Search Results (649)

This study develops and experimentally validates a battery-coupled wind–photovoltaic power model for auxiliary electrical supply in small-vessel systems. The prototype integrates a 395 W CS6R-395MS monocrystalline photovoltaic module (CSI Solar Co., Ltd., Suzhou, Jiangsu, China), a 200 W FA200W horizontal-axis wind turbine (VEVOR, Rancho Cucamonga, CA, USA), maximum power point tracking (MPPT) power-conditioning stages, a 24 V/28 Ah AGM VRLA battery bank composed of four BAT212120086 batteries (Victron Energy B.V., Almere, The Netherlands), a 24 V DC bus, and a Phoenix 24/500 pure sine-wave inverter (Victron Energy B.V., Almere, The Netherlands), targeting non-propulsion navigation, communication, and lighting loads on a 5.7 m length overall (LOA) vessel. Field-acquired irradiance, cell temperature, incidence angle, PV voltage, wind speed, and rotor-speed data were used as time-dependent model inputs and compared with synchronized active-power measurements. Across the full 15–24 September 2025 experimental campaign, the maximum absolute relative error remained below 2.69%, while the aggregate statistical validation indices were ME = −0.1041 W, MAE = 0.3988 W, RMSE = 0.4931 W, and MAPE = 0.5946%. For the representative cloud-adverse case study conducted on 21 September 2025, the measured hybrid generation reached $E_{\mathrm{h}\mathrm{y}\mathrm{b}}=611.3 \mathrm{W}\mathrm{h}$ over 8.28 h, corresponding to $C_{\mathrm{R}\mathrm{E}\mathrm{S}}=102.1\%$ of the selected $E_{\mathrm{l}\mathrm{o}\mathrm{a}\mathrm{d}}=599 \mathrm{W}\mathrm{h}/\mathrm{d}\mathrm{a}\mathrm{y}$ auxiliary-load profile and to $C_{\mathrm{h}\mathrm{y}\mathrm{b}+\mathrm{b}\mathrm{a}\mathrm{t}}=158.1\%$ when the usable battery reserve at 50% depth of discharge (DOD) was included. Full article

Offshore wind development has become an important component of the renewable energy transition, yet its rapid expansion has also generated new sustainability challenges for marine biodiversity conservation. In Taiwan, offshore construction activities such as pile driving, drilling, dredging, and seismic surveys have raised growing concerns about anthropogenic underwater noise and its effects on cetaceans and other marine species Although Taiwan established its Cetacean Observer (TCO) system in 2020, the system remains constrained by fragmented authority, limited information transparency, insufficient professional training, unstable employment pathways, and weak cross-agency coordination. Against this background, this study shifts the analytical focus from diagnosing the deficiencies of the existing TCO system or assessing whether the Taiwan Cetacean Observer Association (TCOA) is beneficial to examining how the TCOA should be institutionally designed as a sustainable governance platform under offshore wind development. Drawing on environmental governance, institutional design, and intermediary organization scholarship, as well as document analysis and in-depth interviews with cetacean observers, contractors, marine conservation practitioners, and experts, this study develops a design-oriented institutional architecture for association-based marine conservation governance. Rather than treating the TCOA merely as a professional association, the study conceptualizes it as a governance infrastructure capable of stabilizing coordination, supporting implementation, strengthening professionalization, and enhancing accountability in a fragmented marine governance environment. The study proposes a five-module institutional architecture for a sustainable the TCOA, comprising employment and career support, as well as accountability and public engagement. Together, these modules can strengthen coordination, improve implementation capacity, enhance transparency, support observer professionalization, and build stakeholder trust. This study contributes to sustainability governance research by moving the discussion from whether an observer association is useful to how such an association should be institutionally designed to support long-term marine conservation governance. It also provides transferable insights for coastal jurisdictions seeking to align offshore renewable energy development with marine biodiversity conservation and Sustainable Development Goal 14 (SDG 14). Full article

The rapid electrification of marine transportation has increased the number of hybrid marine microgrids with the addition of renewables and energy storage. The continuously varying propulsion loads, fluctuating sea states, and renewable intermittency introduce significant challenges in bidirectional power transfer and power quality enhancement in marine vessels. This work presents a power-oriented operational strategy for a hybrid Roll-on/Roll-off (Ro-Ro) ferry-based marine microgrid (FMG) integrating diesel generators (DGs), Solar Photovoltaic (PV) arrays, and battery energy storage systems as the primary power sources. The proposed FMG adopts a hybrid AC/DC bus configuration linked through a bidirectional voltage source interlinking converter (ILC). The ILC facilitates multiple functionalities, including effective load compensation, mitigation of Total Harmonic Distortion (THD), continuous power support through bidirectional energy exchange, maintenance of balanced sinusoidal currents, and unity power factor (UPF) operation, thereby providing an integrated solution for improved power quality and reliable microgrid performance. A supervisory control (SC) is devised to operate the FMG seamlessly under islanded modes depending on the availability of power sources. To achieve the above-mentioned objectives, a power-optimized Dual Power-based Instantaneous Power Theory (DP_IPT) is employed and it involves a Sequential Delay Signal Cancelation (SDSC)-based Phase-Locked Loop (PLL) for the effective extraction of sequence components, so as to address the unbalance and nonlinearities in an effective manner with reduced oscillations. The proposed control strategy reduces diesel generator utilization through the effective integration of Solar PV and battery support during anchoring operation. The integration of renewable energy sources substantially enhances clean energy utilization, resulting in the reduction of overall carbon emissions, accounting for a near-40% decrease in emissions compared with the conventional diesel generator (DG)-based operating mode. The proposed FMG and control framework are validated through the Hardware-in-the-Loop (HiL) approach employing an OPAL-RT (OP4512) real-time controller. The HiL investigations demonstrate the efficacious working of the proposed control in achieving less carbonized and enhanced power quality operation for next-generation electrified hybrid maritime microgrids. Full article

This paper evaluates whether hydrogen-based marine fuels were financially feasible in the European maritime sector in mid-2026 without subsidies, grants, contracts for difference, preferential carbon-price treatment, or other public subventions. A techno-economic model compares pure hydrogen fuel cells, hydrogen internal combustion, ammonia combustion and fossil marine fuels for general cargo ships, container ships and passenger liners. The model combines 2026 bunker quotations, fuel-energy properties, EU ETS exposure, FuelEU Maritime requirements, ammonia cost evidence and scenario assumptions for delivered renewable hydrogen. Results show that fossil-fuel-equivalent useful propulsion costs remain substantially lower than hydrogen and ammonia alternatives under a no-support baseline. Current EU policy narrows the gap but does not close it. The hypothesis is confirmed: in mid-2026, hydrogen-based propulsion is not commercially feasible without public support, except for exceptional pilots and premium fixed-route niches. Under the paper’s central scenarios, unsubsidised parity is unlikely before 2032–2035 for short routes and 2035–2040 for larger vessels. Green methanol is treated as a complementary hydrogen-derived pathway whose easier storage and handling may favour selected services, although its lifecycle benefit depends on renewable hydrogen and a sustainable carbon source. Full article

The energy transition and global decarbonization goals have accelerated the development of offshore renewable energy technologies, particularly in deep-water regions, where fixed foundations are limited by technical and economic constraints. Floating structures offer new opportunities for harnessing marine renewable resources, allowing them to be deployed in areas with favorable wind, wave, and oceanographic conditions. This paper presents a comprehensive analysis of European floating structures intended for hybrid renewable energy applications, combining environmental assessment, structural characteristics, hydrodynamic behavior, and energy integration aspects. Unlike previous analyses, which focused primarily on individual technologies, this study offers an integrated perspective on floating platform concepts—including spar, semi-submersible, tension-leg, barge, and FPSO-based solutions—as well as their potential for hybrid energy systems. The analysis shows that platform stability, motion response, and structural adaptability are critical factors affecting energy performance and operational reliability. Furthermore, the analysis highlights that hybrid configurations combining offshore wind, wave, and solar energy with energy storage technologies represent promising pathways toward more autonomous and sustainable offshore infrastructure. Key challenges related to design optimization, environmental loads, and system integration are also identified to support future developments in European offshore renewable energy. Full article

Carbon-based materials like activated carbon (AC) are frequently applied for water treatments and remediation. The increasing use and functionalization of AC, especially with the recent mandate to implement quaternary treatments to remove organic micropollutants (Directive 2024/3019), may inadvertently introduce AC or leachate products to aquatic bodies. Such occurrences pose potential risks to inhabiting organisms, which have been understudied. This study assessed the environmental safety of an AC obtained from spent brewery grains (SBG)—a lignocellulosic biomass—through microwave pyrolysis with potassium carbonate activation. The resulting AC (SBG-AC) was washed, sieved (powder, particle size ≤ 180 µm), and tested for its ecotoxicological effects on the marine mussel Mytilus galloprovincialis at doses of 5, 25, and 50 mg/L. After 28 days of exposure (with weekly water renewal), biochemical parameters related to the mussels’ metabolic capacity and oxidative status were evaluated. Exposure to SBG-AC stimulated the energy metabolism in M. galloprovincialis, at the expense of internal energy reserves (such as glycogen). Although SBG-AC exposure induced antioxidant responses, the significant increase in lipid peroxidation and protein carbonylation at the higher doses (particularly 50 mg/L) suggests that these protective mechanisms were insufficient to prevent oxidative damage. Overall, while SBG-AC offers an effective alternative for water treatment, its ecotoxicity at higher doses raises concerns, emphasizing the need for careful risk assessment and containment measures. Full article

This study aims to evaluate the environmental and social sustainability of organic and conventional potatoes in Italy using the life cycle thinking approach. Both life cycle assessment and social risk assessment analyses covered agricultural production, industrial processing, and packaging. The results highlight that agriculture and refrigeration are the main environmental hotspots in both systems, with water consumption being the most affected category, and electricity use during the industrial phase being important for several impacts. Organic potatoes received a lower impact for marine ecotoxicity and water consumption but were higher for land use than conventional potatoes, while the two systems were quite similar for human toxicity. The social risk assessment indicated that health and safety, followed by labour rights and decent work, are the most critical areas in the life cycle examined, especially in the Italian agricultural context. Finally, this study suggests that improving energy efficiency, increasing the share of renewable electricity, and strengthening circular flows could enhance sustainability in potato production. Full article

Wave energy represents one of the most promising renewable sources due to its high energy density and predictable availability compared to wind and solar power. Despite its potential, technological exploitation remains challenging because of harsh marine environments, high installation and maintenance costs, and the absence of a dominant technology. This work presents a comprehensive review of wave energy conversion technologies and provides a detailed kinematic and dynamic analysis of a novel mechanical system designed to transform oscillatory linear motion into continuous unidirectional rotary motion, suitable for electricity generation. Particular focus is placed on the analytical modeling of the system, the design of a flywheel for energy stabilization, and performance evaluation. Results highlight the feasibility of the proposed configuration and its potential advantages compared to conventional hydraulic systems. Full article

Offshore floating photovoltaics (OFPVs) offer a promising route for expanding solar energy development from land and inland waters to marine space, particularly in China’s coastal regions where electricity demand, land-use constraints, offshore wind infrastructure, and photovoltaic manufacturing capacity are highly concentrated. This review examines the development status, structural concepts, hydrodynamic challenges, research methodologies, reliability issues, and future pathways of OFPV systems in China from the perspective of marine engineering. Demonstration projects, representative platform concepts, and recent studies on environmental loading, platform motion, multi-body interaction, connector and mooring responses, and hydroelastic behavior are systematically synthesized. The review shows that Chinese OFPV technology has progressed from conceptual exploration to prototype testing and sea-based validation, with flexible membrane, steel-frame, semi-submersible, tensioned floating-island, HDPE modular, and composite-material concepts under active investigation. However, mature and replicable engineering solutions remain limited. Key barriers include survivability under extreme sea states, fatigue reliability of large arrays, corrosion, biofouling, material degradation, insufficient long-term field data, and the lack of dedicated design standards. Future development should emphasize array-level hydrodynamic design, coupled connector–mooring optimization, life-cycle reliability assessment, full-scale monitoring, and integration with offshore wind, wave energy, floating breakwaters, aquaculture, and other marine energy systems. Full article

This study presents a mathematics-based simulation model for designing, analyzing, and optimizing offshore green hydrogen stations powered by solar photovoltaic systems, applicable to any location worldwide. Developed in Python, the model integrates environmental, physical, and technological parameters to simulate and forecast hydrogen production via water electrolysis using alkaline (ALK) or proton exchange membrane (PEM) electrolyzers, combined with an adiabatic compressor that enhances energy storage and facilitates integration into smart grids. The five-phase modular methodology includes timeframe definition; estimation of solar electricity generation based on solar trajectory and the geographic orientation of photovoltaic panels; performance modeling of electrolyzers and compressors; and the integration of all components into a cohesive system. A case study demonstrates the model’s real-world applicability. Results from the Gulf of Cadiz case study show a substantial increase in solar energy capture in offshore environments due to reduced atmospheric pollution and sea-surface reflection. The reflected component is modeled as a function of sea-surface flatness. This reflection increases the daily average solar irradiance received by the photovoltaic panels by 8.44%. Under the modeled 2026 conditions and equivalent irradiance levels, the ALK electrolyzer produces 3.347% more hydrogen than the PEM electrolyzer. In addition, a 20% increase in electrolyzer efficiency raises hydrogen production by 32.35%, whereas the same increase in compressor efficiency improves production by 0.758%. These impacts directly correlate with proportional reductions in the photovoltaic panel surface area, driven by increased electricity generation capacity, which translates into smaller infrastructure needs. The model enables quantitative evaluation of trade-offs among solar irradiance, component performance, and system design. It supports cost reduction through optimized sizing and improved integration. This approach contributes to lowering the Levelized Cost of Electricity (LCOE) and promoting the viability of marine-based green hydrogen deployment. Full article

Over the years, industrial demands have determined the main course of electric drives research and development. Modern drive trains are forced to provide extremely efficient operation under a variety of unfavorable circumstances. Moreover, the maintenance of the drive is often a critical factor, including both its reliability in the long-term perspective and deployment costs. In addition, the sophistication of up-to-date industrial machinery increases the number of stochastic disruptions that affect the final control quality. Thus, the Control Theory satisfies the need for a novel, robust strategy by proposing the Active Disturbance Rejection Control (ADRC) algorithm. It stands out with great dynamic performance and versatility. It has been widely tested in a variety of different industrial applications, including aviation, autonomous and unmanned vehicles, marine robots, automotive solutions, renewable energy, and power systems. Many of the above-mentioned applications use electric drive units. This paper elaborates on the review of the current state-of-the-art in the field of electric drive control with the ADRC strategy employed. Then, the ADRC designs regarding multi-mass drive trains are reviewed with emphasis on the speed control issue. This paper evaluates its variants and control approaches depending on the application purpose. Moreover, an exemplary dynamic properties analysis is performed to verify the default effectiveness of the algorithm. Then, the summary section is followed by an indication of possible future research directions. Full article

Driven by the global low-carbon transition and the rapid expansion of marine energy development, offshore integrated energy systems are emerging as a critical configuration for coupling offshore renewable resources, geothermal and subsurface thermal resources, oil and gas infrastructure, hydrogen pathways, multi-carrier networks, and offshore loads. Unlike onshore integrated energy systems, offshore systems are constrained by resource intermittency, harsh marine environments, platform space and weight limits, long-distance transmission, operation and maintenance accessibility, safety risks, and cross-regional governance mechanisms. Recent studies have advanced offshore wind-to-hydrogen systems, oil and gas platform electrification, offshore energy hubs, platform repurposing, and offshore geothermal utilization. However, these studies remain fragmented in terms of system boundaries, multi-energy coupling mechanisms, engineering constraints, and optimization methods. This paper reviews offshore integrated energy systems from the perspectives of system configuration, key integration technologies, optimization and assessment methods, and future research needs. Offshore integrated energy systems are first classified into offshore renewable-energy-dominated systems, offshore wind–hydrogen systems, oil and gas platform integrated systems, offshore energy hubs and multi-carrier networks, decommissioned-platform repurposing systems, and offshore geothermal and repurposed-well systems. Resource-side, conversion-side, storage-side, network-side, and load-side integration technologies are then summarized. Capacity configuration, operational scheduling, stochastic and robust optimization, multi-objective optimization, energy, exergy, economic, and environmental (4E) assessment, advanced exergy analysis, and energy-hub modelling are further reviewed. Finally, key research gaps are identified, including resource uncertainty, offshore engineering constraints, multi-carrier network coupling, insufficient demonstration data, and policy and economic uncertainty. This review provides a structured reference for the modelling, integration, optimization, and demonstration of offshore integrated energy systems for low-carbon transition. Full article

By integrating ecological spatial data, offshore wind energy development zones, and the marine spatial planning (MSP) framework, it is possible to assess the relationship among Taiwan’s offshore renewable energy development, risks to marine biodiversity, and the effectiveness of marine spatial planning. The study adopts a mixed-method spatial–quantitative research design that integrates geospatial modelling, ecological risk assessment, spatial conflict analysis, and governance evaluation for quantification of biodiversity exposure to offshore wind infrastructure. Spatial overlay analysis is employed in the identification of geographic areas where offshore wind development intersects with high biodiversity vulnerability zones. Quantitative spatial indicators are used to assess the extent to which MSP reduces biodiversity exposure to offshore renewable energy infrastructure. The analytical framework integrates two parallel modelling domains including the ecological risk modelling domain and the spatial governance effectiveness domain. The spatial analysis of biodiversity vulnerability across Taiwan’s analyzed offshore areas revealed a BVI range of 0.12 to 0.88. The mean BVI value was 0.51 (S.D. = 0.18). The results further show that over 47% of the analyzed EEZ falls into high and very high vulnerability classes. The total offshore wind area located within high-risk and very high-risk zones accounted for 38% of the wind farm footprint. Smaller proportions occupy very low and low-risk zones, accounting for 7.1% and 21.4%, respectively, while 32.1% of wind infrastructure is in moderate-risk areas. Overlaying MSP boundaries with biodiversity risk zones showed that 62% of high-risk biodiversity areas are encompassed within MSP-designated protection, leaving 38% of high-risk zones unprotected. The findings show that biodiversity preservation and offshore wind development are not mutually exclusive but are rather dependent on efficient spatial planning, integrated governance, and flexible management to maintain sustainability. Full article

Ireland was an early offshore wind pioneer, with Arklow Bank Phase 1 commissioned in 2004 as one of the world’s first commercial offshore wind farms (OWFs). Despite this early start, offshore wind development (OWD) in Ireland remained limited for almost two decades. In recent years, however, the Government of Ireland has declared ambitious offshore renewable energy (ORE) targets, aiming to deliver up to 37 GW of capacity by 2050. One of the key constraints during this period has been the absence of a coherent and integrated marine planning and consenting framework capable of supporting large-scale ORE. This paper examines the evolution of Ireland’s ORE planning and consenting regime, tracing the transition from fragmented, largely “developer-led” arrangements toward a more coordinated and “state-led” framework. It reviews key legislative and policy developments, including the National Marine Planning Framework, the Maritime Area Planning (MAP) Act 2021, the establishment of the Maritime Area Regulatory Authority (MARA), and the introduction of Designated Maritime Area Plans (DMAPs), particularly the South Coast DMAP. The paper also situates Ireland’s recent reforms within selected leading European jurisdictions, highlighting persistent challenges related to governance coordination, permitting complexity, and regulatory sequencing in offshore wind deployment in Ireland. Full article

An empirical model is developed to predict significant wave height and significant wave period using only wind speed at 10 m height, fetch, and water depth. The model distinguishes between fetch-limited and duration-limited sea states within a conditional empirical framework that incorporates modified empirical exponents and corrections into classical wave formulations. Validation was performed using wind and wave data from the Global Forecast System at 26 coastal and offshore stations distributed across eleven different pilot seas and oceans worldwide, encompassing a broad spectrum of marine environments and climatic conditions. The proposed model was benchmarked against established empirical approaches. Results indicate a mean prediction error of 6.6% for the significant wave height and 9.6% for the significant wave period, substantially outperforming conventional formulations whose errors exceed 50% under comparable conditions. Unlike existing empirical models that are restricted to specific regions or sea-state conditions, the proposed model demonstrated strong predictive performance across diverse seas, oceans, and climatic conditions, enabling more reliable wave predictions in data-scarce and dynamically complex marine environments. The developed model was further applied to the Red Sea, where it successfully reproduced the spatial variability of significant wave height and wave period. From the results, it has been found that the developed model provides a practical and transferable tool for wave forecasting, coastal engineering, and offshore renewable energy applications. Full article