Offshore Wind Farming Research Articles

Fit-for-Purpose Information for Offshore Wind Farming Applications—Part-I: Identification of Needs and Solutions

The rapid expansion of offshore wind farms (OWFs) in European seas is accompanied by many challenges, including efficient and safe operation and maintenance, environmental protection, and biodiversity conservation. Effective decision-making for industry and environmental agencies relies on timely, multi-disciplinary marine data to assess the current state and predict the future state of the marine system. Due to high connectivity in space (land–estuarial–coastal sea), socioeconomic (multi-sectoral and cross-board), and environmental and ecological processes in sea areas containing OWFs, marine observations should be fit for purpose in relation to multiple OWF applications. This study represents an effort to map the major observation requirements (Part-I), identify observation gaps, and recommend solutions to fill those gaps (Part-II) in order to address multi-dimension challenges for the OWF industry. In Part-I, six targeted areas are selected, including OWF operation and maintenance, protection of submarine cables, wake and lee effects, transport and security, contamination, and ecological impact assessments. For each application area, key information products are identified, and integrated modeling–monitoring solutions for generating the information products are proposed based on current state-of-the-art methods. The observation requirements for these solutions, in terms of variables and spatial and temporal sampling needs, are therefore identified.

Offshore wind farming in Taiwan

Offshore wind farming in Taiwan int his question and answer with Open Access Government, Dr Song GwoShyh from MMA Global Aqua Co. Ltd. discusses his company's role in offshore wind farming in Taiwan and their ambitions for the future. In response to Taiwan's special environment, for underwater foundation design, geological survey, marine exploration and future official operation, the monitoring and maintenance of the operation of offshore wind farms and wind turbines are worthy of Taiwan's sustained investment and development of soft power, but also can be implemented in Taiwan's offshore wind power localisation field.

Diverse responses of coastal communities to offshore wind farming development in Southern Spain

Abstract Despite having one of the fastest rates of wind power growth in Europe, offshore wind power development in Spain has been relatively slow. One of the factors affecting its deployment is strong local opposition. In this paper, we explore the main factors affecting local perceptions of offshore wind farms in the coastal regions of Southern Spain. We also compare local opinions of on-land and offshore farms, their impacts on local landscapes/seascapes, and their compatibility with local practices and values. To this end, a multi-phase research approach was applied, based on several stages of data collection and analysis and on surveys conducted between 2012 and 2022. Our study shows that the conflicts surrounding offshore wind farms are linked to the perception of the sea and the wind as important local resources and the perceived right of the coastal region to use these resources to generate wealth for their communities. The coastal communities’ values, perceptions, and practices regarding the sea have a fundamental influence on their opinions. Our research indicates that local people are more likely to accept offshore wind farms if they provide socioeconomic benefits for their communities and if joint use of marine resources can be guaranteed.

Prioritizing ecosystem services for marine management through stakeholder engagement

When applying the Ecosystem Services (ES) concept for the management of marine activities it is beneficial to involve stakeholders from the start and incorporate their knowledge in the decision-making process. Doing so can help to identify key ES, to prioritize the development of human activities that positively impact those ES, and to identify potential trade-offs and win-win scenarios between sectors. On the Belgian Continental Shelf (BCS), different marine economic activities share a relatively small area where the demand for space continues to grow to accommodate emerging sectors. In order to systematically capture the stakeholders' opinions on key ecosystem services and to make the relation between specific marine economic activities and the anticipated change these bring to the ES, a stakeholder workshop was organized. Participants had to prioritize a list of fourteen marine ES relevant to the BCS and the highest-ranking ES were coastal protection, biodiversity, offshore wind energy, surface for navigation, and habitat maintenance. In addition, a conceptual diagram was co-developed linking marine activities and ES to highlight potential synergies and trade-offs, with a focus on the fastest growing activity in the BCS - offshore wind farming. The approach presented is easily transferable and can help researchers and decision-makers capture stakeholders’ perceptions regarding the importance of local ES at specific points in time, thus providing a baseline for establishing priorities during ES modeling and management.

Study of Coastal Effects Relevant for Offshore Wind Energy Using Spaceborne Synthetic Aperture Radar (SAR)

Coastal wind speed gradients relevant for offshore windfarming are analysed based on synthetic aperture radar (SAR) data. The study concentrates on situations with offshore wind directions in the German Bight using SAR scenes from the European satellites Sentinel-1A and Sentinel-1B. High resolution wind fields at 10 m height are derived from the satellite data set and respective horizontal wind speed gradients are investigated up to about 170 km offshore. The wind speed gradients are classified according to their general shape with about 60% of the cases showing an overall increase of wind speeds with growing distance from the coast. About half of the remaining cases show an overall wind speed decrease and the other half a decrease with a subsequent increase at larger distances from the coast. An empirical model is fitted to the horizontal wind speed gradients, which has three main parameters, namely, the wind speed over land, the equilibrium wind speed over sea far offshore, and a characteristic adjustment length scale. For the cases with overall wind speed increase, a mean absolute difference of about 2.6 m/s is found between wind speeds over land and wind speeds far offshore. The mean normalised wind speed increase with respect to the land conditions is estimated as 40%. In terms of wind power density at 10 m height this corresponds to an absolute average growth by 0.3 kW/m2 and a normalised increase by 160%. The distance over which the wind speed grows to 95% of the maximum wind speed shows large variations with maximum above 170 km and a mean of 67 km. The impact of the atmospheric boundary layer stability on horizontal wind speed gradients is investigated using additional information on air and sea temperature differences. The absolute SAR-derived wind speed increase offshore is usually higher in unstable situations and the respective adjustment distance is shorter. Furthermore, we have found atypical cases with a wind speed decrease offshore to be often connected to stable atmospheric conditions. A particular low-level jet (LLJ) situation is analysed in more detail using vertical wind speed profiles from a wind LIDAR system.

Zoning of coastal environments based on sediment textural and geochemical characteristics and their major oceanographic constraints: A case study in South Korea

• Coastal zoning aids environmental impact assessment. • Sediment textural and geochemical properties are key characters affecting zoning. • This ( Ahn et al., 2001 ) study applies sediment characters to science-based marine spatial planning . • The South Korean coast can be scientifically divided into three zones. The three zones partly coincide with the previous arbitrarily categorized blocks. • A primary factor constraining the zoning in this case study is tidal range . To assess the environmental impacts of offshore wind farming and sea sand mining, coastal areas are zoned on the basis of their natural oceanographic characteristics. Textural and geochemical properties of South Korean coastal sediments, including mean grain size (Mz), CaCO 3 and organic-matter contents, and metal concentrations (Al, K, Ba, rare earth elements, Zr, etc.), were analyzed and categorized in this case study, practically applying common sediment properties for rational zoning of the South Korean coastal environment. Three characteristic zones are scientifically classified in the study area, although four groups of sediment sampling stations were statistically clustered based on their major sediment properties. Zone 1, in the northwestern part of the Korean west coast, is characterized as covered with coarse-grained sediments containing low concentrations of the measured elements under a macro-tidal regime (6.5–9 m), while Zone 3 is characterized by fine-grained sediments with high elemental concentrations under a micro-tidal regime (>3.5 m). Silty Zone 2 sediments appear to be a mixture of sandy Zone 1 and muddy Zone 3 sediments under a meso-tidal regime. The difference in tidal forces among the zones is proposed as a primary constraint of overall sediment textural and geochemical characteristics, while sediment provenance provides subsequent control. Sediment contamination with anthropogenic pollutants is unperceivable in this case study. However, the K and Li concentrations in coarse-grained feldspar and fine-grained illite, respectively, are likely not limited by the tidal flow regime.

Use of an INLA Latent Gaussian Modeling Approach to Assess Bird Population Changes Due to the Development of Offshore Wind Farms

The utilization of marine renewable energies such as offshore wind farming leads to globally expanding human activities in marine habitats. While knowledge on the responses to offshore wind farms and associated shipping traffic is accumulating now at a fast pace, it becomes important to assess the population impacts on species affected by those activities. In the North Sea, the protected diver species Red-throated Diver (Gavia stellata) and Black-throated Diver (Gavia arctica) widely avoid offshore wind farms. We used an explicit spatio-temporal Bayesian model to get a robust estimate of the diver population during the spring season between 2001 and 2018, based on a set of aerial surveys from long-term monitoring programs within the German North Sea. Despite the erection of 20 offshore wind farms in the study area and marked responses of divers to wind farms, model results indicated that there was no population decline, and overall numbers fluctuated around 16,600 individuals, with average annual 95% CI ranging between 13,400 and 21,360 individuals. Although, avoidance behavior due to wind farm development led to a more narrowly focused spatial distribution of the birds centered in the persistent high concentration zone in the Eastern German Bight Special Protection Area, the results provide no indication of negative fitness consequences on these long-lived species. However, more research is needed on habitat use and food availability in this regard.

A Case Study of Whistle Detection and Localization for Humpback Dolphins in Taiwan

In recent years, Taiwan’s government has focused on policies regarding offshore wind farming near the Indo-Pacific humpback dolphin habitat, where marine mammal observation is a critical consideration. The present research developed an algorithm called National Taiwan University Passive Acoustic Monitoring (NTU_PAM) to assist marine mammal observers (MMOs). The algorithm performs whistle detection processing and whistle localization. Whistle detection processing is based on image processing and whistle feature extraction; whistle localization is based on the time difference of arrival (TDOA) method. To test the whistle detection performance, we used the same data to compare NTU_PAM and the widely used software PAMGuard. To test whistle localization, we designed a real field experiment where a sound source projected simulated whistles, which were then recorded by several hydrophone stations. The data were analyzed to locate the moving path of the source. The results show that localization accuracy was higher when the sound source position was in the detection region composed of hydrophone stations. This paper provides a method for MMOs to conveniently observe the migration path and population dynamics of cetaceans without ecological disturbance.

Evaluating the South Korean public perceptions and acceptance of offshore wind farming: evidence from a choice experiment study

ABSTRACT The South Korean government is attempting to expand the capacity of offshore wind farming (OWF) from 1.2GW in 2017 to 16.5GW in 2030. Accordingly, the environmental impacts of OWF have become a social issue, and the government needs information about the public acceptance of OWF. This paper seeks to evaluate the public acceptance of OWF in South Korea through a choice experiment (CE). The five attributes chosen are the distance from land to the offshore wind farm (Distance), the number of generators in the offshore wind farm (Number), the height of the generators to be seen above sea level (Height), a decrease in marine life (Life), and the location of the offshore wind farm (Location). The price attribute is an increase in yearly household income tax. A mixed logit model is applied to estimating a utility function from the gathered CE data. All the coefficients for the attributes in the utility are estimated with statistical significance. The sign of the coefficient for Distance is positive, but the signs of all other coefficients are negative. The results of estimating the utility function can be useful in evaluating the environmental impacts of an OWF project from a monetary standpoint.

STUDY ON SCOURING IN PILE OF OFFSHORE WIND FARMING BY NUMERICAL ANALYSIS USING BUILDING-CUBE METHOD

In recent years, offshore wind farming has spread all over the world, and there has been rapid growth of not only conventional onshore wind farming but also offshore wind farming in the sea. However, there are many problems to be solved in offshore wind farming. Among them, the scour of the ocean floor caused by wave and tide has a great influence on the support structure. The purpose of this study is to clarify the scour phenomenon from the flow field and vortex generation conditions by numerical simulation using Building Cube Method. We conducted the simulation of the experiment which handles scouring around the monopile performed by Chen et al. (2018). The Building Cube Method was developed by Nakahashi and Kim (2004). In this study, we used CADMAS-BCM (developed by Arikawa et al.) that 3-D Navier-Stokes simulation model using the Building Cube Method. In this model, the 3-D Building Cube Method was applied using multiple roots. Moreover, because the calculation area is divided according to simple rules, it has features such as good compatibility with parallel computers, and grid generation by a simple method is useful for calculating the flow around objects with complex shapes. Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/OlJK_Qw_TwY

Is interactive air sea coupling relevant for simulating the future climate of Europe?

The majority of regional climate change assessments for the Euro-CORDEX region is based on high resolution atmosphere models. These models use prescribed lower boundary conditions, such as sea surface temperatures (SST) from global ocean General Circulation Models (GCMs), that do not respond to changes simulated by the regional atmosphere model, thus lacking an important feedback to the atmosphere. However, research during the past decade indicated that the use of coupled atmosphere–ocean models can lead to significantly altered model solutions compared to standalone atmosphere models for the present day climate imposing some uncertainty on the widely used uncoupled future scenarios. We here present the first multi-model and multi scenario (RCP2.6, RCP4.5, RCP8.5) ensemble of future climate change scenarios downscaled with a coupled atmosphere—ocean model in which sea surface temperature and sea ice fields are explicitly simulated by a coupled state-of-the-art high resolution ocean model and communicated to the atmosphere at 3-hourly time steps. Our ensemble generally confirms results of previous uncoupled ensembles over land areas implying that the coupling effect is restricted mainly to the coupled area and the adjacent coastal zone. By contrast, over the North Sea and Baltic Sea small scale processes point to important coupling effects that mediate the response to climate change and that can not be simulated by uncoupled models. Our results therefore impose general uncertainty on the usage of regional climate change data from uncoupled ensembles over marine areas such as for purposes of offshore wind or mussel farming, the planing of marine protected areas, and marine recreation along the coastal zone. It further sets in question the usage of uncoupled scenario data (such as Euro-CORDEX) to force high resolution ocean models. Comparing coupled and uncoupled hindcast simulations reveals that the coupling effect over land is most pronounced during the warm season when prescribed and modelled sea surface temperatures (SST) differ strongest. In addition, a generally weaker wind regime in summer damps the heat dispersion in the atmosphere so that air temperature anomalies can extent further over land compared to winter. Future projections are discussed under consideration of land-sea warming characteristics for selected climate indices as well as mean seasonal climate change. At the end of the century a clear land-sea pattern is seen in all scenarios with stronger warming over land than over open sea areas. On average land areas warm at a rate 1.5 times faster than areas over the open ocean. Over the coupled area, i.e. the North Sea and Baltic Sea tropical nights are impacted strongest and the Baltic Sea turns out to be a hot spot in future climate. This has been unrecognized in previous studies using high resolution atmosphere models with prescribed SSTs from global models which do not represent small scale ocean processes in the Baltic Sea adequately.

Mapping the future of offshore wind farming

Offshore wind farming is a growing presence in the renewable energy landscape but these ambitious projects rely on precise assessments of the hard to observe underwater landscape they will occupy before construction can even begin.<br/>Many governments around the world are moving toward renewable energy sources to meet their countries energy demands. The reasons behind this are many, ranging from reducing emissions to the safety of nuclear reactors and waste. For countries lying on or near fault lines, such as Taiwan, the latter becomes an even greater concern. When the earth shakes nuclear power plants, in particular, are highly sensitive and susceptible pieces of infrastructure. To avoid potential catastrophe and achieve greener energy sources the current government in Taiwan is aiming to phase out nuclear power in the coming years and they have chosen wind power as the technology to replace a large portion of the energy supply.<br/> In Taiwan the plan to phase of nuclear power and replace it with wind power has one extra challenge. The plan is not to build on land, like the majority of wind turbine projects, but rather to head out to sea. Offshore wind farms (OWF) are becoming a larger part of the wind power market and European countries have mostly been the early adopters. The waters off Taiwan, in the Taiwan Strait, are attractive for offshore wind farming development due to the favourable wind patterns that occur there. This has drawn major interest from European companies and others around the world to place bids on the growing number of wind farming projects. However, before any of these projects can take place an extensive effort to understand more about the environments below the surface must first be completed.<br/>Fortunately for those individuals who are curious as to the make-up and appearance of the ocean floor, such as engineers who plan to construct permanent structures in the depths, many techniques to map the seabed have been developed. Dr Gwo-Shyh Song, from The Institute of Oceanography at The National Taiwan University, in Taipei, is one local researcher who is very familiar with these methods. "I have been working on seafloor mapping around the Taiwan Island for last 20 years," points out Song. "This includes geophysical surveys, reservoir siltation surveys, cable and pipeline route surveys using a variety of techniques like multi-beam sounders and side-scan sonar as well as chirp sub-bottom profilers." When the offshore wind farming initiative needed experienced local researchers, he was one of a few people with the prerequisite expertise and technical skill required. "In 2012, when the OWF project was set into action and promoted by the Taiwanese Government, myself and my graduated students now employed within Global Aqua Survey Ltd started to become involved with many related investigatory projects," he explains.

The large-scale impact of offshore wind farm structures on pelagic primary productivity in the southern North Sea

The increasing demand for renewable energy is projected to result in a 40-fold increase in offshore wind electricity in the European Union by 2030. Despite a great number of local impact studies for selected marine populations, the regional ecosystem impacts of offshore wind farm (OWF) structures are not yet well assessed nor understood. Our study investigates whether the accumulation of epifauna, dominated by the filter feeder Mytilus edulis (blue mussel), on turbine structures affects pelagic primary productivity and ecosystem functioning in the southern North Sea. We estimate the anthropogenically increased potential distribution based on the current projections of turbine locations and reported patterns of M. edulis settlement. This distribution is integrated through the Modular Coupling System for Shelves and Coasts to state-of-the-art hydrodynamic and ecosystem models. Our simulations reveal non-negligible potential changes in regional annual primary productivity of up to 8% within the OWF area, and induced maximal increases of the same magnitude in daily productivity also far from the wind farms. Our setup and modular coupling are effective tools for system scale studies of other environmental changes arising from large-scale offshore wind farming such as ocean physics and distributions of pelagic top predators.

Effects of different wind data sources in offshore wind power assessment

Currently, approximately 5.3% of electricity production in Europe comes from wind energy. The increase of the size and the improved efficiency of wind generators have permitted their utilization offshore, leading to exploitation of offshore wind energy. Although offshore wind farms are well established in northern European countries, in the Mediterranean Sea they are still in their infancy. It is expected that within the next few years, offshore wind farming will grow considerably in this area. The accurate estimation of the wind speed fields is of most importance for the assessment of offshore wind energy resources. In this work, the effects of alternative wind data sources on the wind climate analysis are examined along with the offshore wind power density estimation in four locations across the Aegean Sea. In order to develop correction relations for satellite and model wind data, taking as reference the buoy measurements, the data are analysed and calibrated using the Error-In-Variables approach. The effects of the different data sources on the wind climate analysis and the estimation of the mean wind power density before and after the calibration procedure are presented and discussed. The Error-In-Variables approach performed better and reduced significantly the uncertainties of the alternative data sources.

Near‐surface marine wind profiles from rawinsonde and NORA10 hindcast

With huge investments going into offshore wind farming and strong focus on offshore safety at all levels, there is an increasing demand for high‐resolution wind products in the near‐surface boundary layer. The Norwegian Reanalysis Archive (NORA10) is a dynamical downscaling of ERA‐40 to a spatial resolution of 10–11 km over the northeastern North Atlantic using the High‐Resolution Limited Area Model (HIRLAM). The boundary layer wind speed between 10 and 150 m above the sea surface from NORA10 is used in a large number of applications. In this study, wind speed maps are produced, and the seasonal and decadal variability in wind speed is discussed. The model underestimates the mean wind speed from in situ winds from offshore platforms and 0.5 Hz rawinsonde observations over the sea by 5–10%. One exception is FINO‐1, where there is excellent agreement. Part of the discrepancies may be due to the speed‐up effects over large platform structures. The high sampling rate of the rawinsondes gives good quality recordings of wind speed and temperature in approximately 10 m height intervals for a 10 year period. Mean model wind profile shapes below 150 m above sea level favorable compare with mean wind speed profiles for stable, unstable and neutral conditions from rawinsonde at Polarfront (ocean weather ship in the geographical position 66°N, 2°E). However, in 18% of the cases the wind speed is decreasing with height, which is not reproduced by the model. We suggest that these inverse wind profiles may be related to cold air advection and convection cells, e.g., downstream of cold air outbreaks.

Consequences of a cumulative perspective on marine environmental impacts: Offshore wind farming and seabirds at North Sea scale in context of the EU Marine Strategy Framework Directive

Legal requirements in context of the EU Marine Strategy Framework Directive require increased trans-national cooperation on environmental effects induced by marine uses to achieve Good Environmental Status by 2020. Interactions between offshore wind farms and seabirds represent a valuable example of how a changed spatial perspective might influence the assessment of environmental impacts. This paper addresses the potential consequences of offshore wind farm development at the North Sea scale on selected seabird species with high relevance in context of national approval procedures. It provides a new methodology to estimate the cumulative habitat loss due to ongoing and planned offshore wind farm construction activities within the North Sea's exclusive economic zones of Germany, the Netherlands, Belgium and the United Kingdom. In addition to providing information on the seasonal distribution of important species and initial estimates of potential seabird habitat exclusion due to offshore wind farming, this study highlights the need for increased trans-national cooperation among riparian states and harmonization of conservation approaches to successfully implement the Marine Strategy Framework Directive.

Challenges for marine spatial planning in the context of multiple sea uses, policy arenas and actors based on experiences from the German North Sea

Today, increasing use intensity and establishment of new sea uses such as offshore wind farming can be observed in coastal and marine waters. This development also increases the pressure on coastal and marine ecosystems. The exclusive economic zone of the German North Sea can serve as an example for this development, in particular illustrating the need to combine multiple uses and societal demands within a given sea area. In order to deal with the resulting conflicts and cumulative impacts, new planning tools and integrated approaches to planning and management are developing. While the sea becomes a contested but at the same time politically recognised area, also conflicts rooted in different perceptions, values and attitudes of coastal people can be observed. In order to deal with the current challenges in marine areas, marine spatial planning and similar tools for integrated planning need to be developed in the form of communication processes, which link diverse sets of information and span a dialogue between groups of society and across spatial scales including the transnational dimension.

Offshore Training Simulations

Offshore wind farming is the present trend industry in Germany. To speed up innovations in the field of safer offshore installation and maintenance work, the joint project Safe Offshore Operations was initiated to develop a research network between Lower Saxony universities and non-profit research institutes for fundamental research. The main idea consists of the development of an integrated operator assistance and information system based on a self-organising wireless computer and sensor network. Another objective of the project is the prolongation of the time frames for offshore operations, e.g. by optimisation of the logistics chain and by providing more accurate information about environmental and machinery conditions. Therefore SOOP is not only focussed on the work at sea. It will give better status information about the complete production process off- and onshore.As maritime senior partner, the main part of the research carried out at Jade University of Applied Sciences consists in finding proper scenarios for testing of or training with any system components developed by the project partners. The test criteria and scenarios that describe all environmental difficulties have to be defined, prepared and organised in order to fulfil the ambitious requirements and are finally validated and verified by in-house research activities and developments. Because of the early stage of the project only initial scenarios and their verification shall be presented and discussed by the following paper. Copyright © 2012 IFAC

Conceptualizing the link between marine ecosystem services and human well-being: the case of offshore wind farming

Although the concept of ecosystem services has drawn a prolific amount of recent research, little work has been done on the links between marine ecosystem services and coastal human well-being at a regional scale. Key questions in this context are that of appropriate categories for assessing human well-being and how to link different determinants of human well-being to specific ecosystem services supplied in adjacent marine areas. This paper presents the results of a case study that links tangible and intangible ecosystem benefits to a range of material and immaterial factors constituting human well-being. Determinants of human well-being were defined and indicators selected to make these linkages traceable. Ecosystem services were assessed for the offshore environment along the west coast of Schleswig-Holstein, Germany, based on the assumption of strong future development of offshore wind farming and considering the environmental and socio-economic impacts of such developments on the coastal region. This paper illustrates some conceptual problems in linking ecosystem benefits to human well-being. Based on an economic analysis and a questionnaire survey, two examples are presented where an evidence-based link could be demonstrated between an ecosystem service impacted by offshore wind farming and change in human well-being. The results presented should be understood as an analytic framework and precondition for gathering empirical data.

The Present Status and Future Prospects of Offshore Wind Farming

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