Offshore Wind Resource Research Articles

Assessment Method of Offshore Wind Resource Based on Multi-dimensional Indexes System

Assessment Method of Offshore Wind Resource Based on Multi-dimensional Indexes System

Potential of Offshore Wind Energy in Malaysia: An Investigation into Wind and Bathymetry Conditions and Site Selection

The government has set an ambitious target of renewable energy development in Malaysia. As a promising renewable energy source, wind energy plays an important role in the Malaysia renewable energy roadmap. Compared to onshore wind energy, offshore wind resources with better quality can be provided in the areas away from the coast, which has greater potential to contribute to electricity generation. Wind and bathymetry conditions are two important factors that determine the feasibility and economics of offshore wind turbines. In this paper, an investigation is conducted on wind and bathymetry conditions around Malaysia. The data source mainly originates from the Global Wind Atlas. The conditions of the coastal areas in different states and federal territories of both Peninsular Malaysia and East Malaysia are analysed, with a specific focus on wind speed, wind energy density, and bathymetry conditions in high-wind-speed regions. The data and survey are verified and compared with the past published literature. This paper aims to investigate the wind and bathymetry conditions around Malaysia, assess the potential of offshore wind energy, discuss the feasibility of offshore wind turbines, and provide references for offshore wind development in Malaysia.

Feasibility Study of Offshore Wind Wheel Installation in South China Sea at Malaysia

As the global demand for renewable energy continues to rise, it becomes crucial to investigate the viability of offshore wind power generation. This paper presents a comprehensive feasibility study assessing the viability of the South China Sea wind turbine installation. This study will describe the current situation of wind energy across the world and specifically discusses offshore wind farm technology. The study begins with a comprehensive literature review emphasizing the significance of wind power in mitigating climate change and reducing reliance on fossil fuels. The objectives of this are to study on the availability of offshore wind resources in Malaysia and to analyze the effect of micro-siting towards wind farm energy production and performance. This study indicates the best sites to set up offshore wind farm in Malaysia. According to the data, Mersing has a favorable availability of wind resources, which makes it the best place to put the turbines. Critical review for better understanding about the importance of micro-siting of wind farms social and economic was conducted. The micro-siting technique is helpful since it provides a methodical and well-informed way of choosing a location. It helps decision-makers strike a balance between the project's, the community's, and the environment's demands by considering various elements and tailoring the analysis to the particulars of a certain project. As technology and methodology evolve, the micro-siting approach will become more important in attaining sustainable and efficient development.

Data science in wind energy: a case study for Norwegian offshore wind

In the digital and green transitions, rapidly growing renewable energies are accumulating more and more data. Big data gives room to apply emerging data science to solve challenges in the energy sector. Offshore wind power receives accelerating attention due to its sufficient resources and cleanness. This paper uses data science, including statistical analysis and machine learning, to systematically analyse three coastal wind sites in Norway. The results show that although Norway possesses ample offshore resources, its development could be improved by natural, technical, and economic challenges that can be addressed with the help of data science. Technically, the statistical attributes and forecasting intricacy of offshore wind resources differ across various regions of Norway.

Detailed mapping of technical capacities and economics potential of offshore wind energy: A case study in South-eastern Australia

Australia has significant offshore wind resources that can support ever-increasing power demand and hence provide a long-term contribution to the net-zero target by 2050. Although some offshore wind farm projects are proposed in Australia, the industry is not mature enough to justify the benefits and display economic opportunities. More specifically, the techno-economic analysis of offshore wind energy has not been systematically mapped in Australia. Therefore, the investigation of the spatial variation of technical feasibility and economic potential of offshore wind is vital to identify the potential regions and to develop strategies for future offshore wind farm developments in Australia. This paper presents detailed mappings of the techno-economic potential of offshore wind energy in Victoria-Tasmania’s exclusive economic zone. Offshore wind energy resources are assessed in the paper in terms of energy availability and variability and the feasibility of various offshore wind technologies is investigated, including turbines, foundation types and transmission topologies. In addition, the high-fidelity life-cycle cost models and two innovative evaluation matrices are developed to assess the economic potential of offshore energy farms in South-eastern Australia. The impact of local power system regulation costs and future carbon prices on the viability of offshore wind is also investigated in this paper. It is concluded that the detailed mapping approach and analysis in the paper can provide a systematic tool for industry partners, investors and policymakers at the pre-planning stage of developing offshore renewable energy systems.

Mapping future offshore wind resources in the South China Sea under climate change by regional climate modeling

Cost-effective deployment of wind energy systems benefits from a thorough understanding of wind resources. Therefore, it is imperative to figure out how the spatiotemporal patterns of wind resources will evolve in a warmer future world. Based on a regional climate model system named RegCM4.7, this study investigates the future offshore wind resources under climate change in a tropical ocean, namely the South China Sea (SCS). First, 25-km-resolution wind field information over the SCS is retrieved from a regional climate model driven by 22 global climate models. Then, the simulated wind fields are validated against the reanalysis dataset ERA5 and the Cross-Calibrated Multi-Platform satellite dataset. Subsequently, the spatial distribution and temporal variation of wind resources under climate change are comprehensively assessed, and the inter-annual and intra-annual wind resource variability is quantified by the robust coefficient of determination. Last, the significance, robustness, and uncertainty of climate change signals are evaluated. It is projected that the wind power density will increase by 10–20 % in the northern SCS but decrease by 10–30 % in the southern SCS in 2081–2100 (compared to 1985–2004) under the Representative Concentration Pathway 8.5.

Complementarity and development potential assessment of offshore wind and solar resources in China seas

The intensification of global energy crisis has attracted worldwide attention on the development of offshore renewable resources. An accurate assessment of spatiotemporal distribution and resources feature of offshore wind and solar (OWS) energy helps to facilitate the proper development and utilization of China’s offshore renewable resources. The published ERA5 reanalysis database from 2012 to 2021 is employed to comprehensively evaluate the richness and variability of OWS resources in China seas. Subsequently, the complementarity between these two resources is estimated using Kendall’s correlation coefficient, and results indicate the complementarity show seasonal changes in most of the China seas. However, in South China Sea, these two offshore renewable resources are complementary throughout the year. Furthermore, by considering various restrictions such as bathymetry and offshore distance, four typical regions in China seas are selected and their power generation characteristics are calculated. Among these regions, the typical region located in South China Sea exhibits the highest annual energy output, with a 100 km2 combined offshore wind-solar system generating 15.29 TWh. In addition, the advantage of joint system in suppressing output fluctuations is confirmed, which encouraging the confidence in combined development of OWS energy.

Conceptual design and optimisation of a novel hybrid device for capturing offshore wind and wave energy

AbstractThe access to the offshore wind resource in the deep sea requires the development of innovative solutions which reduce the cost of energy. Novel technologies propose the hybrid combination of wind and wave energy to improve the synergy between these technologies sharing costs, such as mooring and electrical connexion. This work proposes a novel hybrid wind and wave energy system integrating a floating offshore wind turbine with three-point absorbers wave energy converters (WECs). The WECs are an integral part of the floating structure and contribute significantly to the hydrostatic and dynamic stability of the system. Their geometry is optimised considering a cylindrical, semi-cylindrical and spherical shape for the Pantelleria case study. The cylindrical shape with the largest radius and the lowest height is the optimal solution in terms of reducing structural costs and maximising the performance of the WECs. The in-house hydrostatic stability tool and the time domain model MOST are used to optimise the WECs, with a combined meta-heuristic genetic algorithm with the Kriging surrogate model and a local Nelder–Mead optimization in the final simulations. The power of the WECs is estimated with both linear and variable motor flow hydraulic PTOs to obtain a more realistic electrical power generation. Generally, the hybrid device proved to be more competitive than the floating wind turbine alone, with a LCOE reduction up to 11%. Performance of the hybrid device can be further improved when more energetic sites are considered, as the energy generated by the WECs is higher.

A novel decomposition-based approach for non-stationary hub-height wind speed modelling

An accurate description of hub-height wind speed characteristics is indispensable to offshore wind resource assessment and structure reliability analysis. However, given the assumption of stationarity in wind speeds that is violated, the commonly used stationary statistical models will lead to bias, and a non-stationary frequency analysis is required. In this paper, a novel decomposition-based non-stationary modelling approach was proposed. To decompose time series into deterministic and stochastic components, a procedure was designed by combining signal decomposition methods and recurrence quantification analysis and the performances of seven signal decomposition methods were evaluated under various represent non-stationary scenarios via numerical experiments. Then the non-stationary model was established by aggregating the modelled two components. Compared with other methods, the proposed approach is superior, which is of good self-adaption to data and relies on no hypotheses and explanatory covariates, guaranteeing the simplicity and reliability of the constructed models. Additionally, the SSA-based procedure is capable of capturing complicated non-stationary patterns while preserving the higher-order moments of the underlying stochastic process. The capacity of the proposed approach was verified using wind speed data at six positions distributed along China's coastline. Results emphasize the importance of the consideration of non-stationarity and the necessity of this study.

The properties of the global offshore wind turbine fleet

Offshore wind capacity increased massively in recent years. Sufficient wind potential must be available to realize the ambitious goals regarding further wind capacity expansion. Thus, the goal of this study is to quantify the meteorological, geographical, and technical properties of the current global offshore wind turbine fleet. The offshore wind turbine fleet is classified by twelve factors that belong to meteorological, geographical, and technical factor categories. A comprehensive wind turbine site dataset is evaluated, including 5473 sites in Europe and 3404 in Asia. The factors at the wind turbine sites are derived using publicly available datasets, including a reanalysis wind speed dataset, geodata, and technical properties. The results of this study are that the global median (1) wind speed is 8.7 m/s, (2) water depth is 17 m and (3) distance to shore is 27 km. The distance to the nearest wind turbine is 5.1 times the rotor diameter. The factors studied have a high regional variability. While Asian offshore wind turbines operate in shallower water closer to the shores than European, European wind turbine sites provide higher wind resources. The regional differences indicate that the wind potential and wind turbine siting criteria differ depending on the country. The factor values obtained are reference values for future offshore wind resource assessments and estimates of the wind potential from a regional to global scale.

Numerical investigation of wake-induced lifetime fatigue load of two floating wind turbines in tandem with different spacings

Floating wind turbine (FWT) is a promising technology to utilize offshore wind resources. For offshore wind farms, wakes can result in 5%–15% increase in fatigue load on the downstream turbine rotor. Current offshore wind turbine design standard lacks accounting for the different wake characteristics and wake-induced fatigue load of the FWT from that of their fixed counterparts. Considering a scenario of two tandem FWTs, this study investigates the wake characteristics of a semi-submersible FWT accounting for multi-degree-of-freedom (DOF) dynamic motion characteristics and its wake effect on fatigue load of downstream unit with different spacing configurations. A comparison with the effective turbulence intensity method suggested in the current IEC 61400-1 standard is also carried out. With an interactive analysis framework composed of computational fluid dynamics (CFD) wake simulation and time domain aero-hydro-servo-elastic simulation for FWT, lifetime wake-induced fatigue loads are analyzed through a full range of turbine normal operational conditions. Results show that the wake characteristics of the FWT show a distinct difference between below-rated and above-rated conditions due to the feature of FWT's controller. Moreover, the Frandsen model adopted in the current IEC 61400-1 standard highly underestimates the FWT's wake turbulence, causing the predicted lifetime fatigue damage equivalent load at the tower base decreases up to about 10∼15% for a spacing of 8D∼10D under combined wind and wave conditions.

Multi-stage stochastic planning for a long-term low-carbon transition of island power system considering carbon price uncertainty and offshore wind power

The characteristics of isolated grids lead island power systems to rely on stable conventional generation, which is not environmentally friendly and has high carbon emissions. This paper proposes a low-carbon transition model for island power systems considering large-scale offshore wind resources and the long-term uncertainty of carbon prices. First, a detailed model for offshore wind power systems is proposed considering the interaction of multiple wind farms and three transmission technologies. Second, a multi-stage power system planning model is established including the upgrading and decommissioning of thermal units. Meanwhile, an improved long-term carbon price uncertainty modeling method based on the binomial tree is proposed. Then, focusing on the uncertainty of carbon prices, a multi-stage stochastic optimization model is established, and the stochastic nested decomposition algorithm is used to solve the problem. Finally, numerical results show that the low-carbon transition develops plenty of offshore wind power as the primary power source and usually adopts a fractional frequency transmission system for offshore wind integration. The uncertainty of carbon prices has a significant impact on the transition: in the high carbon price realization, the annual carbon emissions are only 0.088 Mt, while in the low carbon price realization, the annual emissions are 0.255 Mt.

Harnessing the Wind Down Under: Applying the UNCLOS Framework to the Regulation of Offshore Wind by Australia and New Zealand

This article considers how the 1982 United Nations Convention on the Law of the Sea (UNCLOS) applies to the production of energy from wind in waters under national jurisdiction, with a focus on the nascent regulatory frameworks for offshore wind in Australia and New Zealand. It explores the particular characteristics of offshore wind—which raise different regulatory issues than traditional offshore activities such as fishing and oil and gas exploitation—and explores how key provisions of UNCLOS will affect the way in which coastal states regulate offshore wind in their waters. Against this backdrop, it considers how the international law framework might apply in the specific context of Australia and New Zealand, where domestic legal frameworks are currently being established to regulate vast and valuable offshore wind resources.

Marine spatial planning and offshore wind: preliminary principles for Australia

Australia is endowed with some of the richest and most diverse renewable energy resources. Its offshore wind resources alone equate to an estimated 5,000 Gigawatts (GW) of electricity potential. Given these substantial estimates, offshore wind energy will likely represent a key pillar of Australia’s future renewable energy mix. Australia’s palpable offshore energy potential is increasingly understood and acknowledged. Yet, the critical legal and policy question remains of how its new regulatory framework to enable offshore wind development, the Offshore Electricity Infrastructure Act 2021 Act (Cth) (OEI Act), will interact with existing marine sectors and the marine environment. Marine Spatial Planning (MSP) may provide the missing process puzzle piece to enable more strategic coordination of the Australian offshore wind sector within the marine environment. This article adopts a socio-legal approach, examining and drawing upon international experiences to explore the potential adoption of MSP in the Australian offshore wind context. In so doing, the article argues for a coordinated approach to develop a federal MSP process to support and promote strategic offshore wind operations with existing sea users while preserving the Australian marine environment.

Climate-change impacts on offshore wind resources in the Mediterranean Sea

The evolution of offshore wind resources in the Mediterranean Sea up to 2100 is studied following the latest climate-change scenarios, the Shared Socioeconomic Pathways. Three scenarios are considered: a high emissions scenario, i.e., fossil-fuelled development; a business-as-usual scenario, in which current emission levels are maintained; and a low-emissions scenario. Particularly, the low-emissions scenario is of special interest since it represents the achievement of the targets set by the Paris Agreement and EU’s Green Deal, which is a novelty in this type of work. A multi-model ensemble is constructed to reduce individual uncertainties with the Global Climate Models that are found to perform best in the Mediterranean Sea. With the exception of the low-emissions scenario, the results show a generalised decline in mean wind power density and augmented variability by 2100. This decline is more pronounced in the high-emissions scenario, with a widespread drop in mean wind power density of ∼20%, rising to 30% around the Balearic Islands. By contrast, the low-emissions scenario anticipates strong, localised growth in certain areas around the Italian Peninsula and off Lebanon and Israel. As for the seasonal variability, profound changes are predicted depending on the scenario and period considered, with increases of up to 80% and decreases of up to 40% in mean seasonal wind power density. These trends have significant implications for wind energy production and can serve as a background for future downscaling initiatives. On the positive side, the comparison between the three scenarios indicates that reducing carbon emissions in line with international climate accords may indeed help to mitigate the decline in wind resources in the Mediterranean Sea and the increase in their variability.

Gaussian mixture models for the optimal sparse sampling of offshore wind resource

Abstract. Wind resource assessment is a crucial step for the development of offshore wind energy. It relies on the installation of measurement devices, whose placement is an open challenge for developers. Indeed, the optimal sensor placement for field reconstruction is an open challenge in the field of sparse sampling. As for the application to offshore wind field reconstruction, no similar study was found, and standard strategies are based on semi-empirical choices. In this paper, a sparse sampling method using a Gaussian mixture model on numerical weather prediction data is developed for offshore wind reconstruction. It is applied to France's main offshore wind energy development areas: Normandy, southern Brittany and the Mediterranean Sea. The study is based on 3 years of Météo-France AROME's data, available through the MeteoNet data set. Using a Gaussian mixture model for data clustering, it leads to optimal sensor locations with regards to wind field reconstruction error. The proposed workflow is described and compared to state-of-the-art methods for sparse sampling. It constitutes a robust yet simple method for the definition of optimal sensor siting for offshore wind field reconstruction. The described method applied to the study area output sensor arrays of respectively seven, four and four sensors for Normandy, southern Brittany and the Mediterranean Sea. Those sensor arrays perform approximately 20 % better than the median Monte Carlo case and more than 30 % better than state-of-the-art methods with regards to wind field reconstruction error.

Techno-economic assessment of offshore wind energy potential at selected sites in the Gulf of Guinea

Offshore wind power has been found to stand out among the most dynamic renewable energy technologies. With its long coastal line, Nigeria has an overwhelming advantage in developing marine energy resources to relieve the power crisis effectively. This work analyzed and characterized observation data of sea-surface wind speed and direction at 30-minute intervals between 1979 and 2015 at five synoptic offshore stations in the Gulf of Guinea. The seasonal variations in hourly surface wind speed and directions as well as the Weibull distribution of wind speed and wind power at 100 m hub height were examined. The wind shears, capacity factors, and accumulated energy outputs for seven offshore wind turbine types were determined for the selected locations. In addition, the economic analysis of the selected offshore turbines using levelized cost of energy was carried out, while sensitivity analysis of the total levelized cost of energy to key input parameters was further determined. The results revealed large spatial and temporal variations in wind speed and wind power in the Gulf of Guinea. The most viable offshore site for wind energy exploitation was Agbami (the deepest offshore site), while Bonny (the shallow coastal site) had the least. The findings established very good fits (having mean bias (between −0.08 ms−1 and −2.44 ms−1), percentage bias (between −0.47% and −13.98%), correlation coefficients (between 0.97 and 0.98), Chi-square (between 0.2 and 1.2), and root mean square error (between 1.2 ms−1 and 3.1 ms−1)) between Weibull distribution and the actual wind data. The wind turbines with the highest and the lowest wind power densities, capacity factors, and power outputs across the seasons and sites were V236-15.0 MW and Siemens SWT113, respectively. The levelized cost of energy was considered for the deep waters due to the moderately high-capacity factors. The highest values ranged between 101.48 and 137.12 USD/MWh at Sea Eagle with V236-15 MW and V117-4.2 MW, respectively, while the lowest ranged from 52.29 to 69.66 USD/MWh at Agbami with V236-15 MW and Siemens (SWT113), respectively. The exploitation of Nigeria’s offshore wind resources could also be dedicated to producing renewable hydrogen and can serve to meet the country’s ambitious targets set for carbon neutrality by 2060.

Study on aerodynamic performance of inverted cone vertical axis wind turbine with different rotor configurations

Offshore wind resources are abundant. Vertical axis wind turbines (VAWTs) are suitable for working in the sea environment because of their low cost and high reliability. In this paper, an offshore floating inverted cone vertical axis wind turbine (ICVAWT) is proposed. The 3D unsteady computational fluid dynamics (CFD) method is utilized to model the ICVAWT. The turbulence model SST k−ω is used to solve the Navier–Stokes equation, and the setting parameters of the solver and the independent grid are determined. The scale experimental prototype is designed using the similarity theory and the wind tunnel experiment is carried out. The experimental results verify the validity of the CFD model. The aerodynamic performance of nine ICVAWT configurations is analyzed by using the CFD model, and the effects of inverted cone angle and blade number on the power coefficient and operation stability of the ICVAWT are studied. It is found that when the inverted cone angle is 45°, and the number of blades is three (called the optimal configuration), the power coefficient is the highest at 0.309 (the optimal tip speed ratio is 3.5). With the increase in inverted cone angle and blade number, the fluctuation of wind turbine operating torque decreases. According to the distribution of each physical quantity in the flow field, the changes in aerodynamic performance are explained. Further research on the optimized configuration is carried out.

Enhancing offshore wind resource assessment with LIDAR-validated reanalysis datasets: A case study in Gujarat, India

Enhancing offshore wind resource assessment with LIDAR-validated reanalysis datasets: A case study in Gujarat, India

The Co-development of Offshore Wind and Hydrogen in the UK – A Case Study of Milford Haven South Wales

Green hydrogen produced from renewable energy resources can not only contribute to the decarbonisation of different energy sectors, but also serve as a carrier for long-distance delivery of renewable generation, offering a cost-effective way to exploit the renewables far from electrical grids. To facilitate the co-development of offshore wind and hydrogen, the paper develops a modelling framework to dispatch power and hydrogen flows across dedicated offshore wind hydrogen production systems to meet onshore hydrogen demands while keeping similar state of charge levels between multiple systems. Then the hydrogen supply to shore and the system investments and ongoing costs are discounted to their present values to calculate the levelised cost of hydrogen, which is minimised by the particle swarm optimsiation algorithm to suggest the best capacities of hydrogen system components including converters, desalination devices, electrolysers, compressors and storage assets. The proposed modelling framework is tested based on a case study at Milford Haven South Wales which is evaluated to have massive offshore wind resources in the Celtic Sea and comparable demands for hydrogen by 2040. The optimisation results are presented based on the techno-economic input parameters projected for 2030 and 2050 scenarios and discussed alongside the influences of technology advances on the system optimisation and resulting metrics including the levelised costs of hydrogen, net present values and potential levels of green hydrogen supply to Milford Haven.