A Comparison Between the Preliminary Design Studies of a Fixed and A Floating Support Structure For A 5 Mw Offshore Wind Turbine In The North Sea

2010 ◽  
Author(s):  
M Collu ◽  
◽  
A J Kolios ◽  
A Chahardehi ◽  
F Brennan ◽  
...  
Keyword(s):  
Wind Turbine ◽  
North Sea ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Preliminary Design ◽  
Support Structure ◽  
Design Studies ◽  
The North ◽  
The North Sea

Feasibility of an Offshore Wind Farm in the North Sea Region

2019 ◽  
Author(s):  
Auraluck Pichitkul ◽  
Lakshmi N. Sankar ◽  
Jechiel Jagoda
Keyword(s):  
Wind Turbine ◽  
North Sea ◽  
Wind Farm ◽  
Cost Model ◽  
Turbine Rotor ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
The West ◽  
The North ◽  
The North Sea

Abstract Preliminary design and feasibility investigation of a 2-MW wind turbine for offshore wind farm operation are presented in this study. A region in the North Sea, to the west of the West Frisian Islands offshore of Dutch coast is selected as a potential wind farm site due to its high availability of wind resources. Based on the wind data of the selected site and operating requirements of the wind farm, preliminary sizing and conceptual design of wind turbine rotor blades are carried out. Performance of the rotor design is first assessed by classical blade element-momentum theory, followed by state-of-the-art commercial CFD software. Economics and feasibility analysis of this wind turbine operating in an offshore wind farm setting is conducted using DOE/NREL scaling cost model. The feasibility investigation results reveal that the cost of energy (COE) for operating the current wind turbine design at the selected wind farm site is considerably lower than the average COE in the Netherlands, indicating high potential of commercially making profits. Environmental impact studies have also been done.

Efficient Indicators for Screening of Random Waves for Wave Impacts on a Jacket Platform and a Fixed Offshore Wind Turbine

2019 ◽  
Author(s):  
Tim Bunnik ◽  
Jule Scharnke ◽  
Erik-Jan de Ridder
Keyword(s):  
North Sea ◽  
Large Diameter ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Probability Level ◽  
Wave Impact ◽  
The North ◽  
Statistical Variation ◽  
The North Sea ◽  
Design Loads

Abstract Renewed interest in wave impact assessment has risen for various reasons: • The low airgap of some existing Mobile Units in the North Sea • The COSL Innovator incident and related to this topic the new DNV-GL guidelines (OTG 13 and OTG 14). • the installation of many large-diameter monopile foundations for wind turbines in increasingly deep water in the North Sea. • The installation of many large-diameter wind turbines in increasingly deep water in the North Sea. • Seabed subsidence (and maybe water level rises due to global warming) and their effect on the decreasing airgap of fixed platforms. Wave impact assessment has been the subject of many recent studies and research projects, and there has been a strong knowledge and tool development during the last decade, both within model testing and numerical (CFD) analysis (Huang et.al (2017), de Ridder et.al, (2017), Vestbøstad et. al. (2017), Bunnik et.al. (2018)). However, there is still a lack of efficient methods and tools to properly analyze wave impacts and derive the statistical variation of these impacts in the sea states to which these structures are exposed during their lifetime. To reduce the statistical uncertainties that are naturally arising in estimates of design loads related to extreme waves, sufficient data must be gathered. In order to estimate the design loads it is common practice not to investigate all possible sea states (i.e. long-term analysis) but to investigate a few sea states and assume that the design value occurs at a prescribed probability level in the sea states with the same probability level (i.e. contour line approach). The estimate of the design value at that probability level is then based on results from a limited number of random realizations of these sea states. For linear or weakly nonlinear response types it is possible to estimate design loads accurately with a quite limited number of realizations. For strongly nonlinear problems however this is not possible due to the large statistical variation in the maximum observations, inherent to a random nonlinear process. Estimating accurately the tail of the load distribution requires many more realizations. This approach is restricted by time and costs and eventually one may have to accept an estimated design load with a large statistical uncertainty and account for the uncertainty with a higher safety margin. In this paper an improved methodology for estimating design loads related to extreme wave impacts will be presented. The methodology is based on screening many 3-hour realizations of the design sea states with simplified, fast but sufficiently accurate methods and to focus only on the potentially critical events with a model containing a more complete description of the physics. This can be either a model test or a non-linear impact simulation (i.e. CFD analysis). By doing this many more rare/critical events can be assessed, reducing the statistical uncertainty in the estimate of the design load. A screening method/wave impact indicator will be presented for a jacket platform and for a fixed offshore wind turbine. Existing model test data is used to show the correlation between indicator and actual impact events and to derive the efficiency of the impact indicators.

Monitoring Changes in the Soil and Foundation Characteristics of an Offshore Wind Turbine Using Automated Operational Modal Analysis

2013 ◽  
Vol 569-570 ◽  
pp. 652-659 ◽  
Author(s):  
Gert de Sitter ◽  
Wout Weitjens ◽  
Mahmoud El-Kafafy ◽  
Christof Devriendt
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Continuous Monitoring ◽  
Low Frequency ◽  
Operational Modal Analysis ◽  
Human Interaction ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Support Structure ◽  
Lower Natural Frequency

This paper will show the first results of a long term monitoring campaign on an offshore wind turbine in the Belgian North Sea. It will focus on the vibration levels and resonant frequencies of the fundamental modes of the support structure. These parameters will be crucial to minimize O&M costs and to extend the lifetime of offshore wind turbine structures. For monopile foundations for example, scouring and reduction in foundation integrity over time are especially problematic because they reduce the fundamental structural resonance of the support structure, aligning that resonance frequency more closely to the lower frequencies. Since both the broadband wave energy and the rotating frequency of the turbine are contained in this low frequency band, the lower natural frequency can create resonant behavior increasing fatigue damage. Continuous monitoring of the effect of scour on the dynamics of the wind turbine will help to optimize the maintenance activities on the scour protection system. To allow a proper continuous monitoring during operation, reliable state-of-the-art operational modal analysis techniques should be used and these are presented in this paper. The methods are also automated, so that no human-interaction is required and the system can track the natural frequencies and damping ratios in a reliable manner.

Accessibility assessment for operation and maintenance of offshore wind farms in the North Sea

Wind Energy ◽  
2016 ◽  
Vol 20 (4) ◽  
pp. 637-656 ◽  
Author(s):  
Michele Martini ◽  
Raúl Guanche ◽  
Iñigo J. Losada ◽  
César Vidal
Keyword(s):  
North Sea ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms ◽  
The North ◽  
Operation And Maintenance ◽  
The North Sea

scholarly journals Evidence for the effects of decommissioning man-made structures on marine ecosystems globally: a systematic map protocol

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Anaëlle J. Lemasson ◽  
Antony M. Knights ◽  
Murray Thompson ◽  
Gennadi Lessin ◽  
Nicola Beaumont ◽  
...  
Keyword(s):  
North Sea ◽  
Evidence Synthesis ◽  
Marine Ecosystem ◽  
Offshore Wind ◽  
Systematic Map ◽  
Management Options ◽  
The North ◽  
Ecosystem Effects ◽  
Published Evidence ◽  
The North Sea

Abstract Background Numerous man-made structures (MMS) have been installed in various parts of the ocean (e.g. oil and gas structures, offshore wind installations). Many are now at, or nearing, the end of their intended life. Currently, we only have a limited understanding of decommissioning effects. In many locations, such as the North Sea, regulations restrict decommissioning options to complete removal, with little consideration of alternative management options might offer. To generate a reliable evidence-base to inform the decision-making processes pertaining to marine MMS management, we propose a wide-encompassing systematic map of published research on the ecosystem effects (including ecosystem services) of marine MMS while in place and following cessation of operations (i.e. including effects of alternative decommissioning options). This map is undertaken as part of the UKRI DREAMS project which aims to develop a system to show the relative effects of implementing different decommissioning strategies in the North Sea. Method For the purpose of this map, we will keep our focus global, in order to subsequently draw comparisons between marine regions. The proposed map will aim to answer the following two primary questions: 1. What published evidence exists for the effects of marine man-made structures while in place on the marine ecosystem? 2. What published evidence exists for the effects of the decommissioning of marine man-made structures on the marine ecosystem? The map will follow the Collaboration for Environmental Evidence Guidelines and Standards for Evidence Synthesis in Environmental Management. Searches will be run primarily in English in at least 13 databases and 4 websites. Returns will be screened at title/abstract level and at full-text against pre-defined criteria. Relevant meta-data will be extracted for each study included. Results will be used to build a database of evidence, which will be made freely available. This map, expected to be large, will improve our knowledge of the available evidence for the ecosystem effects of MMS in the global marine environment. It will subsequently inform the production of multiple systematic-reviews and meta-analyses.

Sign in / Sign up

Export Citation Format

Share Document