scholarly journals The use of 'ecological risk' for assessing effects of human activities: An example including eutrophication and offshore wind farm construction in the north sea

2008 ◽  
Vol 5 ◽  
pp. 1-20 ◽  
Author(s):  
Corinna Nunneri ◽  
Hermann Josef Lenhart ◽  
Benjamin Burkhard ◽  
Franciscus Colijn ◽  
Felix Müller ◽  
...  
Keyword(s):  
Ecological Risk ◽  
Wind Farm ◽  
Ecological Integrity ◽  
Wind Farms ◽  
Well Being ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
The North ◽  
Use Of Resources

This paper takes the move from the uncertainty surrounding ecosystem thresholds and addresses the issue of ecosystem-state assessment by means of ecological integrity indicators and 'ecological risk'. The concept of 'ecological risk' gives a measure of the likelihood of ecosystem failure to provide the level of natural ecological goods and services expected/desired by human societies. As a consequence of human pressures (use of resources and discharge into the environment), ecosystem thresholds can be breached thus resulting in major threats to human health, safety and well-being. In this study we apply the concept of 'ecological risk' to two case-studies in the German exclusive economic zone: eutrophication and construction of offshore wind farms. The effects of different future scenarios for single-uses upon ecosystem integrity are analysed as well as the effects of one combined scenario. We conclude that in the short term construction of offshore wind farms can influence some processes to a much larger degree than eutrophication, however, combined impacts deriving from eutrophication and offshore wind farm construction need a more detailed analysis. Due to non-linear ecosystem processes, effects of combined or multiple uses of marine resources in terms of 'ecological risk', cannot be extrapolated from single-use scenarios.

Sea-Keeping Analysis of an Offshore Wind Farm Installation Vessel During the Jack-Up Process

2014 ◽  
Author(s):  
Philip H. Augener ◽  
Hannes Hatecke
Keyword(s):  
Wind Farm ◽  
Wind Farms ◽  
Weather Conditions ◽  
Offshore Wind ◽  
Shallow Waters ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
The North ◽  
The North Sea ◽  
Jack Up

Offshore wind farms are not planned in sheltered and shallow waters any longer. Especially in the North Sea there exist many approved offshore wind farm projects at water depth between 30 and 50 meters. In particular the installation process of these projects is strongly influenced by weather conditions and the sea-keeping capabilities of the installation vessels. For reliable planning of the entire project, not only the weather statistics, but also the vessel’s sea-keeping capabilities need to be known accurately. For this purpose different kinds of sea-keeping analyses can be conducted. In this paper a sea-keeping analysis is presented, where the focus is upon the jack-up process. For the numerical computation the sea-keeping code E4ROLLS is applied. The results of this sea-keeping analysis are operational limitations for the jack-up process, caused by two different criteria derived from jack-up classification requirements.

Optimization of Floating Offshore Wind Energy Systems Using an Extended Pattern Search Method

2016 ◽  
Author(s):  
Caitlin Forinash ◽  
Bryony DuPont
Keyword(s):  
Wind Farm ◽  
Wind Farms ◽  
Power Production ◽  
Pattern Search ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Power Development ◽  
Offshore Wind Farms ◽  
Onshore Wind ◽  
Extended Pattern Search

An Extended Pattern Search (EPS) approach is developed for offshore floating wind farm layout optimization while considering challenges such as high cost and harsh ocean environments. This multi-level optimization method minimizes the costs of installation and operations and maintenance, and maximizes power development in a unidirectional wind case by selecting the size and position of turbines. The EPS combines a deterministic pattern search algorithm with three stochastic extensions to avoid local optima. The EPS has been successfully applied to onshore wind farm optimization and enables the inclusion of advanced modeling as new technologies for floating offshore wind farms emerge. Three advanced models are incorporated into this work: (1) a cost model developed specifically for this work, (2) a power development model that selects hub height and rotor radius to optimize power production, and (3) a wake propagation and interaction model that determines aerodynamic effects. Preliminary results indicate the differences between proposed optimal offshore wind farm layouts and those developed by similar methods for onshore wind farms. The objective of this work is to maximize profit; given similar parameters, offshore wind farms are suggested to have approximately 24% more turbines than onshore farms of the same area. EPS layouts are also compared to those of an Adapted GA; 100% efficiency is found for layouts containing twice as many turbines as the layout presented by the Adapted GA. Best practices are derived that can be employed by offshore wind farm developers to improve the layout of platforms, and may contribute to reducing barriers to implementation, enabling developers and policy makers to have a clearer understanding of the resulting cost and power production of computationally optimized farms; however, the unidirectional wind case used in this work limits the representation of optimized layouts at real wind sites. Since there are currently no multi-turbine floating offshore wind farm projects operational in the United States, it is anticipated that this work will be used by developers when planning array layouts for future offshore floating wind farms.

scholarly journals Current Source Converter Based Offshore Wind Farm: Configuration and Control

2021 ◽  
Author(s):  
Miteshkumar Nandlal Popat
Keyword(s):  
Wind Farm ◽  
Current Source ◽  
Wind Farms ◽  
Offshore Wind ◽  
Grid Integration ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
Control Scheme ◽  
Current Source Converter ◽  
Grid Side

Recently, offshore wind farms have emerged as the most promising sector in the global renewable energy industry. The main reasons for the rapid development of offshore wind farms includes much better wind resources and smaller environmental impact (e.g., audible noise and visual effect). However, the current state of the offshore wind power presents economic challenges significantly greater than onshore. In this thesis, a novel interconnecting method for permanent magnet synchronous generator (PMSG)-based offshore wind farm is proposed, where cascaded pulse-width modulated (PWM) current-source converters (CSCs) are employed on both generator- and grid-side. With the converters in cascade to achieve high operating voltages, the proposed method eliminates the need for bulky and very costly offshore converter substation which is usually employed in voltage source converter (VSC) high voltage DC (HVDC)-based counterparts. Related research in terms of control schemes and grid integration are carried out to adapt the proposed cascaded CSC-based offshore wind farm configuration. The large distance between generator- and grid-side CSC in the proposed wind farm configuration addresses significant challenges for the system control. In order to overcome the problem, a novel decoupled control scheme is developed. The active and reactive power control on the grid-side converters are achieved without any exchange of information from the generator-side controller. Therefore, the long distance communication links between the generator- and grid-side converters are eliminated and both controllers are completely decoupled. At the same time, the maximum power tracking control is achieved for the generator-side converters that enable full utilization of the wind energy. Considering inconsistent wind speed at each turbine, a coordinated control scheme is proposed for the cascaded CSC-based offshore wind farm. In proposed control strategy, the wind farm supervisory control (WFSC) is developed to generate the optimized dc-link current control. This enables all the turbines to independently track their own MPPT even with inconsistent wind speed at each turbine. Grid integration issues, especially the fault ride-through (FRT) capability for the cascaded CSC-based offshore wind farm are addressed. Challenges in implementing existing FRT methods to the proposed offshore wind farm are identified. Based on this, a new FRT strategy using inherent short circuit operating capability of the CSC is developed. Moreover, the mitigation strategy is developed to ensure the continuous operation of the cascaded CSC-based offshore wind farm when one or more turbines fail to operate. Simulation and experimental verification for various objectives are provided throughout the thesis. The results validate the proposed solutions for the main challenges of the cascaded current source converter based offshore wind farm.

scholarly journals A Novel Method for Navigational Risk Assessment in Wind Farm Waters Based on the Fuzzy Inference System

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Peilin Lv ◽  
Rong Zhen ◽  
Zheping Shao
Keyword(s):  
Risk Assessment ◽  
Fuzzy Inference System ◽  
Wind Farm ◽  
Fuzzy Inference ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
Inference System ◽  
Natural Factors

Offshore wind power is an effective way to solve the energy crisis problem and achieve sustainable economic development. Aiming at the problems that the navigational risk of ships in the waters of offshore wind farms is difficult to quantify due to complex factors, this paper proposes a method of navigational risk assessment in the waters of offshore wind farms based on a fuzzy inference system. Firstly, through the analysis of the factors affecting the navigation system of wind farm waters, it is found that the navigational risk is affected by natural factors and navigational environment factors. Then, the visibility, the number of traffic flows, the number of encounter areas, and the distance between the sailing route and the wind farm are extracted to evaluate the risk of natural factors and the risk of the sailing environment in the navigation system of the wind farm waters, respectively. Considering the mutual influence of the factors, the fuzzy inference rules of navigational risk influence are established according to the expert experience, and a method of navigational risk assessment based on the fuzzy inference system in offshore wind farm waters is developed. In order to verify the effectiveness of the proposed method, a comprehensive evaluation of the navigational risk of wind farm waters in Changle offshore sea of Fujian Province is carried out, and the evaluation results are consistent with the actual situation. The proposed method has important theoretical significance for the navigational safety supervision of offshore wind farm waters.

The Experiences From the First Rounds of Offshore Wind Farm Installation in the German EEZ (Both Baltic and North Sea) and Lessons Learnt to Achieve Serial Production Status: A Consultant’s Perspective

2014 ◽  
Author(s):  
Ekkehard Stade
Keyword(s):  
Wind Farm ◽  
Oil And Gas ◽  
Wind Farms ◽  
Oil And Gas Industry ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Gas Industry ◽  
Offshore Wind Farms ◽  
Near Misses ◽  
Construction Operation

Offshore wind farms present a lesser safety risk to operators and contractors than traditional oil and gas installations. In the post Macondo world this does not come as a surprise since the risks involved in construction, operation and maintenance of an offshore wind farm are by far lower. Even with higher probability of incidents and near misses (due to serial construction) the severity/ impact of those is considerably lower. On the other hand projects are complex, profit margins are what they are called: marginal. Hence there is no room for errors, perhaps in form of delays. If, for example, the installation completion of the turbines and the inner array cabling/ export cables are not perfectly in tune, the little commercial success that can be achieved is rapidly diminishing by costly compensation activities. The paper will try to present solutions to the most pressing challenges and elaborate on the effect those would have had, had they been implemented at the beginning of the projects. How can a sustainable new industry evolve by learning from established industries? Presently, there is a view that offshore wind is a short-lived business. Particularly representatives of the oil and gas industry raise such concern. Apart from the obvious bias of those voices, this controversy is also caused by the fact that offshore wind seems to have a tendency to try and re-invent the wheel rather than using established procedures. Even with a relatively stable commitment to the offshore wind development regardless of the respective government focus within European coastal states the industry suffers from financing issues, subsidies, over-regulation due to lack of expertise within authorities and other challenges. The avoidance of those is key to a successful development for this industry in other areas of the planet. In conjunction with a stable commitment this is essential in order to attract the long lead-time projects and to establish the complex supply chains to achieve above goals. The paper will look at the short but intensive history of the industry and establish mitigation to some of the involved risks of offshore wind farm EPCI.

scholarly journals A Spatial Analysis of the Potentials for Offshore Wind Farm Locations in the North Sea Region: Challenges and Opportunities

2020 ◽  
Vol 9 (2) ◽  
pp. 96 ◽  
Author(s):  
Gusatu ◽  
Yamu ◽  
Zuidema ◽  
Faaij
Keyword(s):  
Protected Areas ◽  
North Sea ◽  
Water Depth ◽  
Wind Farm ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms ◽  
The North ◽  
Challenges And Opportunities ◽  
The North Sea

Over the last decade, the accelerated transition towards cleaner means of producing energy has been clearly prioritised by the European Union through large-scale planned deployment of wind farms in the North Sea. From a spatial planning perspective, this has not been a straight-forward process, due to substantial spatial conflicts with the traditional users of the sea, especially with fisheries and protected areas. In this article, we examine the availability of offshore space for wind farm deployment, from a transnational perspective, while taking into account different options for the management of the maritime area through four scenarios. We applied a mixed-method approach, combining expert knowledge and document analysis with the spatial visualisation of existing and future maritime spatial claims. Our calculations clearly indicate a low availability of suitable locations for offshore wind in the proximity of the shore and in shallow waters, even when considering its multi-use with fisheries and protected areas. However, the areas within 100 km from shore and with a water depth above –120 m attract greater opportunities for both single use (only offshore wind farms) and multi-use (mainly with fisheries), from an integrated planning perspective. On the other hand, the decrease of energy targets combined with sectoral planning result in clear limitations to suitable areas for offshore wind farms, indicating the necessity to consider areas with a water depth below –120 m and further than 100 km from shore. Therefore, despite the increased costs of maintenance and design adaptation, the multi-use of space can be a solution for more sustainable, stakeholder-engaged and cost-effective options in the energy deployment process. This paper identifies potential pathways, as well as challenges and opportunities for future offshore space management with the aim of achieving the 2050 renewable energy targets.

Performance Analysis of Offshore Mono-Pile Wind Turbine Co-Located With Floating Photovoltaic Systems in Shark Bay, Australia

2021 ◽  
Author(s):  
Morteza Bahadori ◽  
Hassan Ghassemi
Keyword(s):  
Wind Turbine ◽  
Hybrid System ◽  
Wind Farm ◽  
Wind Farms ◽  
Power Production ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
Shark Bay

Abstract In recent years, as more offshore wind farms have been constructed, the possibility of integrating various offshore renewable technologies is increased. Using offshore wind and solar power resources as a hybrid system provides several advantages including optimized marine space utilization, reduced maintenance and operation costs, and relieving wind variability on output power. In this research, both offshore wind and solar resources are analyzed based on accurate data through a case study in Shark Bay (Australia), where bathymetric information confirms using offshore bottom-fixed wind turbine regarding the depth of water. Also, the power production of the hybrid system of co-located bottom-fixed wind turbine and floating photovoltaic are investigated with the technical characteristics of commercial mono-pile wind turbine and photovoltaic panels. Despite the offshore wind, the solar energy output has negligible variation across the case study area, therefore using the solar platform in deep water is not an efficient option. It is demonstrated that the floating solar has a power production rate nearly six times more than a typical offshore wind farm with the same occupied area. Also, output energy and surface power density of the hybrid offshore windsolar system are improved significantly compared to a standalone offshore wind farm. The benefits of offshore wind and solar synergies augment the efficiency of current offshore wind farms throughout the world.

Support for Offshore Monopile Installation Through the Trench Cutter Technology

2013 ◽  
Vol 155 (A3) ◽  
Keyword(s):  
Wind Farm ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Case Histories ◽  
Offshore Wind Farms ◽  
Soil Layers ◽  
Drilling Technique ◽  
Hard Soil ◽  
Under Construction

Europe is currently facing an energetic revolution. Several offshore wind farm projects are currently under construction or under planning in North and Baltic Sea. Typical foundation structures for offshore wind farms are steel open-ended monopiles with large diameters up to 6 m. Currently, the monopiles are installed by driving with large impact hammers. However, there are many situations where pile refusal is reached, due to hard soil layers or erratic blocks. Driving and drilling technique is therefore applied. This manuscript briefly describes the trench cutter technology normally used for foundation works on land. Three case histories onshore and one offshore project are discussed and the evolution of the trench cutter technology for supporting the installation of offshore monopile is described.

Application of Offshore Concrete Constructions for Ocean Renewable Energy Storage (ORES)

2014 ◽  
Vol 521 ◽  
pp. 703-706 ◽  
Author(s):  
Wei Feng Li ◽  
Su Hua Ma ◽  
Xiao Dong Shen
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Wind Farm ◽  
Wind Farms ◽  
Excess Energy ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
Ocean Renewable Energy ◽  
Renewable Energy Storage

Storage of energy generated by offshore wind farms still addresses one of the vexing problems inherent in offshore renewable energy such as offshore wind or solar energy how to store excess energy. Researchers tried to apply concrete in the energy storage of offshore wind farm recently, including the OTEC artificial energy islands, the MITS Ocean Renewable Energy Storage (ORES) and Belgiums energy atoll, and the progresses were reviewed.

scholarly journals Investigating the Converter-Driven Stability of an Offshore HVDC System

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2341
Author(s):  
Matthias Quester ◽  
Fisnik Loku ◽  
Otmane El Azzati ◽  
Leonel Noris ◽  
Yongtao Yang ◽  
...  
Keyword(s):  
Wind Farm ◽  
Short Circuit ◽  
Impedance Measurement ◽  
Wind Farms ◽  
Offshore Wind ◽  
Voltage Source ◽  
Response Analysis ◽  
Offshore Wind Farms ◽  
The North ◽  
Ac Transmission

Offshore wind farms are increasingly built in the North Sea and the number of HVDC systems transmitting the wind power to shore increases as well. To connect offshore wind farms to adjacent AC transmission systems, onshore and offshore modular multilevel converters transform the transmitted power from AC to DC and vice versa. Additionally, modern wind farms mainly use wind turbines connected to the offshore point of common coupling via voltage source converters. However, converters and their control systems can cause unwanted interactions, referred to as converter-driven stability problems. The resulting instabilities can be predicted by applying an impedance-based analysis in the frequency domain. Considering that the converter models and system data are often confidential and cannot be exchanged in real systems, this paper proposes an enhanced impedance measurement method suitable for black-box applications to investigate the interactions. A frequency response analysis identifies coupling currents depending on the control system. The currents are subsequently added to the impedance models to achieve higher accuracy. The proposed method is applied to assess an offshore HVDC system’s converter-driven stability, using impedance measurements of laboratory converters and a wind turbine converter controller replica. The results show that the onshore modular multilevel converter interacts with AC grids of moderate short-circuit ratios. However, no interactions are identified between the offshore converter and the connected wind farm.

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