigating the fracture distribution of Mesozoic clastic rocks and addresses the challenge of understanding the failure mechanism of these rocks in the Chengdao–Zhuanghai region. Full article

This article presents the value-added production-sharing contract (VAPSC), an extension of traditional production-sharing contracts (PSCs), which encompasses raw materials production, subsequent processing, and the final ‘sharing’ of goods. Developing countries often face challenges in oil and gas exploration, production, and sector development, necessitating new collaborative frameworks between governments, industries, and international companies. The study justifies the economic terms of VAPSC that align with Lebanon’s national regulations, focusing on offshore gas production and the subsequent production and sale of liquefied natural gas (LNG). The research evaluates VAPSC application in Lebanon through a case study involving offshore gas field development, LNG plant construction, and consequent LNG-sharing. Results demonstrate the VAPSC potential to promote petroleum sector development by generating added value for both the state and society, as well as economic efficiency for the contractor. The research contributes to contract theory by introducing VAPSC as a novel framework for integrating hydrocarbon extraction, subsequent processing, and value-added product distribution, offering a replicable model for other resource-rich developing nations. The main findings include the design of a new type of contract—VAPSC—along with an economic-mathematical model for optimizing government-investor partnerships and the definition of key contractual terms. Full article

Marine environments provide a unique opportunity to blend offshore wind energy production and marine fishery activities as complementary technologies. This study investigated the morphological characteristics (length and weight) and biomass yield of seaweed (Undaria pinnatifida) in a model marine environment with mariculture within an offshore wind farm in southwestern Korea. The mean lengths in the first cultivation trials of U. pinnatifida sporophytes increased from 1.8 ± 0.1 cm in November 2021 to 120–170 cm in March 2022 (density, 39.8 plants m⁻¹; final wet weight, 98.6–249.1 g (mean 146.8 ± 20.4 g, n = 20 ind.); yield 5842 g m⁻¹). Further, for the second cultivation trial, the length of the sporophytes increased from 1.5 ± 0.1 cm in November 2021 to 120–150 cm in April 2022 (density, 49.3 plants m⁻¹; final wet weight, 83.0–251.6 g (mean 155.7 ± 19.0 g; n = 20 ind.); yield, 7676 g m⁻¹), and, owing to the increase in water temperature and light intensity due to seasonal changes around the offshore wind power farm, the second cultivation trials showed signs of chlorosis. Considering the environment, we judged seaweed growth to be normal. Therefore, when applying this model to grow U. pinnatifida, seasonal temperature changes, the purpose of the product, and the nutritional status of the open-sea area should be considered. These results may improve seaweed farming in offshore wind farms in the future. Full article

The LNG maritime industry started to anticipate offshore LNG production in tandem with increasing demand for FLNG platforms as offshore gas resources were developed further. The rapid expansion of FLNG deployment demands equipment and procedures that handle challenges associated with weight and space constraints. The chemical composition of LNG will result in slightly fewer CO₂ emissions. While not significant, another crucial aspect is that LNG predominantly comprises methane, which is acknowledged as a greenhouse gas and is more harmful than CO₂. This requires investigation into clean energy fuel supply for power generation systems, carbon emissions from the process, and thermodynamic analysis and optimisation. Focus on supplying fuel for FLNG power generation to reduce the essential management of boil-off fuel gas, which can be researched on the direct reforming method of hydrogen as a marine fuel gas to support the power generation system. The principal reason for choosing hydrogen over other energy sources is its exceptional energy-to-mass ratio (H/C ratio). The most effective method for hydrogen production is the methane reforming process, recognised for generating significant quantities of hydrogen. To optimise the small-scale plant with a carbon capture system (CCS) as integrated into the reforming process to produce blue hydrogen fuel with zero carbon emissions, this research selection focuses on two alternative processes: steam methane reforming (SMR) and autothermal reforming (ATR). Furthermore, the research article will contribute to other floating production platforms, such as FPSOs and FSRUs, and will be committed to clean energy policies that mandate the support of green alternatives in substitution of hydrocarbon fuel utilisation. Full article

Hydraulic technology has been instrumental in the extensive application of offshore mechanical equipment, particularly in drilling platforms and ships, where high-performance hydraulic fluids are essential for safe and efficient operations. Addressing the urgent need for water-based hydraulic fluids as an alternative to traditional oil-based fluids, this study introduces a novel water-based hydraulic fluid fortified with phytic acid, derived from plant seeds, to achieve low biotoxicity, low coefficient of friction, and reduced frictional heat generation. The integration of phytic acid has significantly enhanced the lubricating performance, reducing the average coefficient of friction to as low as 0.013, as tested by the four-ball tester, which is the lowest value reported to date. Real-time monitoring of the temperature rise of the friction testing apparatus using an infrared thermal imager revealed a 78.6% reduction in temperature increase. Acute toxicity assays using Brine Shrimp demonstrated that the 96 h LC50 value for the water–glycol flame-resistant hydraulic fluid with added phytic acid exceeded 26,304 mg/L, indicating low toxicity. Characterization analyses elucidated the mechanisms underlying the improved tribological properties, highlighting the potential of this eco-friendly fluid for safe and efficient offshore operations. Full article

The coupling of offshore wind energy with hydrogen production involves complex energy flow dynamics and management challenges. This study explores the production of hydrogen through a PEM electrolyzer powered by offshore wind farms and Lithium-ion batteries. A digital twin is developed in Python with the aim of supporting the sizing and carrying out a techno-economic analysis. A controller is designed to manage energy flows on an hourly basis. Three scenarios are analyzed by fixing the electrolyzer capacity to meet a steel plant’s hydrogen demand while exploring different wind farm configurations where the electrolyzer capacity represents 40%, 60%, and 80% of the wind farm. The layout is optimized to account for the turbine wake. Results reveal that when the electrolyzer capacity is 80% of the wind farm, a better energy balance is achieved, with 87.5% of the wind production consumed by the electrolyzer. In all scenarios, the energy stored is less than 5%, highlighting its limitation as a storage solution in this application. LCOE and LCOH differ minimally between scenarios. Saved emissions from wind power reach 268 ${\mathrm{kton}}_{{\mathrm{CO}}_2}$/year while those from hydrogen production amount to 520 ${\mathrm{kton}}_{{\mathrm{CO}}_2}$/year, underlying the importance of hydrogen in hard-to-abate sectors. Full article

The diffusion characteristics of thermal discharge from coastal power plants were studied by analyzing the Ningde Nuclear Power Plant and Kemen Power Plant, which are located in different geographical regions in China. The former is in the open sea, and the latter is in a well-sheltered bay. In the vicinity of the outfall areas of the two power plants, large-area surface temperature observations and tidal current observations were conducted. The results indicate that the thermal discharge diffusion characteristics of coastal power plants located in different geographical environments are significantly different. In the well-sheltered sea area of the Kemen Power Plant, the water temperature diffuses faster along the coast, in line with the direction of tidal movement, and slower in the offshore direction under the influence of rectilinear tidal currents within the bay, resulting in a significantly greater longitudinal diffusion distance of thermal discharge along the shore than the transverse diffusion distance offshore. In the area surrounding the Ningde Nuclear Power Plant, rotational currents diffuse the thermal discharge in various directions, causing the range of temperature rise to expand toward the outer sea. Dominant tidal currents within the tidal cycle in the sea area can influence the distribution of high-temperature rise zones near outfalls. The distribution of high-temperature rise zones predominantly occurs on the side with the higher average tidal velocity, either the ebb tide side if its velocity is greater than that of the flood tide or the flood tide side otherwise. Full article

The energy transition requires substantial financial investments and the adoption of innovative technological solutions. The aim of this paper is to analyze the economic and technological aspects of implementing zero-emission strategies as a key component of the transition toward a carbon-neutral economy. The study assesses the costs, benefits, and challenges of these strategies, with a particular focus on wind farms and nuclear power, including small modular reactors (SMRs). The paper presents an in-depth examination of key examples, including onshore and offshore wind farms, as well as nuclear energy from both large-scale and small modular reactors. It highlights their construction and operating costs, associated benefits, and challenges. The investment required to generate 1 MW of energy varies significantly depending on the technology: onshore wind farms range from $1,300,000 to $2,100,000, offshore wind farms from $3,000,000 to $5,500,000, traditional nuclear power plants from $3,000,000 to $5,000,000, while small modular reactors (SMRs) require between $5,000,000 and $10,000,000 per MW. The discussion underscores the critical role of wind farms in diversifying renewable energy sources while addressing the high capital requirements and technical complexities of nuclear power, including both traditional large-scale reactors and emerging SMRs. By evaluating these energy solutions, the article contributes to a broader understanding of the economic and technological challenges essential for advancing a sustainable energy future. Full article

Although successful in protecting planted mangrove plants, the effectiveness of emergent detached offshore structures in increasing vegetation cover has yet to be definitively determined. We selected Tien Giang Province, Vietnam as an appropriate case study to address this question. We analyzed multiyear (2000 and 2022) shoreline changes and calculated the enhanced vegetation index (EVI) together with ground truthing in pursuit of the objectives of the study. Our findings suggest that emergent detached offshore structures have yet to lead to an increase in vegetation cover or promote mangrove growth. The vegetation growth steadily increased, as did the high level of natural mangrove growth with fully grown mangrove trees, even before the structures were constructed. By 2015, all the categories increased slightly except for low vegetation cover (LVC) and medium vegetation cover (MVC). LVC decreased from 390 ha in 2010 to 291 ha in 2015, while MVC decreased from 305 ha in 2010 to 275 ha in 2015. By 2020, all the categories decreased slightly except for non-vegetation cover—Barren lands (NVC2) and MVC. NVC2 decreased slightly from 404 ha in 2015 to 368 ha in 2015. The MVC decreased slightly from 275 ha in 2015 to 212 ha in 2020. Non-vegetation cover—Intertidal mudflats (NVC1)—LVC, and high vegetation cover (HVC) increased slightly from 2015 (326 ha, 291 ha, and 249 ha, respectively) to 2020 (368 ha, 292 ha, and 298 ha, respectively). By 2022, NVC2, MVC, and HVC remained unchanged, while NVC1 and LVC increased slightly from 368 ha and 292 ha in 2015, respectively, to 380 ha and 302 ha, respectively. The increase in vegetation cover and the natural regeneration of mangrove species were partly due to the adaptation of mangrove species to the site (river mouth areas), particularly the protection provided by Ngang Island offshore, and the construction of these structures. In addition, these structures were constructed in a rather stable area (slightly eroded and estuarine area) and therefore have yet to provide any noticeable benefits for mangrove regeneration three to five years after their construction. In the future, the morpho dynamic and hydrodynamic elements of the site should be adequately considered during the design and construction of these structures to increase vegetation cover and promote natural mangrove regeneration. Full article

Marine nuclear power plants (MNPPs) represent items of forward-looking high-end engineering equipment combining nuclear power and ocean engineering, with unique advantages and broad application prospects. When a nuclear accident occurs, it causes considerable economic losses and casualties. The traditional accident analysis of nuclear power plants only considers the failure of a single system or component, without considering the coupling between the system and the operator, the environment, and other factors. In this study, the cause mechanism of nuclear accidents in MNPPs is analyzed from the perspective of a social technology system. The causal analysis model is constructed by using the internal core causal analysis (e.g., technical control) and external stimulation causal analysis (e.g., social intervention) of accidents, after which the mechanism of the coupled evolution of each influencing factor is analyzed. A Bayesian network inference model is used to quantify the coupling relationship between the factors that affect the deterioration of nuclear accidents. The results show that the main influencing factors are pump failure, valve failure, insufficient response time, poor psychological state, unfavorable sea conditions, unfavorable offshore operating environments, communication failure, inappropriate organizational procedures, inadequate research and design institutions, inadequate regulatory agencies, and inadequate policies. These 12 factors have a high degree of causality and are the main factors influencing the deterioration of the small break loss of coolant accident (SBLOCA). In addition, the causal chain that is most likely to influence the development of SBLOCA into a severe accident is obtained. This provides a theoretical basis for preventing the occurrence of marine nuclear power accidents. Full article