WorldWideScience

Sample records for delivering offshore wind

  1. EU-NORSEWIND - Delivering Offshore Wind Speed Data

    DEFF Research Database (Denmark)

    Oldroyd, Andy; Hasager, Charlotte Bay; Stickland, M.T.

    Offshore wind is the major growth area in the wind industry sector today, with a host of large projects being announced and innovative approaches being proposed. However, with all this investment and innovation there remains a key, fundamental missing element - a thorough understanding...

  2. Innovative Offshore Wind Plant Design Study

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, William L. [Glosten Associates, Inc., Seattle, WA (United States); Nordstrom, Charles J. [Glosten Associates, Inc., Seattle, WA (United States); Morrison, Brent J. [Glosten Associates, Inc., Seattle, WA (United States)

    2013-12-18

    Technological advancements in the Glosten PelaStar floating wind turbine system have led to projected cost of energy (COE) reductions from today’s best-in-class offshore wind systems. The PelaStar system is projected to deliver a COE that is 35% lower than that delivered by the current offshore wind plants. Several technology developments have been achieved that directly target significant cost of energy reductions. These include: Application of state-of-the-art steel construction materials and methods, including fatigue-resistant welding techniques and technologies, to reduce hull steel weight; Advancements in synthetic fiber tendon design for the mooring system, which are made possible by laboratory analysis of full-scale sub-rope specimens; Investigations into selected anchor technologies to improve anchor installation methods; Refinement of the installation method, specifically through development of the PelaStar Support Barge design. Together, these technology developments drive down the capital cost and operating cost of offshore wind plants and enable access to superb wind resources in deep water locations. These technology developments also reduce the uncertainty of the PelaStar system costs, which increases confidence in the projected COE reductions.

  3. Grid Integration of Offshore Wind | Wind | NREL

    Science.gov (United States)

    Grid Integration of Offshore Wind Grid Integration of Offshore Wind Much can be learned from the existing land-based integration research for handling the variability and uncertainty of the wind resource Arklow Bank offshore wind park consists of seven GE Wind 3.6-MW wind turbines. Integration and

  4. Offshore wind energy developments

    DEFF Research Database (Denmark)

    Stolpe, Mathias; Buhl, Thomas; Sumer, B. Mutlu

    2014-01-01

    This chapter will give a brief overview of a few of the activities within offshore wind energy research, specifically 1) Support structure optimization, 2) Blade coatings for wind turbines; 3) Scour protection of foundations, 4) Offshore HVDC and 5) Offshore wind services....

  5. Offshore wind energy prospects

    International Nuclear Information System (INIS)

    Gaudiosi, Gaetano

    1999-01-01

    In last two years offshore wind energy is becoming a focal point of national and non national organisations particularly after the limitations of fossil fuel consumption, adopted by many developed countries after Kyoto conference at the end of 1997 on global climate change. North Europe is particularly interested in offshore for the limited land areas still available, due to the intensive use of its territory and its today high wind capacity. Really the total wind capacity in Europe could increase from the 1997 value of 4450 MW up to 40 000 MW within 2010, according the White Paper 1997 of the European Commission; a significant percentage (25%) could be sited offshore up to 10 000 MW, because of close saturation of the land sites at that time. World wind capacity could increase from the 1997 value of 7200 MW up to 60 000 MW within 2010 with a good percentage (20%) offshore 12 000 MW. In last seven years wind capacity in shallow water of coastal areas has reached 34 MW. Five wind farms are functioning in the internal seas of Netherlands, Denmark, Sweden; however such siting is mostly to be considered as semi-offshore condition. Wind farms in real offshore sites, open seas with waves and water depth over 10 m, are now proposed in North Sea at 10-20 km off the coasts of Netherlands, Denmark using large size wind turbine (1-2 MW). In 1997 an offshore proposal was supported in Netherlands by Greenpeace after the OWEMES '97 seminar, held in Italy on offshore wind in the spring 1997. A review is presented in the paper of European offshore wind programs with trends in technology, economics and siting effects. (Author)

  6. Assessing offshore wind potential

    International Nuclear Information System (INIS)

    Adelaja, Adesoji; McKeown, Charles; Calnin, Benjamin; Hailu, Yohannes

    2012-01-01

    Quantifying wind potential is a pivotal initial step in developing and articulating a state’s policies and strategies for offshore wind industry development. This is particularly important in the Great Lakes States where lessons from other offshore environments are not directly applicable. This paper presents the framework developed for conducting a preliminary assessment of offshore wind potential. Information on lake bathymetry and wind resources were combined in simulating alternative scenarios of technically feasible turbine construction depths and distance concerns by stakeholders. These yielded estimates of developable offshore wind areas and potential power generation. While concerns about the visibility of turbines from shore reduce the power that can be generated, engineering solutions that increase the depths at which turbines can be sited increase such potential power output. This paper discusses the costs associated with technical limitations on depth and the social costs related to public sentiments about distance from the shoreline, as well as the possible tradeoffs. The results point to a very large untapped energy resource in the Michigan’s Great Lakes, large enough to prompt policy action from the state government. - Highlights: ▶ We build a theoretical framework for modeling offshore wind power production. ▶ Illustration of the impact of technology and social limitations on offshore wind energy development. ▶ Geospatial modeling of the offshore wind potential of the Great Lakes.

  7. National Offshore Wind Energy Grid Interconnection Study

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, John P. [ABB Inc; Liu, Shu [ABB Inc; Ibanez, Eduardo [National Renewable Energy Laboratory; Pennock, Ken [AWS Truepower; Reed, Greg [University of Pittsburgh; Hanes, Spencer [Duke Energy

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States. A total of 54GW of offshore wind was assumed to be the target for the analyses conducted. A variety of issues are considered including: the anticipated staging of offshore wind; the offshore wind resource availability; offshore wind energy power production profiles; offshore wind variability; present and potential technologies for collection and delivery of offshore wind energy to the onshore grid; potential impacts to existing utility systems most likely to receive large amounts of offshore wind; and regulatory influences on offshore wind development. The technologies considered the reliability of various high-voltage ac (HVAC) and high-voltage dc (HVDC) technology options and configurations. The utility system impacts of GW-scale integration of offshore wind are considered from an operational steady-state perspective and from a regional and national production cost perspective.

  8. Offshore Wind Energy Market Overview (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, I.

    2013-07-01

    This presentation describes the current international market conditions regarding offshore wind, including the breakdown of installation costs, how to reduce costs, and the physical siting considerations considered when planning offshore wind construction. The presentation offers several examples of international existing and planned offshore wind farm sites and compares existing international offshore resources with U.S. resources. The presentation covers future offshore wind trends and cites some challenges that the United States must overcome before it will be able to fully develop offshore wind sites.

  9. Offshore Wind Energy Resource Assessment for Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Doubrawa Moreira, Paula [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scott, George N. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walter D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kilcher, Levi F. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Draxl, Caroline [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lantz, Eric J. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2018-01-02

    This report quantifies Alaska's offshore wind resource capacity while focusing on its unique nature. It is a supplement to the existing U.S. Offshore Wind Resource Assessment, which evaluated the offshore wind resource for all other U.S. states. Together, these reports provide the foundation for the nation's offshore wind value proposition. Both studies were developed by the National Renewable Energy Laboratory. The analysis presented herein represents the first quantitative evidence of the offshore wind energy potential of Alaska. The technical offshore wind resource area in Alaska is larger than the technical offshore resource area of all other coastal U.S. states combined. Despite the abundant wind resource available, significant challenges inhibit large-scale offshore wind deployment in Alaska, such as the remoteness of the resource, its distance from load centers, and the wealth of land available for onshore wind development. Throughout this report, the energy landscape of Alaska is reviewed and a resource assessment analysis is performed in terms of gross and technical offshore capacity and energy potential.

  10. Offshore wind resource estimation for wind energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Mouche, A.

    2010-01-01

    Satellite remote sensing from active and passive microwave instruments is used to estimate the offshore wind resource in the Northern European Seas in the EU-Norsewind project. The satellite data include 8 years of Envisat ASAR, 10 years of QuikSCAT, and 23 years of SSM/I. The satellite observati......Satellite remote sensing from active and passive microwave instruments is used to estimate the offshore wind resource in the Northern European Seas in the EU-Norsewind project. The satellite data include 8 years of Envisat ASAR, 10 years of QuikSCAT, and 23 years of SSM/I. The satellite...... observations are compared to selected offshore meteorological masts in the Baltic Sea and North Sea. The overall aim of the Norsewind project is a state-of-the-art wind atlas at 100 m height. The satellite winds are all valid at 10 m above sea level. Extrapolation to higher heights is a challenge. Mesoscale...... modeling of the winds at hub height will be compared to data from wind lidars observing at 100 m above sea level. Plans are also to compare mesoscale model results and satellite-based estimates of the offshore wind resource....

  11. Offshore Wind Power Planning in Korea

    DEFF Research Database (Denmark)

    Seo, Chul Soo; Cha, Seung-Tae; Park, Sang Ho

    2012-01-01

    this possible, Korea has announced the National offshore power roadmap and is now in pursuit. However, large scale offshore wind farms can incur many problems, such as power quality problems, when connecting to a power system.[1][2] Thus, KEPCO is on the process of a research study to evaluate the effects...... that connecting offshore wind power generation to a power system has on the power system. This paper looks over offshore wind power planning in Korea and describes the development of impact assessment technology of offshore wind farms.......Wind power generation is globally recognized as the most universal and reliable form of renewable energy. Korea is currently depending mostly on coal and petroleum to generate electrical power and is now trying to replace them with renewable energy such as offshore wind power generation. To make...

  12. Second wind in the offshore wind industry

    International Nuclear Information System (INIS)

    Philippe, Edouard; Neyme, Eric; Deboos, Christophe; Villageois, Jean-Remy; Gouverneur, Philippe; Gerard, Bernard; Fournier, Eric; Petrus, Raymond; Lemarquis, David; Dener, Marc; Bivaud, Jean-Pierre; Lemaire, Etienne; Nielsen, Steffen; Lafon, Xavier; Lagandre, Pierre; Nadai, Alain; Pinot de Villechenon, Edouard; Westhues, Markus; Herpers, Frederick; Bisiaux, Christophe; Sperlich, Miriam; Bales, Vincent; Vandenbroeck, Jan; His, Stephane; Derrey, Thierry; Barakat, Georges; Dakyo, Brayima; Carme, Laurent; Petit, Frederic; Ytournel, Sophie; Westhues, Markus; Diller, Armin; Premont, Antoine de; Ruer, Jacques; Lanoe, Frederic; Declercq, Jan; Holmager, Morten; Fidelin, Daniel; Guillet, Jerome; Dudziak, Gregory; Lapierre, Anne; Couturier, Ludovic; Audineau, Jean-Pierre; Rouaix, Eric; De Roeck, Yann-Herve; Quesnel, Louis; Duguet, Benjamin

    2011-06-01

    After several keynote addresses, this publication contains contributions and Power Point presentations proposed during this conference on the development of offshore wind energy. The successive sessions addressed the following issues: the offshore mass production of electricity (examples of Denmark and Belgium, laying and protecting offshore cables), the space, economic and environmental planning (the Danish experience, the role of the Coastal area integrated management, importance of the public debate, so on), the logistics of port infrastructures (simulation tools, example of Bremerhaven, issues related to project management), innovation at the core of industrial strategies (high power wind turbines, the 6 MW Alstom turbine, chain value and innovation in offshore wind energy, the Vertiwing innovating project of a floating wind turbine, a bench test in Charleston, foundations, gravity base structures, the British experience, the Danish experience), the economic and organisational conditions for development, the validation and certification of technologies

  13. Offshore Wind Market and Economic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Bruce Duncan [Navigant Consulting, Inc., Chicago, IL (United States)

    2014-08-27

    This report is the third annual assessment of the U.S. offshore wind market. It includes the following major sections: Section 1: key data on developments in the offshore wind technology sector and the global development of offshore wind projects, with a particular focus on progress in the United States; Section 2: analysis of policy developments at the federal and state levels that have been effective in advancing offshore wind deployment in the United States; Section 3: analysis of actual and projected economic impact, including regional development and job creation; Section 4: analysis of developments in relevant sectors of the economy with the potential to affect offshore wind deployment in the United States

  14. The economics of offshore wind

    International Nuclear Information System (INIS)

    Green, Richard; Vasilakos, Nicholas

    2011-01-01

    This paper presents an overview of the main issues associated with the economics of offshore wind. Investment in offshore wind systems has been growing rapidly throughout Europe, and the technology will be essential in meeting EU targets for renewable energy in 2020. Offshore wind suffers from high installation and connection costs, however, making government support essential. We review various support policies used in Europe, concluding that tender-based feed-in tariff schemes, as used in Denmark, may be best for providing adequate support while minimising developers' rents. It may prove economic to build an international offshore grid connecting wind farms belonging to different countries that are sited close to each other. (author)

  15. The economics of offshore wind

    Energy Technology Data Exchange (ETDEWEB)

    Green, Richard; Vasilakos, Nicholas [Department of Economics, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2011-02-15

    This paper presents an overview of the main issues associated with the economics of offshore wind. Investment in offshore wind systems has been growing rapidly throughout Europe, and the technology will be essential in meeting EU targets for renewable energy in 2020. Offshore wind suffers from high installation and connection costs, however, making government support essential. We review various support policies used in Europe, concluding that tender-based feed-in tariff schemes, as used in Denmark, may be best for providing adequate support while minimising developers' rents. It may prove economic to build an international offshore grid connecting wind farms belonging to different countries that are sited close to each other. (author)

  16. Investigation of Wind Turbine Rotor Concepts for Offshore Wind Farms

    International Nuclear Information System (INIS)

    Ceyhan, Özlem; Grasso, Francesco

    2014-01-01

    Current plans in offshore wind energy developments call for further reduction of cost of energy. In order to contribute to this goal, several wind turbine rotor concepts have been investigated. Assuming the future offshore wind turbines will operate only in the offshore wind farms, the rotor concepts are not only evaluated for their stand-alone performances and their potential in reducing the loads, but also for their performance in an offshore wind farm. In order to do that, the 10MW reference wind turbine designed in Innwind.EU project is chosen as baseline. Several rotor parameters have been modified and their influences are investigated for offshore wind turbine design purposes. This investigation is carried out as a conceptual parametrical study. All concepts are evaluated numerically with BOT (Blade optimisation tool) software in wind turbine level and with Farmflow software in wind farm level for two wind farm layouts. At the end, all these concepts are compared with each other in terms of their advantages and disadvantages

  17. Danish offshore wind - Key environmental issues

    International Nuclear Information System (INIS)

    2006-11-01

    Danish experience from the past 15 years shows that offshore wind farms, if placed right, can be engineered and operated without significant damage to the marine environment and vulnerable species. The comprehensive environmental monitoring programmes of Horns Rev Offshore Wind Farm and Nysted Offshore Wind Farm confirm that, under the rieght conditions, even big wind farms pose low risk to birds, mammals and fish, even though there will be changes in the living conditions of some species by an increase in habitat heterogeneity. The monitoring also shows that appropriate siting of offshore wind farms is an essential precondition for ensuring limited impact on nature and the environment, and that careful spatial planning is necessary to avoid damaging cumulative impacts. Due consideration to limiting the impacts on nature together with positive attitudes towards offshore wind farms in local communities and challenging energy policy objectives at national and international levels mean that prospects look bright for future offshore expansion. (au)

  18. Wind energy in offshore grids

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten

    special characteristics of offshore grids. With an operational real options approach, it is furthermore illustrated how different support schemes and connections to additional countries affect the investment case of an offshore wind farm and the income of the transmission system operator. The investment...... and investment implications under different regulatory frameworks are a hitherto underrepresented research field. They are addressed by this thesis. Offshore grids between several countries combine the absorption of wind energy with international power trading. However, the inclusion into an offshore grid......This cumulative PhD thesis deals with wind integration in offshore grids from an economic point of view. It is composed of a generic part and eight papers. As the topic has mostly been analysed with a focus on topology and technical issues until now, market-operational questions in offshore grids...

  19. 2016 Offshore Wind Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schwabe, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stehly, Tyler [National Renewable Energy Lab. (NREL), Golden, CO (United States); Spitsen, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-08-07

    The 2016 Offshore Wind Technologies Market Report is intended to provide stakeholders with quantitative information about the offshore wind market, technology, and cost trends in the United States and worldwide.

  20. China: an emerging offshore wind development hotspot. With a new assessment of China's offshore wind potential

    Energy Technology Data Exchange (ETDEWEB)

    Reinvang, Rasmus; Enslow, Rachel; Beaumont, Hubert

    2010-08-15

    This study provides new and more detailed estimates of the offshore wind energy resources in China, with particular focus on Southern China. The study points out that the offshore wind industry is ramping up in China with at least 11.9GW in the development pipeline per April 2010. The study estimates the offshore wind potential of China (excluding Taiwan) to 11,580TWh/year. The study proves estimates and wind energy resource maps per province. Fujian, Zhejiang and Hainan stand out with the highest offshore wind speeds in China while Guangdong also shows significant potential, with annual wind speed averages of 6.5-10.2m/s and an energy density range of 12-36GWh/km2. Even though current offshore wind development is mainly taking place in Fujian and Jiangsu, this study shows that the potential is likely even greater in other provinces. The study was developed by the Chinese Wind Energy Association (CWEA) and Sun Yat-sen University, and commissioned by WWF as part of a project funded by the Norwegian Agency of development Coopeartion (Norad). Methodology and constraints: The wind resource analysis improves upon previous studies in estimating the wind energy generation potential for offshore wind power in China, with available meteorological data adjusted for influence of typhoons. The study models how much energy offshore wind can produce along China's coast up to 100km from the shore by calculating the energy output of theoretical wind farms by applying the power curve of a 3MW turbine at a 100m hub height. In addition the study further expands by giving special consideration to the deep-sea offshore potential at +50m water depths. The study focuses particularly on the coastline from Shandong down to Hainan. The final results provide good indication of the offshore wind resource in China when comparing one area to the other. The report can therefore be used as a preliminary tool to identifying most interesting provinces and locations for offshore wind

  1. Offshore wind farm repowering optimization

    DEFF Research Database (Denmark)

    Hou, Peng; Enevoldsen, Peter; Hu, Weihao

    2017-01-01

    is focused on optimization of offshore wind farm repowering, which is one option for the wind farm owner at end of life for the offshore wind farm. The LCoE is used as the evaluation index to identify whether it is economical to invest in such a way. In an optimized repowering strategy, different types...... of wind turbines are selected to replace the original wind turbines to reconstruct the wind farm, which is demonstrated to be better than the refurbishment approach which replaces the old wind turbines with the same type. The simulations performed in this research reveal that the reconstructed wind farm......, which consists of multiple types of wind turbine, has a smaller LCoE (10.43%) than the refurbishment approach, which shows the superiority of the proposed method. This research contributes an optimization tool to the wind industry, which consequently drives down the cost of energy produced by offshore...

  2. Cost optimization of wind turbines for large-scale offshore wind farms

    International Nuclear Information System (INIS)

    Fuglsang, P.; Thomsen, K.

    1998-02-01

    This report contains a preliminary investigation of site specific design of off-shore wind turbines for a large off-shore wind farm project at Roedsand that is currently being proposed by ELKRAFT/SEAS. The results were found using a design tool for wind turbines that involve numerical optimization and aeroelastic calculations of response. The wind climate was modeled in detail and a cost function was used to estimate costs from manufacture and installation. Cost of energy is higher for off-shore installations. A comparison of an off-shore wind farm site with a typical stand alone on-shore site showed an increase of the annual production of 28% due to the difference in wind climate. Extreme loads and blade fatigue loads were nearly identical, however,fatigue loads on other main components increased significantly. Optimizations were carried out to find the optimum overall off-shore wind turbine design. A wind turbine for the off-shore wind farm should be different compared with a stand-alone on-shore wind turbine. The overall design changed were increased swept area and rated power combined with reduced rotor speed and tower height. Cost was reduced by 12% for the final 5D/14D off-shore wind turbine from 0.306 DKr/kWh to 0.270 DKr/kWh. These figures include capital costs from manufacture and installation but not on-going costs from maintenance. These results make off-shore wind farms more competitive and comparable to the reference on-shore stand-alone wind turbine. A corresponding reduction of cost of energy could not be found for the stand alone on-shore wind turbine. Furthermore the fatigue loads on wind turbines in on-shore wind farms will increase and cost of energy will increase in favor of off-shore wind farms. (au) EFP-95; EU-JOULE-3; 21 tabs., 7 ills., 8 refs

  3. Lake Michigan Offshore Wind Feasibility Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Boezaart, Arnold [GVSU; Edmonson, James [GVSU; Standridge, Charles [GVSU; Pervez, Nahid [GVSU; Desai, Neel [University of Michigan; Williams, Bruce [University of Delaware; Clark, Aaron [GVSU; Zeitler, David [GVSU; Kendall, Scott [GVSU; Biddanda, Bopi [GVSU; Steinman, Alan [GVSU; Klatt, Brian [Michigan State University; Gehring, J. L. [Michigan State University; Walter, K. [Michigan State University; Nordman, Erik E. [GVSU

    2014-06-30

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the

  4. RAMSI management model and evaluation criteria for Nordic offshore wind asset

    Energy Technology Data Exchange (ETDEWEB)

    Tiusanen, R.; Jaennes, J. [VTT Technical Research Centre of Finland, Espoo (Finland); Liyanage, J. P. [Univ. of Stavanger, Center for Industrial Asset Management (Norway)

    2012-07-01

    The offshore wind energy sector is in the early stages of development, but it is growing fast. Due to the European Union's renewable-energy and climate goals along with national legislation, the offshore wind sector will develop strongly over the coming years in Europe. In the offshore wind energy sector, there are many different wind-turbine designs ranging from traditional mono pile structures to floating platforms, depending on the water depth. Today, most offshore turbines are based on onshore turbine designs, and turbine technology continues to develop incrementally. At the same time, there is strong demand in the market for new, innovative designs for offshore wind turbines whose main focus is reliability and cost efficiency. For floating offshore wind turbine designs, there may be new types of uncertainty and system risks compared with onshore wind turbines. Wind turbines in cold climates, such as those experienced in the Nordic countries, may be exposed to extreme conditions, such as formation of ice or very low temperatures that are outside the design limits of standard wind turbines. In the offshore wind energy sector, specification, implementation and verification of the so-called R&M's (Reliability, Availability, Maintainability, Safety and Inspect ability) requirements during development work are important for companies delivering wind turbines, from the perspective of system integrity. Decisions made before the formal design phase strongly determine the costs and benefits gained during the whole life cycle of a wind turbine. The benefits of implementing the R&M's program include support with investment decisions, cost management, improved management of resource requirements, systematic support with development and implementation of products, and integration of dependability and safety requirements. This publication outlines a model for managing R&M's factors during the conceptual design phase of an offshore wind turbine. The model

  5. Noise from offshore wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Soendergaard, B.; Plovsing, B.

    2005-07-01

    Noise assessment of wind turbines through calculations is based on sound power levels measured according to e.g. IEC 61400-11. With larger wind turbines and distances some of the calculation models give erroneous results. Noise propagation over water is different from propagation over land. For that reason it is important be able to make valid noise assessments for offshore wind farms. A suggestion for an offshore measurement method is described and a survey of models for noise propagation offshore has been made. (au)

  6. Offshore wind resources at Danish measurement sites

    Energy Technology Data Exchange (ETDEWEB)

    Barthelmie, R J; Courtney, M S; Lange, B; Nielsen, M; Sempreviva, A M [Risoe National Lab., Dept. of Wind Energy and Atmospheric Physics, Roskilde (Denmark); Svenson, J; Olsen, F [SEAS, Haslev (Denmark); Christensen, T [Elsamprojekt, Fredericia (Denmark)

    1999-03-01

    In order to characterise wind and turbulence characteristics at prospective offshore wind energy sites, meteorological observations from a number of purpose-built offshore monitoring sites have been analyzed and compared with long wind speed time series. New analyses have been conducted on the data sets focussing on meteorology, turbulence, extreme winds and wind and wave interactions. Relationships between wind speed, turbulence and fetch are highly complex. Minimum turbulence intensity offshore is associated with wind speeds of about 12 m/s. At lower wind speeds, stability effects are important while at higher winds speeds wind and wave interactions appear to dominate. On average, turbulence intensity offshore at 48 m height is approximately 0.08 if no coastal effects are present. However, the effect of the coastal discontinuity persists in wind speed and turbulence characteristics for considerable distances offshore. The majority of the adjustment of appears to occur within 20 km of the coast. (au)

  7. Far offshore wind conditions in scope of wind energy

    NARCIS (Netherlands)

    Holtslag, M.C.

    2016-01-01

    Far offshore atmospheric conditions are favourable for wind energy purposes since mean wind speeds are relatively high (i.e., high power production) while turbulence levels are relatively low (i.e., less fatigue loads) compared to onshore conditions. Offshore wind energy, however, is still expensive

  8. Attitude and acceptance of offshore wind farms

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Möller, B.

    2011-01-01

    farms attributes on attitude towards offshore wind farms. The results point towards that the travel time and the attributes of the nearest offshore wind farm influence the attitude significantly. Travel time has mixed effects on the attitude, whilst offshore wind farms with many turbines generate more...... a novel contribution to this field. First of all, we give a thorough review of the studies that have analysed the relation between experience with wind turbines and attitude. In addition, we supplement the review by analysing the effect of travel distance to the nearest offshore wind farm and the wind...

  9. Power-flow control and stability enhancement of four parallel-operated offshore wind farms using a line-commutated HVDC link

    DEFF Research Database (Denmark)

    Wang, Li; Wang, Kuo-Hua; Lee, Wei-Jen

    2010-01-01

    This paper presents an effective control scheme using a line-commutated high-voltage direct-current (HVDC) link with a designed rectifier current regulator (RCR) to simultaneously perform both power-fluctuation mitigation and damping improvement of four parallel-operated 80-MW offshore wind farms...... delivering generated power to a large utility grid. The proposed RCR of the HVDC link is designed by using modal control theory to contribute adequate damping to the studied four offshore wind farms under various wind speeds. A systematic analysis using a frequency-domain approach based on eigenvalue...... characteristics to the studied offshore wind farms under various wind speeds but also effectively mitigate power fluctuations of the offshore wind farms under wind-speed disturbance conditions....

  10. Development of Offshore Wind Power Industry

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao

    2011-01-01

    The offshore wind power development target as initially proposed in "The 12=Five-Year" on energy recourses development and renewable energy recourses currently under development is to reach 5m KW by 2015 and 30m KW by 2020. With the unfolding of offshore wind turbine planning from different areas, the curtain of offshore wind power development for our country's "The 12=Five-Year" has been opened.

  11. Offshore Wind Power

    DEFF Research Database (Denmark)

    Negra, Nicola Barberis

    reliability models, and a new model that accounts for all relevant factors that influence the evaluations is developed. According to this representation, some simulations are performed and both the points of view of the wind farm owner and the system operator are evaluated and compared. A sequential Monte...... Carlo simulation is used for these calculations: this method, in spite of an extended computation time, has shown flexibility in performing reliability studies, especially in case of wind generation, and a broad range of results which can be evaluated. The modelling is then extended to the entire power......The aim of the project is to investigate the influence of wind farms on the reliability of power systems. This task is particularly important for large offshore wind farms, because failure of a large wind farm might have significant influence on the balance of the power system, and because offshore...

  12. Mechanisms blocking the dynamics of the European offshore wind energy innovation system – Challenges for policy intervention

    International Nuclear Information System (INIS)

    Jacobsson, Staffan; Karltorp, Kersti

    2013-01-01

    Decarbonizing electricity production in the EU may necessitate building new “low-carbon” capacity (excluding nuclear investments) to deliver 3500 TWh by 2050. Offshore wind power has the potential to contribute substantially to fill this gap. Realizing this potential is, however, difficult since deployment offshore does not constitute a simple diversification by the onshore wind turbine industry to a new segment. This paper identifies factors obstructing the development of the northern European innovation system centered on offshore wind power, specifies a set of associated policy challenges and discusses various policy responses. - Highlights: • Offshore wind power has a strategic role in decarbonizing EU's supply of electricity. • There are numerous obstacles to deployment of offshore wind turbines. • We specify seven major policy challenges in diverse policy domains. • Managing these requires coordination of interventions across policy domains and national boundaries

  13. 2016 Offshore Wind Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Musial, Walter; Beiter, Philipp; Schwabe, Paul; Tian, Tian; Stehly, Tyler; Spitsen, Paul; Robertson, Amy; Gevorgian, Vahan

    2017-08-08

    The 2016 Offshore Wind Technologies Market Report was developed by the National Renewable Energy Laboratory (NREL) for the U.S. Department of Energy (DOE) and is intended to provide offshore wind policymakers, regulators, developers, researchers, engineers, financiers, and supply chain participants, with quantitative information about the offshore wind market, technology, and cost trends in the United States and worldwide. In particular, this report is intended to provide detailed information on the domestic offshore wind industry to provide context to help navigate technical and market barriers and opportunities. The scope of the report covers the status of the 111 operating offshore wind projects in the global fleet through December 31, 2016, and provides the status and analysis on a broader pipeline of 593 projects at some stage of development. In addition, this report provides a wider assessment of domestic developments and events through the second quarter of 2017 to provide a more up-to-date discussion of this dynamically evolving industry.

  14. Understanding public responses to offshore wind power

    International Nuclear Information System (INIS)

    Haggett, Claire

    2011-01-01

    This paper is about understanding the role and importance of public responses to offshore wind power. It builds on a framework for understanding social acceptance and opposition to onshore turbines, and reviews the emerging research on offshore wind. While less is known about how people will respond to offshore than onshore wind, there is now an emerging body of research. From this literature, several common factors which influence responses have emerged and are discussed here: the (continued) role of visual impact; place attachment to the local area; lack of tangible benefits; relationships with developers and outsiders; and the role of the planning and decision-making systems. The paper argues that, as with onshore developments, the public should be included in decision-making about offshore wind farms, and that they have a key role which should not be underestimated. The paper concludes with some thoughts about the means to involve people and how effected communities might be effectively acknowledged, identified and engaged. - Research Highlights: →Comprehensive review of public responses to offshore wind literature. →Applies key lessons and analytic insights from onshore wind to offshore wind. →Emphasizes the role and importance of the public in the planning and implementation of offshore wind energy.

  15. Wind energy in offshore grids

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, S.T.

    2013-01-15

    This cumulative PhD thesis deals with wind integration in offshore grids from an economic point of view. It is composed of a generic part and eight papers. As the topic has mostly been analysed with a focus on topology and technical issues until now, market-operational questions in offshore grids and investment implications under different regulatory frameworks are a hitherto underrepresented research field. They are addressed by this thesis. Offshore grids between several countries combine the absorption of wind energy with international power trading. However, the inclusion into an offshore grid affects the economics of an offshore wind park. It is shown that the spot market income is lower if an offshore wind farm is placed in an interconnector and subject to nodal pricing instead of having a national affiliation. Moreover, congestion in the interconnector can prevent the wind farm from correcting its wind forecast errors in a specific onshore balancing group. An analytical approach with a transmission system operator and a wind farm as stakeholders illustrates resulting incentives for strategic behaviour. Depending on the regulatory regime, they may be inclined to announce more or less generation than expected at the closure of the day-ahead spot market. This can lead to a suboptimal utilisation of the infrastructure and associated socio-economic losses. These and possibly undesired reallocative effects between the parties can be avoided if the regulatory regime is adjusted to reflect special characteristics of offshore grids. With an operational real options approach, it is furthermore illustrated how different support schemes and connections to additional countries affect the investment case of an offshore wind farm and the income of the transmission system operator. The investment framework has also been addressed with a policy study about possible combinations of support schemes and international cooperation mechanisms between countries to achieve their

  16. Offshore wind power in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, H. [VTT Energy, Espoo (Finland)

    1998-12-31

    The objectives of the project were to estimate the technical offshore wind power potential of the Gulf of Bothnia, with cost assessments, to study icing conditions and ice loads, and to design a foundation suitable for the environmental conditions. The technical offshore potential from Vaasa to Tornio is huge, more than 40 TWh/a, although the cost of offshore wind power is still higher than on land. Wind turbines have not previously been designed for the icing conditions found in Gulf of Bothnia and the recommendations for load cases and siting of megawatt-class turbines are an important result of the project. (orig.)

  17. Offshore Wind Energy Cost Modeling Installation and Decommissioning

    CERN Document Server

    Kaiser, Mark J

    2012-01-01

    Offshore wind energy is one of the most promising and fastest growing alternative energy sources in the world. Offshore Wind Energy Cost Modeling provides a methodological framework to assess installation and decommissioning costs, and using examples from the European experience, provides a broad review of existing processes and systems used in the offshore wind industry. Offshore Wind Energy Cost Modeling provides a step-by-step guide to modeling costs over four sections. These sections cover: ·Background and introductory material, ·Installation processes and vessel requirements, ·Installation cost estimation, and ·Decommissioning methods and cost estimation.  This self-contained and detailed treatment of the key principles in offshore wind development is supported throughout by visual aids and data tables. Offshore Wind Energy Cost Modeling is a key resource for anyone interested in the offshore wind industry, particularly those interested in the technical and economic aspects of installation and decom...

  18. Siemens Wind Power 3.6 MW wind turbines for large offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Akhmatov, Vladislav; Nygaard Nielsen, Joergen; Thisted, Jan; Groendahl, Erik; Egedal, Per; Noertoft Frydensbjerg, Michael; Jensen, Kim Hoej [Siemens Wind Power A/S, Brande (Denmark)

    2008-07-01

    Siemens Wind power A/S is the key player on the offshore wind power market. The Siemens Wind Power 3.6 MW variable-speed wind turbine is among the word's largest, most advanced and competitive wind turbines with a solid portfolio of large offshore wind farms. Transmission system operators and developers require dynamic wind turbine models for evaluation of fault-ride-through capability and investigations of power system stability. The even larger size of the on- and offshore wind farms has entailed that the grid impact of the voltage and frequency control capability of the wind farm can be appropriated modelled and evaluated. Siemens Wind Power has developed a dynamic model of the 3.6 MW variable-speed wind turbine with the fault-ride-through sequences and models of the voltage and frequency controllers to be applied for large offshore wind farms. The dynamic models have been implemented in the commercially available simulation tools such as DIgSILENT PowerFactory and Siemens PTI PSS/E and successfully validated from measurements. (orig.)

  19. The Offshore New European Wind Atlas

    Science.gov (United States)

    Karagali, I.; Hahmann, A. N.; Badger, M.; Hasager, C.; Mann, J.

    2017-12-01

    The New European Wind Atlas (NEWA) is a joint effort of research agencies from eight European countries, co-funded under the ERANET Plus Program. The project is structured around two areas of work: development of dynamical downscaling methodologies and measurement campaigns to validate these methodologies, leading to the creation and publication of a European wind atlas in electronic form. This atlas will contain an offshore component extending 100 km from the European coasts. To achieve this, mesoscale models along with various observational datasets are utilised. Scanning lidars located at the coastline were used to compare the coastal wind gradient reproduced by the meso-scale model. Currently, an experimental campaign is occurring in the Baltic Sea, with a lidar located in a commercial ship sailing from Germany to Lithuania, thus covering the entire span of the south Baltic basin. In addition, satellite wind retrievals from scatterometers and Synthetic Aperture Radar (SAR) instruments were used to generate mean wind field maps and validate offshore modelled wind fields and identify the optimal model set-up parameters.The aim of this study is to compare the initial outputs from the offshore wind atlas produced by the Weather & Research Forecasting (WRF) model, still in pre-operational phase, and the METOP-A/B Advanced Scatterometer (ASCAT) wind fields, reprocessed to stress equivalent winds at 10m. Different experiments were set-up to evaluate the model sensitivity for the various domains covered by the NEWA offshore atlas. ASCAT winds were utilised to assess the performance of the WRF offshore atlases. In addition, ASCAT winds were used to create an offshore atlas covering the years 2007 to 2016, capturing the signature of various spatial wind features, such as channelling and lee effects from complex coastal topographical elements.

  20. Denmark - supplier of competitive offshore wind solutions. Megavind's strategy for offshore wind research, development and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    In May 2006, the Danish Government presented a report on promoting environmentally effective technology and established a number of innovative partnerships. The partnerships intend to strengthen public-private cooperation between the state, industry, universities and venture capital to accelerate innovation for a number of green technologies. The partnership for wind energy is called Megavind. Megavind's strategy for offshore wind describes the offshore challenges and suggests research, development and demonstration (RD and D) priorities to enable offshore wind power become to competitive with other energy technologies. The strategy lists key recommendations as well as key thematic priorities and for each of these a number of RD and D priorities. Under each thematic priority references are made to the European Strategic Energy Technology plan (SET-plan), which prioritises offshore wind RD and D in Europe. (LN)

  1. Conference on offshore wind power in France and Germany

    International Nuclear Information System (INIS)

    Meyer, Ronny; Furois, Timothee; Nolte, Nico; Lanoe, Frederic; Lehmann-Matthaei, Bjoern; Ifflaender, Andree; Courcambeck, Alexandre; Giese, Norbert; Kavafyan, Philippe; Bjaert, Niels; Wagner, Andreas; Guillet, Jerome

    2014-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on offshore wind power in France and Germany. In the framework of this French-German exchange of experience, about 120 participants exchanged views on the planning and authorisation procedures implemented in both countries and on the installation, connection to the grid and maintenance of offshore wind turbines. environmental impacts and usage conflicts linked with offshore wind farms exploitation were addressed as well. This document brings together the available presentations (slides) made during this event: 1 - Update: Offshore Wind In Germany (Ronny Meyer); 2 - Offshore wind development in France (Timothee Furois); 3 - The Licensing Procedure for Offshore Wind Farms in the German EEZ (Nico Nolte); 4 - Spatial Planning and Permitting in France: What leverage for more efficiency? (Frederic Lanoe); 5 - Results of 10 years environmental research on FINO-platforms (Bjoern Lehmann-Matthaei); 6 - Offshore Grid Connection - Status Quo and Overview (Andree Ifflaender); 7 - Grid connection of Offshore Wind in France: Situation, perspectives and recommendations (Alexandre Courcambeck); 8 - Controlling risks and warranting safety: Best practices for the installation, exploitation and maintenance of offshore wind turbines (Norbert Giese); 9 - Offshore wind Bremerhaven experience: An essential asset for the development of a complete Wind Offshore industry in France (Philippe Kavafyan); 10 - Standardizing and Cost Reduction -Lessons Learned from London Array (Niels Bjaert); 11 - Offshore Wind energy in Germany: System Benefits and Cost Reduction Potentials. Presentation of study results from prognos/fichtner and Fraunhofer-IWeS (Andreas Wagner); 12 - Offshore Wind energy financing - opportunities and risks (Jerome Guillet)

  2. Pricing offshore wind power

    International Nuclear Information System (INIS)

    Levitt, Andrew C.; Kempton, Willett; Smith, Aaron P.; Musial, Walt; Firestone, Jeremy

    2011-01-01

    Offshore wind offers a very large clean power resource, but electricity from the first US offshore wind contracts is costlier than current regional wholesale electricity prices. To better understand the factors that drive these costs, we develop a pro-forma cash flow model to calculate two results: the levelized cost of energy, and the breakeven price required for financial viability. We then determine input values based on our analysis of capital markets and of 35 operating and planned projects in Europe, China, and the United States. The model is run for a range of inputs appropriate to US policies, electricity markets, and capital markets to assess how changes in policy incentives, project inputs, and financial structure affect the breakeven price of offshore wind power. The model and documentation are made publicly available. - Highlights: → We calculate the Breakeven Price (BP) required to deploy offshore wind plants. → We determine values for cost drivers and review incentives structures in the US. → We develop 3 scenarios using today's technology but varying in industry experience. → BP differs widely by Cost Scenario; relative policy effectiveness varies by stage. → The low-range BP is below regional market values in the Northeast United States.

  3. RBI Optimization of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2009-01-01

    methods for oil & gas installations, a framework for optimal inspection and maintenance planning of offshore wind turbines is presented. Special aspects for offshore wind turbines considered are the fatigue loading characteristics where usually the wind loading are dominating the wave loading, wake......Wind turbines for electricity production have increased significantly the last years both in production capability and size. This development is expected to continue also in the coming years. Offshore wind turbines with an electricity production of 5-10 MW are planned. Typically, the wind turbine...... support structure is a steel structure consisting of a tower and a monopile, tripod or jacket type foundation. This paper considers aspects of inspection and maintenance planning of fatigue prone details in jacket and tripod type of wind turbine support structures. Based on risk-based inspection planning...

  4. Offshore Wind Power at Rough Sea

    DEFF Research Database (Denmark)

    Petersen, Kristian Rasmus; Madsen, Erik Skov; Bilberg, Arne

    2013-01-01

    This study compare the current operations and maintenance issues of one offshore wind park at very rough sea conditions and two onshore wind parks. Through a detailed data analysis and case studies this study identifies how improvements have been made in maintenance of large wind turbines. Howeve......, the study has also revealed the need for new maintenance models including a shift from breakdown and preventive maintenances and towards more predictive maintenance to reduce the cost of energy for offshore wind energy installations in the future.......This study compare the current operations and maintenance issues of one offshore wind park at very rough sea conditions and two onshore wind parks. Through a detailed data analysis and case studies this study identifies how improvements have been made in maintenance of large wind turbines. However...

  5. Sensitivity analysis of floating offshore wind farms

    International Nuclear Information System (INIS)

    Castro-Santos, Laura; Diaz-Casas, Vicente

    2015-01-01

    Highlights: • Develop a sensitivity analysis of a floating offshore wind farm. • Influence on the life-cycle costs involved in a floating offshore wind farm. • Influence on IRR, NPV, pay-back period, LCOE and cost of power. • Important variables: distance, wind resource, electric tariff, etc. • It helps to investors to take decisions in the future. - Abstract: The future of offshore wind energy will be in deep waters. In this context, the main objective of the present paper is to develop a sensitivity analysis of a floating offshore wind farm. It will show how much the output variables can vary when the input variables are changing. For this purpose two different scenarios will be taken into account: the life-cycle costs involved in a floating offshore wind farm (cost of conception and definition, cost of design and development, cost of manufacturing, cost of installation, cost of exploitation and cost of dismantling) and the most important economic indexes in terms of economic feasibility of a floating offshore wind farm (internal rate of return, net present value, discounted pay-back period, levelized cost of energy and cost of power). Results indicate that the most important variables in economic terms are the number of wind turbines and the distance from farm to shore in the costs’ scenario, and the wind scale parameter and the electric tariff for the economic indexes. This study will help investors to take into account these variables in the development of floating offshore wind farms in the future

  6. Life cycle assessment of offshore and onshore sited wind farms

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-10-15

    This report makes up the final reporting for the project 'Life cycle assessment (LCA) of turbines Analysis of possibilities of product directed environmental optimisation'. The purpose of the project is to carry through a life cycle assessment of an offshore wind farm and an onshore wind farm, respectively, as a basis for assessment of environmental improvement possibilities for wind farms through their life cycles. Likewise, the results are used to elaborate an environmental declaration of contents for power delivered to the grid from both types of wind farms. The project states the environmental impact for electricity produced at Horns Reef offshore wind farm and Tjaereborg onshore wind farm, respectively, as representatives for contemporary Danish offshore wind farms and onshore wind farms, respectively. Tjaereborg onshore wind farm is placed at an utmost favourably location with regard to wind, which means that the production at this wind farm is high compared with other onshore wind farms in Denmark. The high production rate is a factor that is taken into account when assessing the impact on the environment emanating from this wind farm. The results of the environmental life cycle assessments that have been carried out for the two wind farms do not show significant variance. If it is taken into account that Tjaereborg onshore wind farm is placed utmost favourably, the comparison shows that power from an average located onshore wind farm would have a more adverse or corresponding environmental impact as an unfavourably located offshore wind farm. The results show that it is the turbines that causes the largest environmental impact and not to a very high extent the transmission grid. For the turbines, the all-important environmental contribution comes from manufacturing and removal of the turbines, as it is the materials that cause the large environmental strain. The operation of the wind farms gives practically no contribution to the total

  7. Switching overvoltages in offshore wind power grids

    DEFF Research Database (Denmark)

    Arana Aristi, Ivan

    and cables are presented. In Chapter 4 results from time domain measurements and simulations of switching operations in offshore wind power grids are described. Specifically, switching operations on a single wind turbine, the collection grid, the export system and the external grid measured in several real...... offshore wind farms are shown together with simulation results. Switching operations in offshore wind power grids can be simulated with different electromagnetic transient programs. Different programs were used in the project and compared results are included in Chapter 4. Also in Chapter 4 different......Switching transients in wind turbines, the collection grid, the export system and the external grid in offshore wind farms, during normal or abnormal operation, are the most important phenomena when conducting insulation coordination studies. However, the recommended models and methods from...

  8. China, Norway and offshore wind development. A win-win wind relationship?

    Energy Technology Data Exchange (ETDEWEB)

    Enslow, Rachel

    2010-03-15

    This study published by WWF Norway, outlines the status of offshore wind power development in China and looks at how the Norwegian offshore industry can contribute to speed it up. Today China is the world's fastest growing market for renewable energy. China's annual offshore wind energy generation potential is 11,000 TWh, similar to that of the North Sea. The study estimates that in the next decade China will install 30 GW of offshore wind energy generation capacity. This could mitigate 1.3 billion tons of CO{sub 2} over the 20 year asset lifetime (more than the total Norwegian emissions forecast over the same period). To unleash China's potential and speed up development of offshore wind energy production, however, bridges must to be built between stakeholders with the relevant experience and the best available technology and policy makers and project developers in China. This study puts forward possible ways for future cooperation between China and Norway - a country with a world leading offshore industry cluster - in order to leverage mutual strengths to upscale and commercialize offshore wind technology for the global market. (Author)

  9. China, Norway and offshore wind development. A win-win wind relationship?

    Energy Technology Data Exchange (ETDEWEB)

    Enslow, Rachel

    2010-03-15

    This study published by WWF Norway, outlines the status of offshore wind power development in China and looks at how the Norwegian offshore industry can contribute to speed it up. Today China is the world's fastest growing market for renewable energy. China's annual offshore wind energy generation potential is 11,000 TWh, similar to that of the North Sea. The study estimates that in the next decade China will install 30 GW of offshore wind energy generation capacity. This could mitigate 1.3 billion tons of CO{sub 2} over the 20 year asset lifetime (more than the total Norwegian emissions forecast over the same period). To unleash China's potential and speed up development of offshore wind energy production, however, bridges must to be built between stakeholders with the relevant experience and the best available technology and policy makers and project developers in China. This study puts forward possible ways for future cooperation between China and Norway - a country with a world leading offshore industry cluster - in order to leverage mutual strengths to upscale and commercialize offshore wind technology for the global market. (Author)

  10. Offshore wind development research.

    Science.gov (United States)

    2014-04-01

    Offshore wind (OSW) development is a new undertaking in the US. This project is a response to : New Jerseys 2011 Energy Master Plan that envisions procuring 22.5% of the states power : originating from renewable sources by 2021. The Offshore Wi...

  11. Reliability evaluation for offshore wind farms

    DEFF Research Database (Denmark)

    Zhao, Menghua; Blåbjerg, Frede; Chen, Zhe

    2005-01-01

    In this paper, a new reliability index - Loss Of Generation Ratio Probability (LOGRP) is proposed for evaluating the reliability of an electrical system for offshore wind farms, which emphasizes the design of wind farms rather than the adequacy for specific load demand. A practical method...... to calculate LOGRP of offshore wind farms is proposed and evaluated....

  12. Design off-shore wind climate

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G C; Joergensen, H E [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    Specific recommendations of off-shore turbulence intensities, applicable for design purposes, are lacking in the present IEC-code. The present off-shore wind climate analysis presents the distribution of the turbulence standard deviation around the mean turbulence standard deviation, conditioned on the mean wind speed. Measured distributions, based on a huge amount of measuring data from two shallow water off-shore sites, are parameterized by fitting to a three parameter Weibull distribution. Combining a simple heuristic load model with the parameterized probability density functions of the turbulence standard deviations, an empirical off-shore design turbulence intensity is evaluated that in average yields the same fatigue damage as the distributed turbulence intensity. The proposed off-shore design turbulence intensity is, within the IEC code framework, applicable for extreme as well as for fatigue load determination. (au)

  13. Offshore Wind Energy Systems Engineering Curriculum Development

    Energy Technology Data Exchange (ETDEWEB)

    McGowan, Jon G. [Univ. of Massachusetts, Amherst, MA (United States); Manwell, James F. [Univ. of Massachusetts, Amherst, MA (United States); Lackner, Matthew A. [Univ. of Massachusetts, Amherst, MA (United States)

    2012-12-31

    Utility-scale electricity produced from offshore wind farms has the potential to contribute significantly to the energy production of the United States. In order for the U.S. to rapidly develop these abundant resources, knowledgeable scientists and engineers with sound understanding of offshore wind energy systems are critical. This report summarizes the development of an upper-level engineering course in "Offshore Wind Energy Systems Engineering." This course is designed to provide students with a comprehensive knowledge of both the technical challenges of offshore wind energy and the practical regulatory, permitting, and planning aspects of developing offshore wind farms in the U.S. This course was offered on a pilot basis in 2011 at the University of Massachusetts and the National Renewable Energy Laboratory (NREL), TU Delft, and GL Garrad Hassan have reviewed its content. As summarized in this report, the course consists of 17 separate topic areas emphasizing appropriate engineering fundamentals as well as development, planning, and regulatory issues. In addition to the course summary, the report gives the details of a public Internet site where references and related course material can be obtained. This course will fill a pressing need for the education and training of the U.S. workforce in this critically important area. Fundamentally, this course will be unique due to two attributes: an emphasis on the engineering and technical aspects of offshore wind energy systems, and a focus on offshore wind energy issues specific to the United States.

  14. Visual disamenities from off-shore wind farms in Denmark

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Dubgaard, Alex; Tranberg, Jesper

    2006-01-01

    Expansion of the off-shore wind power plays a significant role in the energy policies of many EU countries. However, off-shore wind farms create visual disamenities. These disamenities can be reduced by locating wind farms at larger distances from the coast – and accepting higher costs per k......Wh produced. Base on the choices among alternative wind farm outlays, the preferences for reducing visual disamenities of off-shore wind farms were elicited using the Choice Experiment Method. The results show a clear picture; the respondents in three independent samples are willing to pay for mowing future...... off-shore wind farms away from the shore to reduce the wind farms visibility. However, the results also denote that the preferences vary with regards to the experiences with visual disamenities of off-shore wind farms. The respondents Horns Revs sample, where the off-shore wind farm is located...

  15. Tidal influence on offshore wind fields and resource predictions[Efficient Development of Offshore Windfarms

    Energy Technology Data Exchange (ETDEWEB)

    Khan, D. [Entec UK Ltd., Doherty Innovation Centre, Penicuik (United Kingdom); Infield, D. [Loughborough Univ., Centre for Renewable Energy Systems Tecnology, Loughborough (United Kingdom)

    2002-03-01

    The rise and fall of the sea surface due to tides effectively moves an offshore wind turbine hub through the wind shear profile. This effect is quantified using measured data from 3 offshore UK sites. Statistical evidence of the influence of tide on mean wind speed and turbulence is presented. The implications of this effect for predicting offshore wind resource are outlined. (au)

  16. Indian offshore wind energy policy - lessons from Europe

    Energy Technology Data Exchange (ETDEWEB)

    Mani, S.; Dhingra, T. [Univ. of Petroleum and Energy Studies (UPES), Dehradun (India)

    2012-07-01

    Indian Economy is growing at 8% for the past few years and is expected to continue this momentum into the foreseeable future. To sustain this growth, power sector needs to build additional generation capacity at an unprecedented pace. However, continued dependence on fossil fuels (especially Coal and Oil) to power the growth of electricity generation capacity, is hardly sustainable in the long run. The reasons are well known - Environmental concerns, depleting fossil fuel resources, excessive dependency on Oil imports - that it hardly merits repetition. Renewable Energy source forms a miniscule portion (25 GW, {approx} 12%) of India's overall Energy consumption today (202 GW). The share of wind energy (17 GW) is 67% of the total renewable energy basket. But the contribution from offshore wind farms is non-existent, as all the wind energy generated in India is only through onshore Wind farms. India needs a policy framework to encourage the development of offshore wind farms. Several European countries, most notably the UK, Germany and Denmark, have effective offshore wind energy policies that have helped them to accelerate the growth of their offshore wind energy sector. This paper does an exhaustive study to identify the building blocks of a successful offshore wind energy policy initiative adopted by selected European countries, which can be leveraged by India to articulate its own offshore wind energy policy. This paper also suggests a model to predict the log-odds of growth of offshore wind energy sector in India. (Author)

  17. Design optimization of offshore wind farms with multiple types of wind turbines

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2017-01-01

    Most studies on offshore wind farm design assume a uniform wind farm, which consists of an identical type of wind turbines. In order to further reduce the cost of energy, we investigate the design of non-uniform offshore wind farms, i.e., wind farms with multiple types of wind turbines and hub-he...

  18. Operation and maintenance of offshore wind farms

    DEFF Research Database (Denmark)

    Petersen, Kristian R.; Madsen, Erik Skov; Bilberg, Arne

    The offshore wind industry is booming and larger, more efficient wind-turbines have constantly been introduced into the market. However, research within the field of the operation and maintenance (O&M) of offshore wind farms is limited as the field is still immature. In this paper, two current ma...... maintenance models - RCM and TPM - are discussed in this context. Furthermore, through a case study, the paper looks into Modularization and SSLP, as these concepts can be utilized to optimize maintenance. This is a new approach for the offshore wind industry....

  19. IEA Wind Task 26: Offshore Wind Farm Baseline Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Smart, Gavin [Offshore Renewable Energy Catapult, Blyth, Northumberland (United Kingdom); Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Warner, Ethan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sperstad, Iver Bakken [SINTEF Energy Research, Trondheim (Norway); Prinsen, Bob [Ecofys, Utrecht (Netherlands). TKI Wind Op Zee; Lacal-Arantegui, Roberto [European Commission Joint Research Centre (JRC), Brussels (Belgium)

    2016-06-02

    This document has been produced to provide the definition and rationale for the Baseline Offshore Wind Farm established within IEA Wind Task 26--Cost of Wind Energy. The Baseline has been developed to provide a common starting point for country comparisons and sensitivity analysis on key offshore wind cost and value drivers. The baseline project reflects an approximate average of the characteristics of projects installed between 2012 and 2014, with the project life assumed to be 20 years. The baseline wind farm is located 40 kilometres (km) from construction and operations and maintenance (O&M) ports and from export cable landfall. The wind farm consists of 100 4-megawatt (MW) wind turbines mounted on monopile foundations in an average water depth of 25 metres (m), connected by 33-kilovolt (kV) inter-array cables. The arrays are connected to a single offshore substation (33kV/220kV) mounted on a jacket foundation, with the substation connected via a single 220kV export cable to an onshore substation, 10km from landfall. The wind farm employs a port-based O&M strategy using crew-transfer vessels.

  20. Offshore Wind Turbine Design

    DEFF Research Database (Denmark)

    Frandsen, Sten; Hansen, Erik Asp; Ibsen, Lars Bo

    2006-01-01

    Current offshore wind turbine design methods have matured to a 1st generation state, manifested in the draft of a possible standard, IEC 61400-3 (2005). It is now time to investigate the possibilities of improving existing methods. To do so in an efficient manner a clear identification of the most...... important uncertainty drivers specific for offshore wind turbine design loads is required. Describing the initial efforts in a Danish research project, the paper points to focal points for research and development. These are mainly: soil-structure interaction, improved modelling of wave loads from deep...

  1. Energy from Offshore Wind: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Musial, W.; Butterfield, S.; Ram, B.

    2006-02-01

    This paper provides an overview of the nascent offshore wind energy industry including a status of the commercial offshore industry and the technologies that will be needed for full market development.

  2. Efficient promotion of electricity production from offshore wind; Effiziente Foerderung der Stromerzeugung aus Offshore-Wind

    Energy Technology Data Exchange (ETDEWEB)

    Panzer, Christian; Auer, Hans; Lettner, Georg [Technische Univ. Wien (Austria). Energy Economics Group (EEG)

    2014-03-15

    Efficient promotion of electricity production from offshore wind stands in dynamic relationship with various influence factors, the most important of which are promotion instruments, topographic givens, regulation of grid connection, and supraregional market integration concepts. Using three case studies from different countries to highlight national differences in the promotion of offshore wind power plants the present analysis points out ways of improving the efficiency of promotion instruments.

  3. Offshore wind farm Bockstigen - installation and operation experience

    Energy Technology Data Exchange (ETDEWEB)

    Lange, B [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark); Aagaard, E; Andersen, P E; Moeller, A [Wind World af 1997 A/S, Noerresundby (Denmark); Niklasson, S; Wickman, A [Vindkompaniet, Degerhamn (Sweden)

    1999-03-01

    The first Swedish offshore wind farm Bockstigen is operating since March 1998 near the coast of Gotland. It was built as a demonstration project by the Swedish wind farm developer Vindkompaniet, the Danish wind turbine manufacturer Wind World and the British offshore construction company Seacore and partly funded under the EU-THERMIE program. Bockstigen is the fourth offshore wind farm world-wide. While at previous wind farms the main emphasis laid on the demonstration of the technical feasibility of offshore wind energy utilisation, Bockstigen was aimed at demonstrating its economic viability. A number of innovative concepts have been employed: Drilled monopile foundations were used to save costs. A new construction method has been applied making use of a jack-up barge. A new control system for the turbines and the whole wind farm was developed, which controls the maximum power output, the flicker and the reactive power consumption depending on online measurements of the actual grid state. These new developments have been implemented successfully. A substantial cost reduction compared to previous offshore projects could be achieved. (au)

  4. Using Satellite SAR to Characterize the Wind Flow around Offshore Wind Farms

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Vincent, Pauline; Badger, Jake

    2015-01-01

    Offshore wind farm cluster effects between neighboring wind farms increase rapidly with the large-scale deployment of offshore wind turbines. The wind farm wakes observed from Synthetic Aperture Radar (SAR) are sometimes visible and atmospheric and wake models are here shown to convincingly repro...

  5. Denmark - supplier of competitive offshore wind solutions. Megavind's strategy for offshore wind research, development and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    In May 2006, the Danish Government presented a report on promoting environmentally effective technology and established a number of innovative partnerships. The partnerships intend to strengthen public-private cooperation between the state, industry, universities and venture capital to accelerate innovation for a number of green technologies. The partnership for wind energy is called Megavind. Megavind's strategy for offshore wind describes the offshore challenges and suggests research, development and demonstration (RD and D) priorities to enable offshore wind power become to competitive with other energy technologies. The strategy lists key recommendations as well as key thematic priorities and for each of these a number of RD and D priorities. Under each thematic priority references are made to the European Strategic Energy Technology plan (SET-plan), which prioritises offshore wind RD and D in Europe. (LN)

  6. Offshore Wind Farms

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Hasager, Charlotte Bay; Courtney, Michael

    2015-01-01

    : the rotor, the nacelle, the tower, and the foundation. Further the determinations of the essential environmental conditions are treated: the wind field, the wave field, the sea current, and the soil conditions. The various options for grid connections, advantages, and disadvantages are discussed. Of special...... concern are the problems associated with locating the turbines close together in a wind farm and the problems of placing several large wind farms in a confined area. The environmental impacts of offshore wind farms are also treated, but not the supply chain, that is, the harbors, the installation vessels...

  7. CFD for wind and tidal offshore turbines

    CERN Document Server

    Montlaur, Adeline

    2015-01-01

    The book encompasses novel CFD techniques to compute offshore wind and tidal applications. Computational fluid dynamics (CFD) techniques are regarded as the main design tool to explore the new engineering challenges presented by offshore wind and tidal turbines for energy generation. The difficulty and costs of undertaking experimental tests in offshore environments have increased the interest in the field of CFD which is used to design appropriate turbines and blades, understand fluid flow physical phenomena associated with offshore environments, predict power production or characterise offshore environments, amongst other topics.

  8. Prospects of the French offshore wind power market

    International Nuclear Information System (INIS)

    Anon.

    2011-12-01

    This market study about the French offshore wind power industry presents: 1 - the bases of the offshore wind power market: wind turbine operation principle, foundations and scale change; 2 - business model of offshore wind power projects: logistical, technical and financial challenges, cost structure and profitability of projects (investment, power generation costs, incentive mechanisms), project development time; 3 - European and French regulatory framework: the energy/climate package, the French 'Grenelle de l'Environnement' commitments for the development of renewable energies; 4 - start up of the French offshore wind power market: the onshore wind power market looking for growth relaying, the lateness of the offshore market, outlines of the call for bids and of the first phase launching (schedule, selected sites and candidates), market development stakes and opportunities; 5 - offshore wind power overview in Europe - lessons for the French market prospects: status of the European market (installed power/country, projects in progress), European leaders of the market (analysis of the British, Danish and German markets successful takeoff), specificities of the French market (are all favourable conditions present?); 6 - takeoff of the French market - what opportunities on the overall value chain?: front-end of the industry (manufacturers and component suppliers: industry structure, competition, R and D, subcontractors in France), back-end of the industry (developers/operators: sector analysis, ambitions, alliances, competences), specific French know-how in offshore installation and connection of wind turbines (reconversion of harbour areas, re-positioning of shipbuilding industry). (J.S.)

  9. Integration of Wave and Offshore Wind Energy in a European Offshore Grid

    DEFF Research Database (Denmark)

    Chozas, Julia Fernandez; Sørensen, H. C.; Korpås, M.

    2010-01-01

    of offshore renewable energy sources. According to this, the paper covers i) public and private initiatives for offshore transmission networks, ii) the synergies between the wave and the offshore wind energy sector within an offshore grid, iii) power transmission options for offshore generation and iv...

  10. Tuno Knob Offshore Wind Farm

    International Nuclear Information System (INIS)

    Madsen, P.S.

    1996-01-01

    In 1995 Midtkraft Power Company built Denmark's second offshore wind farm as a demonstration project. The project purpose is first of all to investigate the environmental aspects of offshore wind energy. The two primary objects are to study the impact on bird life and to test different methods for predicting the visual effect. The wind farm consists of 10 pitch-regulated Vestas V39 500 kW wind turbines placed on box caisson foundations in a shallow water area 6 km east of Jutland. The project has been implemented successfully under a very narrow time schedule, and during the first 6 months in operation, the production has been approx. 30% higher than expected. (author)

  11. A novel floating offshore wind turbine concept

    DEFF Research Database (Denmark)

    Vita, Luca; Schmidt Paulsen, Uwe; Friis Pedersen, Troels

    2009-01-01

    This paper will present a novel concept of a floating offshore wind turbine. The new concept is intended for vertical-axis wind turbine technology. The main purpose is to increase simplicity and to reduce total costs of an installed offshore wind farm. The concept is intended for deep water...... and large size turbines....

  12. Quantifying the hurricane risk to offshore wind turbines.

    Science.gov (United States)

    Rose, Stephen; Jaramillo, Paulina; Small, Mitchell J; Grossmann, Iris; Apt, Jay

    2012-02-28

    The U.S. Department of Energy has estimated that if the United States is to generate 20% of its electricity from wind, over 50 GW will be required from shallow offshore turbines. Hurricanes are a potential risk to these turbines. Turbine tower buckling has been observed in typhoons, but no offshore wind turbines have yet been built in the United States. We present a probabilistic model to estimate the number of turbines that would be destroyed by hurricanes in an offshore wind farm. We apply this model to estimate the risk to offshore wind farms in four representative locations in the Atlantic and Gulf Coastal waters of the United States. In the most vulnerable areas now being actively considered by developers, nearly half the turbines in a farm are likely to be destroyed in a 20-y period. Reasonable mitigation measures--increasing the design reference wind load, ensuring that the nacelle can be turned into rapidly changing winds, and building most wind plants in the areas with lower risk--can greatly enhance the probability that offshore wind can help to meet the United States' electricity needs.

  13. A GLANCE AT OFFSHORE WIND TURBINE FOUNDATION STRUCTURES

    Directory of Open Access Journals (Sweden)

    Jianhua Zhang

    2016-06-01

    Full Text Available Energy poverty and climate change are crucial issues we face in our societies. Offshore wind energy has been a reliable solution to both of these problems - solving our growing energy problems while reducing CO2 emission. Innovative foundation design is one of the setbacks faced by this industry. Designing and constructing a cost effective offshore wind farm is greatly hampered by technical and infrastructural challenges, especially in foundation structures. This paper provides a detailed overview of issues related to this problem, with the aim of eliminating the frequent misunderstandings which can arise among engineers and investors working in the offshore wind energy sector. It begins by investigating the latest data and recommendations regarding the design and deployment of various kinds of offshore wind turbine (OWT foundations. It provides a framework which enables us to study the different OWT foundations, including prototypes and their limitations. Various structural failure modes are highlighted and corrosion measures are presented. Moreover, various removal methods of support structures are put forward. Finally, this paper presents the setbacks preventing the spread of offshore wind energy and the future works for offshore wind energy applications.

  14. Quantifying the hurricane catastrophe risk to offshore wind power.

    Science.gov (United States)

    Rose, Stephen; Jaramillo, Paulina; Small, Mitchell J; Apt, Jay

    2013-12-01

    The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. We present a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes. Using this method, we estimate the fraction of offshore wind power simultaneously offline and the cumulative damage in a region. In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously because of hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. We also estimate the risks to single wind farms in four representative locations; we find the risks are significant but lower than those estimated in previously published results. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk. © 2013 Society for Risk Analysis.

  15. Development opportunities for the UK offshore wind industry

    International Nuclear Information System (INIS)

    1999-01-01

    This report summarises the results of a study investigating the UK's ability to compete for the construction of offshore wind farms. The European offshore wind farm market is examined, and the UK offshore construction equipment and wind farm construction methods are analysed, and recommendations for a purpose build or modified construction vessel are presented. The appendix gives UK construction companies addresses and contact names

  16. Water-hydraulic power transmission for offshore wind farms

    NARCIS (Netherlands)

    Diepeveen, N.F.B.; Jarquin Laguna, A.; Kempenaar, A.S.

    2012-01-01

    The current state of the art of offshore wind turbine power transmission technology is expensive, heavy and maintenance intensive. The Delft Offshore Turbine project considers a radically new concept for power transmission in an offshore wind farm: using seawater as power transmission medium. For

  17. Scour around Offshore Wind Turbine Foundations

    DEFF Research Database (Denmark)

    Petersen, Thor Ugelvig

    Over the last decades several offshore wind farms have been installed and commissioned in the European waters. Typically the foundations of the wind turbines are protected against scour at the base by installing scour protection with rock dump. The Egmond aan Zee offshore wind farm located about 10...... the performance (stability) of the scour protection and to quantify the edge scour development at the circumference of the scour protection. The survey campaign showed considerable edge scour of up to 2.7 m, which was expected from design considerations. However, no clear information exists on the mechanisms...... causing the edge scour development around scour protections at offshore wind turbine foundations. The purpose of the present thesis is to investigate and explain the development of the edge scour in such applications, and describe the flow mechanism causing the scour. Furthermore, the dissertation also...

  18. Floating Foundations for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Andersen, Morten Thøtt

    The concept of harnessing the power of the wind dates all the way back to the first ships traversing the seas. Later, windmills enabled the use of wind power for industrial purposes. Since then, technology has allowed the production of clean renewable energy through the use of wind turbines....... These turbines have traditionally been placed on land, but several factors have urged a move to offshore locations. Now the boundaries are being pushed into deeper and deeper waters, where the idea of floating offshore wind turbines has emerged. In less than a decade, these have gone from scattered small...

  19. Terminology Guideline for Classifying Offshore Wind Energy Resources

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walt [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    The purpose of this guideline is to establish a clear and consistent vocabulary for conveying offshore wind resource potential and to interpret this vocabulary in terms that are familiar to the oil and gas (O&G) industry. This involves clarifying and refining existing definitions of offshore wind energy resource classes. The terminology developed in this guideline represents one of several possible sets of vocabulary that may differ with respect to their purpose, data availability, and comprehensiveness. It was customized to correspond with established offshore wind practices and existing renewable energy industry terminology (e.g. DOE 2013, Brown et al. 2015) while conforming to established fossil resource classification as best as possible. The developers of the guideline recognize the fundamental differences that exist between fossil and renewable energy resources with respect to availability, accessibility, lifetime, and quality. Any quantitative comparison between fossil and renewable energy resources, including offshore wind, is therefore limited. For instance, O&G resources are finite and there may be significant uncertainty associated with the amount of the resource. In contrast, aboveground renewable resources, such as offshore wind, do not generally deplete over time but can vary significantly subhourly, daily, seasonally, and annually. The intent of this guideline is to make these differences transparent and develop an offshore wind resource classification that conforms to established fossil resource classifications where possible. This guideline also provides methods to quantitatively compare certain offshore wind energy resources to O&G resource classes for specific applications. Finally, this guideline identifies areas where analogies to established O&G terminology may be inappropriate or subject to misinterpretation.

  20. Optimized power generation in offshore wind parks

    NARCIS (Netherlands)

    Oliveira Filho, J. de; Papp, Z.

    2011-01-01

    Electricity generation on offshore wind parks has an increasing economic importance - the European Commission foresees that 12% of the wind energy will be produced on offshore installations by 2020, and this share is likely to increase further in the following years. However, the continuously

  1. Offshore wind market outlook in Northern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Pimenta de Miranda, Wilfried; Trulsson, Ola; Ekloef, Eva-Britt; Niemenen, Karel

    2010-08-15

    After more than 10 years of slow developments, the offshore wind market is now accelerating. Thanks to a sustained political drive from UK and Germany, the rest of Northern Europe is now following the path as offshore wind is being recognized as one of the key resources available to the EU to meet its renewable energy ambitions. Exposed to increasing technical issues, rising costs and the financial crisis, lessons learned are now being shared and integrated throughout Europe and appropriate regulatory and planning reforms are now being deployed to speed the deployment of offshore wind. (Author)

  2. Comparison of SAR Wind Speed Retrieval Algorithms for Evaluating Offshore Wind Energy Resources

    DEFF Research Database (Denmark)

    Kozai, K.; Ohsawa, T.; Takeyama, Y.

    2010-01-01

    Envisat/ASAR-derived offshore wind speeds and energy densities based on 4 different SAR wind speed retrieval algorithms (CMOD4, CMOD-IFR2, CMOD5, CMOD5.N) are compared with observed wind speeds and energy densities for evaluating offshore wind energy resources. CMOD4 ignores effects of atmospheri...

  3. Economic optimization of offshore wind farms

    International Nuclear Information System (INIS)

    Pauling, T.

    1996-09-01

    The study on the title subject continues the development of a cost model for offshore wind farms started at the Institute for Wind Energy (IW) in 1995, and applies it on different kinds of cost analyses. The model will be considered within the European research project 'Structural and Economic Optimization of Bottom-Mounted Offshore Wind Energy Converters' (Opti-OWECS, JOR3-CT95-0087) co-ordinated by the IW, where also the cost analyses and optimization will be extended. The conclusions of the investigations have already been presented at the European Union Wind Energy Conference '96 at Goeteborg, Sweden. In Chapter 1, a short overview of former offshore studies and projects is given, especially those dealing with cost analysis. Typical cost breakdowns of offshore and onshore wind farms are compared. Chapter 2 contains a brief description of the cost model in its present state. The recent improvements and extensions are documented in Chapter 3, and a validation by means of a recalculation of two former offshore studies is carried out in Chapter 4. In Chapter 5, four different offshore sites are compared with respect to the same farm size and an optimized farm design: Jade in the German part of the North Sea near Wilhelmshafen; Swansea Bay in the Bristol Channel at the British Atlantic Coast; Rostock at the German Baltic Coast, and IJmuiden in the Dutch part of the North Sea. In Chapter 6, a sensitivity study is carried out for a variety of site, design and economical parameters. The results of this project are summarized in Chapter 7, and an outlook is given in Chapter 8. The appendix contains among others a description of the SCOptiM2 code, where the model is implemented, as well as data obtained from the parameter studies and design optimizations. 30 figs., 8 tabs., 6 appendices, 40 refs

  4. The offshore trend: Structural changes in the wind power sector

    International Nuclear Information System (INIS)

    Markard, Jochen; Petersen, Regula

    2009-01-01

    In recent years, the wind power sector has begun to move offshore, i.e. to use space and good wind speeds on the open sea for large scale electricity generation. Offshore wind power, however, is not just technologically challenging but also a capital intensive and risky business that requires particular financial and organizational resources not all potential investors might have. We therefore address the question, what impact offshore wind power may have on ownership and organizational structures in the wind power sector. We compare on- and offshore wind park ownership in Denmark, the UK and Germany. The analysis shows that offshore wind power in all three countries is dominated by large firms, many of which are from the electricity sector. In Denmark and the UK, also investors from the gas and oil industry play an important role in the offshore wind business. This development represents a major shift for countries such as Germany and Denmark, in which the wind power sector has grown and matured on the basis of investments by individuals, farmers, cooperatives and independent project developers. The structural changes by which offshore wind power is accompanied have consequences for turbine manufacturers, project developers, investors, associations and policy makers in the field.

  5. Site selection for offshore wind farms along the Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    ManiMurali, R.; Vidya, P.J.; Modi, P.; JayaKumar, S.

    This study deals with locating the potential sites for offshore wind farms and also deals with feasibility of installing offshore wind farms through scientific examination of the requirements along the coast of India Offshore wind energy is almost...

  6. Mid-Atlantic Offshore Wind Interconnection and Transmission (MAOWIT)

    Energy Technology Data Exchange (ETDEWEB)

    Kempton, Willett [Univ. of Delaware, Newark, DE (United States)

    2016-04-05

    This project has carried out a detailed analysis to evaluate the pros and cons of offshore transmission, a possible method to decrease balance-of-system costs and permitting time identified in the DOE Office Wind Strategic Plan (DOE, 2011). It also addresses questions regarding the adequacy of existing transmission infrastructure and the ability of existing generating resources to provide the necessary Ancillary Services (A/S) support (spinning and contingency reserves) in the ISO territory. This project has completed the tasks identified in the proposal: 1. Evaluation of the offshore wind resource off PJM, then examination of offshore wind penetrations consistent with U.S. Department of Energy’s (DOE) targets and with their assumed resource size (DOE, 2011). 2. Comparison of piecemeal radial connections to the Independent System Operator (ISO) with connections via a high-voltage direct current (HVDC) offshore network similar to a team partner. 3. High-resolution examination of power fluctuations at each node due to wind energy variability 4. Analysis of wind power production profiles over the Eastern offshore region of the regional ISO to assess the effectiveness of long-distance, North- South transmission for leveling offshore wind energy output 5. Analysis of how the third and fourth items affect the need for ISO grid upgrades, congestion management, and demand for Ancillary Services (A/S) 6. Analysis of actual historic 36-hr and 24-hr forecasts to solve the unit commitment problem and determine the optimal mix of generators given the need to respond to both wind variability and wind forecasting uncertainties.

  7. Offshore wind energy potential in China

    DEFF Research Database (Denmark)

    Hong, Lixuan; Möller, Bernd

    2011-01-01

    and economic costs. However, the influence of tropical cyclone risks on these regions and detailed assessments at regional or local scale are worth of further discussions. Nevertheless, the models and results provide a foundation for a more comprehensive regional planning framework that would address......This paper investigates available offshore wind energy resources in China’s exclusive economic zone (EEZ) with the aid of a Geographical Information System (GIS), which allows the influence of technical, spatial and economic constraints on offshore wind resources being reflected in a continuous...... space. Geospatial supply curves and spatial distribution of levelised production cost (LPC) are developed, which provide information on the available potential of offshore wind energy at or below a given cost, and its corresponding geographical locations. The GIS-based models also reflect the impacts...

  8. 2014-2015 Offshore Wind Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Aaron

    2015-11-18

    This presentation provides an overview of progress toward offshore wind cost reduction in Europe and implications for the U.S. market. The presentation covers an overview of offshore wind developments, economic and performance trends, empirical evidence of LCOE reduction, and challenges and opportunities in the U.S. market.

  9. Offshore wind turbines reliability, availability and maintenance

    CERN Document Server

    Tavner, Peter

    2012-01-01

    The first book to specifically focus on offshore wind turbine technology and which addresses practically wind turbine reliability and availability. The book draws on the author's experience of power generation reliability and availability and the condition monitoring of that plant to describe the problems facing the developers of offshore wind farms and the solutions available to them to raise availability, reduce cost of energy and improve through life cost.

  10. New Models for Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Petersen, Kristian R.

    component that was causing a large amount of downtime were identified. Further analysis with the Reliability-Centred Maintenance concept helped determine the most appropriate maintenance strategy. In the final perspective, long-term strategic decisions were the focus. Asset Management and especially Asset...... Life-Cycle Management were studied using a case study. The case study analysis was used to generate strategies to help managers perform maintenance more proactively and to prepare the management of the offshore wind farm turbines for the future. Existing literature on Asset Life-Cycle Management has......Operations and maintenance (O&M) processes are important for keeping offshore wind turbines in operation. Costs related to such activities constitute approximately 30% of the lifetime cost of an offshore wind farm project. Currently, the offshore wind energy industry has shown a rapid increase...

  11. Offshore wind energy. An overview on the activities in Germany; Offshore-Windenergie. Ein Ueberblick ueber die Aktivitaeten in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Worm, Anja [media consulta Deutschland GmbH, Berlin (Germany)

    2013-02-15

    The brochure under consideration provides an overview of the activities of offshore wind energy in Germany. The first offshore wind farms are built and generate more electricity than expected. The offshore wind farms serve as a field of learning for new technologies. The power of offshore wind farms opened new prospects for the economy. The northern Federal States of Germany as well as the traditional locations for mechanical engineering and steel production benefit from offshore wind energy.

  12. Wake losses optimization of offshore wind farms with moveable floating wind turbines

    International Nuclear Information System (INIS)

    Rodrigues, S.F.; Teixeira Pinto, R.; Soleimanzadeh, M.; Bosman, Peter A.N.; Bauer, P.

    2015-01-01

    Highlights: • We present a layout optimization framework for wind farms with moveable turbines. • Using moveable wind turbines in optimized layouts maximizes energy production. • Turbine and wind farm designers should cooperate to optimize offshore wind projects. - Abstract: In the future, floating wind turbines could be used to harvest energy in deep offshore areas where higher wind mean speeds are observed. Currently, several floating turbine concepts are being designed and tested in small scale projects; in particular, one concept allows the turbine to move after installation. This article presents a novel layout optimization framework for wind farms composed of moveable floating turbines. The proposed framework uses an evolutionary optimization strategy in a nested configuration which simultaneously optimizes the anchoring locations and the wind turbine position within the mooring lines for each individual wind direction. The results show that maximum energy production is obtained when moveable wind turbines are deployed in an optimized layout. In conclusion, the framework represents a new design optimization tool for future offshore wind farms composed of moveable floating turbines

  13. Conceptual Model of Offshore Wind Environmental Risk Evaluation System

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Richard M.; Copping, Andrea E.; Van Cleve, Frances B.; Unwin, Stephen D.; Hamilton, Erin L.

    2010-06-01

    In this report we describe the development of the Environmental Risk Evaluation System (ERES), a risk-informed analytical process for estimating the environmental risks associated with the construction and operation of offshore wind energy generation projects. The development of ERES for offshore wind is closely allied to a concurrent process undertaken to examine environmental effects of marine and hydrokinetic (MHK) energy generation, although specific risk-relevant attributes will differ between the MHK and offshore wind domains. During FY10, a conceptual design of ERES for offshore wind will be developed. The offshore wind ERES mockup described in this report will provide a preview of the functionality of a fully developed risk evaluation system that will use risk assessment techniques to determine priority stressors on aquatic organisms and environments from specific technology aspects, identify key uncertainties underlying high-risk issues, compile a wide-range of data types in an innovative and flexible data organizing scheme, and inform planning and decision processes with a transparent and technically robust decision-support tool. A fully functional version of ERES for offshore wind will be developed in a subsequent phase of the project.

  14. Review report 2004. The Danish offshore wind farm demonstration project: Horns Rev and Nysted offshore wind farms. Environmental impact assessment and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-10-15

    The present review report presents the two wind farms Horns Rev and Nysted with regard to environmental characteristics and the results of the environmental studies carried out in connection with the Environmental Impact Assessment (EIA) and the baseline and monitoring programmes at the two sites. The descriptions of the programmes are based on extracts from the individual annual reports. Detailed information on method, programmes and conclusions can be found in these reports (see Appendix 1). This review report is divided into two parts. The first part contains a description of the potential environmental impacts of offshore wind farms and the potentially affected part of the environment. The second part includes a description of Horns Rev and Nysted Offshore Wind Farm and the environmental studies carried out here until the end of 2003. Appendix I is a list of the literature published on the studies carried out at Horns Rev and Nysted Offshore Wind Farm. Appendix II is a list of some of the literature relevant to the demonstration projects but not directly related to the projects. The offshore wind farm situated in the Roedsand area is officially denoted Nysted Offshore Wind Farm, and in the present report the denotation 'Nysted' will be used as well when referring to Nysted Offshore Wind Farm. The denotation Roedsand will be used when referring to the actual area Roedsand. (au)

  15. Review report 2003. The Danish offshore wind farm demonstration project: Horns Rev and Nysted offshore wind farms. Environmental impact assessment and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-15

    The present review report presents the two wind farms Homs Rev and Nysted, with regard to environmental characteristics and the results of the environmental studies carried out in connection with the Environmental Impact Assessment (EIA) and the baseline and monitoring programmes at the two sites. The descriptions of the programmes are based on extracts from the individual annual reports. Detailed information on methods, programmes and conclusions can be found in these reports. This review report is divided into two parts. The first part contains a description of the potential environmentally impacts of offshore wind farms and the potentially affected part of the environment. The second part includes a description of Horns Rev and Nysted Offshore Wind Farm and the environmental studies carried out here until the end of 2003. Appendix I is a list of the literature published on the studies carried out at Hors Rev and Nysted Offshore Wind Farm. Appendix II is a list of some of the literature relevant to the demonstration projects but not directly related to the projects. The offshore wind farm situated at the bdsand area is officially denoted Nysted Offshore Wind Farm, and in the present report the denotation 'Nysted' will be used as well when referring to Nysted Offshore Wind Farm. The denotation Roedsand will be used when referring to the actual area Roedsand. (au)

  16. Review report 2004. The Danish offshore wind farm demonstration project: Horns Rev and Nysted offshore wind farms. Environmental impact assessment and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-10-15

    The present review report presents the two wind farms Horns Rev and Nysted with regard to environmental characteristics and the results of the environmental studies carried out in connection with the Environmental Impact Assessment (EIA) and the baseline and monitoring programmes at the two sites. The descriptions of the programmes are based on extracts from the individual annual reports. Detailed information on method, programmes and conclusions can be found in these reports (see Appendix 1). This review report is divided into two parts. The first part contains a description of the potential environmental impacts of offshore wind farms and the potentially affected part of the environment. The second part includes a description of Horns Rev and Nysted Offshore Wind Farm and the environmental studies carried out here until the end of 2003. Appendix I is a list of the literature published on the studies carried out at Horns Rev and Nysted Offshore Wind Farm. Appendix II is a list of some of the literature relevant to the demonstration projects but not directly related to the projects. The offshore wind farm situated in the Roedsand area is officially denoted Nysted Offshore Wind Farm, and in the present report the denotation 'Nysted' will be used as well when referring to Nysted Offshore Wind Farm. The denotation Roedsand will be used when referring to the actual area Roedsand. (au)

  17. Design Load Basis for Offshore Wind turbines

    DEFF Research Database (Denmark)

    Natarajan, Anand; Hansen, Morten Hartvig; Wang, Shaofeng

    2016-01-01

    DTU Wind Energy is not designing and manufacturing wind turbines and does therefore not need a Design Load Basis (DLB) that is accepted by a certification body. However, to assess the load consequences of innovative features and devices added to existing offshore turbine concepts or new offshore...... turbine concept developed in our research, it is useful to have a full DLB that follows the current design standard and is representative of a general DLB used by the industry. It will set a standard for the offshore wind turbine design load evaluations performed at DTU Wind Energy, which is aligned...... with the challenges faced by the industry and therefore ensures that our research continues to have a strong foundation in this interaction. Furthermore, the use of a full DLB that follows the current standard can improve and increase the feedback from the research at DTU Wind Energy to the international...

  18. Offshore winds from a new generation of European satellites

    DEFF Research Database (Denmark)

    Badger, Merete; Karagali, Ioanna; Ahsbahs, Tobias Torben

    at sea. All are important for the planning, operation, and maintenance of offshore wind farms. Typical shortcomings of SAR-based wind fields include a low sampling frequency and a need for advanced data processing in order to retrieve the wind speed at 10 m above sea level. A new generation of European...... satellites and services could lower these barriers for applications in wind energy significantly. The Sentinel-1 A/B missions by the European Space Agency (ESA) deliver C-band SAR observations at an unprecedented coverage and spatial resolution. Over the seas of Europe, approximately 200 new acquisitions...... of Europe over time. The accuracy of this new product is currently under investigation. TerraSAR-X is an X-band SAR mission by the German Aerospace Center (DLR). It offers very high-resolution imagery, which may be used for detailed studies of e.g. wind farm wakes. TerraSAR-X imagery is acquired on...

  19. Offshore winds mapped from satellite remote sensing

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay

    2014-01-01

    the uncertainty on the model results on the offshore wind resource, it is necessary to compare model results with observations. Observations from ground-based wind lidar and satellite remote sensing are the two main technologies that can provide new types of offshore wind data at relatively low cost....... The advantages of microwave satellite remote sensing are 1) horizontal spatial coverage, 2) long data archives and 3) high spatial detail both in the coastal zone and of far-field wind farm wake. Passive microwave ocean wind speed data are available since 1987 with up to 6 observations per day with near...

  20. POSSPOW: Possible Power of Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Giebel, Gregor; Göçmen, Tuhfe; Sørensen, Poul Ejnar

    2013-01-01

    Introduction In recent years, the very large offshore wind farms were designed as wind power plants, including possibilities to contribute to the stability of the grid by offering grid services (also called ancillary services). One of those services is reserve power, which is achieved by down......-regulating the wind farm from its maximum possible power. The power can be ramped up quite quickly, but the influence of wakes makes it difficult to assess the exact amount of down-regulation available to sell. Currently, Transmission System Operators (TSOs) have no real way to determine exactly the possible power...... will be verified on some of the large offshore wind farms owned by Vattenfall, and possibly in a DONG Energy wind farm too. Dedicated experiments to the wind flow in large offshore wind farms are planned. Main body of abstract Modern wind turbines have a SCADA signal called possible power. In normal operation...

  1. Healthy offshore workforce? A qualitative study on offshore wind employees' occupational strain, health, and coping.

    Science.gov (United States)

    Mette, Janika; Velasco Garrido, Marcial; Harth, Volker; Preisser, Alexandra M; Mache, Stefanie

    2018-01-23

    Offshore work has been described as demanding and stressful. Despite this, evidence regarding the occupational strain, health, and coping behaviors of workers in the growing offshore wind industry in Germany is still limited. The purpose of our study was to explore offshore wind employees' perceptions of occupational strain and health, and to investigate their strategies for dealing with the demands of offshore work. We conducted 21 semi-structured telephone interviews with employees in the German offshore wind industry. The interviews were transcribed and analyzed in a deductive-inductive approach following Mayring's qualitative content analysis. Workers generally reported good mental and physical health. However, they also stated perceptions of stress at work, fatigue, difficulties detaching from work, and sleeping problems, all to varying extents. In addition, physical health impairment in relation to offshore work, e.g. musculoskeletal and gastrointestinal complaints, was documented. Employees described different strategies for coping with their job demands. The strategies comprised of both problem and emotion-focused approaches, and were classified as either work-related, health-related, or related to seeking social support. Our study is the first to investigate the occupational strain, health, and coping of workers in the expanding German offshore wind industry. The results offer new insights that can be utilized for future research in this field. In terms of practical implications, the findings suggest that measures should be carried out aimed at reducing occupational strain and health impairment among offshore wind workers. In addition, interventions should be initiated that foster offshore wind workers' health and empower them to further expand on effective coping strategies at their workplace.

  2. A methodology for the prediction of offshore wind energy resources

    Energy Technology Data Exchange (ETDEWEB)

    Watson, S J; Watson, G M [Rutherford Appleton Lab., Oxfordshire (United Kingdom); Holt, R.J. [Univ. of East Anglia, Climatic Research Unit, Norwich (United Kingdom)] Barthelmie, R.J. [Risoe National Lab., Dept. of Wind Energy and Atmospheric Physics, Roskilde (Denmark); Zuylen, E.J. van [Ecofys Energy and Environment, Utrecht (Netherlands)] Cleijne, J.W. [Kema Sustainable, Arnhem (Netherlands)

    1999-03-01

    There are increasing constraints on the development of wind power on land. Recently, there has been a move to develop wind power offshore, though the amount of measured wind speed data at potential offshore wind farm sites is sparse. We present a novel methodology for the prediction of offshore wind power resources which is being applied to European Union waters. The first stage is to calculate the geostrophic wind from long-term pressure fields over the sea area of interest. Secondly, the geostrophic wind is transformed to the sea level using WA{sup s}P, taking account of near shore topography. Finally, these values are corrected for land/sea climatology (stability) effects using an analytical Coastal discontinuity Model (CDM). These values are further refined using high resolution offshore data at selected sites. The final values are validated against existing offshore datasets. Preliminary results are presented of the geostrophic wind speed validation in European Union waters. (au)

  3. Overall Optimization for Offshore Wind Farm Electrical System

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Cong

    2017-01-01

    Based on particle swarm optimization (PSO), an optimization platform for offshore wind farm electrical system (OWFES) is proposed in this paper, where the main components of an offshore wind farm and key technical constraints are considered as input parameters. The offshore wind farm electrical...... system is optimized in accordance with initial investment by considering three aspects: the number and siting of offshore substations (OS), the cable connection layout of both collection system (CS) and transmission system (TS) as well as the selection of electrical components in terms of voltage level...... that save 3.01% total cost compared with the industrial layout, and can be a useful tool for OWFES design and evaluation....

  4. Offshore wind potential evaluation and remote sensing imagery; Evaluation du potentiel eolien offshore et imagerie satellitale

    Energy Technology Data Exchange (ETDEWEB)

    Fichaux, N.

    2003-12-15

    Offshore wind energy may help to contribute to the respect of the Kyoto objectives by Europe. It is a key issue to struggle against global change. To sit the future offshore wind parks, it is necessary to accurately evaluate the spatial repartition of the wind potential. We demonstrate that the offshore wind potential shall be represented by maps of wind statistics. As remote sensing is a tool for measuring space physical phenomena, we evaluate its potentialities for mapping wind statistics. Space-borne scatterometers enables the obtention of wind statistics, but far from our areas of interest and at low spatial resolution. Synthetic Aperture Radar (SAR) enables the computation of high resolution wind maps over our areas of interest, but are unsuitable to compute wind statistics. We define the mathematical framework of a statistical method. That method enables to take advantage of both scatterometer and SAR to compute maps of wind statistics at high spatial resolution over the areas of interest. It enables remote sensing to be used operationally to map the offshore wind potential. (author)

  5. Offshore wind investments – Realism about cost developments is necessary

    International Nuclear Information System (INIS)

    Schwanitz, Valeria Jana; Wierling, August

    2016-01-01

    Data available from the recent boom in European offshore wind investments contradict widely held expectations about a decline in costs per kW. Our review shows that scenario projections for investment costs are systematically flawed by over-optimistic assumptions. Contrasting offshore wind technology with onshore wind and nuclear power, we argue that offshore wind could be a candidate for negative learning since a trend towards more complex OWP (offshore wind parks) exists and uncertainty remains high. We estimate technical uncertainty and input cost uncertainty to calculate whether investments in offshore wind technology are profitable today. Applying a real option model to two reference plants using empirically derived parameter values, we allow for sunk cost and the possibility to abandon the investment. We find that for a large parameter range, investments are not profitable, even with substantial support such as feed-in tariffs under the German Energy Act. Therefore, policy incentives for building larger and more complex offshore wind parks bear a high risk to fail in their aim of bringing down investment costs. Policies that instead incentivize the optimization of offshore wind technology – in particular by increasing the load factor and material efficiency and bringing down decommissioning costs – are more sustainable. - Highlights: • We review offshore wind power investments. • Contrary to expectations costs increase. • It is unlikely to see a turn in the near future as complexity is growing. • We deploy an empirically based real option model. • Investments are not profitable across a large parameter range.

  6. Fixed-speed active-stall wind turbines in offshore applications

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Nielsen, Arne Hejde

    2005-01-01

    A large offshore wind farm in the East Danish power system was commissioned in 2003 at Rodsand. The power capacity of the wind farm is 165 MW divided between 72 wind turbines. For this large offshore application, robust and well-known wind technology has been chosen in the form of fixed-speed, ac...

  7. IFREMER-ADEME colloquium 'Offshore renewable energies: offshore wind energy - sea currents and waves. Collection of abstracts

    International Nuclear Information System (INIS)

    2004-10-01

    This document contains programme and abstracts of contributions presented during a colloquium. These contributions first addresses the context, and regulatory and economic aspects of offshore wind and sea energy: specificities related to the Public Maritime Domain for the implantation of offshore wind turbines, economy of sea energies within a perspective of de-carbonation of the world energy sector, case of offshore wind turbines and assessment of economic impacts of the implantation of sea renewable energy production units, financing stakes for offshore wind energy projects. A second set of contribution addresses the state-of -the-art and feedbacks for offshore wind energy installations. The third set addresses the assessment of resource potential, measurements, models and production prediction for offshore wind energy: case of French coasts, use of radar for remote sensing, wind climatology modelling, data acquisition for wind farm and data processing. The fourth set of contributions addresses the state-of-the-art, feedback, and R and D for sea current energy, while the fifth one addressed the same aspects for sea wave energy. Technology, installations, maintenance and storage in the field of wind energy are then addressed, and the last set deals with environmental and social-economical impacts of sea renewable energies

  8. Using Satellite SAR to Characterize the Wind Flow around Offshore Wind Farms

    Directory of Open Access Journals (Sweden)

    Charlotte Bay Hasager

    2015-06-01

    Full Text Available Offshore wind farm cluster effects between neighboring wind farms increase rapidly with the large-scale deployment of offshore wind turbines. The wind farm wakes observed from Synthetic Aperture Radar (SAR are sometimes visible and atmospheric and wake models are here shown to convincingly reproduce the observed very long wind farm wakes. The present study mainly focuses on wind farm wake climatology based on Envisat ASAR. The available SAR data archive covering the large offshore wind farms at Horns Rev has been used for geo-located wind farm wake studies. However, the results are difficult to interpret due to mainly three issues: the limited number of samples per wind directional sector, the coastal wind speed gradient, and oceanic bathymetry effects in the SAR retrievals. A new methodology is developed and presented. This method overcomes effectively the first issue and in most cases, but not always, the second. In the new method all wind field maps are rotated such that the wind is always coming from the same relative direction. By applying the new method to the SAR wind maps, mesoscale and microscale model wake aggregated wind-fields results are compared. The SAR-based findings strongly support the model results at Horns Rev 1.

  9. U.S. Offshore Wind Manufacturing and Supply Chain Development

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Bruce Duncan [Navigant Consulting, Inc.

    2013-02-22

    The objective of the report is to provide an assessment of the domestic supply chain and manufacturing infrastructure supporting the U.S. offshore wind market. The report provides baseline information and develops a strategy for future development of the supply chain required to support projected offshore wind deployment levels. A brief description of each of the key chapters includes: » Chapter 1: Offshore Wind Plant Costs and Anticipated Technology Advancements. Determines the cost breakdown of offshore wind plants and identifies technical trends and anticipated advancements in offshore wind manufacturing and construction. » Chapter 2: Potential Supply Chain Requirements and Opportunities. Provides an organized, analytical approach to identifying and bounding the uncertainties associated with a future U.S. offshore wind market. It projects potential component-level supply chain needs under three demand scenarios and identifies key supply chain challenges and opportunities facing the future U.S. market as well as current suppliers of the nation’s land-based wind market. » Chapter 3: Strategy for Future Development. Evaluates the gap or competitive advantage of adding manufacturing capacity in the U.S. vs. overseas, and evaluates examples of policies that have been successful . » Chapter 4: Pathways for Market Entry. Identifies technical and business pathways for market entry by potential suppliers of large-scale offshore turbine components and technical services. The report is intended for use by the following industry stakeholder groups: (a) Industry participants who seek baseline cost and supplier information for key component segments and the overall U.S. offshore wind market (Chapters 1 and 2). The component-level requirements and opportunities presented in Section 2.3 will be particularly useful in identifying market sizes, competition, and risks for the various component segments. (b) Federal, state, and local policymakers and economic development

  10. Quantifying offshore wind resources from satellite wind maps: Study area the North Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Barthelmie, Rebecca Jane; Christiansen, Merete B.

    2006-01-01

    Offshore wind resources are quantified from satellite synthetic aperture radar (SAR) and satellite scatterometer observations at local and regional scale respectively at the Horns Rev site in Denmark. The method for wind resource estimation from satellite observations interfaces with the wind atlas...... of the Horns Rev wind farm is quantified from satellite SAR images and compared with state-of-the-art wake model results with good agreement. It is a unique method using satellite observations to quantify the spatial extent of the wake behind large offshore wind farms. Copyright © 2006 John Wiley & Sons, Ltd....... analysis and application program (WAsP). An estimate of the wind resource at the new project site at Horns Rev is given based on satellite SAR observations. The comparison of offshore satellite scatterometer winds, global model data and in situ data shows good agreement. Furthermore, the wake effect...

  11. Hydropower flexibility and transmission expansion to support integration of offshore wind

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Farahmand, Hossein; Jaehnert, S.

    2016-01-01

    is one of the fast responding sources of electricity, thus power systems with considerable amounts of flexible hydro power can potentially offer easier integration of offshore wind power. The interaction between offshore wind and hydro power can be benefic, especially when looking at how the flexibility......In 2013, offshore wind grew over 50%. This increase, concentrated in a relatively small geographical area, can lead to an increased variability of the power produced by offshore wind. The variability is one of the key issues, along transmission, in integrating offshore wind power. Hydro power...... of hydro generation can match the variability of offshore wind, allowing for larger shares of variable generation to be integrated in the power systems without decreasing its stability. The analysis includes two interrelated models, a market model and a flow-based model. The results show that hydropower...

  12. Environmental considerations of offshore wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Ryckman, A. [Natural Resource Solutions Inc., Kitchener, ON (Canada)

    2010-07-01

    The environmental considerations of offshore wind energy projects in the Great Lakes region were discussed from the viewpoint of an environmental consulting firm. Existing projects and proposals were discussed in relation to site-specific conditions and the environmental studies required at the proposed sites. North American facilities that are now undergoing baseline studies in the Great Lakes include the Cape Wind and Nai Kun wind farms. Impact to fisheries in the lakes is expected to occur largely during the construction phases of the developments. However, additional noise, sedimentation, and lakebed losses have the potential to impact local fish populations. Some turbine foundations create a a reef effect that increases local fish populations. Baseline fisheries data as well as substrate and habitat assessments of the lakebed are required. Impacts on birds include collision and displacement impacts. Migratory birds and staging or wintering waterfowl may be displaced from feeding areas. Radar- and plane-based surveys should be used to identify large rafts of birds in offshore habitats, while boat surveys can be used to confirm species and identify diurnal migrants. The migratory paths of bats over the Great Lakes are not well-understood. It is expected that offshore wind developments will have little impact on terrestrial vegetation. Impacts will be localized at shoreline connection points and construction areas. Shoreline habitats, wetlands, dunes and beach habitats may also be impacted. Post-construction surveys should include avian and bat mortality, waterfowl usage, and fish habitat and substrates. Further studies were recommended, as there are limited guidelines for determining the effects of offshore wind energy developments. tabs., figs.

  13. Offshore Wind Turbines Situated in Areas with Strong Currents

    DEFF Research Database (Denmark)

    Jensen, Morten S.; Juul Larsen, Brian; Frigaard, Peter

    Prediction of local scour caused by offshore wind turbine foundations using empirical formulae or numerical models.......Prediction of local scour caused by offshore wind turbine foundations using empirical formulae or numerical models....

  14. Optimal Risk-Based Inspection Planning for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Rangel-Ramirez, Jose G.; Sørensen, John Dalsgaard

    2008-01-01

    , inspection and maintenance activities are developed. This paper considers aspects of inspection and maintenance planning of fatigue prone details in jacket and tripod types of wind turbine support structures. Based oil risk-based inspection planning methods used for oil & gas installations, a framework......Wind turbines for electricity production have increased significantly the last years both in production capability and size. This development is expected to continue also in the coining years. The Support structure for offshore wind turbines is typically a steel structure consisting of a tower...... for optimal inspection and maintenance planning of offshore wind turbines is presented. Special aspects for offshore wind turbines are considered: usually the wind loading are dominating the wave loading, wake effects in wind farms are important and the reliability level is typically significantly lower than...

  15. Wave and offshore wind potential for the island of Tenerife

    International Nuclear Information System (INIS)

    Veigas, M.; Iglesias, G.

    2013-01-01

    Highlights: • The island aims to reduce its carbon footprint by developing renewable energy. • The substantial wave and offshore wind resources around the island are examined. • One area is appropriate for installing a hybrid wave–offshore wind farm. - Abstract: The island of Tenerife, a UNESCO Biosphere Reserve in the Atlantic Ocean, aims to be energy self-sufficient in order to reduce its carbon footprint. To accomplish this goal it should develop the renewable sources, in particular wave and offshore wind energy. The objectives of this work are twofold; (i) to characterize the wave and offshore wind power distribution around the island and (ii) to determine which offshore area is best suited for their exploitation, taking into account the resource and other conditioning factors such as the bathymetry, distance to the coastline and ports, and offshore zoning. To carry out this research, hindcast wave and wind data obtained with numerical models are used alongside observations from meteorological stations. One area, in the vicinity of Puerto de la Cruz, is identified as having great potential for installing a hybrid floating wave–wind farm. Both resources are characterized for the area selected: the wave resource in terms of wave directions, significant wave heights and energy periods; the offshore wind resource in terms of directions and speeds in addition to the seasonality for the both resources. It is found that most of the wave resource is provided by N and NNW waves with significant wave heights between 1.5 m and 3.0 m and energy periods between 10 s and 14 s. It follows that the Wave Energy Converters deployed in the area should have maximum efficiency in those ranges. As for the offshore wind resource, most of the energy corresponds to NNE and NE winds with speeds between 9 and 14 m s −1 , which should be taken into account when selecting the offshore wind turbines

  16. Wind turbines and transmission systems for offshore wind projects in planning stage

    Energy Technology Data Exchange (ETDEWEB)

    Madariaga, Ander; Martin, Jose Luis; Martinez de Alegria, Inigo; Zamora, Inmaculada [University of the Basque Country (UPV/EHU), Bilbao (Spain). Engineering Faculty; Ceballos, Salvador [Parque Tecnologico de Bizkaia, Derio (Spain). Tecnalia Research and Innovation

    2012-07-01

    This paper reviews the current situation of the offshore wind turbines (OWTs) and the transmission systems (TSs) for offshore wind projects in the planning stage. Bearing in mind that offshore wind projects can last between seven and ten years from the first environmental studies to the commissioning, research engineers from companies and academia consider the solutions already available, but also to the new proposals expected to be ready in time for the project under consideration. Regarding the wind energy conversion systems (WECSs) installed in the OWTs, their main characteristics are reviewed considering turbines in the 4.1 to 10.0 MW range. Regarding the TSs, the current situation of point-to-point HVAC and HVDC links is presented, as well as some ideas related to future DC grids currently under study. (orig.)

  17. Wave run-up on offshore wind turbine foundations

    DEFF Research Database (Denmark)

    Baden, Elisabeth; Skourup, Jesper; Andersen, Thomas Lykke

    2012-01-01

    Wave run-up on appurtenances like boat landings, ladders, platforms and J-tubes of Offshore Wind Turbine foundations have in some cases caused severe and costly damage to these installations. A well-known example of large run-up was registered at the foundations of Horns Reef Offshore Wind Farm, ...

  18. The effects of meshed offshore grids on offshore wind investment – a real options analysis

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten; Kitzing, Lena

    2012-01-01

    Offshore wind farms in future meshed offshore grids could be subject to different regulatory regimes. Feed-in tariffs would absorb market risk from wind farm operators, whereas price premium mechanisms leave operators exposed to market price signals. In this case, it plays a decisive role which...... price applies to a node in an offshore grid. The offshore node will either be integrated into any of the neighbouring markets, with access to the respective maximum price, or be subject to separate nodal pricing. We investigate the different regulatory regimes for connections to one to four countries...... based on a stochastic model capturing uncertainties in prices and line failures. The stochastic analysis shows that in case the wind park is granted access to the respective maximum price, there is a significant option value connected to the operational flexibility of accessing several markets: The wind...

  19. The effects of meshed offshore grids on offshore wind investment – a real options analysis

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten; Kitzing, Lena

    2012-01-01

    based on a stochastic model capturing uncertainties in prices and line failures. The stochastic analysis shows that in case the wind park is granted access to the respective maximum price, there is a significant option value connected to the operational flexibility of accessing several markets: The wind......Offshore wind farms in future meshed offshore grids could be subject to different regulatory regimes. Feed-in tariffs would absorb market risk from wind farm operators, whereas price premium mechanisms leave operators exposed to market price signals. In this case, it plays a decisive role which...... price applies to a node in an offshore grid. The offshore node will either be integrated into any of the neighbouring markets, with access to the respective maximum price, or be subject to separate nodal pricing. We investigate the different regulatory regimes for connections to one to four countries...

  20. National Offshore Wind Energy Grid Interconnection Study Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, John P. [ABB, Inc., Cary, NC (United States); Liu, Shu [ABB, Inc., Cary, NC (United States); Ibanez, Eduardo [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pennock, Ken [AWS Truepower, Albany, NY (United States); Reed, Gregory [Univ. of Pittsburgh, PA (United States); Hanes, Spencer [Duke Energy, Charlotte, NC (United States)

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States.

  1. National Offshore Wind Energy Grid Interconnection Study Full Report

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, John P. [ABB, Inc., Cary, NC (United States); Liu, Shu [ABB, Inc., Cary, NC (United States); Ibanez, Eduardo [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pennock, Ken [AWS Truepower, Albany, NY (United States); Reed, Gregory [Univ. of Pittsburgh, PA (United States); Hanes, Spencer [Duke Energy, Charlotte, NC (United States)

    2014-07-30

    The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States.

  2. Quantifying the Impact of Wind Turbine Wakes on Power Output at Offshore Wind Farms

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Pryor, Sara; Frandsen, Sten Tronæs

    2010-01-01

    There is an urgent need to develop and optimize tools for designing large wind farm arrays for deployment offshore. This research is focused on improving the understanding of, and modeling of, wind turbine wakes in order to make more accurate power output predictions for large offshore wind farms...

  3. From laggard to leader: Explaining offshore wind developments in the UK

    International Nuclear Information System (INIS)

    Kern, Florian; Smith, Adrian; Shaw, Chris; Raven, Rob; Verhees, Bram

    2014-01-01

    Offshore wind technology has recently undergone rapid deployment in the UK. And yet, up until recently, the UK was considered a laggard in terms of deploying renewable energy. How can this burst of offshore wind activity be explained? An economic analysis would seek signs for newfound competitiveness for offshore wind in energy markets. A policy analysis would highlight renewable energy policy developments and assess their contribution to economic prospects of offshore wind. However, neither perspective sheds sufficient light on the advocacy of the actors involved in the development and deployment of the technology. Without an account of technology politics it is hard to explain continuing policy support despite rising costs. By analysing the actor networks and narratives underpinning policy support for offshore wind, we explain how a fairly effective protective space was constructed through the enroling of key political and economic interests. - Highlights: • UK is world leader in offshore wind deployment. • Article explains boom in deployment by looking at the politics of renewable energy policy. • Offshore wind is supported by a variety of actors with aligned political and economic interests. • Analysis highlights the importance of a system builder

  4. Conference on offshore wind energy in France and Germany: challenges of a promising segment

    International Nuclear Information System (INIS)

    Chrupek, Thierry; Falk, Thorsten; Hofmann, Stefanie; Gouverneur, Philippe; Le Visage, Christophe; Saint Martin, Gro de; Meyerjuergens, Tim; Dachicourt, Pierre-Georges; Hube, Wilfried

    2008-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on the development of offshore wind energy in France and Germany. In the framework of this French-German exchange of experience, more than 100 participants exchanged views on offshore wind energy development, and on the conflicts of usage between fishermen and offshore wind farms. This document brings together the available presentations (slides) made during this event: 1 - Offshore wind energy development in France (Thierry Chrupek); 2 - Present day situation of offshore wind energy development and use in Germany (Thorsten Falk); 3 - Risks and profitability of offshore wind energy (Philippe Gouverneur); 4 - Sea and shore integrated management: what impacts for offshore wind energy? (Christophe Le Visage); 5 - Towards and offshore grid? (Gro de Saint Martin); 6 - Grid connection of offshore wind farms in Germany (Tim Meyerjuergens); 7 - Conflicts of usage between professional fishing and offshore wind farms (Pierre-Georges Dachicourt); 8 - Ecological evaluative research for the use of offshore wind energy - Advantages, projects and studies. Environmental follow-up of wind energy projects (Stefanie Hofmann); 9 - Alpha Ventus offshore test park: context, progress of the installation and next steps (Wilfried Hube)

  5. Shifting towards offshore wind energy—Recent activity and future development

    International Nuclear Information System (INIS)

    Kaldellis, J.K.; Kapsali, M.

    2013-01-01

    To date, most of the existing wind farms have been built on-land but during the last few years many countries have also invested in offshore applications. The shift towards offshore wind project developments has mainly been driven by European energy policies, especially in north-west countries. In offshore sites the winds are stronger and steadier than on-land, making wind farms more productive with higher capacity factors. On the other hand, although offshore wind energy is not in its infancy period, most of the costs associated with its development are still much higher from onshore counterparts; however some recent technological progress may have the potential to narrow this gap in the years to come. In the present work, an overview of the activity noted in the field of offshore wind energy is carried out, with emphasis being given on the current status and future trends of the technology employed, examining at the same time energy production and availability issues as well as economic considerations. - Highlights: ► An overview of the activity noted in the field of offshore wind energy is carried out. ► Emphasis is given on the current status and future trends of the technology. ► Wind energy production and availability issues are discussed. ► Economic issues such as investment and energy production costs are also analysed.

  6. Coordinated control of wind power plants in offshore HVDC grids

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.

    2017-01-01

    power between different countries, and different synchronous areas. It is very likely that they will then be combined with offshore wind power plant (OWPP) connections in the North Sea, transforming it in a multi terminal DC (MTDC) grid and, therefore, in a fully meshed offshore DC grid in near future......During the recent years, there has been a significant penetration of offshore wind power into the power system and this trend is expected to continue in the future. The North Sea in Europe has higher potential for offshore wind power; therefore, the North Seas Countries' Offshore Grid initiative....... However, increased penetration of offshore wind power into the power system poses several challenges to its security. This thesis deals with two main research challenges, (1) Develop, and analyze the coordinated control strategies for AC voltage and reactive power control in the cluster of OWPPs connected...

  7. Analysis of North Sea Offshore Wind Power Variability

    NARCIS (Netherlands)

    Buatois, A.; Gibescu, M.; Rawn, B.G.; Van der Meijden, M.A.M.M.

    2014-01-01

    This paper evaluates, for a 2030 scenario, the impact on onshore power systems in terms of the variability of the power generated by 81 GW of offshore wind farms installed in the North Sea. Meso-scale reanalysis data are used as input for computing the hourly power production for offshore wind

  8. Offshore Wind Energy Permitting: A Survey of U.S. Project Developers

    Energy Technology Data Exchange (ETDEWEB)

    Van Cleve, Frances B.; Copping, Andrea E.

    2010-11-30

    The U.S. Department of Energy (DOE) has adopted a goal to generate 20% of the nation’s electricity from wind power by 2030. Achieving this “20% Wind Scenario” in 2030 requires acceleration of the current rate of wind project development. Offshore wind resources contribute substantially to the nation’s wind resource, yet to date no offshore wind turbines have been installed in the U.S. Progress developing offshore wind projects has been slowed by technological challenges, uncertainties about impacts to the marine environment, siting and permitting challenges, and viewshed concerns. To address challenges associated with siting and permitting, Pacific Northwest National Laboratory (PNNL) surveyed offshore wind project developers about siting and project development processes, their experience with the environmental permitting process, and the role of coastal and marine spatial planning (CMSP) in development of the offshore wind industry. Based on the responses to survey questions, we identify several priority recommendations to support offshore wind development. Recommendations also include considerations for developing supporting industries in the U.S. and how to use Coastal and Marine Spatial Planning (CMSP) to appropriately consider ocean energy among existing ocean uses. In this report, we summarize findings, discuss the implications, and suggest actions to improve the permitting and siting process.

  9. Comparative evaluation of different offshore wind turbine installation vessels for Korean west–south wind farm

    Directory of Open Access Journals (Sweden)

    Dang Ahn

    2017-01-01

    Full Text Available The purpose of this study is to evaluate various means of wind power turbines installation in the Korean west–south wind farm (Test bed 100 MW, Demonstrate site 400 MW. We presented the marine environment of the southwest offshore wind farm in order to decide the appropriate installation vessel to be used in this site. The various vessels would be WTIV (Wind turbine installation vessel, jack-up barge, or floating crane … etc. We analyzed the installation cost of offshore wind turbine and the transportation duration for each vessel. The analysis results showed the most suitable installation means for offshore wind turbine in the Korean west–south wind farm.

  10. 2014 Offshore Wind Market and Economic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Bruce [Navigant Consulting, Inc., Burlington, MA (United States)

    2014-08-25

    The objective of this report is to provide a comprehensive annual assessment of the U.S. offshore wind market.This 3rd annual report focuses on new developments that have occurred in 2014. The report provides stakeholders with a reliable and consistent data source addressing entry barriers and U.S. competitiveness in the offshore wind market. Available for download are both the full report and the report's underlying data.

  11. Effects of offshore wind farms on birds

    DEFF Research Database (Denmark)

    Petersen, Ib Krag; Fox, Anthony David; Desholm, Mark

    På konferencen "Offshore Wind Energy Development Site Assessment and Characterization: Evaluation of the Current Status and European Experience" blev der gjort rede for danske erfaringer med effekten af havvindmølleparker på havfugle.......På konferencen "Offshore Wind Energy Development Site Assessment and Characterization: Evaluation of the Current Status and European Experience" blev der gjort rede for danske erfaringer med effekten af havvindmølleparker på havfugle....

  12. Assessment of Ports for Offshore Wind Development in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Elkinton, Chris [DNV GL; Blatiak, Alicia; Ameen, Hafsa

    2014-03-21

    As offshore wind energy develops in the United States, port facilities will become strategic hubs in the offshore wind farm supply chain because all plant and transport logistics must transit through these facilities. Therefore, these facilities must provide suitable infrastructure to meet the specific requirements of the offshore wind industry. As a result, it is crucial that federal and state policy-makers and port authorities take effective action to position ports in the offshore wind value chain to take best advantage of their economic potential. The U.S. Department of Energy tasked the independent consultancy GL Garrad Hassan (GL GH) with carrying out a review of the current capability of U.S. ports to support offshore wind project development and an assessment of the challenges and opportunities related to upgrading this capability to support the growth of as many as 54 gigawatts of offshore wind installed in U.S. waters by 2030. The GL GH report and the open-access web-based Ports Assessment Tool resulting from this study will aid decision-makers in making informed decisions regarding the choice of ports for specific offshore projects, and the types of investments that would be required to make individual port facilities suitable to serve offshore wind manufacturing, installation and/or operations. The offshore wind industry in the United States is still in its infancy and this study finds that additional port facilities capable of supporting offshore wind projects are needed to meet the anticipated project build-out by 2030; however, no significant barriers exist to prevent the development of such facilities. Furthermore, significant port capabilities are in place today with purpose-build port infrastructure currently being built. While there are currently no offshore wind farms operating in the United States, much of the infrastructure critical to the success of such projects does exist, albeit in the service of other industries. This conclusion is based

  13. Offshore Wind Farm Clusters - Towards new integrated Design Tool

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Réthoré, Pierre-Elouan; Peña, Alfredo

    In EERA DTOC testing of existing wind farm wake models against four validation data test sets from large offshore wind farms is carried out. This includes Horns Rev-1 in the North Sea, Lillgrund in the Baltic Sea, Roedsand-2 in the Baltic Sea and from 10 large offshore wind farms in Northern Euro...

  14. Scour Forecasting for Offshore Wind Parks

    DEFF Research Database (Denmark)

    Hartvig, Peres Akrawi

    In an effort to minimize the costs of offshore wind parks, the present research deals with optimizing a certain aspect of the support structure, namely the approach to scour. Scour is the phenomenon of seabed changes in the vicinity of the support structure that arises when the support structure......, scour forecasts facilitate the comparison between a scour design based on either deployment of scour-protection or enhanced structural design. The broad goal is to develop a method that produces accurate scour forecasts for offshore wind parks. The present research investigates more specifically which...

  15. Interconnector capacity allocation in offshore grids with variable wind generation

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten

    2013-01-01

    the interconnector capacity should be allocated for wind generation and for international power trading. The main difficulty arises from the stochastic nature of wind generation: in a case with radial connections to the national coast, the wind park owner has the possibility of aggregating the offshore wind park....... It is concluded that treating offshore generation as a single price zone within the interconnector reduces the wind operator’s ability to pool it with other generation. Furthermore, a single offshore price zone between two markets will always receive the lower spot market price of the neighbouring zones, although...

  16. Optimal Structural Reliability of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Tarp-Johansen, N.J.

    2005-01-01

    The main failure modes of modern large wind turbines are fatigue failure of wings, hub, shaft and main tower, local buckling of main tower, and failure of the foundation. This paper considers reliability-based optimal design of wind turbines. Compared to onshore wind turbines and building...... structures, humans spent little time in the vicinity of offshore wind turbines and the probability of human injury during storm conditions is small. Further environmental pollution will also in general be small in case of failure. One could therefore argue that the reliability level of offshore wind turbines...... can be lower than for onshore wind turbines and other civil engineering structures and can be assessed by reliability-based cost-optimization. Specifically this paper considers the main tower and foundation. Both fatigue and ultimate strength failure modes are included. Different formulations...

  17. Offshore Wind Energy Ready to Power a Sustainable Europe. Final Report. Concerted Action on Offshore Wind Energy in Europe

    International Nuclear Information System (INIS)

    2001-12-01

    The objective of the project Concerted Action on Offshore Wind Energy in Europe [CA-OWEE] is to define the current state of the art of offshore wind energy in Europe through gathering and evaluation of information from across Europe and to disseminate the resulting knowledge to all interested, in order to help stimulate the development of the industry. The project is being funded by the European Commission and will be completed at the end of 2001. The knowledge gathered will be freely available through an internet site, a workshop and a printed report. This project divides offshore wind energy into five clusters of subjects and reviews the recent history and summarise the current state of affairs, relating to: Cluster 1 offshore technology, of the wind turbines and the support structures, Cluster 2 grid integration, energy supply and financing, Cluster 3 resources and economics, Cluster 4 activities and prospects, Cluster 5 social acceptance, environmental impact and politics. The conclusions from these surveys are then used to define recommendations for the future RTD strategy for Europe. The project's 17 partners come from 13 countries, thus covering the majority of the European Community's coastline. The partners cover a wide range of expertise and include developers, utilities, consultants, research institutes and universities

  18. National Offshore Wind Strategy: Facilitating the Development of the Offshore Wind Industry in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Gilman, Patrick [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maurer, Ben [National Renewable Energy Lab. (NREL), Golden, CO (United States); Feinberg, Luke [National Renewable Energy Lab. (NREL), Golden, CO (United States); Duerr, Alana [National Renewable Energy Lab. (NREL), Golden, CO (United States); Peterson, Lauren [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walt [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beiter, Phillipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Golladay, Jennifer [Dept. of the Interior (DOI), Washington DC (United States); Stromberg, Jessica [Dept. of the Interior (DOI), Washington DC (United States); Johnson, Isis [Dept. of the Interior (DOI), Washington DC (United States); Boren, Doug [Dept. of the Interior (DOI), Washington DC (United States); Moore, Annette [Dept. of the Interior (DOI), Washington DC (United States)

    2016-09-01

    The U.S. Department of Energy, through its Wind Energy Technologies Office, and U.S. Department of the Interior, through its Bureau of Ocean Energy Management, have jointly produced this updated national strategy to facilitate the responsible development of offshore wind energy in the United States.

  19. Life cycle assessment of the offshore wind farm alpha ventus

    International Nuclear Information System (INIS)

    Wagner, Hermann-Josef; Baack, Christoph; Eickelkamp, Timo; Epe, Alexa; Lohmann, Jessica; Troy, Stefanie

    2011-01-01

    Due to better wind conditions at sea, offshore wind farms have the advantage of higher electricity production compared to onshore and inland wind farms. In contrast, a greater material input, leading to increased energy consumptions and emissions during the production phase, is required to build offshore wind farms. These contrary effects are investigated for the first German offshore wind farm alpha ventus in the North Sea. In a life cycle assessment its environmental influence is compared to that of Germany's electricity mix. In comparison to the mix, alpha ventus had better indicators in nearly every investigated impact category. One kilowatt-hour electricity, generated by the wind farm, was burdened with 0.137 kWh Primary Energy-Equivalent and 32 g CO 2 -Equivalent, which represented only a small proportion of the accordant values for the mix. Furthermore, the offshore foundations as well as the submarine cable were the main energy intensive components. The energetic and greenhouse gas payback period was less than one year. Therefore, offshore wind power, even in deep water, is compatible with the switch to sustainable electricity production relying on renewable energies. Additional research, taking backup power plants as well as increasingly required energy storage systems into account, will allow further calculation. -- Highlights: → Offshore wind energy represents an environmentally friendly way of power generation. → The offshore foundations and the submarine cable are energy intensive components. → Alpha ventus emits 30 g CO 2 per kWh electricity over the entire life cycle. → Less specific emissions occur in comparison to the existing German electricity grid. → The energetic and greenhouse gas payback periods are less than one year.

  20. Study on optimized decision-making model of offshore wind power projects investment

    Science.gov (United States)

    Zhao, Tian; Yang, Shangdong; Gao, Guowei; Ma, Li

    2018-02-01

    China’s offshore wind energy is of great potential and plays an important role in promoting China’s energy structure adjustment. However, the current development of offshore wind power in China is inadequate, and is much less developed than that of onshore wind power. On the basis of considering all kinds of risks faced by offshore wind power development, an optimized model of offshore wind power investment decision is established in this paper by proposing the risk-benefit assessment method. To prove the practicability of this method in improving the selection of wind power projects, python programming is used to simulate the investment analysis of a large number of projects. Therefore, the paper is dedicated to provide decision-making support for the sound development of offshore wind power industry.

  1. Offshore wind farm harmonic resonance analysis, part I : Converter harmonic model

    NARCIS (Netherlands)

    Sun, Yin; De Jong, Erik; Cobben, J. F.G.; Cuk, Vladimir

    2017-01-01

    Offshore wind power technology has matured significantly and now directly competes with conventional and onshore wind power generation. Thanks to continuous technological developments and significant cost reduction, offshore wind power is closing the gap with the onshore wind power about the

  2. Offshore Wind Jobs and Economic Development Impact: Four Regional Scenarios (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Tegen, S.

    2014-11-01

    NREL's Jobs and Economic Development Impact (JEDI) Model for Offshore Wind, is a computer tool for studying the economic impacts of fixed-bottom offshore wind projects in the United States. This presentation provides the results of an analysis of four offshore wind development scenarios in the Southeast Atlantic, Great Lakes, Mid-Atlantic, and Gulf of Mexico regions.

  3. Offshore wind energy, who will risk investment?

    International Nuclear Information System (INIS)

    Dupin, Ludovic; Moragues, Manuel

    2013-01-01

    As Europe plans to install 40 GW of offshore wind energy production by 2020 and only 5 GW are already installed, investment is a crucial issue for a still immature industry and in a context where risk management is critical, notably during construction (harsh working conditions, costs of construction, of maintenance and costs related to delays). Other aspects are also related to financial risks like, for example, the cost of offshore wind farm connection to the grid (this has been an underestimated issue in Germany). Then operation and exploitation have to face climate events although, according to relatively recent exploitation data, availability is quite good. The durability of political support is not so sure in a context of political and regulatory instability and of economic crisis. In France, after the first bidding, the wind energy industrial sector is emerging and many small and medium companies enter this activity in the trail of Areva and Alstom, with thousands of job creations and export perspectives. Some offshore wind turbines are briefly presented (by Alstom, Areva, RE Power, Siemens and Vestas)

  4. Three-Dimensional Wind Profiling of Offshore Wind Energy Areas With Airborne Doppler Lidar

    Science.gov (United States)

    Koch, Grady J.; Beyon, Jeffrey Y.; Cowen, Larry J.; Kavaya, Michael J.; Grant, Michael S.

    2014-01-01

    A technique has been developed for imaging the wind field over offshore areas being considered for wind farming. This is accomplished with an eye-safe 2-micrometer wavelength coherent Doppler lidar installed in an aircraft. By raster scanning the aircraft over the wind energy area (WEA), a three-dimensional map of the wind vector can be made. This technique was evaluated in 11 flights over the Virginia and Maryland offshore WEAs. Heights above the ocean surface planned for wind turbines are shown to be within the marine boundary layer, and the wind vector is seen to show variation across the geographical area of interest at turbine heights.

  5. Discussion paper : offshore wind facilities renewable energy approval requirements

    International Nuclear Information System (INIS)

    2010-06-01

    This paper discussed a proposed shoreline exclusion zone for offshore wind projects in Ontario. Considerations relevant to offshore wind projects and the protection of human health, cultural heritage, and the environment were also discussed. The paper was prepared in order to provide greater clarity to renewable energy developers and to Ontario residents about the offshore wind policy that is currently being considered by the Ontario Government. Feedback received from the discussion paper will be used to propose policy and associated regulatory amendments. A 5 km shoreline exclusion zone for all offshore wind facilities was proposed. Some projects may be required to be located beyond the proposed exclusion zone. Proposed developments within the exclusion zone must meet all applicable requirements, including those related to cultural and natural heritage. The zone will establish a distance between drinking water intakes, and ensure that sediment dredging and other construction-related activities do not impact drinking water quality, and ensure that potential noise levels are within acceptable levels. The zone will establish a distance between near-shore activities and wind facilities, and also help to maintain the ecological health of inland waters. Guidelines and technical requirements for wind facility operators were also included.

  6. A New Coordinated Voltage Control Scheme for Offshore AC Grid of HVDC Connected Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Cutululis, Nicolaos Antonio; Rather, Zakir Hussain

    2015-01-01

    This paper proposes a coordinated voltage control scheme (CVCS) which enhances the voltage ride through (VRT) capability of an offshore AC grid comprised of a cluster of offshore wind power plants (WPP) connected through AC cables to the offshore voltage source converter based high voltage DC (VSC......-HVDC) converter station. Due to limited short circuit power contribution from power electronic interfaced variable speed wind generators and with the onshore main grid decoupled by the HVDC link, the offshore AC grid becomes more vulnerable to dynamic voltage events. Therefore, a short circuit fault...... in the offshore AC Grid is likely to have significant implications on the voltage of the offshore AC grid, hence on the power flow to the onshore mainland grid. The proposed CVCS integrates individual local reactive power control of wind turbines and of the HVDC converter with the secondary voltage controller...

  7. Monitoring and evaluation of Blyth Offshore Wind Farm. NAVAID (Navigational Aid) requirements for UK offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Pepper, L.

    2001-07-01

    The principle aim of this report is to review and evaluate the Navigational Aid (NAVAID) requirements for the Blyth Offshore Wind Farms as specified by Trinity House. The effectiveness of the NAVAIDs was monitored and reviewed by the project team with the assistance of the harbour master and the local vessel operators regularly using Blyth Harbour. This report particularly looks at the reasons for the NAVAID specification and the practicalities of using a similar system on larger offshore wind farms. The document not only describes the specification, but also reviews its effectiveness including any difficulties that were encountered during the installation. (author)

  8. Effects on harbour porpoises from Roedsand 2 Off-shore Wind Farm

    Energy Technology Data Exchange (ETDEWEB)

    Teilmann, J.; Tougaard, J.; Carstensen, J.

    2012-11-15

    E.ON Vind Sverige has been commissioned the construction of Roedsand 2 Offshore Wind Farm comprising 90 wind turbines, south of Lolland-Falster, Denmark. The location of the wind farm is 3 km west of the existing Nysted Offshore Wind Farm with 72 turbines. In combination the two wind farms represents the largest wind farm area in the world. Porpoises were monitored by automatic acoustic dataloggers (T-PODs) according to a statistical BACI design and deployed during baseline (Sep 2008-Feb 2009) and during operation (Sep 2011-Mar 2012). These instruments were deployed at 10 stations covering a coastal stretch of 35 km from Gedser to Roedby, including the wind farm area with reference areas on both sides. In addition, background noise at four of the T-POD stations was recorded by automatic noise loggers. In order to assess the potential cumulative effect of two adjacent wind farms, similar data from the Nysted Offshore Wind Farm were also analysed. We found no overall change in echolocation activity over the entire monitoring area from baseline to operation of Roedsand 2 Offshore Wind Farm. Also, there was no significant change in the echolocation activity in Roedsand 2 Offshore Wind Farm relative to each or a combination of the three reference areas, i.e. changes from baseline to operation were similar in the impact and reference areas. Also no significant change in noise levels audible to porpoises was found. This could be due to a generally high noise level in the area, masking the turbine noise or that the noise loggers in the wind farm were deployed between the wind turbines, i.e. at distances {approx}350-450 m from the turbines. This study also shows that the echolocation activity is still significantly lower in Nysted Offshore Wind Farm since the baseline in 2001-2002, although the difference seem to gradually diminish possibly due to a habituation of the porpoises to the wind farm or better feeding posibilities. We found no cumulative effect of the two wind

  9. A review of the European offshore wind innovation system

    NARCIS (Netherlands)

    Wieczorek, A.J.; Negro, S.O.; Harmsen, R.; Heimeriks, G.J.; Luo, L.; Hekkert, M.P.

    2013-01-01

    Offshore wind has the potential of becoming an important pillar of the future European energy system. It can contribute to policy objectives on climate change, energy security, green growth and social progress. However, the large potential of offshore wind does not automatically lead to a large

  10. Risk-based Inspection Planning Optimisation of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramirez, José Rangel; Sørensen, John Dalsgaard

    2011-01-01

    Wind industry is substantially propelled and the future scenarios designate offshore locations as important sites for energy production. With this development, offshore wind farms represent a feasible option to accomplish the needed energy, bringing with it technical and economical challenges......, but considering the lower reliability level for wind turbines. This framework is addressing fatigue prone details in welded steel joints typically located in the wind turbine substructure. The increase of turbulence in-wind farms (IWF) due to wake effects is taken into account using a code-based turbulence model...

  11. A fair wind for the offshore

    International Nuclear Information System (INIS)

    Houot, G.

    2009-01-01

    The wind power future will take into account the sea. But to increase, the offshore channel must manage its organization and create a real cross-border cooperation. The author presents an economic analysis of the market with a special attention to the french sector. A map of the offshore sites in Europe is provided. (A.L.B.)

  12. Responses of two marine top predators to an offshore wind farm.

    Science.gov (United States)

    Vallejo, Gillian C; Grellier, Kate; Nelson, Emily J; McGregor, Ross M; Canning, Sarah J; Caryl, Fiona M; McLean, Nancy

    2017-11-01

    Quantifying the likely effects of offshore wind farms on wildlife is fundamental before permission for development can be granted by any Determining Authority. The effects on marine top predators from displacement from important habitat are key concerns during offshore wind farm construction and operation. In this respect, we present evidence for no significant displacement from a UK offshore wind farm for two broadly distributed species of conservation concern: common guillemot ( Uria aalge ) and harbor porpoise ( Phocoena phocoena ). Data were collected during boat-based line transect surveys across a 360 km 2 study area that included the Robin Rigg offshore wind farm. Surveys were conducted over 10 years across the preconstruction, construction, and operational phases of the development. Changes in guillemot and harbor porpoise abundance and distribution in response to offshore wind farm construction and operation were estimated using generalized mixed models to test for evidence of displacement. Both common guillemot and harbor porpoise were present across the Robin Rigg study area throughout all three development phases. There was a significant reduction in relative harbor porpoise abundance both within and surrounding the Robin Rigg offshore wind farm during construction, but no significant difference was detected between the preconstruction and operational phases. Relative common guillemot abundance remained similar within the Robin Rigg offshore wind farm across all development phases. Offshore wind farms have the potential to negatively affect wildlife, but further evidence regarding the magnitude of effect is needed. The empirical data presented here for two marine top predators provide a valuable addition to the evidence base, allowing future decision making to be improved by reducing the uncertainty of displacement effects and increasing the accuracy of impact assessments.

  13. Observation of high-resolution wind fields and offshore wind turbine wakes using TerraSAR-X imagery

    Science.gov (United States)

    Gies, Tobias; Jacobsen, Sven; Lehner, Susanne; Pleskachevsky, Andrey

    2014-05-01

    1. Introduction Numerous large-scale offshore wind farms have been built in European waters and play an important role in providing renewable energy. Therefore, knowledge of behavior of wakes, induced by large wind turbines and their impact on wind power output is important. The spatial variation of offshore wind turbine wake is very complex, depending on wind speed, wind direction, ambient atmospheric turbulence and atmospheric stability. In this study we demonstrate the application of X-band TerraSAR-X (TS-X) data with high spatial resolution for studies on wind turbine wakes in the near and far field of the offshore wind farm Alpha Ventus, located in the North Sea. Two cases which different weather conditions and different wake pattern as observed in the TS-X image are presented. 2. Methods The space-borne synthetic aperture radar (SAR) is a unique sensor that provides two-dimensional information on the ocean surface. Due to their high resolution, daylight and weather independency and global coverage, SARs are particularly suitable for many ocean and coastal applications. SAR images reveal wind variations on small scales and thus represent a valuable means in detailed wind-field analysis. The general principle of imaging turbine wakes is that the reduced wind speed downstream of offshore wind farms modulates the sea surface roughness, which in turn changes the Normalized Radar Cross Section (NRCS, denoted by σ0) in the SAR image and makes the wake visible. In this study we present two cases at the offshore wind farm Alpha Ventus to investigate turbine-induced wakes and the retrieved sea surface wind field. Using the wind streaks, visible in the TS-X image and the shadow behind the offshore wind farm, induced by turbine wake, the sea surface wind direction is derived and subsequently the sea surface wind speed is calculated using the latest generation of wind field algorithm XMOD2. 3. Case study alpha ventus Alpha Ventus is located approximately 45 km from the

  14. 3. International Workshop on Transmission Networks for Offshore Wind Farms. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, T [ed.

    2002-07-01

    The emphasis is on both theoretical discussions and on practical applications. After almost a decade with mainly demonstration projects in the area of offshore wind power, this year will see the first large commercial offshore wind projects with more than 50 MW installed capacity and more and more larger projects are scheduled for the coming years. Also more and more energy policy makers, electric utilities as well as the media recognize the enormous potential of offshore wind power as a large-scale sustainable energy source. The development in this area results in new ideas, questions and research proposals. Such a new topic is, hydrogen production using offshore wind farms.

  15. Offshore wind energy : balancing risk and reward

    International Nuclear Information System (INIS)

    Nerland, C.

    2010-01-01

    Offshore wind energy developments are expected to increase as the demand for renewable energy sources grows. This poster presentation described a method of balancing risk and reward in offshore wind energy projects. The method was based on risk assessment strategies used by the oil and gas industry. The dedicated framework considered schedules; budgets; performance; and operating and maintenance costs. A value chain assessment method was used to optimize the balance between risk and reward by evaluating uncertainties and risk related to each project element and its relationship to other elements within an integrated dynamic model designed to determine the net present value of a project. The decision-making criteria included the RISKEX risk expenditure strategy designed to consider the balance between risk exposure, capital expenditures, and operational expenditures in relation to the statistical cost of unplanned repairs, and lost production capacity. A case study of a large offshore wind farm was used to demonstrate the method. tabs., figs.

  16. Efficient promotion of electricity production from offshore wind

    International Nuclear Information System (INIS)

    Panzer, Christian; Auer, Hans; Lettner, Georg

    2014-01-01

    Efficient promotion of electricity production from offshore wind stands in dynamic relationship with various influence factors, the most important of which are promotion instruments, topographic givens, regulation of grid connection, and supraregional market integration concepts. Using three case studies from different countries to highlight national differences in the promotion of offshore wind power plants the present analysis points out ways of improving the efficiency of promotion instruments.

  17. Large-scale offshore wind farms in Denmark. Update of ''Future offshore sites for wind turbines 2025''; Stor-skala havmoelleparker i Danmark. Opdatering af fremtidens havmoelleplaceringer

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-15

    This updating of the ''Future offshore sites for wind turbines 2025'', is made by the Offshore Wind Farm Committee and adjusts primarily the existing sites in relation to a updated data basis. The sites are adjusted within the already identified areas, and no new areas are therefore included. In addition to an update of the underlying data base, including the revised sailing routes, the new Natura 2000 sites and mineral resources, there are now further collected knowledge about the seabed in the designated areas. Moreover, the underlying assumptions for construction costs and grid connection updated, which has resulted in a revised socio-economic priority of the areas. The Offshore Wind Farm Committee's report confirms that the placement of the 600 MW Kriegers Flak Offshore Wind Farm in the Baltic Sea is the best location for Denmark's next major offshore wind farm. Kriegers Flak Offshore Wind Farm is already included in the Government's energy strategy. (LN)

  18. Offshore wind power experiences, potential and key issues for deployment

    Energy Technology Data Exchange (ETDEWEB)

    Lemming, J.; Morthorst, P.E.; Clausen, Niels-Erik

    2009-01-15

    Wind power has been growing at spectacular rates. Today it is the largest non-hydro renewable power technology. Worldwide there is 74 GW of installed capacity which is 1.7% of power generation capacity and in 2006 it accounted for 0.82% of electricity production. However, offshore wind still only counts for a very small amount and development has only taken place in North European counties round the North Sea and the Baltic Sea over the last 15 years. Offshore wind is still some 50% more expensive than onshore wind, but more wind resources and lesser visual impacts from larger turbines are expected to compensate for the higher installation costs in the long term. Most offshore wind farms are installed in British, Swedish and Danish waters, and present-day costs of installing wind energy in the UK are between 1,200 to 1,600 GBP/kW (1,781 to 2,375 Euro/kW) offshore, while in Sweden investment costs were 1,800 Euro/kW, and in Denmark 1,200 to 1,700 Euro/kW, though investment costs for a new wind farm are expected be in the range of 2.0 to 2.2 mill. Euro/MW for a near-shore shallow depth facility. Future developments in offshore wind technology concerning aerodynamics, structural dynamics, structural design, machine elements, electrical design and grid integration could drive investment costs from present-day range of 1.9 to 2.2 mill. Euro/MW down to 1.35 - 1.54 mill.Euro/MW in 2050, which accounts for a reduction of costs of approx. 35%. In order to sum up progress and identify future research needs, the International Energy Agency (IEA) Wind agreement Task 11 should arrange a new meeting concerning long term research needs for reviewing 'the long term strategy for 2000 to 2020' from 2001, to come up with suggestions / recommendations on how to define and proceed with, the necessary research activities of the IEA Wind Agreement and governments involved on key wind issues related to offshore technologies. (au)

  19. Towards a mature offshore wind energy technology - guidelines from the opti-OWECS project

    Science.gov (United States)

    Kühn, M.; Bierbooms, W. A. A. M.; van Bussel, G. J. W.; Cockerill, T. T.; Harrison, R.; Ferguson, M. C.; Göransson, B.; Harland, L. A.; Vugts, J. H.; Wiecherink, R.

    1999-01-01

    The article reviews the main results of the recent European research project Opti-OWECS (Structural and Economic Optimisation of Bottom-Mounted Offshore Wind Energy Converters'), which has significantly improved the understanding of the requirements for a large-scale utilization of offshore wind energy. An integrated design approach was demonstrated for a 300 MW offshore wind farm at a demanding North Sea site. Several viable solutions were obtained and one was elaborated to include the design of all major components. Simultaneous structural and economic optimization took place during the different design stages. An offshore wind energy converter founded on a soft-soft monopile was tailored with respect to the distinct characteristics of dynamic wind and wave loading. The operation and maintenance behaviour of the wind farm was analysed by Monte Carlo simulations. With an optimized maintenance strategy and suitable hardware a high availability was achieved. Based upon the experience from the structural design, cost models for offshore wind farms were developed and linked to a European database of the offshore wind energy potential. This enabled the first consistent estimate of cost of offshore wind energy for entire European regions.

  20. Prospects for generating electricity by large onshore and offshore wind farms

    Science.gov (United States)

    Volker, Patrick J. H.; Hahmann, Andrea N.; Badger, Jake; Jørgensen, Hans E.

    2017-03-01

    The decarbonisation of energy sources requires additional investments in renewable technologies, including the installation of onshore and offshore wind farms. For wind energy to remain competitive, wind farms must continue to provide low-cost power even when covering larger areas. Inside very large wind farms, winds can decrease considerably from their free-stream values to a point where an equilibrium wind speed is reached. The magnitude of this equilibrium wind speed is primarily dependent on the balance between turbine drag force and the downward momentum influx from above the wind farm. We have simulated for neutral atmospheric conditions, the wind speed field inside different wind farms that range from small (25 km2) to very large (105 km2) in three regions with distinct wind speed and roughness conditions. Our results show that the power density of very large wind farms depends on the local free-stream wind speed, the surface characteristics, and the turbine density. In onshore regions with moderate winds the power density of very large wind farms reaches 1 W m-2, whereas in offshore regions with very strong winds it exceeds 3 W m-2. Despite a relatively low power density, onshore regions with moderate winds offer potential locations for very large wind farms. In offshore regions, clusters of smaller wind farms are generally preferable; under very strong winds also very large offshore wind farms become efficient.

  1. Panorama 2016 - Offshore wind power

    International Nuclear Information System (INIS)

    Vinot, Simon

    2015-11-01

    While onshore wind power is a rapidly growing global industry, the offshore wind power market remains in its consolidation and globalization phase. This most mature of renewable marine energies continues to develop and can no longer be considered a niche industry. This fact sheet evaluates the market over the last several years, looking at its potential and its current rank in terms of electricity production costs. (author)

  2. Offshore Wind Energy in Denmark

    DEFF Research Database (Denmark)

    Möller, Bernd; Hong, Lixuan; Hvelplund, Frede

    for Denmark and invites to reconsider the technological and institutional choices made. Based on a continuous resource-economic model operating in a geographical information systems (GIS) environment, which describes resources, costs and area constraints in a spatially explicit way, the relation between......Offshore wind energy has developed in terms of turbine and project size, and currently undergoes a significant up-scaling to turbines and parks at greater distance to shore and deeper waters. Expectations to the positive effect of economies of scale on power production costs, however, have...... availability of locations, driven by accelerating requirements of environmental concern, park size and public acceptance, is one important driver. Mounting risk of mega-projects and the infinite demand for renewable energy is another likely cause. The present paper addresses the scale of offshore wind parks...

  3. The (R)evolution of China: Offshore Wind Diffusion

    DEFF Research Database (Denmark)

    Poulsen, Thomas; Hasager, Charlotte Bay

    2017-01-01

    This research presents an industry level gap analysis for Chinese offshore wind, which serves as a way to illuminate how China may fast track industry evolution. The research findings provide insight into how the Chinese government strongly and systematically decrees state-owned Chinese firms...... successfully forge long-term alliances also for future Chinese wind energy export projects. Examples of past efforts of collaboration not yielding desired results have been included as well. At policy level, recommendations are provided on how the evolution of the Chinese offshore wind power industry can...... be fast-tracked to mirror the revolutionary pace, volume, and velocity which the Chinese onshore wind power industry has mustered....

  4. Life cycle assessment of onshore and offshore wind energy-from theory to application

    International Nuclear Information System (INIS)

    Bonou, Alexandra; Laurent, Alexis; Olsen, Stig I.

    2016-01-01

    Highlights: • An LCA of 2 onshore and 2 offshore wind power plants was performed. • Onshore wind power performs better than offshore per kWh delivered to the grid. • Materials are responsible for more than 79% and 70% of climate change impacts onshore and offshore respectively. • The bigger, direct drive turbines perform better than the smaller geared ones. • Climate change is a good KPI for wind power plant hotspot identification. - Abstract: This study aims to assess the environmental impacts related to the provision of 1 kWh to the grid from wind power in Europe and to suggest how life cycle assessment can inform technology development and system planning. Four representative power plants onshore (with 2.3 and 3.2 MW turbines) and offshore (4.0 and 6.0 MW turbines) with 2015 state-of-the-art technology data provided by Siemens Wind Power were assessed. The energy payback time was found to be less than 1 year for all technologies. The emissions of greenhouse gases amounted to less than 7 g CO_2-eq/kWh for onshore and 11 g CO_2-eq/kWh for offshore. Climate change impacts were found to be a good indicator for overall hotspot identification however attention should also be drawn to human toxicity and impacts from respiratory inorganics. The overall higher impact of offshore plants, compared to onshore ones, is mainly due to larger high-impact material requirements for capital infrastructure. In both markets the bigger turbines with more advanced direct drive generator technology is shown to perform better than the smaller geared ones. Capital infrastructure is the most impactful life cycle stage across impacts. It accounts for more than 79% and 70% of climate change impacts onshore and offshore respectively. The end-of-life treatment could lead to significant savings due to recycling, ca. 20–30% for climate change. In the manufacturing stage the impacts due to operations at the case company do not exceed 1% of the total life cycle impacts. This finding

  5. Quantifying the Benefits of Combining Offshore Wind and Wave Energy

    Science.gov (United States)

    Stoutenburg, E.; Jacobson, M. Z.

    2009-12-01

    For many locations the offshore wind resource and the wave energy resource are collocated, which suggests a natural synergy if both technologies are combined into one offshore marine renewable energy plant. Initial meteorological assessments of the western coast of the United States suggest only a weak correlation in power levels of wind and wave energy at any given hour associated with the large ocean basin wave dynamics and storm systems of the North Pacific. This finding indicates that combining the two power sources could reduce the variability in electric power output from a combined wind and wave offshore plant. A combined plant is modeled with offshore wind turbines and Pelamis wave energy converters with wind and wave data from meteorological buoys operated by the US National Buoy Data Center off the coast of California, Oregon, and Washington. This study will present results of quantifying the benefits of combining wind and wave energy for the electrical power system to facilitate increased renewable energy penetration to support reductions in greenhouse gas emissions, and air and water pollution associated with conventional fossil fuel power plants.

  6. Availability evaluation of offshore wind energy networks within the Dutch power system

    NARCIS (Netherlands)

    Tuinema, B.W.; Gibescu, M.; Kling, W.L.

    2010-01-01

    In the future, a large-scale expansion of offshore wind energy is expected in the Netherlands. For this large-scale expansion, a well-designed offshore network is needed. Different network configurations will lead to other availability of the offshore network and therefore also the offshore wind

  7. An economic assessment of tropical cyclone risk on offshore wind farms

    DEFF Research Database (Denmark)

    Hong, Lixuan; Möller, Bernd

    2012-01-01

    and cost and setting design parameters for offshore wind turbines are then discussed. The impact of tropical cyclones on offshore wind farms likes a double-edged sword, which might be advantageous for some regions in terms of increasing full-loaded hours of turbines, but also disadvantageous for others due....... A probabilistic tropical cyclone event model is applied to evaluate 20-year, 30-year, 50-year and 100-year recurrence of extreme wind speeds by geographical location. Combining a damage model derived from empirical loss data and an investment cost model within a Geographical Information System (GIS), the annual...... to its destructive effects. However, specific design standards and insurance of turbines would help reduce risks and economic losses of offshore wind farms in tropical cyclone-prone areas and expand exploitable locations for future offshore wind farms....

  8. An assessment of the environmental effects of offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This report focuses on the development of an approach to the formal environmental assessment of large-scale offshore wind farms around the UK coast which will be required by EU Directives. The legislative background and policy framework are outlined, and key issues to be addressed in the environmental assessment are highlighted. Available information on the manufacture and transportation of wind farm equipment, turbine and cable installation, operation of an offshore wind farm, and wind farm decommissioning is reviewed and recommendations are given. The role of offshore wind power in meeting the UK's commitment to reducing emissions of carbon dioxide and other greenhouse gases and its targets for generating 10% of the UK's electricity from renewable energy sources is discussed.

  9. Floating axis wind turbines for offshore power generation—a conceptual study

    International Nuclear Information System (INIS)

    Akimoto, Hiromichi; Tanaka, Kenji; Uzawa, Kiyoshi

    2011-01-01

    The cost of energy produced by offshore wind turbines is considered to be higher than land based ones because of the difficulties in construction, operation and maintenance on offshore sites. To solve the problem, we propose a concept of a wind turbine that is specially designed for an offshore environment. In the proposed concept, a floater of revolutionary shape supports the load of the wind turbine axis. The floater rotates with the turbine and the turbine axis tilts to balance the turbine thrust, buoyancy and gravity. The tilt angle is passively adjustable to wind force. The angle is 30° at rated power. The simplicity of the system leads to further cost reduction of offshore power generation.

  10. 2016 Offshore Wind Energy Resource Assessment for the United States

    Energy Technology Data Exchange (ETDEWEB)

    Musial, Walt [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heimiller, Donna [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scott, George [National Renewable Energy Lab. (NREL), Golden, CO (United States); Draxl, Caroline [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    This report, the 2016 Offshore Wind Energy Resource Assessment for the United States, was developed by the National Renewable Energy Laboratory, and updates a previous national resource assessment study, and refines and reaffirms that the available wind resource is sufficient for offshore wind to be a large-scale contributor to the nation's electric energy supply.

  11. Dynamic Properties of Offshore Wind Turbine Foundations

    DEFF Research Database (Denmark)

    Damgaard, Mads

    ages structurally over its service life. Well-covered in the field of earthquake engineering, the dynamic response of civil engineering structures is highly dependent on the impedance of the soil–foundation system. For offshore wind turbine applications, however, the hysteretical and geometrical......, there is a general consensus that offshore wind-generated electricity is still too expensive to be competitive with conventional energy sources. As a consequence, the overall weight of the turbine and foundation is kept to a minimum resulting in a flexible and dynamically active structural system—even at low...

  12. Life cycle assessment of a floating offshore wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Weinzettel, Jan [Department of Electrotechnology, Faculty of Electrical Engineering, Czech Technical University in Prague, Technicka 2, Praha 166 27 (Czech Republic); Charles University in Prague Environment Center, U Krize 8, Prague 158 00 (Czech Republic); Reenaas, Marte; Solli, Christian [Industrial Ecology Programme, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway); Hertwich, Edgar G. [Industrial Ecology Programme, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway); Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim (Norway)

    2009-03-15

    A development in wind energy technology towards higher nominal power of the wind turbines is related to the shift of the turbines to better wind conditions. After the shift from onshore to offshore areas, there has been an effort to move further from the sea coast to the deep water areas, which requires floating windmills. Such a concept brings additional environmental impact through higher material demand. To evaluate additional environmental burdens and to find out whether they can be rebalanced or even offset by better wind conditions, a prospective life cycle assessment (LCA) study of one floating concept has been performed and the results are presented in this paper. A comparison with existing LCA studies of conventional offshore wind power and electricity from a natural gas combined cycle is presented. The results indicate similar environmental impacts of electricity production using floating wind power plants as using non-floating offshore wind power plants. The most important stage in the life cycle of the wind power plants is the production of materials. Credits that are connected to recycling these materials at the end-of-life of the power plant are substantial. (author)

  13. Panorama 2013 - Offshore wind power

    International Nuclear Information System (INIS)

    Vinot, Simon

    2012-10-01

    While onshore wind power is already a well-developed global industry, offshore wind power is still in the consolidation and globalization phase. The most mature of marine renewable energies is beginning to venture off the European coast and even to other continents, driven by public policies and the ever increasing number of players joining this promising market, which should evolve into deeper waters thanks to floating structures. (author)

  14. Wake Influence on Dynamic Load Characteristics of Offshore Floating Wind Turbines

    DEFF Research Database (Denmark)

    Jeon, Minu; Lee, Soogab; Kim, Taeseong

    2016-01-01

    Because the flow conditions of an offshore floating wind turbine and onshore fixed wind turbine differ, it is debatable whether the aerodynamic load predictions of an offshore floating wind turbine using the conventional blade-element momentum theory, which does not consider the dynamic wake effe...

  15. Design tool for offshore wind farm cluster planning

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Madsen, Peter Hauge; Giebel, Gregor

    2015-01-01

    In the framework of the FP7 project EERA DTOC: Design Tool for Offshore wind farm Cluster, a new software supporting the planning of offshore wind farms was developed, based on state-of-the-art approaches from large scale wind potential to economic benchmarking. The model portfolio includes WAs......P, FUGA, WRF, Net-Op, LCoE model, CorWind, FarmFlow, EeFarm and grid code compliance calculations. The development is done by members from European Energy Research Alliance (EERA) and guided by several industrial partners. A commercial spin-off from the project is the tool ‘Wind & Economy’. The software...... by the software and several tests were performed. The calculations include the smoothing effect on produced energy between wind farms located in different regional wind zones and the short time scales relevant for assessing balancing power. The grid code compliance was tested for several cases and the results...

  16. 2014–2015 Offshore Wind Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Aaron Smith, Tyler Stehly, Walt Musial

    2015-09-30

    This report provides data and analysis to assess the status of the U.S. offshore wind industry through June 30, 2015. It builds on the foundation laid by the Navigant Consortium, which produced three market reports between 2012 and 2014. The report summarizes domestic and global market developments, technology trends, and economic data to help U.S. offshore wind industry stakeholders, including policymakers, regulators, developers, financiers, and supply chain participants, to identify barriers and opportunities.

  17. A green energy for a blue growth: offshore wind energy. Proposals by France Energie Eolienne for the development of a competitive and job-creating offshore wind energy sector

    International Nuclear Information System (INIS)

    2013-06-01

    This report outlines the significant and efficient contribution of wind energy to the energy mix, highlights the high potential of offshore wind energy for France, and stresses the need of an ambitious programme as a sine qua non condition for the development of this sector. It also makes ten proposals for this development. It describes how to specify ambitious objectives for offshore wind turbines (grounded or floating) in compliance with the French potential and the European market. It analyses means to reach an ambitious objective of 15 GW of grounded offshore wind energy and 6 GW of floating offshore wind energy by 2030. It discusses how benefits can be drawn from such a development for the community and future generations

  18. The optimal access system for future far-offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Obdam, T.S.; Rademakers, L.W.M.M.; Savenije, L.B. [ECN Wind Energy, Petten (Netherlands)

    2013-12-15

    Operation and maintenance (O and M) of offshore wind turbines is one of the main cost drivers of offshore wind energy. One of the aspects critical for an efficient and cost-effective O and M strategy is the selection of the access system which is used to transfer technicians and, optionally, small spare parts. Currently, most offshore wind farms are located close to shore, and their size is relatively small. For these farms the typical access system consists of catamaran-like workboats, which are used to transfer both technicians and small spare parts. As wind farms move further offshore this O and M concept might no longer be cost-effective. Currently, different alternative O and M concepts are being considered for the future far-offshore sites. In this paper an extensive and holistic comparison of different O and M concepts including different access system solutions is presented. This analysis has been performed using the OMCECalculator, ECN's software for advanced O and M cost modelling. Different sites have been considered, which are typical for the future offshore wind farms that will be commissioned during the next five years. The results of the performed analyses indicate that when moving further offshore harbour-based O and M strategies are no longer economical, even when helicopters are added to the mix. Looking at farm-based O and M concepts a supply vessel with a compensated access gangway offers great potential. However, the calculations also indicate that its ability to transfer small spare parts, in addition to technicians, is crucial.

  19. Physical Modelling of Silt in Relation to Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Holmsgaard, Rikke

    precisely so that the competitiveness of offshore wind turbines can be improved. Carrying out in situ tests offshore is very expensive. Therefore, all experiment regarding this project is conducted onshore. A field in Dronninglund was found useful for this purpose since the subsoil at the field mainly......Offshore wind energy is a sustainable form of energy that can help reduce the emission of greenhouse gases and increase the share of renewable energy. In order to ensure that offshore wind energy can continue to be a competitive source of energy compared to other types of renewable energy...... consists of silty soil and the water table is situated just below the surface so the field is comparable to offshore conditions. In connection with the project, CPT and SCPT (Seismic Cone Penetration Test) were conducted in the field, just like large soil samples were collected with the purpose of carrying...

  20. Global long-term cost dynamics of offshore wind electricity generation

    NARCIS (Netherlands)

    Gernaat, David E H J; Van Vuuren, Detlef P.; Van Vliet, Jasper; Sullivan, Patrick; Arent, Douglas J.

    2014-01-01

    Using the IMAGE/TIMER (The Targets IMage Energy Regional) long-term integrated assessment model, this paper explores the regional and global potential of offshore wind to contribute to global electricity production. We develop long-term cost supply curve for offshore wind, a representation of the

  1. Development of Seismic Demand for Chang-Bin Offshore Wind Farm in Taiwan Strait

    Directory of Open Access Journals (Sweden)

    Yu-Kai Wang

    2016-12-01

    Full Text Available Taiwan is located on the Pacific seismic belt, and the soil conditions of Taiwan’s offshore wind farms are softer than those in Europe. To ensure safety and stability of the offshore wind turbine supporting structures, it is important to assess the offshore wind farms seismic forces reasonably. In this paper, the relevant seismic and geological data are obtained for Chang-Bin offshore wind farm in Taiwan Strait, the probabilistic seismic hazard analysis (PSHA is carried out, and the first uniform hazard response spectrum for Chang-Bin offshore wind farm is achieved. Compared with existing design response spectrum in the local regulation, this site-specific seismic hazard analysis has influence on the seismic force considered in the design of supporting structures and therefore affects the cost of the supporting structures. The results show that a site-specific seismic hazard analysis is required for high seismic area. The paper highlights the importance of seismic hazard analysis to assess the offshore wind farms seismic forces. The follow-up recommendations and research directions are given for Taiwan’s offshore wind turbine supporting structures under seismic force considerations.

  2. Assessment of Offshore Wind System Design, Safety, and Operation Standards

    Energy Technology Data Exchange (ETDEWEB)

    Sirnivas, Senu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walt [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bailey, Bruce [AWS Trupower LLC, Albany, NY (United States); Filippelli, Matthew [AWS Trupower LLC, Albany, NY (United States)

    2014-01-01

    This report is a deliverable for a project sponsored by the U.S. Department of Energy (DOE) entitled National Offshore Wind Energy Resource and Design Data Campaign -- Analysis and Collaboration (contract number DE-EE0005372; prime contractor -- AWS Truepower). The project objective is to supplement, facilitate, and enhance ongoing multiagency efforts to develop an integrated national offshore wind energy data network. The results of this initiative are intended to 1) produce a comprehensive definition of relevant met-ocean resource assets and needs and design standards, and 2) provide a basis for recommendations for meeting offshore wind energy industry data and design certification requirements.

  3. On the Application of Fluid Power Transmission in Offshore Wind Turbines

    NARCIS (Netherlands)

    Diepeveen, N.F.B.

    2013-01-01

    Offshore wind energy is currently characterized by the high costs associated with installation and operation. Gearboxes in particular have been singled out as a key source of the high maintenance costs of offshore wind farms. For a given wind speed, the torque of the rotor increases cubically with

  4. Control of offshore wind farms with HVDC grid connection

    Energy Technology Data Exchange (ETDEWEB)

    Weigel, Stefan; Weise, Bernd; Poeller, Markus [DIgSILENT GmbH, Gomaringen (Germany)

    2010-07-01

    This paper analyzes various aspects related to the operation of HVDC connected offshore wind farms. The main interest is on the behavior during on- and offshore faults. Different control strategies for VSC-HVDC and ''classical'' thyristor-based HVDC links are presented and analyzed via network simulations. Wind generators with fully-rated converters and wind generators with doubly-fed induction generators are considered as generator types. The feasibility, advantages and disadvantages of the various options are discussed in detail. (orig.)

  5. Validated Loads Prediction Models for Offshore Wind Turbines for Enhanced Component Reliability

    DEFF Research Database (Denmark)

    Koukoura, Christina

    To improve the reliability of offshore wind turbines, accurate prediction of their response is required. Therefore, validation of models with site measurements is imperative. In the present thesis a 3.6MW pitch regulated-variable speed offshore wind turbine on a monopole foundation is built...... are used for the modification of the sub-structure/foundation design for possible material savings. First, the background of offshore wind engineering, including wind-wave conditions, support structure, blade loading and wind turbine dynamics are presented. Second, a detailed description of the site...

  6. Offshore wind energy - Proceedings of the 2009 Le Havre International Meetings

    International Nuclear Information System (INIS)

    Gerard, Bernard; Rufenacht, Antoine; Marchand, Philippe; Perrot, Jean-Yves; Blanchard, Loic; Leredde, Bruno; Gouverneur, Philippe; Buch, Mette; Westra, Chris; Deswartes, Fabien; Kaelble, Laure; Lutsen, Didier; Kolb, Jean-Mathieu; Moine, Sebastien; Kipke, Ruediger; Coelingh, Jan; Fagot, Guillaume; Noury, Bruno; Herpers, Frederick; Bersani, Catherine; Lanoe, Frederic; Grosdemange, Didier; Uhl, Frederic; Lapierre, Anne; Dumarquez, Philippe; Ruer, Jacques; Huberson, Serge; Barakat, Georges; Cooke, Richard; Reisse, Eric; Bihel, Pierre-Nicolas; Mohr, Rainer; Goesswein, Jens; Brossard, Jerome; Duval, Stephane; Bonnefond, Thierry; Jacquemin, Jerome; His, Stephane; Fazio, Bertrand; Theobald, Fabrice; Boeuf, Marc; Ruer, Jacques; Mercher, Gerard; Poitou, Pascal; Lemarquis, David; Bal, Jean-Louis; Abonnel, Cyrille; Mouslim, Hakim; Rousset, Jean-Marc; Brochard, Emmanuel; Lengyel, Jacques; Antolini, Andre; Gerard, Bernard

    2009-11-01

    This document gathers keynote addresses, contributions and Power Point presentations of a colloquium on the development of offshore wind energy. This colloquium comprises several sessions: the strategy of offshore wind energy development, the planning of wind energy development, the keys of wind energy development, the associated environmental, technological and industrial challenges, the industrial and port deployment for the development of marine energies

  7. Key challenges of offshore wind power: Three essays addressing public acceptance, stakeholder conflict, and wildlife impacts

    Science.gov (United States)

    Bates, Alison Waterbury

    energy. Areas that are highly valuable to the fishing industry are determined by examining fishing effort in three high-value fishing sectors (sea scallops, clam fisheries, and high-value mobile fisheries). Ultimately, the results identify locations where the industries are conflicting and where they are compatible. This quantitative analysis of the potential tradeoffs between the commercial fishing industry and offshore wind development benefits wind developers, states, and federal regulators by helping advance offshore wind power to meet national priorities. Finally, the third essay addresses wildlife impacts through a comprehensive review of the impacts to marine mammals and the regulatory context to manage these impacts. Regulators, scientists, and stakeholders are interested in the potential impacts from pre-construction surveys, turbine installation, operation and maintenance, and decommissioning of offshore wind sites. This article reviews both commissioned reports and peer-reviewed literature to provide a comprehensive overview of the expected impacts of offshore wind energy to marine mammals. Impacts include noise, which is generated during three stages of development: investigation/construction, operation, and decommissioning. Additional potential effects arise from electromagnetic fields, changes in prey abundance and distribution, and the creation of artificial reefs and 'de-facto' marine protected areas. Because offshore wind power may also deliver substantial long-term benefits to wildlife and humans in the form of reduced CO2 emissions, implementation of mitigation measures to reduce negative impacts to marine mammals may be a plausible option to help this industry advance. An overview of mitigation options is reviewed, as well as the legal framework protecting marine mammals from anthropogenic impacts. Finally, the essay makes several recommendations where government and wind developers can improve research and regulatory processes to increase efficiency

  8. International activities and experience in offshore wind power generation; Internationale Aktivitaeten und Erfahrungen im Bereich der Offshore-Windenergienutzung

    Energy Technology Data Exchange (ETDEWEB)

    Rehfeldt, K.; Gerdes, G.J.

    2002-01-01

    Current activities in the area of offshore wind energy are being made only in the European Community in the form of concrete plans or as projects. Denmark and Sweden began as pioneers in the setting up of offshore wind parks along their coast in the Baltic Sea. As a world-wide first, Denmark saw the practicality of offshore wind energy as a way of reducing the emission of CO{sub 2} and opening new doors in the wind energy branch. Essential is not to name the ambitious goals, but that at the designated suitable regions, pilot projects are implemented therefore initiating extensive research and development projects. Our European neighbours have shown us through their own experience what great potential and underlying dynamic offshore wind energy has. The development of projects can be given with confidence to private sector, if however the main consensus from promoters and environmentalists is desired, then in this instance the governmental participation as a guide would be desirable. (orig.)

  9. Study on offshore wind farm integration mode and reactive power compensation

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Xiaoyan; Hong, Lijun; Fu, Yang [Shanghai Univ. of Electrical Power (China). Power and Automation Engineering Dept.

    2013-07-01

    Two typical offshore wind farm grid-connected modes are introduced and dynamic characteristics under their modes are compared from the simulation by PSS/E. The result shows that offshore wind farm with VSC-HVDC has better dynamic characteristics on fault isolation, reactive power compensation, and fault ride through ability. In addition, STATCOM has been applied to the offshore wind farm, the simulation results indicates that it can improve the bus voltage stability in fault and maintain the voltage level under a small perturbation.

  10. Remote sensing observation used in offshore wind energy

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Pena Diaz, Alfredo; Christiansen, Merete Bruun

    2008-01-01

    Remote sensing observations used in offshore wind energy are described in three parts: ground-based techniques and applications, airborne techniques and applications, and satellite-based techniques and applications. Ground-based remote sensing of winds is relevant, in particular, for new large wind...

  11. Mapping seabird sensitivity to offshore wind farms.

    Science.gov (United States)

    Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N; Caldow, Richard W G; Hume, Duncan

    2014-01-01

    We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented.

  12. Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

    Science.gov (United States)

    Sant, T.; Buhagiar, D.; Farrugia, R. N.

    2014-06-01

    A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

  13. Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

    International Nuclear Information System (INIS)

    Sant, T; Buhagiar, D; Farrugia, R N

    2014-01-01

    A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units

  14. 2014-2015 Offshore Wind Technologies Market Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stehly, Tyler [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    This report provides data and analysis to assess the status of the U.S. offshore wind industry through June 30, 2015. It builds on the foundation laid by the Navigant Consortium, which produced three market reports between 2012 and 2014. The report summarizes domestic and global market developments, technology trends, and economic data to help U.S. offshore wind industry stakeholders, including policymakers, regulators, developers, financiers, and supply chain participants, to identify barriers and opportunities. Title page contains link to associated data tables posted at http://www.nrel.gov/docs/fy15osti/64283_data_tables.xlsx.

  15. Offshore Wind Power Production in Critical Weather Conditions

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Sørensen, Poul Ejnar

    2012-01-01

    control the power balance during offshore storm passages. The demonstration will be done on Horns Rev 2 wind farm. In the same project, the impact of a storm front passage over the system security, for the whole Danish system, and with the expected offshore wind power in 2020 will be investigated....... This paper will present the results of up-scaling the impact that a storm front passage will have on the Danish power system in 2020, given that the existing wind turbine storm controller is not replaced. The simulations are done with CorWind and the analysis is focusing on establishing a reference case...... and quantifying the balancing reserve requirements needed in order to keep the security of the power system....

  16. Performance of the CORDEX regional climate models in simulating offshore wind and wind potential

    Science.gov (United States)

    Kulkarni, Sumeet; Deo, M. C.; Ghosh, Subimal

    2018-03-01

    This study is oriented towards quantification of the skill addition by regional climate models (RCMs) in the parent general circulation models (GCMs) while simulating wind speed and wind potential with particular reference to the Indian offshore region. To arrive at a suitable reference dataset, the performance of wind outputs from three different reanalysis datasets is evaluated. The comparison across the RCMs and their corresponding parent GCMs is done on the basis of annual/seasonal wind statistics, intermodel bias, wind climatology, and classes of wind potential. It was observed that while the RCMs could simulate spatial variability of winds, well for certain subregions, they generally failed to replicate the overall spatial pattern, especially in monsoon and winter. Various causes of biases in RCMs were determined by assessing corresponding maps of wind vectors, surface temperature, and sea-level pressure. The results highlight the necessity to carefully assess the RCM-yielded winds before using them for sensitive applications such as coastal vulnerability and hazard assessment. A supplementary outcome of this study is in form of wind potential atlas, based on spatial distribution of wind classes. This could be beneficial in suitably identifying viable subregions for developing offshore wind farms by intercomparing both the RCM and GCM outcomes. It is encouraging that most of the RCMs and GCMs indicate that around 70% of the Indian offshore locations in monsoon would experience mean wind potential greater than 200 W/m2.

  17. Probabilistic Calibration of Fatigue Design Factors for Offshore Wind Turbine Support Structures

    DEFF Research Database (Denmark)

    Ramirez, José Rangel; Sørensen, John Dalsgaard

    2010-01-01

    for the considered offshore wind turbines in such a way that the specific uncertainties for the fatigue life are accounted in a rational manner. Similar approaches have been used for offshore oil & gas sub-structures, but the required reliability level for offshore wind turbines is generally lower and the fatigue......This paper describes a reliability-based approach to determine fatigue design factors (FDF) for offshore wind turbine support structures made of steel. The FDF values are calibrated to a specific reliability level and linked to a specific inspection and maintenance (I&M) strategy used...

  18. Offshore wind options for 2013; Offshore wind kansen voor 2013

    Energy Technology Data Exchange (ETDEWEB)

    Van der Meij-Kranendonk, J.

    2012-11-15

    In the USA researchers and companies are busy to the make knowledge and experiences gained elsewhere in the world suitable for the American market and to increase new knowledge in their own country. A brief overview is given of the activities in the US with regard to offshore wind energy [Dutch] Amerikaanse onderzoekers en bedrijven zijn druk bezig om de kennis en ervaring die opgedaan is elders in de wereld geschikt te maken voor de Amerikaanse markt en om nieuwe kennis op te doen in eigen land.

  19. Review of Methodologies for Offshore Wind Resource Assessment in European Seas

    DEFF Research Database (Denmark)

    Sempreviva, Anna Maria; Barthelmie, Rebecca Jane; Pryor, Sara

    2008-01-01

    promising wind farm sites and (ii) a site specific evaluation of wind climatology and vertical profiles of wind and atmospheric turbulence, in addition to an assessment of historical and possibly future changes due to climate non-stationarity. Phase (i) of the process can involve use of in situ observations......The wind resource offshore is generally larger than at geographically nearby onshore sites, which can offset the higher installation, operation and maintenance costs associated with offshore wind parks. Successful offshore wind energy development relies to some extent on accurate prediction of wind......) of the project often still requires in situ observations (which may or may not be supplemented with ground-based remote sensing technologies) and application of tools to provide a climatological context for the resulting measurements. Current methodologies for undertaking these aspects of the resource assessment...

  20. SAT-WIND project. Final report[Winds from satellites for offshore and coastal wind energy mapping and wind-indexing

    Energy Technology Data Exchange (ETDEWEB)

    Hasager, C.B.; Astrup, P.; Nielsen, M. (and others)

    2007-04-15

    The SAT-WIND project 'Winds from satellites for offshore and coastal wind energy mapping and wind-indexing' was a research project funded by STVF/DSF in the years 2003 to 2006 (Sagsnr. 2058-03-0006). The goal of the project was to verify the applicability of satellite wind maps derived from passive microwave, altimeter, scatterometer and imaging Synthetic Aperture Radar (SAR) technologies for wind energy tools for wind resources and wind-indexing. The study area was the Danish Seas including the North Sea, interior seas and the Baltic Sea. The report describes technical details on the satellite data sources including: 1) passive microwave (SSM/I, AMSR-E), 2) passive microwave polarimetric (WindSat), 3) scatterometer (ERS, QuikSCAT, Midori-2 and NSCAT), 4) altimeter (ERS, Topex, Poseidon, GFO-1, Jason-1), 5) SAR (ERS, Envisat). The SAR wind maps were treated in S-WAsP developed by Risoe National Laboratory in cooperation with GRAS A/S in the innovative project SAT-WIND-SMV (Sagsnr. 2104-05-0084) in the years 2005 and 2006 in parallel with SAT-WIND. The results from the SAT-WIND project are presented. These include ocean wind statistics, offshore wind resource estimates and comparison results for wind-indexing. (au)

  1. SAT-WIND project. Final report[Winds from satellites for offshore and coastal wind energy mapping and wind-indexing

    Energy Technology Data Exchange (ETDEWEB)

    Hasager, C B; Astrup, P; Nielsen, M [and others

    2007-04-15

    The SAT-WIND project 'Winds from satellites for offshore and coastal wind energy mapping and wind-indexing' was a research project funded by STVF/DSF in the years 2003 to 2006 (Sagsnr. 2058-03-0006). The goal of the project was to verify the applicability of satellite wind maps derived from passive microwave, altimeter, scatterometer and imaging Synthetic Aperture Radar (SAR) technologies for wind energy tools for wind resources and wind-indexing. The study area was the Danish Seas including the North Sea, interior seas and the Baltic Sea. The report describes technical details on the satellite data sources including: 1) passive microwave (SSM/I, AMSR-E), 2) passive microwave polarimetric (WindSat), 3) scatterometer (ERS, QuikSCAT, Midori-2 and NSCAT), 4) altimeter (ERS, Topex, Poseidon, GFO-1, Jason-1), 5) SAR (ERS, Envisat). The SAR wind maps were treated in S-WAsP developed by Risoe National Laboratory in cooperation with GRAS A/S in the innovative project SAT-WIND-SMV (Sagsnr. 2104-05-0084) in the years 2005 and 2006 in parallel with SAT-WIND. The results from the SAT-WIND project are presented. These include ocean wind statistics, offshore wind resource estimates and comparison results for wind-indexing. (au)

  2. Feasibility study of offshore wind turbine installation in Iran compared with the world

    Energy Technology Data Exchange (ETDEWEB)

    Mostafaeipour, Ali [Industrial Engineering Department, Yazd University, Yazd (Iran)

    2010-09-15

    Renewable energies have potential for supplying of relatively clean and mostly local energy. Wind energy generation is expected to increase in the near future and has experienced dramatic growth over the past decade in many countries. Offshore winds are generally stronger and more constant than onshore winds in many areas. The economic feasibility for utilization of offshore wind energy depends on the favorable wind conditions in the area. The present paper analyses offshore wind speed in global scale and also studies feasibility of introducing this technology for harnessing wind in Persian Gulf, Caspian Sea, Urmia Lake and Gulf of Oman. Wind speed data were collected from different sources. The ocean surface winds at a 10 m height from satellite passes as processed by NOAA/NESDIS, from near real-time data collected by NASA/JPL's Sea Winds Scatterometer aboard the QuikSCAT. Development of renewable energy is one of priority research goals in Iran. There are many installed wind turbines in suitable regions like Manjil and Binalood, but there has not been any offshore wind installation yet in Iran. It is suggested that policy makers to invest and pay more attentions toward harnessing renewable energy sources like offshore wind in Persian Gulf and Gulf of Oman in southern parts of Iran. (author)

  3. Effects of an Offshore Wind Farm (OWF on the Common Shore Crab Carcinus maenas: Tagging Pilot Experiments in the Lillgrund Offshore Wind Farm (Sweden.

    Directory of Open Access Journals (Sweden)

    Olivia Langhamer

    Full Text Available Worldwide growth of offshore renewable energy production will provide marine organisms with new hard substrate for colonization in terms of artificial reefs. The artificial reef effect is important when planning offshore installations since it can create habitat enhancement. Wind power is the most advanced technology within offshore renewable energy sources and there is an urgent need to study its impacts on the marine environment. To test the hypothesis that offshore wind power increases the abundance of reef species relative to a reference area, we conduct an experiment on the model species common shore crab (Carcinus maenas.Overall, 3962 crabs were captured, observed, marked and released in 2011 and 1995 crabs in 2012. Additionally, carapace size, sex distribution, color morphs and body condition was recorded from captured crabs. We observed very low recapture rates at all sites during both years which made evaluating differences in population sizes very difficult. However, we were able to estimate population densities from the capture record for all three sites. There was no obvious artificial reef effect in the Lillgrund wind farm, but a spill-over effect to nearby habitats cannot be excluded. We could not find any effect of the wind farm on either, morphs, sex distribution or condition of the common shore crab. Our study found no evidence that Lillgrund wind farm has a negative effect on populations of the common shore crab. This study provides the first quantitative and experimental data on the common shore crab in relation to offshore wind farms.

  4. Unravelling historical cost developments of offshore wind energy in Europe

    NARCIS (Netherlands)

    Voormolen, J. A.; Junginger, H. M.; van Sark, W. G J H M

    2016-01-01

    This paper aims to provide insights in the cost developments of offshore wind energy in Europe. This is done by analysing 46 operational offshore wind farms commissioned after 2000. An increase of the Capital Expenditures (CAPEX) is found that is linked to the distance to shore and depth of more

  5. Preliminary Design of a Multi-Column TLP Foundation for a 5-MW Offshore Wind Turbine

    OpenAIRE

    Yongsheng Zhao; Jianmin Yang; Yanping He

    2012-01-01

    Currently, floating wind turbines (FWTs) may be the more economical and suitable systems with which to exploit offshore wind energy in deep waters. Among the various types of floating foundations for offshore wind farms, a tension leg platform (TLP) foundation can provide a relatively stable platform for currently available offshore wind turbines without requiring major modifications. In this study, a new multi-column TLP foundation (WindStar TLP) was developed for the NREL 5-MW offshore wind...

  6. Energy Analysis of Offshore Systems | Wind | NREL

    Science.gov (United States)

    markets enables the compilation of a database of installed and proposed project costs. These are used to offshore wind projects Discounted cash-flow analysis (with the University of Delaware) to identify the level costs based on wind turbine size, annual energy production, and operation costs. The model

  7. IEA Wind Task 23 Offshore Wind Technology and Deployment. Subtask 1 Experience with Critical Deployment Issues. Final Technical Report

    DEFF Research Database (Denmark)

    Lemming, Jørgen Kjærgaard

    The final report for IEA Wind Task 23, Offshore Wind Energy Technology and Deployment, is made up of two separate reports: Subtask 1: Experience with Critical Deployment Issues and Subtask 2: Offshore Code Comparison Collaborative (OC3). The Subtask 1 report included here provides background...... information and objectives of Task 23. It specifically discusses ecological issues and regulation, electrical system integration and offshore wind, external conditions, and key conclusions for Subtask 1. The Subtask 2 report covers OC3 background information and objectives of the task, OC3 benchmark exercises...... of aero-elastic offshore wind turbine codes, monopile foundation modeling, tripod support structure modeling, and Phase IV results regarding floating wind turbine modeling....

  8. Fundamentals for remote condition monitoring of offshore wind turbines

    DEFF Research Database (Denmark)

    McGugan, Malcolm; Larsen, Gunner Chr.; Sørensen, Bent F.

    In the future, large wind turbines will be placed offshore in considerable numbers. Since access will be difficult and costly, it is preferable to use monitoring systems to reduce the reliance on manual inspection. The motivation for the effort reported here is to create the fundamental basis...... of the wind turbine blades that can integrate with existing SCADA tools to improve management of large offshore wind farms, and optimise the manual inspection/maintenance effort. Various sensor types, which have previously been identified as technically (and economically) capable of detecting the early...

  9. Offshore wind development research (technical brief).

    Science.gov (United States)

    2014-04-01

    The study addresses all aspects of Offshore Wind (OSW) development. This includes identifying : vessel types, vessel installation methods, needs and operating characteristics through all phases : of OSW installation, construction, operations and main...

  10. MARE-WINT. New Materials and Reliability in Offshore Wind Turbine Technology

    DEFF Research Database (Denmark)

    This book provides a holistic, interdisciplinary overview of offshore wind energy, and is a must-read for advanced researchers. Topics, from the design and analysis of future turbines, to the decommissioning of wind farms, are covered. The scope of the work ranges from analytical, numerical...... and experimental advancements in structural and fluid mechanics, to novel developments in risk, safety & reliability engineering for offshore wind. The core objective of the current work is to make offshore wind energy more competitive, by improving the reliability, and operations and maintenance (O&M) strategies...... of wind turbines. The research was carried out under the auspices of the EU-funded project, MARE-WINT. The work seeks to bridge the gap between research and a rapidly-evolving industry....

  11. Development of Offshore Wind Recommended Practice for U.S. Waters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Musial, W. D.; Sheppard, R. E.; Dolan, D.; Naughton, B.

    2013-04-01

    This paper discusses how the American Petroleum Institute oil and gas standards were interfaced with International Electrotechnical Commission and other wind turbine and offshore industry standards to provide guidance for reliable engineering design practices for offshore wind energy systems.

  12. EWeA Offshore 2013 - Side event: 'Offshore wind energy - Potentialities and industrial opportunities in France and in Germany. French-German cross perspectives

    International Nuclear Information System (INIS)

    Genachte, Anne-Benedicte; Kavafyan, Philippe; Wagner, Andreas; Bour, Gregoire

    2013-01-01

    At the EWEA Offshore 2013 exhibition, the French-German office for Renewable energies (OFAEnR) organised a side-conference on Offshore wind energy and its Potentialities and industrial opportunities in France and in Germany. In the framework of this French-German exchange of experience, about 50 participants exchanged views on the conditions for the development of a durable offshore wind energy industry both in France and in Germany. This document brings together the available presentations (slides) made during this event: 1 - Supporting industrial development of offshore wind in Europe (Anne-Benedicte Genachte); 2 - Offshore wind energy: the Bremerhaven experience. An asset for the deployment of a complete industrial field in France (Philippe Kavafyan); 3 - Status, Prospects and Challenges for Offshore Wind energy in Germany - incl. Legal Framework and Presentation of cost reduction study results (Andreas Wagner); 4 - Offshore grid connection in Germany - Challenges and recommendations (Gregoire Bour)

  13. Can Weather Radars Help Monitoring and Forecasting Wind Power Fluctuations at Large Offshore Wind Farms?

    DEFF Research Database (Denmark)

    Trombe, Pierre-Julien; Pinson, Pierre; Madsen, Henrik

    2011-01-01

    The substantial impact of wind power fluctuations at large offshore wind farms calls for the development of dedicated monitoring and prediction approaches. Based on recent findings, a Local Area Weather Radar (LAWR) was installed at Horns Rev with the aim of improving predictability, controlability...... and potentially maintenance planning. Additional images are available from a Doppler radar covering the same area. The parallel analysis of rain events detection and of regime sequences in wind (and power) fluctuations demonstrates the interest of employing weather radars for a better operation and management...... of offshore wind farms....

  14. Offshore wind power: does France remain ashore?

    International Nuclear Information System (INIS)

    Bongrain, T.

    2015-01-01

    France benefits from favorable geographical conditions for offshore wind power but the development of a dedicated industrial sector is slow. 6 projects of wind power farms where turbines are rooted in the seabed are expected to operate progressively from 2018, they represent a cumulated power capacity of 2920 MW. A call for projects has been launched by French authorities for floating offshore wind farms off Brittany and in the mediterranean sea but it will not be sufficient to help to fulfill the declared goal of 40% of the electricity produced in France should be of renewable origin. The main weakness is the cost and countries like Germany benefit from the shallow waters of the North sea to install wind farms at lower costs. The solution could be the development in France of an industrial sector dedicated to floating wind turbines that are easier to install in deep water and can be settled farther off the coast to meet the demand of environmentalists for seascape preservation. More sites could become available for floating wind turbines than for seabed-rooted ones and as the consequence the market for floating systems may become more important. (A.C.)

  15. Motion Performance and Mooring System of a Floating Offshore Wind Turbine

    Institute of Scientific and Technical Information of China (English)

    Jing Zhao; Liang Zhang; Haitao Wu

    2012-01-01

    The development of offshore wind farms was originally carried out in shallow water areas with fixed (seabed mounted) structures.However,countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas.The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform.This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine (FOWT) system.The wind turbine was modeled as a wind block with a certain thrust coefficient,and the hydrodynamics and mooring system dynamics of the platform were calculated by SESAM software.The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined.The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.

  16. Motion performance and mooring system of a floating offshore wind turbine

    Science.gov (United States)

    Zhao, Jing; Zhang, Liang; Wu, Haitao

    2012-09-01

    The development of offshore wind farms was originally carried out in shallow water areas with fixed (seabed mounted) structures. However, countries with limited shallow water areas require innovative floating platforms to deploy wind turbines offshore in order to harness wind energy to generate electricity in deep seas. The performances of motion and mooring system dynamics are vital to designing a cost effective and durable floating platform. This paper describes a numerical model to simulate dynamic behavior of a new semi-submersible type floating offshore wind turbine (FOWT) system. The wind turbine was modeled as a wind block with a certain thrust coefficient, and the hydrodynamics and mooring system dynamics of the platform were calculated by SESAM software. The effect of change in environmental conditions on the dynamic response of the system under wave and wind loading was examined. The results indicate that the semi-submersible concept has excellent performance and SESAM could be an effective tool for floating wind turbine design and analysis.

  17. Mapping seabird sensitivity to offshore wind farms.

    Directory of Open Access Journals (Sweden)

    Gareth Bradbury

    Full Text Available We present a Geographic Information System (GIS tool, SeaMaST (Seabird Mapping and Sensitivity Tool, to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented.

  18. Conference on offshore wind energy development in France and Germany - Legal framework, research results and perspectives

    International Nuclear Information System (INIS)

    Schulz, Joerg; Schlegelmilch, Kai; Schulze, Karsten; Abromeit, Carolin; Jensen, Lars Bie; Svendsen, Anne; Schwebel, Olivier; Huebner, Gundula; Heidmann, Roger; Piet, Olivier; Roudil, Jean-Philippe; Fuchs, Tina

    2010-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on offshore wind energy development in France and Germany. In the framework of this French-German exchange of experience, about 170 participants exchanged views on the actual policies, on the offshore potentialities of both countries and on the recent logistics, services, training and software innovations. This document brings together the available presentations (slides) made during this event: 1 - Opening talk by Joerg Schulz, Bremerhaven's Major; 2 - The Future of the Offshore Wind energy in Germany - Key elements of the German energy Concept (Kai Schlegelmilch); 3 - Offshore wind farms: A commercial perspective - Offshore projects profitability (Karsten Schulze); 4 - Offshore Wind Farms in the German EEZ - experiences with the German Approval Procedure: criteria for a successful approval procedure (Carolin Abromeit); 5 - Offshore Wind Parks and fishery in Denmark - Involvement and compensation of commercial fishery in Denmark (Lars Bie Jensen); 6 - Tourism, property value, residents interest and offshore parks - Usage conflicts or regional development? (Anne Svendsen); 7 - Logistics for offshore wind projects - classic ports usable? An overview (Roger Heidmann); 8 - Offshore wind energy and French harbours (Olivier Piet); 9 - French offshore wind power market and component suppliers (Jean-Philippe Roudil); 10 - Trident software - the Offshore Wind Manager. Review and Forecast after one year of construction (Tina Fuchs)

  19. Potential climatic impacts and reliability of large-scale offshore wind farms

    International Nuclear Information System (INIS)

    Wang Chien; Prinn, Ronald G

    2011-01-01

    The vast availability of wind power has fueled substantial interest in this renewable energy source as a potential near-zero greenhouse gas emission technology for meeting future world energy needs while addressing the climate change issue. However, in order to provide even a fraction of the estimated future energy needs, a large-scale deployment of wind turbines (several million) is required. The consequent environmental impacts, and the inherent reliability of such a large-scale usage of intermittent wind power would have to be carefully assessed, in addition to the need to lower the high current unit wind power costs. Our previous study (Wang and Prinn 2010 Atmos. Chem. Phys. 10 2053) using a three-dimensional climate model suggested that a large deployment of wind turbines over land to meet about 10% of predicted world energy needs in 2100 could lead to a significant temperature increase in the lower atmosphere over the installed regions. A global-scale perturbation to the general circulation patterns as well as to the cloud and precipitation distribution was also predicted. In the later study reported here, we conducted a set of six additional model simulations using an improved climate model to further address the potential environmental and intermittency issues of large-scale deployment of offshore wind turbines for differing installation areas and spatial densities. In contrast to the previous land installation results, the offshore wind turbine installations are found to cause a surface cooling over the installed offshore regions. This cooling is due principally to the enhanced latent heat flux from the sea surface to lower atmosphere, driven by an increase in turbulent mixing caused by the wind turbines which was not entirely offset by the concurrent reduction of mean wind kinetic energy. We found that the perturbation of the large-scale deployment of offshore wind turbines to the global climate is relatively small compared to the case of land

  20. DOD Offshore Wind Mission Compatibility Assessments

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set represents the results of analyses conducted by the Department of Defense to assess the compatibility of offshore wind development with military assets...

  1. Numerical investigation of interactions between marine atmospheric boundary layer and offshore wind farm

    Science.gov (United States)

    Lyu, Pin; Chen, Wenli; Li, Hui; Shen, Lian

    2017-11-01

    In recent studies, Yang, Meneveau & Shen (Physics of Fluids, 2014; Renewable Energy, 2014) developed a hybrid numerical framework for simulation of offshore wind farm. The framework consists of simulation of nonlinear surface waves using a high-order spectral method, large-eddy simulation of wind turbulence on a wave-surface-fitted curvilinear grid, and an actuator disk model for wind turbines. In the present study, several more precise wind turbine models, including the actuator line model, actuator disk model with rotation, and nacelle model, are introduced into the computation. Besides offshore wind turbines on fixed piles, the new computational framework has the capability to investigate the interaction among wind, waves, and floating wind turbines. In this study, onshore, offshore fixed pile, and offshore floating wind farms are compared in terms of flow field statistics and wind turbine power extraction rate. The authors gratefully acknowledge financial support from China Scholarship Council (No. 201606120186) and the Institute on the Environment of University of Minnesota.

  2. Willingness to pay for reduced visual disamenities from offshore wind farms in Denmark

    International Nuclear Information System (INIS)

    Ladenburg, Jacob; Dubgaard, Alex

    2007-01-01

    Expansion of offshore wind power plays a significant role in the energy policies of many EU countries. However, offshore wind farms create visual disamenities. These disamenities can be reduced by siting wind farms at larger distances from the coast-and accepting higher costs per kWh produced. In this paper willingness to pay for reducing the visual disamenities from future offshore wind farms is elicited using the economic valuation method Choice Experiments. The valuation scenario comprises the location of 720 offshore wind turbines (equivalent to 3600 MW) in farms at distances equal to: 12, 18 or 50 km from the shore, relative to an 8 km baseline. Using a fixed effect logit model average willingness to pay amounts were estimated as: 46, 96 and 122 Euros/household/year for having the wind farms located at 12, 18 and 50 km from the coast as opposed to 8 km. The results also reveal that WTP deviates significantly depending on the age of respondents and their experiences with offshore wind farms

  3. DC Collection Network Simulation for Offshore Wind Farms

    DEFF Research Database (Denmark)

    Vogel, Stephan; Rasmussen, Tonny Wederberg; El-Khatib, Walid Ziad

    2015-01-01

    The possibility to connect offshore wind turbines with a collection network based on Direct Current (DC), instead of Alternating Current (AC), gained attention in the scientific and industrial environment. There are many promising properties of DC components that could be beneficial such as......: smaller dimensions, less weight, fewer conductors, no reactive power considerations, and less overall losses due to the absence of proximity and skin effects. This work describes a study about the simulation of a Medium Voltage DC (MVDC) grid in an offshore wind farm. Suitable converter concepts...

  4. Collection System Cable Routing and Wake Losses Optimization in Offshore Wind Farms

    NARCIS (Netherlands)

    Fragoso Rodrigues, S.M.; Bauer, P.; Bosman, P.A.N.; Pierik, J.

    2014-01-01

    Offshore wind farms with high installed capacities and located further from the shore are starting to be built by northern European countries. Furthermore, it is expected that by 2020, several dozens of large offshore wind farms will be built in the Baltic, Irish and North seas. These wind farms

  5. Offshore system for integration of the wind energy; Sistema offshore para integracao de energia eolica

    Energy Technology Data Exchange (ETDEWEB)

    Decker, Jan de [3E, Brussels (Belgium); Tambke, Jens [Universidade de Oldemburg (Germany). ForWind; Voelker, J. [Dena - Agencia Alema de Energia (Germany); Michalowska-Knap, Katarzyna [Instituto de Energia Renovavel (Poland)

    2010-09-15

    The Offshore Grid project aims to analyze the conditions required for the development of an offshore transmission network to integrate renewable energy (wind) to the national electrical systems, securely and efficiently. Regulatory aspects, technical, economic and political are considered, that will help the various players in the industry to have a common view on the offshore power grids in Europe.

  6. Potential for Jobs and Economic Development from Offshore Wind in California

    Energy Technology Data Exchange (ETDEWEB)

    Tegen, Suzanne

    2016-11-02

    In California's future scenarios, energy demand increases with population growth and productivity. Decision-makers will have to make choices about which energy resources to utilize, and offshore wind offers one option for carbon-free electricity with the potential for increased local jobs. This presentation discusses results from an NREL report, Floating Offshore Wind in California: Gross Potential for Jobs and Economic Impacts from Two Future Scenarios. Presenter Suzanne Tegen describes the Jobs and Economic Development Impact (JEDI) model and its results for two offshore wind scenarios in California. She discusses different assumptions and how they affect the scenarios.

  7. Different Transportation and Maintenance Strategies for Offshore Wind Farms

    DEFF Research Database (Denmark)

    Ambühl, Simon; Sørensen, John Dalsgaard

    as different maintenance strategies are considered. The report contains a case study where the presented approach is applied to a wind turbine farm and a sensitivity study of the different parameters like the operational range of the boat/helicopter, the electricity price, real rate of interest, inspection......Inspections as well as transportation of personnel and repair parts are a significant contributor to the levelized cost of energy for offshore wind turbines. There are different operation and maintenance (O&M) strategies for offshore wind turbines. Maintenance can be performed preventively...... of energy using different maintenance and transportation strategies....

  8. Electrical network limitations on large-scale deployment of offshore wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Power, P.B.

    2001-07-01

    In this report we have summarised the electrical network limitations to the connection of offshore wind energy schemes in the United Kingdom. The offshore wind resource in the United Kingdom could enable energy production in excess of 230 TWh to be realised. The wind resource of the UK coast should enable 4 GW of wind generation (13.4 GWh assuming 30% load factor) to be developed, providing appropriate technical and commercial arrangements can be made. (author)

  9. Offshore wind industry capabilities in the UK

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This report summarises the results of a questionnaire survey distributed to companies and organisations interested in opportunities in offshore wind energy industries that may results in the improved competitiveness of the industry. The potential areas of advantage for the UK offshore industry are examined including resource and design conditions, turbine design and manufacture, electrical systems, operation and maintenance, project management and finance. Networking and communications are considered.

  10. Reliability of offshore wind power production under extreme wind conditions. Deliverable D 9.5. Work Package 9: Electrical grid

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Zeni, Lorenzo

    years, with each year simulated with five random seeds, leading to a total of 25 annual wind power time series for six large offshore wind farms, summing up to a little over 330 wind turbines. Two storm control strategies were used. The analysis involved several aspects inspired from reliability studies....... The aspects investigated are storm events occurrences and durations, storm control strategy impact on the capacity factor (lost production), the loss of production (power produced from wind drops below a certain threshold due to high wind speeds and storm controller) and finally, the wind power production......Reliability of offshore wind production under extreme wind conditions was investigated in this report. The wind power variability from existing and future large offshore wind farms in Western Denmark were simulated using the Correlated Wind model developed at Risø. The analysis was done for five...

  11. Offshore Wind Turbine Foundation Model Validation with Wind Farm Measurements and Uncertainty Quantification

    DEFF Research Database (Denmark)

    Koukoura, Christina; Natarajan, Anand; Krogh, Thomas

    2013-01-01

    The variation in simulated monopile substructure loads is quantified by validating an aero-hydro-servo-elastic design tool with offshore foundation load measurements. A three bladed 3.6MW pitch controlled variable speed wind turbine for offshore monopile foundations is modeled in the HAWC2...

  12. Offshore wind energy storage concept for cost-of-rated-power savings

    International Nuclear Information System (INIS)

    Qin, Chao; Saunders, Gordon; Loth, Eric

    2017-01-01

    Highlights: •Investigated CAES + HPT system concept for offshore wind energy; •Validated cost model for offshore wind farm including CAPEX and OPEX items; •Quantified cost-of-rated-power savings associated with CAES + HPT concept; •Estimated savings of 21.6% with CAES + HPT for a sample $2.92 billion project. -- Abstract: The size and number of off-shore wind turbines over the next decade is expected to rapidly increase due to the high wind energy potential and the ability of such farms to provide utility-scale energy. In this future, inexpensive and efficient on-site wind energy storage can be critical to address short-time (hourly) mismatches between wind supply and energy demand. This study investigates a compressed air energy storage (CAES) and hydraulic power transmission (HPT) system concept. To assess cost impact, the NREL Cost and Scaling Model was modified to improve accuracy and robustness for offshore wind farms with large turbines. Special attention was paid to the support structure, installation, electrical interface and connections, land leasing, and operations and maintenance cost items as well as specific increased/reduced costs reductions associated with CAES + HPT systems. This cost model was validated and applied to a sample $2.92 billion project Virginia Offshore case It was found that adaption of CAES + HPT can lead to a substantial savings of 21.6% of this 20-year lifetime cost by dramatically reducing capital and operating cost of the generator and power transmission components. However, there are several additional variables that can impact the off-shore energy policy and planning for this new CAES + HPT concept. Furthermore, these cost-savings are only first-order estimates based on linear mass-cost relationships, and thus detailed engineering and economic analysis are recommended.

  13. Offshore wind energy development in France and Germany: what role for territories? Final dissertation

    International Nuclear Information System (INIS)

    Douteau, Anne-Laure

    2010-01-01

    'Pays du Bessin au Virois' is a French association of cities. The association is concerned by projects of offshore wind farms. It wants to think about the consequences of the offshore wind farms on the territory, and the integration in the local activities. For that reason the association wanted to learn from the German experience of offshore development. To compare the French and the German situation, this report raises the question of the relationship between an offshore wind farm and a territory. Thanks to the characteristics of an offshore wind farm and of a territory, I built a method to analyze the relationship between a park and a territory. I studied two cases: the French territory Pays du Bessin au Virois related to the three projects of offshore wind parks in the Baie de Seine, and the German territory Ostfriesland, close to the first offshore wind park in Germany, Alpha Ventus. The two cases showed that important topics could be studied for every territory. There are differences between French and German situation. However the comparison sets on interesting actions for the Pays du Bessin au Virois. Another comparison can be realized with Denmark or United Kingdom, which offshore strategy is closer to the French situation. (author) [fr

  14. Transient LES of an offshore wind turbine

    Directory of Open Access Journals (Sweden)

    L. Vollmer

    2017-12-01

    Full Text Available The estimation of the cost of energy of offshore wind farms has a high uncertainty, which is partly due to the lacking accuracy of information on wind conditions and wake losses inside of the farm. Wake models that aim to reduce the uncertainty by modeling the wake interaction of turbines for various wind conditions need to be validated with measurement data before they can be considered as a reliable estimator. In this paper a methodology that enables a direct comparison of modeled with measured flow data is evaluated. To create the simulation data, a model chain including a mesoscale model, a large-eddy-simulation (LES model and a wind turbine model is used. Different setups are compared to assess the capability of the method to reproduce the wind conditions at the hub height of current offshore wind turbines. The 2-day-long simulation of the ambient wind conditions and the wake simulation generally show good agreements with data from a met mast and lidar measurements, respectively. Wind fluctuations due to boundary layer turbulence and synoptic-scale motions are resolved with a lower representation of mesoscale fluctuations. Advanced metrics to describe the wake shape and development are derived from simulations and measurements but a quantitative comparison proves to be difficult due to the scarcity and the low sampling rate of the available measurement data. Due to the implementation of changing synoptic wind conditions in the LES, the methodology could also be beneficial for case studies of wind farm performance or wind farm control.

  15. Integrated installation for offshore wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Way, J.; Bowerman, H.

    2003-07-01

    A project to investigate the feasibility of integrating the offshore installation of foundation, turbine and tower for offshore wind turbines into one operation is described. Three separate objectives are listed. They are: (1) Telescopic tower study - reversible process incorporating lift and lock mechanisms; (2) Transportation study - technical and economic feasibility of transporting and installing a wind turbine unit via a standard barge with minimal conversion and (3) Self-burial system study - to demonstrate the feasibility of self burial of a slab foundation via controlled jetting beneath the slab. The background to the study and the proposed concepts are discussed. The work carried out to date and the costs are reported together with the findings. Recommendations for future work are listed. The work was carried out by Corus UK Ltd and is managed by Future Energy Solutions for the DTI.

  16. Economic valuation of the visual externalities of off-shore wind farms

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Dubgaard, Alex; Martinsen, Louise

    The primary focus of the study presented in this report is visual externalities of off-shore wind farms and the Danish population’s willingness to pay for having these ex-ternalities reduced. The investigation is part of the Danish monitoring programme for off-shore wind farms, comprising several...

  17. EU 2004 Declaration. EU policy workshop development of offshore wind energy. Background document

    International Nuclear Information System (INIS)

    De Bruijne, R.

    2004-09-01

    Participants of the Dutch EU Presidency's 'EU Policy Workshop on the development of offshore wind energy' published this Declaration that called for action at the EU Transport, Energy and Telecom Council on November 29, 2004. The Declaration lists a series of action points on three main issues relating to the development of offshore wind energy in Europe: market development; environment; and grid integration of large scale offshore wind

  18. Analysis of North Sea Offshore Wind Power Variability

    Directory of Open Access Journals (Sweden)

    Aymeric Buatois

    2014-05-01

    Full Text Available This paper evaluates, for a 2030 scenario, the impact on onshore power systems in terms of the variability of the power generated by 81 GW of offshore wind farms installed in the North Sea. Meso-scale reanalysis data are used as input for computing the hourly power production for offshore wind farms, and this total production is analyzed to identify the largest aggregated hourly power variations. Based on publicly available information, a simplified representation of the coastal power grid is built for the countries bordering the North Sea. Wind farms less than 60 km from shore are connected radially to the mainland, while the rest are connected to a hypothetical offshore HVDC (High-Voltage Direct Current power grid, designed such that wind curtailment does not exceed 1% of production. Loads and conventional power plants by technology and associated cost curves are computed for the various national power systems, based on 2030 projections. Using the MATLAB-based MATPOWER toolbox, the hourly optimal power flow for this regional hybrid AC/DC grid is computed for high, low and medium years from the meso-scale database. The largest net load variations are evaluated per market area and related to the extra load-following reserves that may be needed from conventional generators.

  19. IEA Wind Task 23 Offshore Wind Technology and Deployment. Subtask 1 Experience with Critical Deployment Issues. Final Technical Report

    OpenAIRE

    Lemming, Jørgen Kjærgaard

    2010-01-01

    The final report for IEA Wind Task 23, Offshore Wind Energy Technology and Deployment, is made up of two separate reports: Subtask 1: Experience with Critical Deployment Issues and Subtask 2: Offshore Code Comparison Collaborative (OC3). The Subtask 1 report included here provides background information and objectives of Task 23. It specifically discusses ecological issues and regulation, electrical system integration and offshore wind, external conditions, and key conclusions for Subtask 1. ...

  20. Planners to the rescue: spatial planning facilitating the development of offshore wind energy.

    Science.gov (United States)

    Jay, Stephen

    2010-04-01

    The development of offshore wind energy has started to take place surprisingly quickly, especially in North European waters. This has taken the wind energy industry out of the territory of planning systems that usually govern the siting of wind farms on land, and into the world of departmental, sectoral regulation of marine activities. Although this has favoured the expansion of offshore wind energy in some respects, evidence suggests that the practice and principles of spatial planning can make an important contribution to the proper consideration of proposals for offshore wind arrays. This is especially so when a strategic planning process is put in place for marine areas, in which offshore wind is treated as part of the overall configuration of marine interests, so that adjustments can be made in the interests of wind energy. The current process of marine planning in the Netherlands is described as an illustration of this. (c) 2009 Elsevier Ltd. All rights reserved.

  1. IEA Wind Task 23, offshore wind technology and deployment. Subtask 1: Experience with critical deployment issues. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Lemming, J

    2010-10-15

    The final report for IEA Wind Task 23, Offshore Wind Energy Technology and Deployment, is made up of two separate reports: Subtask 1: Experience with Critical Deployment Issues and Subtask 2: Offshore Code Comparison Collaborative (OC3). The Subtask 1 report included here provides background information and objectives of Task 23. It specifically discusses ecological issues and regulation, electrical system integration and offshore wind, external conditions, and key conclusions for Subtask 1. A comprehensive approach to planning is needed that integrates impacts on ecology, the effects of electrical infrastructure, and the layout of wind farms. Governments, which usually finance ecological research, should disclose results for wide dissemination as they become available. As example the workshop held suggested that documents covering the issues like offshore wind energy legislation, Guidelines for EIAs and SEAs and best practices need to be produced and distributed on a regular basis, as ecological research progresses and experience from the planning and operation of existing wind farms emerges. Research should help strike the balance between optimum regulation and the need to get projects up and running. Such research is needed to increase understanding of offshore wind metrology and its impact on electrical power fluctuations. More work is needed to develop special grid code and standards for offshore. The transient behavior of large cable installations (switching / harmonic/ Behavior and modeling of large HV cable systems) must be better understood. Connection and control systems must be developed for large offshore wind farms. Work is needed to develop the technical architecture of offshore wind grid systems. Public access to measurements (e.g., turbine power output, meteorological masts, buoys) is important, especially for model validation. Determining wake effects is currently the most important challenge in wind engineering. Emphasis should be put into

  2. Grid Integration of Offshore Wind Farms via VSC-HVDC – Dynamic Stability Study

    DEFF Research Database (Denmark)

    Liu, Hongzhi

    farms could seriously impact the operation and stability of their interconnected power system. To assist in maintaining the power system stability when large disturbances occur in the grid, modern offshore wind farms consisting of variable-speed wind turbines are required to provide ancillary services...... such as voltage and frequency control. The greater distance to shore makes commonly used high voltage AC (HVAC) connection unsuitable economically and technically for large offshore wind farms. Alternatively, voltage source converter (VSC)-based high voltage DC (HVDC) transmission becomes more attractive...... and practical to integrate large-scale offshore wind farms into the onshore power grid, owing to its high capacity, advanced controllability and stabilization potential for AC networks etc. In this dissertation, some of the key technical issues with grid integration of large-scale offshore wind farms via VSC...

  3. Monitoring and evaluation of Blyth Offshore wind farm: Health and Safety guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Pepper, L

    2002-07-01

    Experiences during the construction, operation and maintenance of the wind farm off the coast of Blyth in Northumberland are used to assess the practicality of implementing existing draft British Wind Energy Association (BWEA) guidelines. These best practice guidelines, which were drawn up in consultation with the Health and Safety Executive (HSE) offer advice on health and safety issues specific to the wind industry in the UK. The guidelines are intended to cover both onshore and offshore sites; common advice is followed by advice specific to offshore sites. The Blyth Offshore project, the first offshore wind farm in the UK, features two 2 MW turbines installed on a submerged rocky outcrop about 1 km from the coast in a depth of about 6 m at low tide and a tidal range of about 5 m. The report concluded that, from the experience at Blyth, the draft guidelines will provide a useful tool for those involved in all stages of a wind farm project.

  4. Weather radars – the new eyes for offshore wind farms?

    DEFF Research Database (Denmark)

    Trombe, Pierre-Julien; Pinson, Pierre; Vincent, Claire Louise

    2014-01-01

    Offshore wind fluctuations are such that dedicated prediction and control systems are needed for optimizing the management of wind farms in real-time. In this paper, we present a pioneer experiment – Radar@Sea – in which weather radars are used for monitoring the weather at the Horns Rev offshore...... inputs to prediction systems for anticipating changes in the wind fluctuation dynamics, generating improved wind power forecasts and developing specific control strategies. However, integrating weather radar observations into automated decision support systems is not a plug-and-play task...... observed at Horns Rev and (iv) we discuss the future perspectives for weather radars in wind energy. Copyright © 2013 John Wiley & Sons, Ltd....

  5. Monitoring of offshore wind farm using reliable communication

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, K.G.; Gajranib, K.; Bhargavac, A. [Rajasthan Technical Univ.. Dept. of Electrical Engineering, Kota (India)

    2012-07-01

    Due to rapid exhaustion of fossil fuels, new renewable technologies for electricity generation are insisted upon to meet the continuous growing demand of energy all across the globe. Wind energy as a green energy is a favorable option, among other available renewable sources. The offshore wind farm capacity is growing rapidly, but it's uncertain and intermittent nature offers great challenges to power system engineers. The cost of repair and down time, results into extensive damage and reduced profitability. This necessitates the requirement of fast and reliable communication network for the monitoring and controlling of the wind farm. In this paper, we have proposed the communication network for medium offshore wind farm (160MW). The wind farm consists of four clusters; each cluster comprises of 10 Wind Turbines (WTs), each of capacity 4MW. A WT can be represented by nine logical nodes according to IEC-61400-25 standard. The functions of logical nodes are modeled in terms of analogue /status/control information. The wind farm has been modeled in OPNET modeler and the performance of the communication network is evaluated in terms of End to End delay and packet drop, using Synchronous Optical NETwork (SONET) standard. (Author)

  6. Monitoring of offshore wind farm using reliable communication

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, K G; Gajranib, K; Bhargavac, A [Rajasthan Technical Univ. Dept. of Electrical Engineering, Kota (India)

    2012-07-01

    Due to rapid exhaustion of fossil fuels, new renewable technologies for electricity generation are insisted upon to meet the continuous growing demand of energy all across the globe. Wind energy as a green energy is a favorable option, among other available renewable sources. The offshore wind farm capacity is growing rapidly, but it's uncertain and intermittent nature offers great challenges to power system engineers. The cost of repair and down time, results into extensive damage and reduced profitability. This necessitates the requirement of fast and reliable communication network for the monitoring and controlling of the wind farm. In this paper, we have proposed the communication network for medium offshore wind farm (160MW). The wind farm consists of four clusters; each cluster comprises of 10 Wind Turbines (WTs), each of capacity 4MW. A WT can be represented by nine logical nodes according to IEC-61400-25 standard. The functions of logical nodes are modeled in terms of analogue /status/control information. The wind farm has been modeled in OPNET modeler and the performance of the communication network is evaluated in terms of End to End delay and packet drop, using Synchronous Optical NETwork (SONET) standard. (Author)

  7. Fatigue Reliability of Offshore Wind Turbine Systems

    DEFF Research Database (Denmark)

    Marquez-Dominguez, Sergio; Sørensen, John Dalsgaard

    2012-01-01

    of appropriate partial safety factors / fatigue design factors (FDF) for steel substructures of offshore wind turbines (OWTs). The fatigue life is modeled by the SN approach. Design and limit state equations are established based on the accumulated fatigue damage. The acceptable reliability level for optimal...... fatigue design of OWTs is discussed and results for reliability assessment of typical fatigue critical design of offshore steel support structures are presented....

  8. Wake losses optimization of offshore wind farms with moveable floating wind turbines

    NARCIS (Netherlands)

    S.F. Rodrigues; R. Teixeira Pinto (Rodrigo); M. Soleimanzadeh (Maryam); P.A.N. Bosman (Peter); P. Bauer (Pavol)

    2015-01-01

    htmlabstractIn the future, floating wind turbines could be used to harvest energy in deep offshore areas where higher wind mean speeds are observed. Currently, several floating turbine concepts are being designed and tested in small scale projects; in particular, one concept allows the turbine to

  9. Assessment of Wind Datasets for Estimating Offshore Wind Energy along the Central California Coast

    Science.gov (United States)

    Wang, Y. H.; Walter, R. K.; Ruttenberg, B.; White, C.

    2017-12-01

    Offshore renewable energy along the central California coastline has gained significant interest in recent years. We present a comprehensive analysis of near-surface wind datasets available in this region to facilitate future estimates of wind power generation potential. The analyses are based on local NDBC buoys, satellite-based measurements (QuickSCAT and CCMP V2.0), reanalysis products (NARR and MERRA), and a regional climate model (WRF). There are substantial differences in the diurnal signal during different months among the various products (i.e., satellite-based, reanalysis, and modeled) relative to the local buoys. Moreover, the datasets tended to underestimate wind speed under light wind conditions and overestimate under strong wind conditions. In addition to point-to-point comparisons against local buoys, the spatial variations of bias and error in both the reanalysis products and WRF model data in this region were compared against satellite-based measurements. NARR's bias and root-mean-square-error were generally small in the study domain and decreased with distance from coastlines. Although its smaller spatial resolution is likely to be insufficient to reveal local effects, the small bias and error in near-surface winds, as well as the availability of wind data at the proposed turbine hub heights, suggests that NARR is an ideal candidate for use in offshore wind energy production estimates along the central California coast. The framework utilized here could be applied in other site-specific regions where offshore renewable energy is being considered.

  10. Offshore Code Comparison Collaboration within IEA Wind Task 23: Phase IV Results Regarding Floating Wind Turbine Modeling; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jonkman, J.; Larsen, T.; Hansen, A.; Nygaard, T.; Maus, K.; Karimirad, M.; Gao, Z.; Moan, T.; Fylling, I.

    2010-04-01

    Offshore wind turbines are designed and analyzed using comprehensive simulation codes that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity, and controls of the turbine, along with the incident waves, sea current, hydrodynamics, and foundation dynamics of the support structure. This paper describes the latest findings of the code-to-code verification activities of the Offshore Code Comparison Collaboration, which operates under Subtask 2 of the International Energy Agency Wind Task 23. In the latest phase of the project, participants used an assortment of codes to model the coupled dynamic response of a 5-MW wind turbine installed on a floating spar buoy in 320 m of water. Code predictions were compared from load-case simulations selected to test different model features. The comparisons have resulted in a greater understanding of offshore floating wind turbine dynamics and modeling techniques, and better knowledge of the validity of various approximations. The lessons learned from this exercise have improved the participants' codes, thus improving the standard of offshore wind turbine modeling.

  11. Fully vs. Sequentially Coupled Loads Analysis of Offshore Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Damiani, Rick; Wendt, Fabian; Musial, Walter; Finucane, Z.; Hulliger, L.; Chilka, S.; Dolan, D.; Cushing, J.; O' Connell, D.; Falk, S.

    2017-06-19

    The design and analysis methods for offshore wind turbines must consider the aerodynamic and hydrodynamic loads and response of the entire system (turbine, tower, substructure, and foundation) coupled to the turbine control system dynamics. Whereas a fully coupled (turbine and support structure) modeling approach is more rigorous, intellectual property concerns can preclude this approach. In fact, turbine control system algorithms and turbine properties are strictly guarded and often not shared. In many cases, a partially coupled analysis using separate tools and an exchange of reduced sets of data via sequential coupling may be necessary. In the sequentially coupled approach, the turbine and substructure designers will independently determine and exchange an abridged model of their respective subsystems to be used in their partners' dynamic simulations. Although the ability to achieve design optimization is sacrificed to some degree with a sequentially coupled analysis method, the central question here is whether this approach can deliver the required safety and how the differences in the results from the fully coupled method could affect the design. This work summarizes the scope and preliminary results of a study conducted for the Bureau of Safety and Environmental Enforcement aimed at quantifying differences between these approaches through aero-hydro-servo-elastic simulations of two offshore wind turbines on a monopile and jacket substructure.

  12. Modeling of the maintenance policy of an offshore wind farm

    International Nuclear Information System (INIS)

    Maddens, L.; Labeau, P.E.

    2004-01-01

    Wind energy has a key position in the market of renewable electricity production means. Offshore wind farms offer additional surfaces to exploit this form of energy, together with more favourable wind conditions. Yet offshore windmills ask for higher investment and maintenance costs. Optimising the latter costs should therefore turn out to be particularly beneficial for this technology. The present paper summarizes the main modelling aspects of the maintenance of a typical offshore wind farm, such as the accessibility of the wind turbines and the impact of weather conditions, the cost of the different transport resources, the number of maintenance teams, a tolerated unavailability of part of the windmills, the opportunity to combine corrective and preventive maintenance actions on one or several windmills. All these features were embedded in a Petri net model of the maintenance policy of the farm, allowing to estimate the maintenance costs entailed by several strategies. Advantages and drawbacks of using Petri nets for the modelling of such a maintenance strategy are finally discussed. (authors)

  13. MEDOW - Multi-terminal DC Grid for Offshore Wind, Final report

    DEFF Research Database (Denmark)

    A DC grid based on multi-terminal voltage-source converter is a newly emerging technology, which is particularly suitable for the connection of offshore wind farms. Multi-terminal DC grids will be the key technology for the European offshore ‘Super Grid’. In the project, DC power flow, DC relaying...... protection, steady state operation, dynamic stability, fault-ride through capability, and impacts of DC grids on the operation of AC grids and power market were studied. Systematic comparison of DC grid topologies and stability control strategies was carried out, and DC grids for offshore wind power...

  14. Load calculation methods for offshore wind turbine foundations

    DEFF Research Database (Denmark)

    Passon, Patrik; Branner, Kim

    2014-01-01

    Calculation of design loads for offshore wind turbine (OWT) foundations is typically performed in a joint effort between wind turbine manufactures and foundation designers (FDs). Ideally, both parties would apply the same fully integrated design tool and model for that purpose. However, such solu...

  15. Impacts of large-scale offshore wind farm integration on power systems through VSC-HVDC

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2013-01-01

    The potential of offshore wind energy has been commonly recognized and explored globally. Many countries have implemented and planned offshore wind farms to meet their increasing electricity demands and public environmental appeals, especially in Europe. With relatively less space limitation......, an offshore wind farm could have a capacity rating to hundreds of MWs or even GWs that is large enough to compete with conventional power plants. Thus the impacts of a large offshore wind farm on power system operation and security should be thoroughly studied and understood. This paper investigates...... the impacts of integrating a large-scale offshore wind farm into the transmission system of a power grid through VSC-HVDC connection. The concerns are focused on steady-state voltage stability, dynamic voltage stability and transient angle stability. Simulation results based on an exemplary power system...

  16. How Expensive Is Expensive Enough? Opportunities for Cost Reductions in Offshore Wind Energy Logistics

    DEFF Research Database (Denmark)

    Poulsen, Thomas; Hasager, Charlotte Bay

    2016-01-01

    This paper reveals that logistics may conservatively amount to 18% of the levelized cost of energy for offshore wind farms. This is the key finding from an extensive case study carried out within the organization of the world’s leading offshore wind farm developer and operator. The case study aimed...... to, and produced, a number of possible opportunities for offshore wind cost reductions through logistics innovation; however, within the case study company, no company-wide logistics organization existed to focus horizontally on reducing logistics costs in general. Logistics was not well defined...... within the case study company, and a logistics strategy did not exist. With full life-cycle costs of offshore wind farms still high enough to present a political challenge within the European Union in terms of legislation to ensure offshore wind diffusion beyond 2020, our research presents logistics...

  17. Grid-connection of offshore wind farms using VSC-HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Xiaofan; Dessaint, Louis A. [Ecole de Technologie Superieure, Montreal, QC (Canada). Dept. of Electrical Engineering; Gagnon, Richard [Hydro-Quebec Research Institute, Montreal, QC (Canada)

    2011-07-01

    In this paper, the structure of variable speed PMSG-based offshore wind farms connected to the grid through VSC-HVDC link is presented. And the system models are developed. Also, the corresponding control strategy for this system is proposed. The control objective of the generator side VSC is to achieve the optimal wind power by adjusting the speed of permanent magnet synchronous generator, while the grid side VSC is to maintain DC voltage constant. Furthermore, a case study of 100MW offshore wind farm consisting of 50 individual 2MW PSMG-based wind turbines is developed in MATLAB/SimPowerSystems. Simulation results show the proposed scheme works well. (orig.)

  18. How Expensive Is Expensive Enough? Opportunities for Cost Reductions in Offshore Wind Energy Logistics

    Directory of Open Access Journals (Sweden)

    Thomas Poulsen

    2016-06-01

    Full Text Available This paper reveals that logistics may conservatively amount to 18% of the levelized cost of energy for offshore wind farms. This is the key finding from an extensive case study carried out within the organization of the world’s leading offshore wind farm developer and operator. The case study aimed to, and produced, a number of possible opportunities for offshore wind cost reductions through logistics innovation; however, within the case study company, no company-wide logistics organization existed to focus horizontally on reducing logistics costs in general. Logistics was not well defined within the case study company, and a logistics strategy did not exist. With full life-cycle costs of offshore wind farms still high enough to present a political challenge within the European Union in terms of legislation to ensure offshore wind diffusion beyond 2020, our research presents logistics as a next frontier for offshore wind constituencies. This important area of the supply chain is ripe to academically and professionally cultivate and harvest in terms of offshore wind energy cost reductions. Our paper suggests that a focused organizational approach for logistics both horizontally and vertically within the company organizations could be the way forward, coupled with a long-term legislative environment to enable the necessary investments in logistics assets and transport equipment.

  19. Hydroacoustic registration of fish abundance of offshore wind farms. Horns Rev offshore wind farm. Annual report 2004.

    Energy Technology Data Exchange (ETDEWEB)

    Hvidt, C.B.; Bruenner, L.; Reier Knudsen, F.

    2005-05-15

    Elsam Engineering AS has approved the implementation of a project concerning the registration of fish communities in Horns Rev Offshore Wind Farm with use of hydroacoustic methods. In a joint effort, Bio/consult as, Carl Bro as and SIMRAD AS have monitored the fish communities at Horns Rev Offshore Wind Farm using a new hydroacoustic methodology. The new hydroacoustic technique combines the use of scientific sonar acoustics with GPS to determine the density, diversity and location of fish. The objectives of this project were to test the possibility of using hydroacoustic techniques as alternative methods to traditional techniques to assess the fish assemblage inhabiting offshore wind farms and to investigate the possible effect from the wind farm and hard bottom substrates (turbine foundations) on fish abundance. The field study was carried out October 9-10, 2004 and consisted of four horizontal hydroacoustic survey transects each covering impact and reference areas. Transects were surveyed in order to achieve identical impact and reference transect pairs concerning environment, topography and time correspondence. The hydroacoustic equipment consisted of a SIMRAD EK60/EY60 echo sounder with a split-beam transducer (Simrad ES 120-4x10) mounted on a pan and tilt unit, a transceiver, a laptop extended with a GPS-receiver and additional large external hard discs. The raw data files from EK60 were converted to echogram files suitable for the post processing application, Sonar5-Pro. The Sonar5-Pro software makes it possible to filter out echo detections from the surface and the bottom, as well as perform cross filter detection. The validity of the results using the hydroacoustic method is high due to the cross filtering and single target tracking technique. From the hydroacoustic results, no or very little effect from the wind farm or from hard bottom substrates was found on the fish densities at Horns Rev Wind Farm at the time of the survey. The execution of the field

  20. Comparing offshore wind farm wake observed from satellite SAR and wake model results

    Science.gov (United States)

    Bay Hasager, Charlotte

    2014-05-01

    Offshore winds can be observed from satellite synthetic aperture radar (SAR). In the FP7 EERA DTOC project, the European Energy Research Alliance project on Design Tools for Offshore Wind Farm Clusters, there is focus on mid- to far-field wind farm wakes. The more wind farms are constructed nearby other wind farms, the more is the potential loss in annual energy production in all neighboring wind farms due to wind farm cluster effects. It is of course dependent upon the prevailing wind directions and wind speed levels, the distance between the wind farms, the wind turbine sizes and spacing. Some knowledge is available within wind farm arrays and in the near-field from various investigations. There are 58 offshore wind farms in the Northern European seas grid connected and in operation. Several of those are spaced near each other. There are several twin wind farms in operation including Nysted-1 and Rødsand-2 in the Baltic Sea, and Horns Rev 1 and Horns Rev 2, Egmond aan Zee and Prinses Amalia, and Thompton 1 and Thompton 2 all in the North Sea. There are ambitious plans of constructing numerous wind farms - great clusters of offshore wind farms. Current investigation of offshore wind farms includes mapping from high-resolution satellite SAR of several of the offshore wind farms in operation in the North Sea. Around 20 images with wind farm wake cases have been retrieved and processed. The data are from the Canadian RADARSAT-1/-2 satellites. These observe in microwave C-band and have been used for ocean surface wind retrieval during several years. The satellite wind maps are valid at 10 m above sea level. The wakes are identified in the raw images as darker areas downwind of the wind farms. In the SAR-based wind maps the wake deficit is found as areas of lower winds downwind of the wind farms compared to parallel undisturbed flow in the flow direction. The wind direction is clearly visible from lee effects and wind streaks in the images. The wind farm wake cases

  1. Automatic Classification of Offshore Wind Regimes With Weather Radar Observations

    DEFF Research Database (Denmark)

    Trombe, Pierre-Julien; Pinson, Pierre; Madsen, Henrik

    2014-01-01

    Weather radar observations are called to play an important role in offshore wind energy. In particular, they can enable the monitoring of weather conditions in the vicinity of large-scale offshore wind farms and thereby notify the arrival of precipitation systems associated with severe wind...... and amplitude) using reflectivity observations from a single weather radar system. A categorical sequence of most likely wind regimes is estimated from a wind speed time series by combining a Markov-Switching model and a global decoding technique, the Viterbi algorithm. In parallel, attributes of precipitation...... systems are extracted from weather radar images. These attributes describe the global intensity, spatial continuity and motion of precipitation echoes on the images. Finally, a CART classification tree is used to find the broad relationships between precipitation attributes and wind regimes...

  2. Effects of offshore wind energy developments on navigation and commercial shipping

    Energy Technology Data Exchange (ETDEWEB)

    Petts, J W

    1999-07-01

    This report summarises the findings of a study examining the impact of the development of offshore wind farms on commercial shipping and navigation in the area of the UK continental shelf. The study methodology is described, and a review of previous studies is carried out. Technological and current developments, wind farm layout and physical limitations, interaction with marine users, and a quantitative assessment are examined, and the protection of offshore wind farms is considered. Appendices give details of admiralty charts and publications, maps, and chart markings for wind turbines. (UK)

  3. Offshore wind farms in the local community - a survey at Nysted offshore wind farm. Background report; Havvindmoeller i lokalomraedet - en undersoegelse ved Nysted havmoellepark. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.

    2005-07-15

    This report is part of a socio-economic project about offshore wind farms' influence on the local community. The project is part of the monitoring programme in connection with the establishment of the offshore wind farms at Horns Rev and Nysted. The socio-economic project consists of a sociological and an environment-economic project. This report is part of the sociological project which has the purpose of identifying attitudes towards the wind farm before and after the erection with a view to identify possible changes in opinions and reasons for these changes. (BA)

  4. Applicability of Synthetic Aperture Radar Wind Retrievals on Offshore Wind Resources Assessment in Hangzhou Bay, China

    DEFF Research Database (Denmark)

    Chang, Rui; Zhu, Rong; Badger, Merete

    2014-01-01

    In view of the high cost and sparse spatial resolution of offshore meteorological observations, ocean winds retrieved from satellites are valuable in offshore wind resource assessment as a supplement to in situ measurements. This study examines satellite synthetic aperture radar (SAR) images from...... ENVISAT advanced SAR (ASAR) for mapping wind resources with high spatial resolution. Around 181 collected pairs of wind data from SAR wind maps and from 13 meteorological stations in Hangzhou Bay are compared. The statistical results comparing in situ wind speed and SAR-based wind speed show a standard...... density functions are compared at one meteorological station. The SAR-based results appear not to estimate the mean wind speed, Weibull scale and shape parameters and wind power density from the full in situ data set so well due to the lower number of satellite samples. Distributions calculated from...

  5. The market value and impact of offshore wind on the electricity spot market: Evidence from Germany

    International Nuclear Information System (INIS)

    Ederer, Nikolaus

    2015-01-01

    Highlights: • Market value of offshore wind based on feed-in and weather data is assessed. • Merit order effect caused by wind energy is simulated for 2006–2014. • Results indicate same impact of on- and offshore wind on market price and value. • Steadier wind resource offshore imposes less variability on market price. • Characteristic of variable wind feed-in cannot be blamed for price deterioration. - Abstract: Although the expansion of offshore wind has recently increased in Germany, as in other countries, it is still forced to defend its role in long-term energy policy plans, particularly against its onshore counterpart, to secure future expansion targets and financial support. The objective of this article is to investigate the economic effects of offshore wind on the electricity spot market and thus open up another perspective that has not been part of the debate about offshore vs. onshore wind thus far. A comprehensive assessment based on a large amount of market, feed-in and weather data in Germany revealed that the market value of offshore wind is generally higher than that of onshore wind. Simulating the merit order effect on the German day-ahead electricity market for the short term and long term in the years 2006–2014 aimed to identify the reason for this observation and show whether it is also an indication of a lower impact on the electricity spot market due to a steadier wind resource prevailing offshore. Although the results suggest no difference regarding the impact on market price and value, they indeed reveal that offshore wind imposes less variability on the spot market price than onshore wind. In addition, the long-term simulation proved that the ongoing price deterioration cannot be blamed on the characteristic of variable wind production

  6. Trends in offshore wind economics – the past and the future

    DEFF Research Database (Denmark)

    Kitzing, Lena; Morthorst, Poul Erik

    2015-01-01

    our data set to investigate trends in investment cost, operation and maintenance cost, financing and profitability, and identify key economic drivers for offshore wind energy. More specifically, we analyse economic consequences in areas such as project sizes, turbine capacity, distance to shore...... and water depth, as well as the interrelations of the economic drivers in the areas. We then proceed to analysing industry expectations of cost reductions for offshore wind. This includes both previous cost reduction expectations and in how far they could be realised, as well as current cost reductions. We...... set them in perspective and identify the most important drivers for cost reductions in European offshore wind in the short and long term....

  7. Optimization of monopiles for offshore wind turbines.

    Science.gov (United States)

    Kallehave, Dan; Byrne, Byron W; LeBlanc Thilsted, Christian; Mikkelsen, Kristian Kousgaard

    2015-02-28

    The offshore wind industry currently relies on subsidy schemes to be competitive with fossil-fuel-based energy sources. For the wind industry to survive, it is vital that costs are significantly reduced for future projects. This can be partly achieved by introducing new technologies and partly through optimization of existing technologies and design methods. One of the areas where costs can be reduced is in the support structure, where better designs, cheaper fabrication and quicker installation might all be possible. The prevailing support structure design is the monopile structure, where the simple design is well suited to mass-fabrication, and the installation approach, based on conventional impact driving, is relatively low-risk and robust for most soil conditions. The range of application of the monopile for future wind farms can be extended by using more accurate engineering design methods, specifically tailored to offshore wind industry design. This paper describes how state-of-the-art optimization approaches are applied to the design of current wind farms and monopile support structures and identifies the main drivers where more accurate engineering methods could impact on a next generation of highly optimized monopiles. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  8. Development of a 5 MW reference gearbox for offshore wind turbines

    OpenAIRE

    Rasekhi Nejad, Amir; Guo, Yi; Gao, Zhen; Moan, Torgeir

    2016-01-01

    This paper presents detailed descriptions, modeling parameters and technical data of a 5MW high-speed gearbox developed for the National Renewable Energy Laboratory offshore 5MW baseline wind turbine. The main aim of this paper is to support the concept studies and research for large offshore wind turbines by providing a baseline gearbox model with detailed modeling parameters. This baseline gearbox follows the most conventional design types of those used in wind turbines. It is based on the ...

  9. Artificial upwelling using offshore wind energy for mariculture applications

    Directory of Open Access Journals (Sweden)

    Álvaro Viúdez

    2016-09-01

    Full Text Available Offshore wind is proposed as an energy source to upwell nutrient-rich deep water to the ocean photic layers. A spar-buoy wind turbine with a rigid tube about 300 m long is proposed as a pipe to drive deep water up to the surface. The minimum energy required to uplift the water is the potential energy difference between surface waters inside and outside the pipe, which depends on the background density profile. The corresponding surface jump or hydraulic head, h, calculated for several analytical and experimental density profiles, is of the order of 10 cm. If the complete turbine power (of the order of several MW is used for raising the water (assuming a 100% pump efficiency, in a frictionless flow, very large water volumes, of the order of thousands of m3 s-1, will be transported to the photic layers. In a more realistic case, taking into account pipe friction in wide pipes, of the order of 10 m radius, and a power delivered to the fluid of 1 MW, the volume transport is still very large, about 500 m3 s-1. However, such a large amount of dense water could sink fast to aphotic layers due to vertical static instability (the fountain effect, ruining the enhancement of primary production. Hence, some ways to increase the turbulent entrainment and avoid the fountain effect are proposed. From the energetic viewpoint, artificial upwelling using offshore wind energy is a promising way to fertilize large open sea regions. This mariculture application is, however, severely subjected to atmosphere and ocean climatology, as well as to ecological dynamics. The general problem is multidisciplinary, and some important physical, engineering and ecological questions need to be seriously addressed to improve our confidence in the approach presented here.

  10. Sociological investigation of the reception of Nysted Offshore wind farm. Annual report 2004[Denmark

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-15

    This annual report presents the work related to the sociological part of a socio-economic project that examines the effects on the local communities of the two demonstration off-shore wind farms: Horns Rev Offshore Wind Farm, west of Blaavands Huk in Jutland, and Nysted Offshore Wind Farm, south of Lolland. The socio-economic project is part of the monitoring programme in connection with the construction of the offshore wind farms. Unlike projects, which examine the impact of the wind farms on nature, the socio-economic project did not start until 2003. The other part of the socio-economic project is an environmental-economic study that among other things examines the preferences of the population in relation to location of the wind farm and the willingness to pay for increasing the distance between the wind farms and the coast. This sociological study is qualitative. The study is divided into three phases, as the aim is to investigate the public community's attitude towards the erection of an offshore wind farm before and after the construction of the wind farm. This aim is based on the assumption that attitudes may change once the wind farm is erected and the population has experienced the visibility of the wind farm, etc. The division into phases is as follows: 1) Phase 1 treats the conditions as they were before the erection of Nysted Offshore Wind Farm. 2) Phase 2 is a study of the development in attitudes towards Horns Rev Offshore Wind Farm a year after erection. 3) Phase 3 comprises a follow-up study of the local area at Nysted Offshore Wind Farm. The Horns Rev study was conclusive and was carried out September-November 2003. The study at Nysted on the other hand implies two parts. The first was carried out April-August 2003 and identified attitudes before the wind farm was completed. A follow-up study in August-December 2004 served the purpose of revealing the extent of attitude changes regarding the wind farm and the development of these changes of

  11. Dynamic modelling of VSC-HVDC for connection of offshore wind farms

    DEFF Research Database (Denmark)

    Rios, Bardo; Garcia-Valle, Rodrigo

    2011-01-01

    A VSC-HVDC (Voltage Source Converter – High Voltage Direct Current) dynamic model with a set of control strategies is developed in DIgSILENT Power-Factory with the objective of analyzing the converter’s operating capability for grid support during grid faults. The investigation is carried out based...... on a 165 MW offshore wind farm with induction generators and a Low Voltage Ride-Through solution of the offshore wind turbines and Static Voltage Compensator units in the point of connection with a grid represented by a reduced four-generator power grid model. VSC-HVDC promises to be a reliable alternative...... solution for interconnection with off-shore wind farms as they become larger, with a higher installed power capacity, increased number of wind turbines, and geographically situated at larger distances from suitable connection points in the transmission grids....

  12. Modelling and Simulation of VSC-HVDC Connection for Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay Kumar; Teodorescu, Remus; Rodriguez, Pedro

    2010-01-01

    Several large offshore wind power plants (WPP) are planned in the seas around Europe. VSC-HVDC is a suitable means of integrating such large and distant offshore WPP which need long submarine cable transmission to the onshore grid. Recent trend is to use large wind turbine generators with full...... scale converters to achieve an optimal operation over a wide speed range. The offshore grid then becomes very much different from the conventional power system grid, in the sense that it is connected to power electronic converters only. A model of the wind power plant with VSC-HVDC connection...

  13. Prospects for generating electricity by large onshore and offshore wind farms

    DEFF Research Database (Denmark)

    Volker, Patrick; Hahmann, Andrea N.; Badger, Jake

    2017-01-01

    large wind farms, winds can decrease considerably from their free-stream values to a point where an equilibrium wind speed is reached. The magnitude of this equilibrium wind speed is primarily dependent on the balance between turbine drag force and the downward momentum influx from above the wind farm......The decarbonisation of energy sources requires additional investments in renewable technologies, including the installation of onshore and offshore wind farms. For wind energy to remain competitive, wind farms must continue to provide low-cost power even when covering larger areas. Inside very...... on the local free-stream wind speed, the surface characteristics, and the turbine density. In onshore regions with moderate winds the power density of very large wind farms reaches 1 W m−2, whereas in offshore regions with very strong winds it exceeds 3 W m−2. Despite a relatively low power density, onshore...

  14. Offshore wind generators: realization?

    International Nuclear Information System (INIS)

    Roche, Catherine

    2012-01-01

    The author discusses the French legal context for the different aspects of the development of offshore wind farms in France: procedures related to electricity production installations (authorization or tender like what has been done for six sites), other administrative authorizations, and connection to the grid. Then, she addresses the various constraints: environmental, social and technical constraints (protected marine areas, constraints related to the tendering process), coast planning documents, tax policy. She finally discusses the installation dismantling

  15. Policy instruments for offshore wind power; Styrmedel foer havsbaserad vindkraft

    Energy Technology Data Exchange (ETDEWEB)

    Soederholm, Patrik (Luleaa Technical Univ., Luleaa (Sweden))

    2009-10-15

    The future economic potential for offshore wind power is considered to be very good, and there is a strong interest in European wind power industry to improve the technology and generate additional experience. To enable such technology and a market introduction of offshore wind power it is believed that a supplementary or an alternative support for the offshore wind energy is required. This report aims to analyze conditions of different financial instruments to effectively support the rollout of offshore wind power in Sweden. Our mandate does not include an analysis whether any funding is economically justified or not, but a discussion about the objectives of such instruments is necessary for the second stage in order to discuss the instrument characteristics and design. The report takes up a number of different arguments in order to target a specific support for any single technology. An important message from this part of the analysis is that the strongest argument that can be used to extend a special generous support for offshore wind power is that its socio-economic costs may be lower, in the long run, than those which currently apply to established power production lines (e.g. on-shore wind). Any funding should be considered primarily as a means of political action, i.e. a measure not to meet today's short-term goals (eg quota requirement of certificate system) but to cut costs in order to reach the future (long term) goals. The offshore wind energy can be a very interesting candidate for such support, not least because of the favorable wind conditions that exist at sea. For these cost reductions to be realized, it is important to establish niche markets for the turbines and construction work that will be necessary. Such a technology policy presupposes a real development and not solely R and D and D projects. The report presents the results of previous research that supports this assumption, but it makes no attempt to assess whether the relevant effects

  16. Metocean Data Needs Assessment for U.S. Offshore Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Bruce H. [AWS Truepower LLC., Albany, NY (United States); Filippelli, Matthew [AWS Truepower LLC., Albany, NY (United States); Baker, Matthew [AWS Truepower LLC., Albany, NY (United States)

    2015-01-01

    A potential barrier to developing offshore wind energy in the United States is the general lack of accurate information in most offshore areas about the wind resource characteristics and external metocean design conditions at the heights and depths relevant to wind turbines and their associated structures and components. Knowledge of these conditions enables specification of the appropriate design basis for wind turbine structures and components so they can withstand the loads expected over a project’s lifetime. Human safety, vessel navigation, and project construction and maintenance activities are equally tied to the metocean environment. Currently, metocean data is sparse in potential development areas and even when available, does not include the detail or quality required to make informed decisions.

  17. Four essays on offshore wind power potential, development, regulatory framework, and integration

    Science.gov (United States)

    Dhanju, Amardeep

    Offshore wind power is an energy resource whose potential in the US has been recognized only recently. There is now growing interest among the coastal states to harness the resource, particularly in states adjacent to the Mid-Atlantic Bight where the shallow continental shelf allows installation of wind turbines using the existing foundation technology. But the promise of bountiful clean energy from offshore wind could be delayed or forestalled due to policy and regulatory challenges. This dissertation is an effort to identify and address some of the important challenges. Focusing on Delaware as a case study it calculates the extent of the wind resource; considers one means to facilitate resource development---the establishment of statewide and regional public power authorities; analyzes possible regulatory frameworks to manage the resource in state-controlled waters; and assesses the use of distributed storage to manage intermittent output from wind turbines. In order to cover a diversity of topics, this research uses a multi-paper format with four essays forming the body of work. The first essay lays out an accessible methodology to calculate offshore wind resource potential using publicly available data, and uses this methodology to access wind resources off Delaware. The assessment suggests a wind resource approximately four times the average electrical load in Delaware. The second essay examines the potential role of a power authority, a quasi-public institution, in lowering the cost of capital, reducing financial risk of developing and operating a wind farm, and enhancing regional collaboration on resource development and management issues. The analysis suggests that a power authority can lower the cost of offshore wind power by as much as 1/3, thereby preserving the ability to pursue cost-competitive development even if the current federal incentives are removed. The third essay addresses the existing regulatory void in state-controlled waters of Delaware

  18. Overplanting in offshore wind power plants in different regulatory regimes

    DEFF Research Database (Denmark)

    Wolter, Christoph; Klinge Jacobsen, Henrik; Rogdakis, Georgios

    2016-01-01

    framework results more favourable to overplanting. The results indicate that current conceivable offshore wind power plants in the UK can increase their economic value by around 30 mio AC when optimising their capacity setup. In Denmark, current regulations are not suitable for overplanting causing loss...... of value when optimising the capacity design of wind power plants.......Offshore wind power’s journey towards being competitive with other generation technologies relies on technical innovation and maturation, but also on further optimisation of proven and mature solutions. Capacity optimisation or so-called overplanting is one example of optimisation, which...

  19. Cross-wind fatigue analysis of a full scale offshore wind turbine in the case of wind–wave misalignment

    DEFF Research Database (Denmark)

    Koukoura, Christina; Brown, Cameron; Natarajan, Anand

    2016-01-01

    Wind–wave misalignment is often necessary to consider during the design of offshore wind turbines due to excitation of side–side vibration and the low aerodynamic damping in that direction. The measurements from a fully instrumented 3.6 MW pitch regulated-variable speed offshore wind turbine were...

  20. Economical and social fallouts of offshore wind energy in regions. The German example

    International Nuclear Information System (INIS)

    Persem, Melanie

    2012-01-01

    This document presents some key information and figures about the regional development of offshore wind energy in Germany: national energy plan, goals and actual development of offshore wind energy, regional investment, Government's commitment and budget allocated, the German wind power industry and its present and future impact on employment, projects in the North and Baltic seas, wind farms and capacity, electricity feed-in tariffs

  1. Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

    DEFF Research Database (Denmark)

    Chang, Rui; Rong, Zhu; Badger, Merete

    2015-01-01

    offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR) and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS). The wind roses from...... (SD) of 2.09 m/s (1.83 m/s) and correlation coefficient of R 0.75 (0.80). When the offshore winds (i.e., winds directed from land to sea) are excluded, the comparison results for wind speeds show an improvement of SD and R, indicating that the satellite data are more credible over the open ocean...

  2. Collection Network Cable Routing and Wake Losses Optimization in Offshore Wind Farms

    NARCIS (Netherlands)

    S.F. Rodrigues; P. Bauer (Pavol); P.A.N. Bosman (Peter); J. Pierik

    2014-01-01

    htmlabstractOffshore wind farms with high installed capacities and located further from the shore are starting to be built by northern European countries. Furthermore, it is expected that by 2020, several dozens of large offshore wind farms will be built in the Baltic, Irish and North seas. These

  3. Impulse Based Substructuring for Coupling Offshore Structures and Wind Turbines in Aero-Elastic Simulations

    NARCIS (Netherlands)

    Van der Valk, P.L.C.; Rixen, D.J.

    2012-01-01

    In order to achieve the goal of 20% renewable energy in 2020, as set by the European Union, large offshore wind farms are either under construction or in development through-out Europe. As many of the "easy" locations are already under development, offshore wind farms are moving further offshore

  4. Willingness to pay for reduced visual disamenities from off-shore wind farms in Denmark

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Dubgaard, Alex

    Expansion of the off-shore wind power capacity plays a significant role in the wind power strategy in many EU countries. However, off-shore wind farms are associated with visual disamenities. The disamenities can be reduced by locating the wind farms at larger distances from the coast. But......, the costs per kWh produced increase as the distance is augmented. In this paper, peoples’ willingness to pay for a reduction in the visual disamenity of off-shore wind farms is elicited using the economic valuation method Choice Experiments. The economic valuation scenario comprises the locations of 3600 MW...... and 50 km from the coast opposed to 8 km. The results also reveal that the WTP deviate strongly with regards to the age of the respondent and the experiences with off-shore wind farms. These properties of the WTP are believed to have significant policy related consequences. Keywords: Visual Disamenities...

  5. Offshore wind farms in the local environment - an examination at Horns Rev Offshore Wind Farm. Background report; Havvindmoeller i lokalomraadet - en undersoegelse ved Horns Rev Havmoellepark. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, Susanne

    2005-07-01

    Horns Rev Offshore Wind Farm was built in 2002. A presentation is made of a sociological, qualitative survey on the local community's reception of the offshore wind farm. The survey aims at identifying attitudes towards the farm before and after the construction, with a view to identifying possible changes in attitudes, and explain the reasons for these (ml)

  6. Coastal and offshore wind energy generation: is it environmentally benign?

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J. C.; Elliott, M.; Cutts, N. D.; Mander, L.; Mendao, V.; Perez-Dominguez, R.; Phelps, A. [Institute of Estuarine and Coastal Studies, University of Hull, Hull, HU6 7RX (United Kingdom); Wilson, J. C. [Amec, Booths Park, Chelford Road, Knutsford, Cheshire, WA16 8QZ (United Kingdom); Mendao, V. [Projecto Delfim, Centro Portugues de Estudo dos Mamiferos Marinhos, Rua Alto do Duque, 45, 1400-009 Lisboa (Portugal)

    2010-07-15

    Offshore and coastal wind power is one of the fastest growing industries in many areas, especially those with shallow coastal regions due to the preferable generation conditions available in the regions. As with any expanding industry, there are concerns regarding the potential environmental effects which may be caused by the installation of the offshore wind turbines and their associated infrastructure, including substations and subsea cables. These include the potential impacts on the biological, physical and human environments. This review discusses in detail the potential impacts arising from offshore wind farm construction, and how these may be quantified and addressed through the use of conceptual models. It concludes that while not environmentally benign, the environmental impacts are minor and can be mitigated through good siting practices. In addition, it suggests that there are opportunities for environmental benefits through habitat creation and conservation protection areas. (authors)

  7. Floating Offshore Wind in Hawaii: Potential for Jobs and Economic Impacts from Three Future Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Tony; Keyser, David; Tegen, Suzanne

    2016-04-18

    Construction of the first offshore wind power plant in the United States began in 2015, off the coast of Rhode Island, using fixed platform structures that are appropriate for shallow seafloors, like those located off the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to be anchored to the deeper seafloor if deployed in Hawaiian waters. To analyze the employment and economic potential for floating offshore wind off Hawaii's coasts, the Bureau of Ocean Energy Management commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical deployment scenarios for Hawaii: 400 MW of offshore wind by 2050 and 800 MW of offshore wind by 2050. The results of this analysis can be used to better understand the general scale of economic opportunities that could result from offshore wind development.

  8. Operation and control of a DC-grid offshore wind farm under DC transmission system faults

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2013-01-01

    . Consequently, the protection and control strategies of dc systems need to be established. This paper studies a dc-grid offshore wind farm, where the wind power collection system and power transmission system adopt dc technology. In this paper, the redundancy of the HVDC transmission system under faults...... is studied, and a fault ridethrough strategy for the dc-grid offshore wind farm is proposed. The proposed strategy can effectively minimize the impacts of the power transmission system disturbance on the offshore wind farm, and on the ac grid. A dc-grid offshore wind farm example is simulated with PSCAD....../EMTDC, and the results validate the feasibility of the presented redundancy configuration and operation approach, and the fault ridethrough control strategy....

  9. Analysis of Anholt offshore wind farm SCADA measurements

    DEFF Research Database (Denmark)

    Hansen, Kurt Schaldemose; Volker, Patrick; Pena Diaz, Alfredo

    SCADA measurements from the Danish Anholt offshore wind farm (ANH) for a period of 2½ years have been qualified. ANH covers 12 km × 22 km and is located between Djursland and the island Anholt in Kattegat, Denmark. This qualification encompasses identification of curtailment and idling periods......, start/stop events and a power curve control for each wind turbine in the wind farm. Data also include wind speed measurements from a nearby WindCube lidar and simulations from the WRF model for the same period as the SCADA. An equivalent wind speed (wsi) is derived from the combined power and pitch...

  10. Offshore wind farms for hydrogen production subject to uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, Nabil [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Processes

    2002-07-01

    Wind power is a source of clean, nonpolluting electricity, which is fully competitive, if installed at favorable wind sites, with fossil fuel and nuclear power generation. Major technical growth has been in Europe, where government policies and high conventional energy costs favor the use of wind power. As part of its strategy, the EU-Commission has launched a target to increase the installed capacity of Wind power from 7 GWe, in 1998 to 40 GWe by year 2012. Wind power is an intermittent electricity generator, thus it does not provide electric power on an 'as needed' basis. Off-peak power generated from offshore wind farms can be utilized for hydrogen production using water electrolysis. Like electricity, hydrogen is a second energy carrier, which will pave the way for future sustainable energy systems. It is environmentally friendly, versatile, with great potentials in stationary and mobile power applications. Water electrolysis is a well-established technology, which depends on the availability of cheap electrical power. Offshore wind farms have longer lifetime due to lower mechanical fatigue loads, yet to be economic, they have to be of sizes greater than 150 MW using large turbines (> 1.5 MW). The major challenge in wind energy assessment is how accurately the wind speed and hence the error in wind energy can be predicted. Therefore, wind power is subject to a great deal of uncertainties, which should be accounted for in order to provide meaningful and reliable estimates of performance and economic figures-of-merit. Failure to account for uncertainties would result in deterministic estimates that tend to overstate performance and underestimate costs. This study uses methods of risk analysis to evaluate the simultaneous effect of multiple input uncertainties, and provide Life Cycle Assessment (LCA) of the-economic viability of offshore wind systems for hydrogen production subject to technical and economical uncertainties (Published in summary form only)

  11. Optimal Selection of AC Cables for Large Scale Offshore Wind Farms

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Zhe

    2014-01-01

    The investment of large scale offshore wind farms is high in which the electrical system has a significant contribution to the total cost. As one of the key components, the cost of the connection cables affects the initial investment a lot. The development of cable manufacturing provides a vast...... and systematical way for the optimal selection of cables in large scale offshore wind farms....

  12. Airfoil family design for large offshore wind turbine blades

    Science.gov (United States)

    Méndez, B.; Munduate, X.; San Miguel, U.

    2014-06-01

    Wind turbine blades size has scaled-up during last years due to wind turbine platform increase especially for offshore applications. The EOLIA project 2007-2010 (Spanish Goverment funded project) was focused on the design of large offshore wind turbines for deep waters. The project was managed by ACCIONA Energia and the wind turbine technology was designed by ACCIONA Windpower. The project included the design of a wind turbine airfoil family especially conceived for large offshore wind turbine blades, in the order of 5MW machine. Large offshore wind turbines suffer high extreme loads due to their size, in addition the lack of noise restrictions allow higher tip speeds. Consequently, the airfoils presented in this work are designed for high Reynolds numbers with the main goal of reducing blade loads and mantainig power production. The new airfoil family was designed in collaboration with CENER (Spanish National Renewable Energy Centre). The airfoil family was designed using a evolutionary algorithm based optimization tool with different objectives, both aerodynamic and structural, coupled with an airfoil geometry generation tool. Force coefficients of the designed airfoil were obtained using the panel code XFOIL in which the boundary layer/inviscid flow coupling is ineracted via surface transpiration model. The desing methodology includes a novel technique to define the objective functions based on normalizing the functions using weight parameters created from data of airfoils used as reference. Four airfoils have been designed, here three of them will be presented, with relative thickness of 18%, 21%, 25%, which have been verified with the in-house CFD code, Wind Multi Block WMB, and later validated with wind tunnel experiments. Some of the objectives for the designed airfoils concern the aerodynamic behavior (high efficiency and lift, high tangential coefficient, insensitivity to rough conditions, etc.), others concern the geometry (good for structural design

  13. Airfoil family design for large offshore wind turbine blades

    International Nuclear Information System (INIS)

    Méndez, B; Munduate, X; Miguel, U San

    2014-01-01

    Wind turbine blades size has scaled-up during last years due to wind turbine platform increase especially for offshore applications. The EOLIA project 2007-2010 (Spanish Goverment funded project) was focused on the design of large offshore wind turbines for deep waters. The project was managed by ACCIONA Energia and the wind turbine technology was designed by ACCIONA Windpower. The project included the design of a wind turbine airfoil family especially conceived for large offshore wind turbine blades, in the order of 5MW machine. Large offshore wind turbines suffer high extreme loads due to their size, in addition the lack of noise restrictions allow higher tip speeds. Consequently, the airfoils presented in this work are designed for high Reynolds numbers with the main goal of reducing blade loads and mantainig power production. The new airfoil family was designed in collaboration with CENER (Spanish National Renewable Energy Centre). The airfoil family was designed using a evolutionary algorithm based optimization tool with different objectives, both aerodynamic and structural, coupled with an airfoil geometry generation tool. Force coefficients of the designed airfoil were obtained using the panel code XFOIL in which the boundary layer/inviscid flow coupling is ineracted via surface transpiration model. The desing methodology includes a novel technique to define the objective functions based on normalizing the functions using weight parameters created from data of airfoils used as reference. Four airfoils have been designed, here three of them will be presented, with relative thickness of 18%, 21%, 25%, which have been verified with the in-house CFD code, Wind Multi Block WMB, and later validated with wind tunnel experiments. Some of the objectives for the designed airfoils concern the aerodynamic behavior (high efficiency and lift, high tangential coefficient, insensitivity to rough conditions, etc.), others concern the geometry (good for structural design

  14. Dynamic Analysis of Mooring Cables with Application to Floating Offshore Wind Turbines

    OpenAIRE

    Petrone, C.; Oliveto, N. D.; Sivaselvan, M. V.

    2015-01-01

    Floating offshore wind turbines are recently being considered widely for adoption in the wind power industry, attracting interest of several researchers and calling for the development of appropriate computational models and techniques. In the present work, a nonlinear finite-element formulation is proposed and applied to the static and dynamic analysis of mooring cables. Numerical examples are presented, and in particular, a mooring cable typically used for floating offshore wind turbines is...

  15. Effect of Second-Order Hydrodynamics on a Floating Offshore Wind Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Roald, L.; Jonkman, J.; Robertson, A.

    2014-05-01

    The design of offshore floating wind turbines uses design codes that can simulate the entire coupled system behavior. At the present, most codes include only first-order hydrodynamics, which induce forces and motions varying with the same frequency as the incident waves. Effects due to second- and higher-order hydrodynamics are often ignored in the offshore industry, because the forces induced typically are smaller than the first-order forces. In this report, first- and second-order hydrodynamic analysis used in the offshore oil and gas industry is applied to two different wind turbine concepts--a spar and a tension leg platform.

  16. Remotely sensed data fusion for offshore wind energy resource mapping; Fusion de donnees satellitaires pour la cartographie du potentiel eolien offshore

    Energy Technology Data Exchange (ETDEWEB)

    Ben Ticha, M.B

    2007-11-15

    Wind energy is a component of an energy policy contributing to a sustainable development. Last years, offshore wind parks have been installed offshore. These parks benefit from higher wind speeds and lower turbulence than onshore. To sit a wind park, it is necessary to have a mapping of wind resource. These maps are needed at high spatial resolution to show wind energy resource variations at the scale of a wind park. Wind resource mapping is achieved through the description of the spatial variations of statistical parameters characterizing wind climatology. For a precise estimation of these statistical parameters, high temporal resolution wind speed and direction measurements are needed. However, presently, there is no data source allying high spatial resolution and high temporal resolution. We propose a data fusion method taking advantage of the high spatial resolution of some remote sensing instruments (synthetic aperture radars) and the high temporal resolution of other remote sensing instruments (scatterometers). The data fusion method is applied to a case study and the results quality is assessed. The results show the pertinence of data fusion for the mapping of wind energy resource offshore. (author)

  17. Offshore code comparison collaboration continuation (OC4), phase I - Results of coupled simulations of an offshore wind turbine with jacket support structure

    DEFF Research Database (Denmark)

    Popko, Wojciech; Vorpahl, Fabian; Zuga, Adam

    2012-01-01

    In this paper, the exemplary results of the IEA Wind Task 30 "Offshore Code Comparison Collaboration Continuation" (OC4) Project - Phase I, focused on the coupled simulation of an offshore wind turbine (OWT) with a jacket support structure, are presented. The focus of this task has been the verif......In this paper, the exemplary results of the IEA Wind Task 30 "Offshore Code Comparison Collaboration Continuation" (OC4) Project - Phase I, focused on the coupled simulation of an offshore wind turbine (OWT) with a jacket support structure, are presented. The focus of this task has been...... the verification of OWT modeling codes through code-to-code comparisons. The discrepancies between the results are shown and the sources of the differences are discussed. The importance of the local dynamics of the structure is depicted in the simulation results. Furthermore, attention is given to aspects...

  18. Modeling and Simulation of Offshore Wind Power Platform for 5 MW Baseline NREL Turbine

    Science.gov (United States)

    Roni Sahroni, Taufik

    2015-01-01

    This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT) is composed of three main structures comprising the rotor/blades, the tower nacelle, and the supporting structure. The modeling analysis was focused on the nacelle and supporting structure. The completed final design was analyzed using finite element modeling tool ANSYS to obtain the structure's response towards loading conditions and to ensure it complies with guidelines laid out by classification authority Det Norske Veritas. As a result, a new model of the offshore wind power platform for 5 MW Baseline NREL turbine was proposed. PMID:26550605

  19. Assessment of offshore wind power potential in the Aegean and Ionian Seas based on high-resolution hindcast model results

    Directory of Open Access Journals (Sweden)

    Takvor Soukissian

    2017-03-01

    Full Text Available In this study long-term wind data obtained from high-resolution hindcast simulations is used to analytically assess offshore wind power potential in the Aegean and Ionian Seas and provide wind climate and wind power potential characteristics at selected locations, where offshore wind farms are at the concept/planning phase. After ensuring the good model performance through detailed validation against buoy measurements, offshore wind speed and wind direction at 10 m above sea level are statistically analyzed on the annual and seasonal time scale. The spatial distribution of the mean wind speed and wind direction are provided in the appropriate time scales, along with the mean annual and the inter-annual variability; these statistical quantities are useful in the offshore wind energy sector as regards the preliminary identification of favorable sites for exploitation of offshore wind energy. Moreover, the offshore wind power potential and its variability are also estimated at 80 m height above sea level. The obtained results reveal that there are specific areas in the central and the eastern Aegean Sea that combine intense annual winds with low variability; the annual offshore wind power potential in these areas reach values close to 900 W/m2, suggesting that a detailed assessment of offshore wind energy would be worth noticing and could lead in attractive investments. Furthermore, as a rough estimate of the availability factor, the equiprobable contours of the event [4 m/s ≤ wind speed ≤ 25 m/s] are also estimated and presented. The selected lower and upper bounds of wind speed correspond to typical cut-in and cut-out wind speed thresholds, respectively, for commercial offshore wind turbines. Finally, for seven offshore wind farms that are at the concept/planning phase the main wind climate and wind power density characteristics are also provided.

  20. Wind power potential outside the Norwegian coast (offshore); Vindkraftpotensialet utenfor norskekysten (offshore)

    Energy Technology Data Exchange (ETDEWEB)

    Hofstad, Knut; Tallhaug, Lars

    2008-07-01

    Norway has a long coastline with good wind conditions, but is different from many other European countries because a big part of the maritime zone close to the coast is very deep (the Norwegian trench). Thus it is only possible to utilize a small part of the offshore field for wind power with today's technology. Developing wind power offshore is today only extended to the areas with shallow water with depth between 5 and 20 meters. The solution for the deeper areas is not commercially available as of yet, but more and more participants, a Norwegian firm (Owec) among others, are working on solutions that will make it possible to establish wind turbines with a solid base as deep as 100 meters (technology based on experiences from the oil industry). A considerable wind power potential in the shallow water areas outside the Norwegian coast has been proven. Meanwhile the potential is strongly dependent on the demand that the generating station must have a minimum distance from the shore. In areas with depths shallower than 20 meters, the potential is estimated from about 6000 to about 30 000 MW, dependent on if the minimum distance from shore is 10 to 1 km. If the maximum depth is extended to 50 m, the potential is about 13 000 to 55 000 MW. Also an approximation is made on how big the wind power potential can be if the maximum depth is extended to 100 m. The potential for wind power will then improve substantially and will be in the area from 40 000 to 140 000 MW. For depths that deep, it may also be pertinent to increase the demand for minimum distance from the shore to 20 km. The potential outside the 20 km limit will be about 12 000 MW. The investigation considers that the development shall not take place in the protected zones or too close to shore. Specific adverse effects of environmental and other specific effects will however not be evaluated. For instance it is not clear what significance the visual impacts and coast scenery will be and what restrictions

  1. Effects of the Tunoe Knob offshore wind farm on birdlife

    International Nuclear Information System (INIS)

    Guillemette, M.; Kyed Larsen, J.; Clausager, I.

    1997-01-01

    As part of the plans of the Danish government to expand offshore wind energy production, The Ministry of Environment and Energy, in collaboration with the Danish power companies, initiated a three-year study of the effects of the Tunoe Knob offshore wind farm on bird life. The aim of this study was to investigate the potential conflict between offshore wind farms and water birds. Danish coastal waters support very large, internationally important concentrations of moulting, migrating and wintering water birds which depend on shallow water areas as major feeding habitats. The wind farm was established at Tunoe Knob, a shoal in Aarhus Bugt, and consisted of ten 500 kW turbines erected in 3-5 m of water during the late summer of 1995. All studies were carried out during the winter period, and results are reported for eider Somateria mollissima and common scoter Melanitta nigra, which composed the great majority of the bird population. In the part of Tunoe knob where the wind farm was build, eider numbers decreased markedly over the study period. However, this decline was comparable to that observed on other parts of Tunoe Knob. Furthermore, detailed mapping showed a high degree of annual and within season variation in spatial distribution over the area, including occurrence in the immediate vicinity of the wind farm. These results suggest that the observed changes in eider numbers in the wind farm area were due to natural variation. (EG) 21 refs

  2. Developing an Indicator System for Measuring the Social Sustainability of Offshore Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Tzay-An Shiau

    2016-05-01

    Full Text Available Taiwan’s government has promoted investment in an offshore wind power farm, and local fishermen have protested. A social impact assessment (SIA has examined the impact of the proposed offshore wind power farm on all stakeholders. The main objective of the present study was to develop an indicator system for measuring the social sustainability of offshore wind power farms; this study also reports on the particular case of Taiwan’s offshore wind power project. This study began by defining 35 social sustainability indicators and selecting 23 representative indicators by using rough set theory. Subsequently, 14 key indicators were constructed using the social construction of technology (SCOT method. Finally, we developed a social impact index for evaluating the social sustainability of offshore wind power farms by using the analytic network process and Dempster-Shafer theory. Our social impact index yields a total score of 0.149 for Taiwan’s pilot offshore wind power project; this result indicates that the pilot project is socially sustainable. A substantial contradiction exists between the fishermen’s protest and the results of the social impact assessment. The findings can assist the government in building a coordination platform for the investors and the fishermen. Government regulation is necessary to set boundaries for fishing areas that protect both the fishermen’s and investors’ rights.

  3. Offshore Wind Farm Layout Design Considering Optimized Power Dispatch Strategy

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; N. Soltani, Mohsen

    2017-01-01

    Offshore wind farm has drawn more and more attention recently due to its higher energy capacity and more freedom to occupy area. However, the investment is higher. In order to make a cost-effective wind farm, the wind farm layout should be optimized. The wake effect is one of the dominant factors...... leading to energy losses. It is expected that the optimized placement of wind turbines (WT) over a large sea area can lead to the best tradeoff between energy yields and capital investment. This paper proposes a novel way to position offshore WTs for a regular shaped wind farm. In addition to optimizing...... the direction of wind farm placement and the spacing between WTs, the control strategy’s impact on energy yields is also discussed. Since the problem is non-convex and lots of optimization variables are involved, an evolutionary algorithm, the particle swarm optimization algorithm (PSO), is adopted to find...

  4. A decision support system for assessing offshore wind energy potential in the North Sea

    International Nuclear Information System (INIS)

    Schillings, Christoph; Wanderer, Thomas; Cameron, Lachlan; Tjalling van der Wal, Jan; Jacquemin, Jerome; Veum, Karina

    2012-01-01

    Offshore wind energy (OWE) in the North Sea has the potential to meet large share of Europe’s future electricity demand. To deploy offshore wind parks in a rational way, the overall OWE potential has to be realistically determined. This has to be done on an international, cross-border level and by taking into account the existing man-made and nature-related uses of the North Sea. As spatial conflicts will arise between existing uses and the new OWE uses, a Decision Support System (DSS) based on a Geographic Information System (GIS) was developed. Based on data of existing sea uses and calculation rules for spatial prioritisation analysis, the DSS helps in identifying areas that are (1) generally suitable for offshore wind power, (2) strictly excluded or (3) negotiable with respect to other existing sea uses. The combination of this conflict analysis together with cost assumptions for offshore wind farms and their expected electricity yield leads to identification of favourable areas for OWE deployment in the North Sea. This approach helps to reduce the conflict between offshore wind deployment and existing sea uses in the North Sea for future planning. The results can assist decision makers in developing transnational roadmaps for OWE. - Highlights: ► Decision Support System (DSS) to identify offshore wind energy (OWE) potential in the North Sea. ► Spatial analysis of existing sea use functions and offshore wind energy potential. ► Input parameters of DSS depend on the level of OWE spatial priority assumed by the user. ► DSS performs the required calculations and provides results in form of maps and statistics. ► DSS available after registration at (www.windspeed.eu).

  5. Impacts of a large array of offshore wind farms on precipitation during hurricane Harvey

    Science.gov (United States)

    Pan, Y.; Archer, C. L.

    2017-12-01

    Hurricane Harvey brought to the Texas coast possibly the heaviest rain ever recorded in U.S. history, which then caused flooding at unprecedented levels. Previous studies have shown that large arrays of offshore wind farms can extract kinetic energy from a hurricane and thus reduce the wind and storm surge. This study will quantitatively test weather the offshore turbines may also affect precipitation patterns. The Weather Research Forecast model is employed to model Harvey and the offshore wind farms are parameterized as elevated drag and turbulence kinetic energy sources. The turbines (7.8 MW Enercon-126 with rotor diameter D=127 m) are placed along the coast of Texas and Louisiana within 100 km from the shore, where the water depth is below 200 meters. Three spacing between turbines are considered (with the number of turbines in parenthesis): 7D×7D (149,936), 9D×9D (84,339), and 11D×11D (56,226). A fourth case (9D×9D) with a smaller area and thus less turbines (33,363) is added to the simulations to emphasize the impacts of offshore turbines installed specifically to protect the city of Houston, which was flooded heavily during hurricane Harvey. The model is integrated for 24 hours from 00UTC Aug 26th, 2017 to 00UTC Aug 27th, 2017. Model results indicate that the offshore wind farms have a strong impact on the distribution of 24-hour accumulated precipitation, with an obvious decrease onshore, downstream of the wind farms, and an increase in the offshore areas, upstream of or within the wind farms. A sector covering the metro-Houston area is chosen to study the sensitivity of the four different wind farm layouts. The spatial-average 24-hour accumulated precipitation is decreased by 37%, 28%, 20% and 25% respectively for the four cases. Compared with the control case with no wind turbines, increased horizontal wind divergence and lower vertical velocity are found where the precipitation is reduced onshore, whereas increased horizontal wind convergence and

  6. Optimisation of electrical system for offshore wind farms via genetic algorithm

    DEFF Research Database (Denmark)

    Chen, Zhe; Zhao, Menghua; Blaabjerg, Frede

    2009-01-01

    An optimisation platform based on genetic algorithm (GA) is presented, where the main components of a wind farm and key technical specifications are used as input parameters and the electrical system design of the wind farm is optimised in terms of both production cost and system reliability....... The power losses, wind power production, initial investment and maintenance costs are considered in the production cost. The availability of components and network redundancy are included in the reliability evaluation. The method of coding an electrical system to a binary string, which is processed by GA......, is developed. Different GA techniques are investigated based on a real example offshore wind farm. This optimisation platform has been demonstrated as a powerful tool for offshore wind farm design and evaluation....

  7. Statistical Evaluation of the Identified Structural Parameters of an idling Offshore Wind Turbine

    International Nuclear Information System (INIS)

    Kramers, Hendrik C.; Van der Valk, Paul L.C.; Van Wingerden, Jan-Willem

    2016-01-01

    With the increased need for renewable energy, new offshore wind farms are being developed at an unprecedented scale. However, as the costs of offshore wind energy are still too high, design optimization and new innovations are required for lowering its cost. The design of modern day offshore wind turbines relies on numerical models for estimating ultimate and fatigue loads of the turbines. The dynamic behavior and the resulting structural loading of the turbines is determined for a large part by its structural properties, such as the natural frequencies and damping ratios. Hence, it is important to obtain accurate estimates of these modal properties. For this purpose stochastic subspace identification (SSI), in combination with clustering and statistical evaluation methods, is used to obtain the variance of the identified modal properties of an installed 3.6MW offshore wind turbine in idling conditions. It is found that one is able to obtain confidence intervals for the means of eigenfrequencies and damping ratios of the fore-aft and side-side modes of the wind turbine. (paper)

  8. Offshore wind energy. Innovators talking; Wind op zee. Innovators aan het woord

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-02-15

    Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on offshore wind energy [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar wind op zee.

  9. Offshore wind energy. Innovators talking; Wind op zee. Innovators aan het woord

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-02-15

    Qualitative studies have been conducted of the results of completed projects focused on energy innovation, spread over the seven themes of the top sector Energy: Energy saving in industry, Energy conservation in the built environment, Gas, Bio-energy, Smart grids, Offshore Wind, Solar PV. This provides insight into the follow-up activities and lessons of some EOS (Energy Research Subsidy) completed projects with the aim to inspire, connect and strengthen the TKIs (Topconsortia for Knowledge and Innovation) and individual companies and researchers working on energy innovation. This report concerns the research on offshore wind energy [Dutch] Er is een kwalitatief onderzoek uitgevoerd naar de resultaten van afgeronde projecten gericht op energie-innovatie, verdeeld over de zeven thema's van de topsector Energie: Energiebesparing in de industrie; Energiebesparing in de gebouwde omgeving; Gas; Bio-energie; Smart grids; Wind op zee; Zon-pv. Daarmee wordt inzicht gegeven in de vervolgactiviteiten en lessen van een aantal afgesloten EOS-projecten (Energie Onderzoek Subsidie) met het oog op het inspireren, verbinden en versterken van de TKI's (Topconsortia voor Kennis en Innovatie) en individuele bedrijven en onderzoekers die werken aan energie-innovatie. Dit rapport betreft het onderzoek naar wind op zee.

  10. Modeling and Simulation of Offshore Wind Power Platform for 5 MW Baseline NREL Turbine

    Directory of Open Access Journals (Sweden)

    Taufik Roni Sahroni

    2015-01-01

    Full Text Available This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT is composed of three main structures comprising the rotor/blades, the tower nacelle, and the supporting structure. The modeling analysis was focused on the nacelle and supporting structure. The completed final design was analyzed using finite element modeling tool ANSYS to obtain the structure’s response towards loading conditions and to ensure it complies with guidelines laid out by classification authority Det Norske Veritas. As a result, a new model of the offshore wind power platform for 5 MW Baseline NREL turbine was proposed.

  11. Optimization of offshore wind farm layout in restricted zones

    International Nuclear Information System (INIS)

    Hou, Peng; Hu, Weihao; Chen, Cong; Soltani, Mohsen; Chen, Zhe

    2016-01-01

    In this research, an optimization method for offshore wind farm layout design is proposed. With the purpose of maximizing the energy production of the wind farm, the wind turbine (WT) positions are optimized. Due to the limitations of seabed conditions, marine traffic limitations or shipwrecks, etc., the WTs are expected to be placed outside specific areas. Based on this fact, a restriction zone concept is proposed in this paper and implemented with the penalty function method. In order to find a feasible solution, a recent proposed stochastic algorithm, particle swarm optimization algorithm with multiple adaptive methods (PSO-MAM) is adopted. The simulation results indicate that the proposed method can find a layout which outperforms a baseline layout of a reference wind farm (RWF) by increasing the energy yield by 3.84%. - Highlights: • The offshore restricted area concept is proposed. • The recent developed PSO-MAM algorithm is arranged to optimize the layout. • The penalty function method is adopted to help find the feasible solution. • The optimized layout increases energy yields 3.84% than reference wind farm.

  12. Modeling and simulation of offshore wind farm O&M processes

    Energy Technology Data Exchange (ETDEWEB)

    Joschko, Philip, E-mail: joschko@informatik.uni-hamburg.de [University of Hamburg, Dept. of Informatics, Vogt-Kölln-Straße 30, 22527 Hamburg (Germany); Widok, Andi H., E-mail: a.widok@htw-berlin.de [University of Hamburg, Dept. of Informatics, Vogt-Kölln-Straße 30, 22527 Hamburg (Germany); Appel, Susanne, E-mail: susanne.appel@hs-bremen.de [HSB Bremen, Institute for Environment and Biotechnology, Neustadtswall 30, 28199 Bremen (Germany); Greiner, Saskia, E-mail: saskia.greiner@hs-bremen.de [HSB Bremen, Institute for Environment and Biotechnology, Neustadtswall 30, 28199 Bremen (Germany); Albers, Henning, E-mail: henning.albers@hs-bremen.de [HSB Bremen, Institute for Environment and Biotechnology, Neustadtswall 30, 28199 Bremen (Germany); Page, Bernd, E-mail: page@informatik.uni-hamburg.de [University of Hamburg, Dept. of Informatics, Vogt-Kölln-Straße 30, 22527 Hamburg (Germany)

    2015-04-15

    This paper describes a holistic approach to operation and maintenance (O&M) processes in the domain of offshore wind farm power generation. The acquisition and process visualization is followed by a risk analysis of all relevant processes. Hereafter, a tool was designed, which is able to model the defined processes in a BPMN 2.0 notation, as well as connect and simulate them. Furthermore, the notation was enriched with new elements, representing other relevant factors that were, to date, only displayable with much higher effort. In that regard a variety of more complex situations were integrated, such as for example new process interactions depending on different weather influences, in which case a stochastic weather generator was combined with the business simulation or other wind farm aspects important to the smooth running of the offshore wind farms. In addition, the choices for different methodologies, such as the simulation framework or the business process notation will be presented and elaborated depending on the impact they had on the development of the approach and the software solution. - Highlights: • Analysis of operation and maintenance processes of offshore wind farms • Process modeling with BPMN 2.0 • Domain-specific simulation tool.

  13. Modeling and simulation of offshore wind farm O&M processes

    International Nuclear Information System (INIS)

    Joschko, Philip; Widok, Andi H.; Appel, Susanne; Greiner, Saskia; Albers, Henning; Page, Bernd

    2015-01-01

    This paper describes a holistic approach to operation and maintenance (O&M) processes in the domain of offshore wind farm power generation. The acquisition and process visualization is followed by a risk analysis of all relevant processes. Hereafter, a tool was designed, which is able to model the defined processes in a BPMN 2.0 notation, as well as connect and simulate them. Furthermore, the notation was enriched with new elements, representing other relevant factors that were, to date, only displayable with much higher effort. In that regard a variety of more complex situations were integrated, such as for example new process interactions depending on different weather influences, in which case a stochastic weather generator was combined with the business simulation or other wind farm aspects important to the smooth running of the offshore wind farms. In addition, the choices for different methodologies, such as the simulation framework or the business process notation will be presented and elaborated depending on the impact they had on the development of the approach and the software solution. - Highlights: • Analysis of operation and maintenance processes of offshore wind farms • Process modeling with BPMN 2.0 • Domain-specific simulation tool

  14. 8th international workshop on large-scale integration of wind power into power systems as well as on transmission networks for offshore wind farms. Proceedings

    International Nuclear Information System (INIS)

    Betancourt, Uta; Ackermann, Thomas

    2009-01-01

    Within the 8th International Workshop on Large-Scale Integration of Wind Power into Power Systems as well as on Transmission Networks for Offshore Wind Farms at 14th to 15th October, 2009 in Bremen (Federal Republic of Germany), lectures and posters were presented to the following sessions: (1) Keynote session and panel; (2) Grid integration studies and experience: Europe; (3) Connection of offshore wind farms; (4) Wind forecast; (5) High voltage direct current (HVDC); (6) German grid code issues; (7) Offshore grid connection; (8) Grid integration studies and experience: North America; (9) SUPWIND - Decision support tools for large scale integration of wind; (10) Windgrid - Wind on the grid: An integrated approach; (11) IEA Task 25; (12) Grid code issues; (13) Market Issues; (14) Offshore Grid; (15) Modelling; (16) Wind power and storage; (17) Power system balancing; (18) Wind turbine performance; (19) Modelling and offshore transformer.

  15. Wind Loads on Ships and Offshore Structures Estimated by CFD

    DEFF Research Database (Denmark)

    Aage, Christian; Hvid, S.L.; Hughes, P.H.

    1997-01-01

    Wind loads on ships and offshore structures could until recently be determined only by model tests, or by statistical methods based on model tests. By the development of Computational Fluid Dynamics or CFD there is now a realistic computational alternative available. In this paper, wind loads...... on a seagoing ferry and on a semisubmersible offshore platform have been estimated by CFD. The results have been compared with wind tunnel model tests and, for the ferry, a few full-scale measurements, and good agreement is obtained. The CFD method offers the possibility of a computational estimate of scale...... effects related to wind tunnel model testing. An example of such an estimate on the ferry is discussed. Due to the time involved in generating the computational mesh and in computing the solution, the CFD method is not at the moment economically competitive to routine wind tunnel model testing....

  16. Offshore wind energy in Mediterranean and other european seas: Technology and potential applications

    International Nuclear Information System (INIS)

    Gaudiosi, G.

    1997-01-01

    In the last six years (1990-1996) the world wide capacity of grid connected offshore wind plants, at the prototypical stage, has reached 12 MW at energy costs some what higher than fifty per cent of similar on shore plants. Additional offshore installations are close to the construction and proposed for some hundreds MW in north european seas. The technology of the offshore wind turbines is evolving parallely to that of the onshore ones

  17. Offshore wind energy in Mediterranean and other european seas: Technology and potential applications

    Energy Technology Data Exchange (ETDEWEB)

    Gaudiosi, G

    1998-12-31

    In the last six years (1990-1996) the world wide capacity of grid connected offshore wind plants, at the prototypical stage, has reached 12 MW at energy costs some what higher than fifty per cent of similar on shore plants. Additional offshore installations are close to the construction and proposed for some hundreds MW in north european seas. The technology of the offshore wind turbines is evolving parallely to that of the onshore ones.

  18. Power system integration of VSC-HVDC connected offshore wind power plants

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Kjær, Philip Carne

    This report presents an overview of challenges and solutions for the integration into the power system of offshore wind power plants (WPPs) connected to onshore grids through a voltage-source converter based high voltage direct current (VSC-HVDC) transmission system. Aspects that are touched upon...... of the network in the vicinity of the HVDC station and (iii) limiting characteristics of WPPs such as inherent control and communication delays, presence of mechanical resonances at the same frequency as POD and active power ramp-rate limitations. Clustering of wind power plants The proof of concept...... introduction to justify the study, describe the state-of-art and formulate the project’s objectives, the report is essentially divided into three parts, as follows. Control principles of offshore AC networks The control of offshore AC networks relies purely on power electronics, especially if Type 4 wind...

  19. The effects of second-order hydrodynamics on a semisubmersible floating offshore wind turbine

    International Nuclear Information System (INIS)

    Bayati, I; Jonkman, J; Robertson, A; Platt, A

    2014-01-01

    The objective of this paper is to assess the second-order hydrodynamic effects on a semisubmersible floating offshore wind turbine. Second-order hydrodynamics induce loads and motions at the sum- and difference-frequencies of the incident waves. These effects have often been ignored in offshore wind analysis, under the assumption that they are significantly smaller than first-order effects. The sum- and difference-frequency loads can, however, excite eigenfrequencies of a floating system, leading to large oscillations that strain the mooring system or vibrations that cause fatigue damage to the structure. Observations of supposed second-order responses in wave-tank tests performed by the DeepCwind consortium at the Maritime Research Institute Netherlands (MARIN) offshore basin suggest that these effects might be more important than originally expected. These observations inspired interest in investigating how second-order excitation affects floating offshore wind turbines and whether second-order hydrodynamics should be included in offshore wind simulation tools like FAST. In this work, the effects of second-order hydrodynamics on a floating semisubmersible offshore wind turbine are investigated. Because FAST is currently unable to account for second-order effects, a method to assess these effects was applied in which linearized properties of the floating wind system derived from FAST (including the 6x6 mass and stiffness matrices) are used by WAMIT to solve the first- and second-order hydrodynamics problems in the frequency domain. The method was applied to the Offshore Code Comparison Collaboration Continuation OC4-DeepCwind semisubmersible platform, supporting the National Renewable Energy Laboratory's 5-MW baseline wind turbine. In this paper, the loads and response of the system caused by the second-order hydrodynamics are analysed and compared to the first-order hydrodynamic loads and induced motions in the frequency domain. Further, the second

  20. German offshore wind turbine farms - status and prospective

    International Nuclear Information System (INIS)

    2004-08-01

    As a consequence of Germany's forthcoming phase-out of nuclear power the German government has initiated a number of activities in order to further development of renewable energy in the future. Offshore wind power has been chosen to play a central part. Although the first wind turbine has yet to be erected in German waters there is no doubt that it is a matter of time before the growing German market will gather speed. The objective of this report is to provide Danish business enterprises with interests in wind power with an insight into the German offshore wind power market and the export possibilities of the present and in the near future. As introduction the report lists the general outlines for construction and operation of wind turbine farms in Germany, furthermore, a number of additional conditions that Danish business enterprises should be aware of are listed. The introduction is followed by an up-to-the -minute status account of all ongoing projects. This part of the report has been made on the basis of a questionnaire send out by the Danish Embassy to project leaders in the business enterprises behind the project planning. Finally, the report provides an overview of all partners behind the planned wind farms. The overview contains contact information as well as information about the composition of project companies and consortiums. (BA)

  1. Natural Frequency and Damping Estimation of an Offshore Wind Turbine Structure

    DEFF Research Database (Denmark)

    Damgaard, Mads; Andersen, Jacob K. F.; Ibsen, Lars Bo

    2012-01-01

    During the last years, offshore wind turbines have increased significantly in size with larger rotors and more powerful generators. The costs are kept as low as possible by reducing the overall weight, which leads to very slender and flexible structures. An improper design may cause resonance due...... of an offshore wind turbine located in the North Sea. Simple Fourier Transformation and least square fitting to the vibration decay of ten “rotor stop” tests make it possible to evaluate the dynamic properties of the wind turbine structure. Based on the traditionally p-y curve method (Winkler type approach...

  2. Baltic 2 offshore wind farm. Challenges and solutions during design and erection of a 288 MW offshore wind power plant; Baltic 2 Offshore Windpark. Herausforderungen und Loesungen waehrend der Design- und Errichtungsphase eines 288 MW Offshore-Windkraftwerks

    Energy Technology Data Exchange (ETDEWEB)

    Stamatelopoulos, Georg-Nikolaus; Kansy, Stefan [EnBW Energie Baden-Wuerttemberg AG, Stuttgart (Germany); Hannibal, John Michael [Siemens AG, Hamburg (Germany). Wind Power and Renewables Div.; Frettloehr, Bjoern [EnBW Energie Baden-Wuerttemberg AG, Hamburg (Germany). Wind und Maritime Technik

    2015-05-01

    Offshore wind offers a great potential for reliable power supply with markedly less future costs. However, offshore also means special requirements related to transport and installation at sea. Even if these requirements alone are very stringent, they are not the only ones that apply. Meeting these challenges requires project organisation comparable to other major projects.

  3. Semi-active control of monopile offshore wind turbines under multi-hazards

    Science.gov (United States)

    Sun, C.

    2018-01-01

    The present paper studies the control of monopile offshore wind turbines subjected to multi-hazards consisting of wind, wave and earthquake. A Semi-active tuned mass damper (STMD) with tunable natural frequency and damping ratio is introduced to control the dynamic response. A new fully coupled analytical model of the monopile offshore wind turbine with an STMD is established. The aerodynamic, hydrodynamic and seismic loading models are derived. Soil effects and damage are considered. The National Renewable Energy Lab monopile 5 MW baseline wind turbine model is employed to examine the performance of the STMD. A passive tuned mass damper (TMD) is utilized for comparison. Through numerical simulation, it is found that before damage occurs, the wind and wave induced response is more dominant than the earthquake induced response. With damage presence in the tower and the foundation, the nacelle and the tower response is increased dramatically and the natural frequency is decreased considerably. As a result, the passive TMD with fixed parameters becomes off-tuned and loses its effectiveness. In comparison, the STMD retuned in real-time demonstrates consistent effectiveness in controlling the dynamic response of the monopile offshore wind turbines under multi-hazards and damage with a smaller stroke.

  4. Design tool for offshore wind farm clusters

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Giebel, Gregor; Waldl, Igor

    2015-01-01

    . The software includes wind farm wake models, energy yield models, inter-array and long cable and grid component models, grid code compliance and ancillary services models. The common score for evaluation in order to compare different layouts is levelized cost of energy (LCoE). The integrated DTOC software...... Research Alliance (EERA) and a number of industrial partners. The approach has been to develop a robust, efficient, easy to use and flexible tool, which integrates software relevant for planning offshore wind farms and wind farm clusters and supports the user with a clear optimization work flow...... is developed within the project using open interface standards and is now available as the commercial software product Wind&Economy....

  5. Review of VSC HVDC Connection for Offshore Wind Power Integration

    DEFF Research Database (Denmark)

    Korompili, Asimenia; Wu, Qiuwei; Zhao, Haoran

    2016-01-01

    Voltage Source Converter (VSC) High Voltage Direct Current (HVDC) connection has become a new trend for long distance offshore wind power transmission. It has been confirmed by a lot of research that the maximum distance of a High Voltage Alternative Current (HVAC) sub-marine cable transmission...... system is limited due to surplus charging current of the cables. The VSC HVDC transmission system has the ability to overcome the limitation and offers other advantages over the HVAC transmission system. This paper is to review the VSC HVDC transmission technology and its application for offshore wind...

  6. Review of control algorithms for offshore wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Spruce, C J; Markou, H; Leithead, W E; Dominguez Ruiz, S

    2005-07-01

    Innovative turbine control strategies could allow the improvements to cost and performance considered essential to reduce the cost of energy from offshore wind farms around the UK. This project reviewed and investigated the possibility for further development of a power control algorithm originally developed by NEG Micon Rotors Ltd for use with offshore wind turbines in the hope that more advanced algorithms would reduce the loads on, and hence the costs of, components such as the foundation/support structure, tower, blades and bedplate. Three models (simulation model, linearisation of the simulation model and control model) were produced in order to conduct the review. Application of these models produced the conclusion that the size of the latest generation of offshore wind turbines has now reached a level where performance is starting to be constrained by fundamental factors in the dynamics caused by the machine's physical size. It was also concluded that an ideal control strategy could achieve potential cost savings for the tower and support structure of 5-10% of the total cost of the turbine plus support structure. Further work to develop controllers to reduce loads in the tower and support structure is urged. The report considers non-linear simulation, the linear model, the control model, general operation of the controller, the drive train damping filter, torque control, pitch control and advanced algorithms, and makes detailed recommendations for future work.

  7. Grid Simulator for Testing a Wind Turbine on Offshore Floating Platform

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, V.

    2012-02-01

    An important aspect of such offshore testing of a wind turbine floating platform is electrical loading of the wind turbine generator. An option of interconnecting the floating wind turbine with the onshore grid via submarine power cable is limited by many factors such as costs and associated environmental aspects (i.e., an expensive and lengthy sea floor study is needed for cable routing, burial, etc). It appears to be a more cost effective solution to implement a standalone grid simulator on a floating platform itself for electrical loading of the test wind turbine. Such a grid simulator must create a stable fault-resilient voltage and frequency bus (a micro grid) for continuous operation of the test wind turbine. In this report, several electrical topologies for an offshore grid simulator were analyzed and modeled.

  8. A Spatial-Economic Cost-Reduction Pathway Analysis for U.S. Offshore Wind Energy Development from 2015-2030

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp; Stehly, Tyler

    2016-10-05

    The potential for cost reduction and economic viability for offshore wind varies considerably within the United States. This analysis models the cost impact of a range of offshore wind locational cost variables across more than 7,000 potential coastal sites in the United States' offshore wind resource area. It also assesses the impact of over 50 technology innovations on potential future costs between 2015 and 2027 (Commercial Operation Date) for both fixed-bottom and floating wind systems. Comparing these costs to an initial assessment of local avoided generating costs, this analysis provides a framework for estimating the economic potential for offshore wind. Analyzing economic potential within this framework can help establish a refined understanding across industries of the technology and site-specific risks and opportunities associated with future offshore wind development. The findings from the original report indicate that under the modeled scenario, offshore wind can be expected to achieve significant cost reductions and may approach economic viability in some parts of the United States within the next 15 years.

  9. The North Sea Offshore Wind Service Industry: Status, perspectives and a joint action plan

    DEFF Research Database (Denmark)

    Andersen, Per Dannemand; Clausen, Niels-Erik; Cronin, Tom

    2018-01-01

    The Offshore Wind Service sector is about to established itself as an industrial sector with an own identity, own organisation, and with large future challenges. The article introduces this new sector, including assessment of present and future market sizes. The overall aim of the research reported...... in this article was to increase the innovation capacity of the European offshore wind servicing (OWS) sector by establishing cross-regional cooperation and intensifying the relationship between research and the offshore wind industry. The article uses the concept of innovation system foresight (ISF). The linking...... of the two concepts of foresight and innovation systems has been explored by several studies, but ISF takes a further integration of the two concepts. The article presents a set of concrete actions at multiple levels to support the development of the offshore wind service sector. The findings provides...

  10. Centrifuge and Numerical Modeling of Monopiles for Offshore Wind Towers Installed in Clay

    OpenAIRE

    Murali, Madhuri; Grajales, Francisco; Beemer, Ryan D.; Biscontin, Giovanna; Aubeny, Charles

    2015-01-01

    This is a metadata record relating to an article that cannot be shared due to publisher copyright. Offshore wind power has gained momentum as a means to diversify the world’s energy infrastructure; however, little is still known of the global stiffness behavior of the large diameter low aspect ratio monopiles which have become the foundation of choice for offshore wind towers. Traditionally, offshore foundations have been associated with gravity structures for the oil and gas industry, whi...

  11. Uncertainty Quantification of the Real-Time Reserves for Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Göçmen, Tuhfe; Giebel, Gregor; Réthoré, Pierre-Elouan

    In order to retain the system stability, the wind power plants are required to provide ancillary services. One of those services is reserve power. Here in this study, we focus on the real-time reserves which can be traded in the balancing markets and are currently used for compensation under...... mandatory downregulation stated by the transmission system operators (TSOs). The PossPOW project (Possible Power of down-regulated Offshore Wind power plants) developed a real-time power curve of available power for offshore wind farms for use during down-regulation. The follow-up Concert project......(control and uncertainties in real-time power curves of offshore wind power plants) aims to quantify and finally reduce the uncertainty in reserve power, bringing the PossPOW algorithm and the state of the art forecasting methods together. The experiments designed to test the available power estimated by the Poss...

  12. 75 FR 68824 - Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore Maryland-Request...

    Science.gov (United States)

    2010-11-09

    ... No. BOEM-2010-0038] Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore..., Interior. ACTION: RFI in Commercial Wind Energy Leasing Offshore Maryland, and Invitation for Comments from... construction of a wind energy project(s) on the Outer Continental Shelf (OCS) offshore Maryland. The BOEMRE...

  13. Expected Effects of Offshore Wind Farms on Mediterranean Marine Life

    Directory of Open Access Journals (Sweden)

    Laura Bray

    2016-03-01

    Full Text Available Current climate policy and issues of energy security mean wind farms are being built at an increasing rate to meet energy demand. As wind farm development is very likely in the Mediterranean Sea, we provide an assessment of the offshore wind potential and identify expected biological effects of such developments in the region. We break new ground here by identifying potential offshore wind farm (OWF “hotspots” in the Mediterranean. Using lessons learned in Northern Europe, and small-scale experiments in the Mediterranean, we identify sensitive species and habitats that will likely be influenced by OWFs in both these hotspot areas and at a basin level. This information will be valuable to guide policy governing OWF development and will inform the industry as and when environmental impact assessments are required for the Mediterranean Sea.

  14. Wind Speed Estimation and Parametrization of Wake Models for Downregulated Offshore Wind Farms within the scope of PossPOW Project

    DEFF Research Database (Denmark)

    Göçmen Bozkurt, Tuhfe; Giebel, Gregor; Poulsen, Niels Kjølstad

    2014-01-01

    With increasing installed capacity, wind farms are requested to downregulate more frequently, especially in the offshore environment. Determination and verification of possible (or available) power of downregulated offshore wind farms are the aims of the PossPOW project (see PossPOW.dtu.dk). Two ...... period. The re-calibrated model has to be further parametrized to include dynamic effects such as wind direction variability and meandering also considering different averaging time scales before implemented in full scale wind farms....

  15. Wind class sampling of satellite SAR imagery for offshore wind resource mapping

    DEFF Research Database (Denmark)

    Badger, Merete; Badger, Jake; Nielsen, Morten

    2010-01-01

    developed for mesoscale modeling of wind resources. Its performance in connection with sampling of SAR scenes is tested against two sets of random SAR samples and meteorological observations at three sites in the North Sea during 2005–08. Predictions of the mean wind speed and the Weibull scale parameter......High-resolution wind fields retrieved from satellite synthetic aperture radar (SAR) imagery are combined for mapping of wind resources offshore where site measurements are costly and sparse. A new sampling strategy for the SAR scenes is introduced, based on a method for statistical......-dynamical downscaling of large-scale wind conditions using a set of wind classes that describe representative wind situations. One or more SAR scenes are then selected to represent each wind class and the classes are weighted according to their frequency of occurrence. The wind class methodology was originally...

  16. Transmission of wave energy through an offshore wind turbine farm

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Johnson, Martin; Sørensen, Ole Rene

    2013-01-01

    condition at infinity. From airborne and Satellite SAR (Synthetic Aperture Radar) a model has been derived for the change of the water surface friction C) inside and on the lee side of the offshore wind farm. The effects have been implemented in a spectral wind wave model,MIKE21 SW, and a parametric study......The transmission of wave energy passing an offshore wind farm is studied. Three effects that can change the wave field are analysed, which is the A) energy dissipation due to drag resistance, B) wave reflection/diffraction from structures, and C) the effect of a modified wind field inside...... and on the lee side of the wind farm. The drag dissipation, A), is quantified by a quadratic resistance law. The effect of B) is parameterised based on 1st order potential theory. A method to find the amount of reflected and transmitted wave energy is developed based on the panel method WAMIT™ and a radiation...

  17. Cooperative control of VSC-HVDC connected offshore wind farm with Low-Voltage Ride-Through capability

    DEFF Research Database (Denmark)

    Liu, Yan; Wang, Xiongfei; Chen, Zhe

    2012-01-01

    The Low-Voltage Ride-Through (LVRT) has become an important grid requirement for offshore wind farms connecting with Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) links. In this paper, a cooperative control strategy with LVRT ability is proposed for a VSC-HVDC connected...... variable speed Squirrel-Cage Induction Generator (SCIG) wind farm. The approach employs a DC-link voltage versus offshore AC-bus frequency droop control on the offshore converter of VSC-HVDC link. Thus, the back-to-back converters of SCIG wind turbines can adjust the generated active power based on the AC......-bus frequency deviations, so that a fast power reduction on the wind farm side can be achieved. The EMTDC/PSCAD simulations are performed on a 300 MW offshore variable speed SCIG wind farm. Simulation results confirm the effectiveness of the proposed control method....

  18. Dynamic Reactive Power Control in Offshore HVDC Connected Wind Power Plants

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Cutululis, Nicolaos Antonio; Rather, Zakir Hussain

    2016-01-01

    This paper presents a coordinated reactive power control for a HVDC connected cluster of offshore wind power plants (WPPs). The reactive power reference for the WPP cluster is estimated by an optimization algorithm aiming at minimum active power losses in the offshore AC Grid. For each optimal......, such as wind turbine (WT) terminal, collector cable, and export cable, on the dynamic voltage profile of the offshore grid is investigated. Furthermore, the dynamic reactive power contribution from WTs from different WPPs of the cluster for such faults has also been studied....... reactive power set point, the OWPP cluster controller generates reactive power references for each WPP which further sends the AC voltage/ reactive power references to the associated WTs based on their available reactive power margin. The impact of faults at different locations in the offshore grid...

  19. Reliability-Based Design and Planning of Inspection and Monitoring of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Marquez-Dominguez, Sergio

    Maintaining and developing a sustainable wind industry is the main motivation of this PhD thesis entitled “Reliability-based design and planning of inspection and monitoring of offshore wind turbines”. In this thesis, statistical methods and probability theory are important mathematical tools used...... and offshore wind turbine foundations with the aim of improving the design, decreasing structural costs and increasing benefits. Recently, wind energy technology has started to adopt risk and reliability based inspection planning (RBI) as a methodology based on Bayesian decision theories together...

  20. An offshore wind farm with dc grid connection and its performance under power system transients

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2011-01-01

    by disconnections. This paper presents a transient performance study of an offshore wind farm with HVDC transmission for grid connection, where the wind turbines in the offshore wind farm are also connected with dc collection network. A power-reduction control strategy (PRCS) for transient performance improvement...

  1. Potential role of power authorities in offshore wind power development in the US

    International Nuclear Information System (INIS)

    Dhanju, Amardeep; Firestone, Jeremy; Kempton, Willett

    2011-01-01

    This article examines how power authorities could facilitate and manage offshore wind power development in US coastal waters. The power authority structure is an American 20th century institution for managing energy resources-a form of a public authority or public corporation dedicated to creating, operating and maintaining electric generation and transmission infrastructure. Offshore wind power is characterized by high capital costs but no fuel costs and thus low operating costs. Therefore a power authority, by virtue of its access to low-cost capital and managerial flexibility, could facilitate offshore wind power development by reducing financial risk of developing and lowering debt payments, thus improving the risk profile and lowering the cost of electricity production. Additionally, power authorities can be made up of multiple states, thus opening the possibility for joint action by neighboring coastal states. Using primary and secondary data, we undertake an in-depth analysis of the potential benefits and shortcomings of a power authority approach. - Highlights: → Proposes an institutional solution in the form of power authority for offshore wind power. → Power authority structure can significantly lower the cost of capital. → Tax-free bond financing available to power authority can significantly reduce the cost of energy. → It can enhance regional collaboration among coastal states to harness the offshore wind potential.

  2. A proposed national wind power R and D program. [offshore wind power system for electric energy supplies

    Science.gov (United States)

    Heronemus, W.

    1973-01-01

    An offshore wind power system is described that consists of wind driven electrical dc generators mounted on floating towers in offshore waters. The output from the generators supplies underwater electrolyzer stations in which water is converted into hydrogen and oxygen. The hydrogen is piped to shore for conversion to electricity in fuel cell stations. It is estimated that this system can produce 159 x 10 to the ninth power kilowatt-hours per year. It is concluded that solar energy - and that includes wind energy - is the only way out of the US energy dilemma in the not too distant future.

  3. Fluctuations of offshore wind generation: Statistical modelling

    DEFF Research Database (Denmark)

    Pinson, Pierre; Christensen, Lasse E.A.; Madsen, Henrik

    2007-01-01

    The magnitude of power fluctuations at large offshore wind farms has a significant impact on the control and management strategies of their power output. If focusing on the minute scale, one observes successive periods with smaller and larger power fluctuations. It seems that different regimes yi...

  4. A Spatial-Economic Cost-Reduction Pathway Analysis for U.S. Offshore Wind Energy Development from 2015–2030

    Energy Technology Data Exchange (ETDEWEB)

    Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kilcher, Levi [National Renewable Energy Lab. (NREL), Golden, CO (United States); Damiani, Rick [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maness, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sirnivas, Senu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stehly, Tyler [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mooney, Meghan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Scott, George [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    This report describes a comprehensive effort undertaken by the National Renewable Energy Laboratory (NREL) to understand the cost of offshore wind energy for markets in the United States. The study models the cost impacts of a range of offshore wind locational cost variables for more than 7,000 potential coastal sites in U.S. offshore wind resource areas. It also assesses the impact of more than 50 technology innovations on potential future costs for both fixed-bottom and floating wind systems. Comparing these costs to an initial site-specific assessment of local avoided generating costs, the analysis provides a framework for estimating the economic potential for offshore wind. The analysis is intended to inform a broad set of stakeholders and enable an assessment of offshore wind as part of energy development and energy portfolio planning. It provides information that federal and state agencies and planning commissions could use to inform initial strategic decisions about offshore wind developments in the United States.

  5. Legal-institutional arrangements facilitating offshore wind energy conversion systems (WECS) utilization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, L.H.

    1977-09-01

    Concern for the continuing sufficiency of energy supplies in the U.S. has tended to direct increasing attention to unconventional sources of supply, including wind energy. Some of the more striking proposals for the utilization of wind energy relate to offshore configurations. The legal-institutional arrangements for facilitating the utilization of offshore wind energy conversion systems (WECS) are examined by positioning three program alternatives and analyzing the institutional support required for the implementation of each.

  6. Evaluation of wind farm efficiency and wind turbine wakes at the Nysted offshore wind farm

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Jensen, L.E.

    2010-01-01

    Here, we quantify relationships between wind farm efficiency and wind speed, direction, turbulence and atmospheric stability using power output from the large offshore wind farm at Nysted in Denmark. Wake losses are, as expected, most strongly related to wind speed variations through the turbine...... thrust coefficient; with direction, atmospheric stability and turbulence as important second order effects. While the wind farm efficiency is highly dependent on the distribution of wind speeds and wind direction, it is shown that the impact of turbine spacing on wake losses and turbine efficiency can...... be quantified, albeit with relatively large uncertainty due to stochastic effects in the data. There is evidence of the ‘deep array effect’ in that wake losses in the centre of the wind farm are under-estimated by the wind farm model WAsP, although overall efficiency of the wind farm is well predicted due...

  7. Bats in Dutch offshore wind farms in autumn 2012

    NARCIS (Netherlands)

    Lagerveld, S.; Jonge Poerink, B.; Haselager, R.; Verdaat, J.P.

    2014-01-01

    In the autumn of 2012, we conducted a pilot study with ultrasonic recorders to assess the occurrence of bats over the North Sea. At Offshore Wind Farm Egmond aan Zee (OWEZ) a recorder was installed at the meteorological mast and at Princess Amalia Wind Farm (PAWP) a recorder was attached to the

  8. Market and regulatory aspects of trans-national offshore electricity networks for wind power interconnection

    NARCIS (Netherlands)

    Roggenkamp, Martha M.; Hendriks, Ralph L.; Ummels, Bart C.; Kling, Wil L.

    Subsea cable connections are an essential part of offshore wind power projects. Apart from direct connections between an offshore wind park to the national grid, several alternatives can be envisaged, including the connection to interconnectors between countries or direct connection to a country

  9. Technological learning in offshore wind energy: Different roles of the government

    International Nuclear Information System (INIS)

    Smit, Thijs; Junginger, Martin; Smits, Ruud

    2007-01-01

    Offshore wind energy is a promising source of renewable electricity, even though its current costs prevent large-scale implementation. Technological learning has improved the technology and its economic performance already, and could result in significant further improvements. This study investigates how technological learning takes place in offshore wind energy and how technological learning is related to different policy regimes. Offshore wind energy developments in Denmark and the United Kingdom have been analysed with a technology-specific innovation systems approach. The results reveal that the dominant forms of learning are learning by doing and learning by using. At the same time, learning by interacting is crucial to achieve the necessary binding elements in the technology-specific innovation system. Generally, most learning processes were performed by self-organizing entities. However, sometimes cultural and technical barriers occurred, excluding component suppliers and knowledge institutes from the innovation system. Danish policies successfully anticipated these barriers and removed them; therefore, the Danish policies can be characterized as pro-active. British policies shaped stable conditions for learning only; therefore, they can be characterized as active. In the future, barriers could hinder learning by interacting between the oil and gas industry, the offshore wind industry and academia. Based on this study, we suggest national and international policy makers to design long-term policies to anticipate these barriers, in order to contribute to technological learning

  10. Floating Offshore Wind in Oregon: Potential for Jobs and Economic Impacts from Two Future Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Tony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Keyser, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States); Speer, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-05-01

    Construction of the first offshore wind power plant in the United States began in 2015, off the coast of Rhode Island, using fixed platform structures that are appropriate for shallow seafloors, like those located off of the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to anchor to the deeper seafloor if deployed off of the West Coast. To analyze the employment and economic potential for floating offshore wind along the West Coast, the Bureau of Ocean Energy Management (BOEM) commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical, large-scale deployment scenarios for Oregon: 5,500 megawatts (MW) of offshore wind deployment in Oregon by 2050 (Scenario A), and 2,900 MW of offshore wind by 2050 (Scenario B). These levels of deployment could power approximately 1,600,000 homes (Scenario A) or 870,000 homes (Scenario B). Offshore wind would contribute to economic development in Oregon in the near future, and more substantially in the long term, especially if equipment and labor are sourced from within the state. According to the analysis, over the 2020-2050 period, Oregon floating offshore wind facilities could support 65,000-97,000 job-years and add $6.8 billion-$9.9 billion to the state GDP (Scenario A).

  11. Short-term ecological effects of an offshore wind farm in the Dutch coastal zone; a compilation

    NARCIS (Netherlands)

    Lindeboom, H.J.; Kouwenhoven, H.J.; Bergman, M.J.N.; Bouma, S.; Brasseur, S.; Daan, R.; Fijn, R.C.; de Haan, D.; Dirksen, S.; van Hal, R.; Hille Ris Lambers, R.; ter Hofstede, R.; Krijgsveld, K.L.; Leopold, M.; Scheidat, M.

    2011-01-01

    The number of offshore wind farms is increasing rapidly, leading to questions about the environmental impact of such farms. In the Netherlands, an extensive monitoring programme is being executed at the first offshore wind farm (Offshore Windfarm Egmond aan Zee, OWEZ). This letter compiles the

  12. OC3—Benchmark Exercise of Aero-elastic Offshore Wind Turbine Codes

    Science.gov (United States)

    Passon, P.; Kühn, M.; Butterfield, S.; Jonkman, J.; Camp, T.; Larsen, T. J.

    2007-07-01

    This paper introduces the work content and status of the first international investigation and verification of aero-elastic codes for offshore wind turbines as performed by the "Offshore Code Comparison Collaboration"(OC3) within the "IEA Wind Annex XXIII - Subtask 2". An overview is given on the state-of-the-art of the concerned offshore wind turbine simulation codes. Exemplary results of benchmark simulations from the first phase of the project are presented and discussed while subsequent phases are introduced. Furthermore, the paper discusses areas where differences between the codes have been identified and the sources of those differences, such as the differing theories implemented into the individual codes. Finally, further research and code development needs are presented based on the latest findings from the current state of the project.

  13. Power Flow Analysis of HVAC and HVDC Transmission Systems for Offshore WindParks

    DEFF Research Database (Denmark)

    da Silva, Filipe Miguel Faria; Castro, Rui

    2009-01-01

    As the onshore wind resource is running shorter, wind power promoters are paying attention to the offshore resources. As in most cases there is no load offshore, wind power must be transmitted to the main land. To do so, two options are available: HVAC and HVDC transmission systems. In this paper...... that HVAC solution is limited by the distance to shore and by the wind transmitted power. HVDC options do not show these limitations, but are more expensive and more delicate to deal with, because there is a lack of operational experience, so far....

  14. Wind power offshore - industrial possibilities for Norway; Vindkraft offshore - industrielle muligheter for Norge

    Energy Technology Data Exchange (ETDEWEB)

    Bysveen, S; Hoelseater, O H; Lier-Hansen, S; Hatlen, S; Soensteby, G. (Energiraadet, Oslo (Norway))

    2008-05-15

    The Europeans alteration of energy policy gives Norway a unique possibility to develop new business activity in the contractor industry as well as become a large exporter of renewable energy to Europe. Sea based wind power marks it self as the area with largest potential and is an area where Norway has a large advantage. This possibility is outlined in this report with offshore wind power as the foundation of business development and energy export to the continent

  15. Harmonic models of a back-to-back converter in large offshore wind farms compared with measurement data

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth

    2009-01-01

    The offshore wind farm with installed back-to-back power converter in wind turbines is studied. As an example the Burbo Bank offshore wind farm with Siemens Wind Power wind turbines is taken into consideration. The wind farm is simulated in DIgSILENT Power Factory software in order to determine...

  16. Offshore Wind Farm Cable Connection Configuration Optimization using Dynamic Minimum Spanning Tree Algorithm

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Zhe

    2015-01-01

    Anew approach, Dynamic Minimal Spanning Tree (DMST) algorithm, whichisbased on the MST algorithm isproposed in this paper to optimizethe cable connectionlayout for large scale offshore wind farm collection system. The current carrying capacity of the cable is considered as the main constraint....... It is amore economicalway for cable connection configurationdesignof offshore wind farm collection system....

  17. Offshore wind resource mapping for Europe by Synthetic Aperture Radar (SAR) satellite data

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete

    2015-01-01

    For the New European Wind Atlas (NEWA) project with 8 participating countries during5 years (March 2015 – March 2020) we will develop a new wind atlas covering most of the European countries as well as most of the offshore areas in Europe. For the offshore atlas we will rely on a combination of s...

  18. Risk analysis for U.S. offshore wind farms: the need for an integrated approach.

    Science.gov (United States)

    Staid, Andrea; Guikema, Seth D

    2015-04-01

    Wind power is becoming an increasingly important part of the global energy portfolio, and there is growing interest in developing offshore wind farms in the United States to better utilize this resource. Wind farms have certain environmental benefits, notably near-zero emissions of greenhouse gases, particulates, and other contaminants of concern. However, there are significant challenges ahead in achieving large-scale integration of wind power in the United States, particularly offshore wind. Environmental impacts from wind farms are a concern, and these are subject to a number of on-going studies focused on risks to the environment. However, once a wind farm is built, the farm itself will face a number of risks from a variety of hazards, and managing these risks is critical to the ultimate achievement of long-term reductions in pollutant emissions from clean energy sources such as wind. No integrated framework currently exists for assessing risks to offshore wind farms in the United States, which poses a challenge for wind farm risk management. In this "Perspective", we provide an overview of the risks faced by an offshore wind farm, argue that an integrated framework is needed, and give a preliminary starting point for such a framework to illustrate what it might look like. This is not a final framework; substantial work remains. Our intention here is to highlight the research need in this area in the hope of spurring additional research about the risks to wind farms to complement the substantial amount of on-going research on the risks from wind farms. © 2015 Society for Risk Analysis.

  19. Offshore code comparison collaboration continuation within IEA Wind Task 30: Phase II results regarding a floating semisubmersible wind system

    DEFF Research Database (Denmark)

    Robertson, Amy; Jonkman, Jason M.; Vorpahl, Fabian

    2014-01-01

    Offshore wind turbines are designed and analyzed using comprehensive simulation tools (or codes) that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity, and controls of the turbine, along with the incident waves, sea current, hydrodynamics, mooring dynamics, and founda......Offshore wind turbines are designed and analyzed using comprehensive simulation tools (or codes) that account for the coupled dynamics of the wind inflow, aerodynamics, elasticity, and controls of the turbine, along with the incident waves, sea current, hydrodynamics, mooring dynamics......, and foundation dynamics of the support structure. This paper describes the latest findings of the code-to-code verification activities of the Offshore Code Comparison Collaboration Continuation project, which operates under the International Energy Agency Wind Task 30. In the latest phase of the project......, participants used an assortment of simulation codes to model the coupled dynamic response of a 5-MW wind turbine installed on a floating semisubmersible in 200 m of water. Code predictions were compared from load case simulations selected to test different model features. The comparisons have resulted...

  20. Offshore Wind Jobs and Economic Development Impacts in the United States: Four Regional Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Tegen, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Keyser, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores-Espino, F. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miles, J. [James Madison Univ., Harrisonburg, VA (United States); Zammit, D. [James Madison Univ., Harrisonburg, VA (United States); Loomis, D. [Great Lakes Wind Network, Cleveland, OH (United States)

    2015-02-01

    This report uses the offshore wind Jobs and Economic Development Impacts (JEDI) model and provides four case studies of potential offshore deployment scenarios in different regions of the United States: the Southeast, the Great Lakes, the Gulf Coast, and the Mid-Atlantic. Researchers worked with developers and industry representatives in each region to create potential offshore wind deployment and supply chain growth scenarios, specific to their locations. These scenarios were used as inputs into the offshore JEDI model to estimate jobs and other gross economic impacts in each region.

  1. Monitoring and evaluation of Blyth Offshore Wind Farm. Projected operation and maintenance costs of UK offshore wind farms based on the experience at Blyth

    Energy Technology Data Exchange (ETDEWEB)

    Greig, E.

    2004-07-01

    This is the fifth of seven reports in this series on specific aspects of the monitoring and evaluation of the Blyth offshore wind farm project. The report assesses the operation and maintenance (O and M) costs for the wind farm in its first full year of operation, and extrapolates these costs to give indicative costs for larger projects. It identifies both planned regular costs and unplanned site maintenance costs; some costs can be attributed to 'troubleshooting' during installation and would not be expected in future years. The Blyth wind farm, the first in the UK, consists of two 2 MW wind turbines installed approximately 1 km from the coast in water about 6 m deep at low tide. The site is exposed to the full impact of the North Sea weather, breaking waves and a significant tidal range (about 5 m). Location, boat availability, weather and insurance are identified as the key factors affecting O and M costs for future offshore wind farms in the UK.

  2. Virginia Offshore Wind Cost Reduction Through Innovation Study (VOWCRIS) (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Maples, B.; Campbell, J.; Arora, D.

    2014-10-01

    The VOWCRIS project is an integrated systems approach to the feasibility-level design, performance, and cost-of-energy estimate for a notional 600-megawatt offshore wind project using site characteristics that apply to the Wind Energy Areas of Virginia, Maryland and North Carolina.

  3. Influence of wave modelling on the prediction of fatigue for offshore wind turbines

    Science.gov (United States)

    Veldkamp, H. F.; van der Tempel, J.

    2005-01-01

    Currently it is standard practice to use Airy linear wave theory combined with Morison's formula for the calculation of fatigue loads for offshore wind turbines. However, offshore wind turbines are typically placed in relatively shallow water depths of 5-25 m where linear wave theory has limited accuracy and where ideally waves generated with the Navier-Stokes approach should be used. This article examines the differences in fatigue for some representative offshore wind turbines that are found if first-order, second-order and fully non-linear waves are used. The offshore wind turbines near Blyth are located in an area where non-linear wave effects are common. Measurements of these waves from the OWTES project are used to compare the different wave models with the real world in spectral form. Some attention is paid to whether the shape of a higher-order wave height spectrum (modified JONSWAP) corresponds to reality for other places in the North Sea, and which values for the drag and inertia coefficients should be used. Copyright

  4. Offshore Wind Resource, Cost, and Economic Potential in the State of Maine

    Energy Technology Data Exchange (ETDEWEB)

    Musial, Walter D. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2018-02-12

    This report provides information for decision-makers about floating offshore wind technologies in the state of Maine. It summarizes research efforts performed at the National Renewable Energy Laboratory between 2015 and 2017 to analyze the resource potential, cost of offshore wind, and economic potential of offshore wind from four primary reports: Musial et al. (2016); Beiter et al. (2016, 2017); and Mone et al. (unpublished). From Musial et al. (2016), Maine's technical offshore wind resource potential ranked seventh in the nation overall with more than 411 terawatt-hours/year of offshore resource generating potential. Although 90% of this wind resource is greater than 9.0-meters-per-second average velocity, most of the resource is over deep water, where floating wind technology is needed. Levelized cost of energy and levelized avoided cost of energy were computed to estimate the unsubsidized 'economic potential' for Maine in the year 2027 (Beiter et al. 2016, 2017). The studies found that Maine may have 65 gigawatts of economic potential by 2027, the highest of any U.S. state. Bottom-line costs for the Aqua Ventus project, which is part of the U.S. Department of Energy's Advanced Technology Demonstration project, were released from a proprietary report written by NREL in 2016 for the University of Maine (Mone et al. unpublished). The report findings were that economies of scale and new technology advancements lowered the cost from $300/megawatt-hour (MWh) for the two-turbine 12-megawatt (MW) Aqua Ventus 1 project, to $126/MWh for the commercial-scale, 498-MW Aqua Ventus-2 project. Further cost reductions to $77/MWh were found when new technology advancements were applied for the 1,000-MW Aqua Ventus-3 project in 2030. No new analysis was conducted for this report.

  5. Towards a Risk-based Decision Support for Offshore Wind Turbine Installation and Operation & Maintenance

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard; Vatne, Sigrid Ringdalen

    2016-01-01

    Costs of operation & maintenance, assembly, transport and installation of offshore wind turbines contribute significantly to the total cost of offshore wind farm. These operations are mostly carried out by specific ships that have to be hired for the operational phase and for duration of installa......Costs of operation & maintenance, assembly, transport and installation of offshore wind turbines contribute significantly to the total cost of offshore wind farm. These operations are mostly carried out by specific ships that have to be hired for the operational phase and for duration...... of installation process, respectively. Duration, and therefore ship hiring costs is, among others, driven by waiting time for weather windows for weather-sensitive operations. Today, state of the art decision making criteria for weather-sensitive operations are restrictions to the significant wave height...... and the average wind velocity at reference height. However, actual limitations are physical, related to response of equipment used e.g. crane wire tension, rotor assembly motions while lifting, etc. Transition from weather condition limits to limits on physical equipment response in decision making would improve...

  6. A decision support system for assessing offshore wind energy potential in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Wanderer, T.; Schillings, C. [German Aerospace Center (DLR), Systems Analysis and Technology Assessment, Stuttgart (Germany); Cameron, L.; Veum, K. [Energy research Center of the Netherlands ECN, Policy Studies Department, Amsterdam (Netherlands); Tjalling van der Wal, J. [IMARES, Wageningen UR, Den Helder (Netherlands); Jacquemin, J. [GL Garrad Hassan, Paris (France)

    2012-10-15

    Offshore wind energy (OWE) in the North Sea has the potential to meet large share of Europe's future electricity demand. To deploy offshore wind parks in a rational way, the overall OWE potential has to be realistically determined. This has to be done on an international, cross-border level and by taking into account the existing man-made and nature-related uses of the North Sea. As spatial conflicts will arise between existing uses and the new OWE uses, a Decision Support System (DSS) based on a Geographic Information System (GIS) was developed. Based on data of existing sea uses and calculation rules for spatial prioritisation analysis, the DSS helps in identifying areas that are (1) generally suitable for offshore wind power, (2) strictly excluded or (3) negotiable with respect to other existing sea uses. The combination of this conflict analysis together with cost assumptions for offshore wind farms and their expected electricity yield leads to identification of favourable areas for OWE deployment in the North Sea. This approach helps to reduce the conflict between offshore wind deployment and existing sea uses in the North Sea for future planning. The results can assist decision makers in developing transnational roadmaps for OWE.

  7. Jobs and Economic Development Impact (JEDI) Model: Offshore Wind User Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, E.; Goldberg, M.; Keyser, D.

    2013-06-01

    The Offshore Wind Jobs and Economic Development Impact (JEDI) model, developed by NREL and MRG & Associates, is a spreadsheet based input-output tool. JEDI is meant to be a user friendly and transparent tool to estimate potential economic impacts supported by the development and operation of offshore wind projects. This guide describes how to use the model as well as technical information such as methodology, limitations, and data sources.

  8. Shadowing effects of offshore wind farms - an idealised mesoscale model study

    DEFF Research Database (Denmark)

    Volker, Patrick; Badger, Jake; Hahmann, Andrea N.

    The study of wind farm (WF) interaction is expected to gain importance, since the offshore wind farm density will increase especially in the North Sea in the near future. We present preliminary results of wind farm interaction simulated by mesoscale models. We use the Explicit Wake Parametrisatio...

  9. Optimization of offshore wind farm layout in restricted zones

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Cong

    2016-01-01

    In this research, an optimization method for offshore wind farm layout design is proposed. With the purpose of maximizing the energy production of the wind farm, the wind turbine (WT) positions are optimized. Due to the limitations of seabed conditions, marine traffic limitations or shipwrecks, etc...... with multiple adaptive methods (PSO-MAM) is adopted. The simulation results indicate that the proposed method can find a layout which outperforms a baseline layout of a reference wind farm (RWF) by increasing the energy yield by 3.84%....

  10. Review of control algorithms for offshore wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Spruce, C.J.; Markou, H.; Leithead, W.E.; Dominguez Ruiz, S.

    2005-07-01

    Innovative turbine control strategies could allow the improvements to cost and performance considered essential to reduce the cost of energy from offshore wind farms around the UK. This project reviewed and investigated the possibility for further development of a power control algorithm originally developed by NEG Micon Rotors Ltd for use with offshore wind turbines in the hope that more advanced algorithms would reduce the loads on, and hence the costs of, components such as the foundation/support structure, tower, blades and bedplate. Three models (simulation model, linearisation of the simulation model and control model) were produced in order to conduct the review. Application of these models produced the conclusion that the size of the latest generation of offshore wind turbines has now reached a level where performance is starting to be constrained by fundamental factors in the dynamics caused by the machine's physical size. It was also concluded that an ideal control strategy could achieve potential cost savings for the tower and support structure of 5-10% of the total cost of the turbine plus support structure. Further work to develop controllers to reduce loads in the tower and support structure is urged. The report considers non-linear simulation, the linear model, the control model, general operation of the controller, the drive train damping filter, torque control, pitch control and advanced algorithms, and makes detailed recommendations for future work.

  11. Applicability of Synthetic Aperture Radar Wind Retrievals on Offshore Wind Resources Assessment in Hangzhou Bay, China

    Directory of Open Access Journals (Sweden)

    Rui Chang

    2014-05-01

    Full Text Available In view of the high cost and sparse spatial resolution of offshore meteorological observations, ocean winds retrieved from satellites are valuable in offshore wind resource assessment as a supplement to in situ measurements. This study examines satellite synthetic aperture radar (SAR images from ENVISAT advanced SAR (ASAR for mapping wind resources with high spatial resolution. Around 181 collected pairs of wind data from SAR wind maps and from 13 meteorological stations in Hangzhou Bay are compared. The statistical results comparing in situ wind speed and SAR-based wind speed show a standard deviation (SD of 1.99 m/s and correlation coefficient of R = 0.67. The model wind directions, which are used as input for the SAR wind speed retrieval, show a high correlation coefficient (R = 0.89 but a large standard deviation (SD = 42.3° compared to in situ observations. The Weibull probability density functions are compared at one meteorological station. The SAR-based results appear not to estimate the mean wind speed, Weibull scale and shape parameters and wind power density from the full in situ data set so well due to the lower number of satellite samples. Distributions calculated from the concurrent 81 SAR and in situ samples agree well.

  12. Electrical Collection and Transmission Systems for Offshore Wind Power: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Green, J.; Bowen, A.; Fingersh, L.J.; Wan, Y.

    2007-03-01

    The electrical systems needed for offshore wind farms to collect power from wind turbines--and transmit it to shore--will be a significant cost element of these systems. This paper describes the development of a simplified model of the cost and performance of such systems.

  13. U.S. Offshore Wind Manufacturing and Supply Chain Development

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Bruce [Navigant Consulting, Inc., Burlington, MA (United States)

    2013-02-22

    This report seeks to provide an organized, analytical approach to identifying and bounding uncertainties around offshore wind manufacturing and supply chain capabilities; projecting potential component-level supply chain needs under three demand scenarios; and identifying key supply chain challenges and opportunities facing the future U.S. market and current suppliers of the nation’s landbased wind market.

  14. Statistical Analysis and Comparison of Harmonics Measured in Offshore Wind Farms

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth

    2011-01-01

    The paper shows statistical analysis of harmonic components measured in different offshore wind farms. Harmonic analysis is a complex task and requires many aspects, such as measurements, data processing, modeling, validation, to be taken into consideration. The paper describes measurement process...... and shows sophisticated analysis on representative harmonic measurements from Avedøre Holme, Gunfleet Sands and Burbo Bank wind farms. The nature of generation and behavior of harmonic components in offshore wind farms clearly presented and explained based on probabilistic approach. Some issues regarding...... commonly applied standards are also put forward in the discussion. Based on measurements and data analysis it is shown that a general overview about wind farm harmonic behaviour cannot be fully observed only based on single-value measurements as suggested in the standards but using more descriptive...

  15. Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Asgarpour, Masoud; Sørensen, John Dalsgaard

    2018-01-01

    The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...... monitoring, fault prediction and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution...

  16. Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Asgarpour, Masoud; Sørensen, John Dalsgaard

    2018-01-01

    monitoring, fault prediction and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution......The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...

  17. Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Asgarpour, Masoud

    2017-01-01

    monitoring, fault detection and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution......The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...

  18. Offshore Wind Farm Research at the NWO Institutes

    NARCIS (Netherlands)

    J.A.S. Witteveen (Jeroen)

    2013-01-01

    htmlabstractFundamental scientific research is essential to take the necessary next step in offshore wind farm innovation. The NWO scientific research institutes play a central role in the Dutch knowledge infrastructure for disseminating scientific discoveries into industrial innovations. Multiple

  19. 76 FR 14681 - Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore Massachusetts...

    Science.gov (United States)

    2011-03-17

    ... No. BOEM-2010-0063] Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore..., Regulation and Enforcement (BOEMRE), Interior. ACTION: Request for Interest (RFI) in Commercial Wind Energy... (BOEMRE) is reopening the comment period on the RFI in Commercial Wind Energy Leasing Offshore...

  20. Regime-based supervisory control to reduce power fluctuations from offshore wind power plants

    DEFF Research Database (Denmark)

    Barahona Garzón, Braulio; Cutululis, Nicolaos Antonio; Trombe, Pierre-Julien

    2013-01-01

    Wind power fluctuations, especially offshore, can pose challenges in the secure and stable operation of the power system. In modern large offshore wind farms, there are supervisory controls designed to reduce the power fluctuations. Their operation is limited due to the fact that they imply loss...... that consider different wind power regimes to derive control setpoints by using a Markov-Switching AutoRegressive model. We evaluate the performance versus measured data in terms of power ramp characteristics and energy efficiency....

  1. Large-scale integration of wind power into power systems as well as on transmission networks for offshore wind power plants. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Betancourt, Uta; Ackermann, Thomas (eds.)

    2013-11-01

    This proceedings contains contributions to the followings main topics: Grid integration experiences; Flexibility and economics of integration; Voltage control issues; Offshore wind power plants; Forecasting; Grid code issues; HVDC connection issues; Frequency control issues; National grid's perspective; Power system balancing; Power system issues; New grid and generators issues; Flexibility with storage and demand side management; AC connected offshore wind power plants; Economic and market issues; Modelling issues; Offshore grid issues.

  2. Exploring China’s offshore wind energy potential in a comprehensive perspectives of technical, environmental and economic constraints

    DEFF Research Database (Denmark)

    Hong, Lixuan; Möller, Bernd

    with projections of current wind turbine technology development to calculate the maximum amount of offshore wind energy that could be generated. Secondly, to calculate practical potential, the migratory path of an endangered bird and existing shipping lanes and submarine cables are excluded from the calculated......Adequate recognition of offshore wind energy potential may have far-reaching influence on the development of future energy strategies. This study aims to investigate available offshore wind energy resource in China’s exclusive economic zones (EEZs) with the aid of a Geographical Information System...... (GIS), which allows the influence of technical, spatial and economic constraints on raw offshore wind potential being reflected in a continuous space. Firstly, based on ocean wind speed data gained from satellite QuikSCAT, raw potential are identified. Those findings are then used along...

  3. Centralized electricity generation in offshore wind farms using hydraulic networks

    NARCIS (Netherlands)

    Jarquin Laguna, A.

    2017-01-01

    The work presented in this thesis explores a new way of generation, collection and transmission of wind energy inside a wind farm, in which the electrical conversion does not occur during any intermediate conversion step before the energy has reached the offshore central platform. A centralized

  4. Stochastic dynamic stiffness of surface footing for offshore wind turbines

    DEFF Research Database (Denmark)

    Vahdatirad, Mohammadjavad; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2014-01-01

    Highlights •This study concerns the stochastic dynamic stiffness of foundations for large offshore wind turbines. •A simple model of wind turbine structure with equivalent coupled springs at the base is utilized. •The level of uncertainties is quantified through a sensitivity analysis. •Estimation...

  5. Sociological investigation of the reception of Horns Rev and Nysted offshore wind farms in the local communities[Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.

    2005-03-15

    This annual report presents the work related to the sociological part of the socio-economic project on the local communities' reception of the Horns Rev Offshore Wind Farm, west of Blaavands Huk in Jutland, and the Nysted Offshore Wind Farm, south of Lolland. The project is part of the monitoring programme in connection with the construction of the offshore wind farms. Unlike projects, which examine the impact of the wind farms on nature, the socio-economic project did not start until 2003. The socio-economic project examines the effects on the local communities. Among other things the environmental-economic part of the project examines the preferences of the population in relation to location of the wind farm and the willingness to pay for increasing the distance between the wind farms and the coast. The sociological survey is qualitative. The survey is divided into three phases, as the aim is to investigate the public community's attitude towards the erection of an offshore wind farm before and after the construction of the wind farm. This aim is based on the assumption that attitudes may change once the wind farm is erected and the population has experienced the visibility of the wind farm, etc. The division into phases is as follows: 1) Phase 1 treats the conditions as they were before the erection of Nysted Offshore Wind Farm. 2) Phase 2 is an investigation of the development in attitudes towards Horns Rev Offshore Wind Farm a year after erection. 3) Phase 3 comprises a follow-up investigation of the local area at Nysted Offshore Wind Farm. This annual report treats phases 1 and 2. Phase 1 was carried out in April-August 2003, and the interviews at Nysted were thus made during the erection of the first offshore wind turbines. Phase 2 was carried out in September-November 2003. The follow-up investigation of the conditions in the local area around Nysted offshore wind farm is to be carried out in August-December 2004. The results of the investigations

  6. Cost reductions for offshore wind power. Exploring the balance between scaling, learning and R and D

    International Nuclear Information System (INIS)

    Van der Zwaan, B.; Rivera-Tinoco, R.; Lensink, S.; Van den Oosterkamp, P.

    2012-01-01

    Offshore wind electricity generation is prospected to increase substantially in the near future at a number of locations, like in the Baltic, Irish and North Sea, and emerge at several others. The global growth of offshore wind technology is likely to be accompanied by reductions in wind park construction costs, both as a result of scaling and learning effects. Since 2005, however, significant cost increases have been observed. A recent surge in commodity prices proves to constitute one of the main drivers of these cost increases. This observation begs the question whether wind turbine manufacturers should return to the laboratory for undertaking R and D that explores the use of alternative materials and bring offshore wind energy closer to competitiveness. It is demonstrated that if one abstracts from material price fluctuations, in particular for metals such as copper and steel, turbine production plus installation cost data publicly available for a series of offshore wind park projects (realized in several European countries since the 1990's) show a cost reduction trend. Hence various other sources of cost increases, such as due to the progressively larger distances from the shore (and correspondingly greater depths at sea) at which wind parks have been (and will be) built, are outshadowed by cost reduction effects. When one expresses the overall cost development for offshore wind energy capacity as an experience curve, a learning rate is found of 3%, which reflects a mixture of economies-of-scale and learning-by-doing mechanisms. Also the impact is quantified on offshore wind power construction costs from the recent tightness in the market for turbine manufacturing and installation services: without the demand-supply response inertia at the origin of this tightness it is estimated that the learning rate would be 5%. Since these learning rates are relatively low - in comparison to those observed for other technologies, and in view of the high current capacity

  7. Floating offshore wind turbines for shallow waters

    NARCIS (Netherlands)

    Bulder, B.H.; Henderson, A.; Huijsmans, R.H.M.; Peeringa, J.M.; Pierik, J.T.G.; Snijders, E.J.B.; Hees, M.Th. van; Wijnants, G.H.; Wolf, M.J.

    2003-01-01

    Bottom mounted Offshore wind turbines seem to have a promising future but they are restricted to shallow waters of Northern Europe. Many projects are planned or are in the phase of construction on the North Sea and the Baltic Sea. All projects that are planned have a water depth up to approximately

  8. Evaluating potentials for future generation off-shore wind-power outside Norway

    Science.gov (United States)

    Benestad, R. E.; Haugen, J.; Haakenstad, H.

    2012-12-01

    With todays critical need of renewable energy sources, it is naturally to look towards wind power. With the long coast of Norway, there is a large potential for wind farms offshore Norway. Although there are more challenges with offshore wind energy installations compared to wind farms on land, the offshore wind is generally higher, and there is also higher persistence of wind speed values in the power generating classes. I planning offshore wind farms, there is a need of evaluation of the wind resources, the wind climatology and possible future changes. In this aspect, we use data from regional climate model runs performed in the European ENSEMBLE-project (van der Linden and J.F.B. Mitchell, 2009). In spite of increased reliability in RCMs in the recent years, the simulations still suffer from systematic model errors, therefore the data has to be corrected before using them in wind resource analyses. In correcting the wind speeds from the RCMs, we will use wind speeds from a Norwegian high resolution wind- and wave- archive, NORA10 (Reistad et al 2010), to do quantile mapping (Themeβl et. al. 2012). The quantile mapping is performed individually for each regional simulation driven by ERA40-reanalysis from the ENSEMBLE-project corrected against NORA10. The same calibration is then used to the belonging regional climate scenario. The calibration is done for each grid cell in the domain and for each day of the year centered in a +/-15 day window to make an empirical cumulative density function for each day of the year. The quantile mapping of the scenarios provide us with a new wind speed data set for the future, more correct compared to the raw ENSEMBLE scenarios. References: Reistad M., Ø. Breivik, H. Haakenstad, O. J. Aarnes, B. R. Furevik and J-R Bidlo, 2010, A high-resolution hindcast of wind and waves for The North Sea, The Norwegian Sea and The Barents Sea. J. Geophys. Res., 116. doi:10.1029/2010JC006402. Themessl M. J., A. Gobiet and A. Leuprecht, 2012

  9. Potential of Offshore Wind Energy and Extreme Wind Speed Forecasting on the West Coast of Taiwan

    Directory of Open Access Journals (Sweden)

    Pei-Chi Chang

    2015-02-01

    Full Text Available It is of great importance and urgency for Taiwan to develop offshore wind power. However, relevant data on offshore wind energy resources are limited. This study imported wind speeds measured by a tidal station and a buoy into the software WAsP to estimate the high-altitude wind speeds in the two areas. A light detection and ranging (Lidar system was set up near the tidal station and buoy. High-altitude wind speeds measured by the Lidar system were compared with the WAsP-estimated values, and it was discovered that the two data sets were consistent. Then, long-term wind speed data observed by buoys and tidal stations at various locations were imported into WAsP to forecast wind speeds at heights of 55–200 m on the west coast of Taiwan. The software WAsP Engineering was used to analyze the extreme wind speeds in the same areas. The results show that wind speeds at 100 m are approximately 9.32–11.24 m/s, which means that the coastal areas of west Taiwan are rich in wind energy resources. When a long-term 10-min average wind speed is used, the extreme wind speed on the west coast is estimated to be between 36.4 and 55.3 m/s.

  10. Preliminary Design of a Multi-Column TLP Foundation for a 5-MW Offshore Wind Turbine

    Directory of Open Access Journals (Sweden)

    Yanping He

    2012-10-01

    Full Text Available Currently, floating wind turbines (FWTs may be the more economical and suitable systems with which to exploit offshore wind energy in deep waters. Among the various types of floating foundations for offshore wind farms, a tension leg platform (TLP foundation can provide a relatively stable platform for currently available offshore wind turbines without requiring major modifications. In this study, a new multi-column TLP foundation (WindStar TLP was developed for the NREL 5-MW offshore wind turbine according to site-specific environmental conditions, which are the same as the OC3-Hywind (NREL conditions. The general arrangement, main structure and mooring system were also designed and investigated through hydrodynamic and natural frequency analyses. The complete system avoids resonance through the rotor excitations. An aero-hydro-servo-elastic coupled analysis was carried out in the time domain with the numerical tool FAST. Statistics of the key parameters were obtained and analysed and comparisons to MIT/NREL TLP are made. As a result, the design requirements were shown to be satisfied, and the proposed WindStar TLP was shown to have favourable motion characteristics under extreme wind and wave conditions with a lighter and smaller structure. The new concept holds great potential for further development.

  11. Optimized Power Dispatch Strategy for Offshore Wind Farms

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Zhang, Baohua

    2016-01-01

    which are related to electrical system topology. This paper proposed an optimized power dispatch strategy (OPD) for minimizing the levelized production cost (LPC) of a wind farm. Particle swarm optimization (PSO) is employed to obtain final solution for the optimization problem. Both regular shape......Maximizing the power production of offshore wind farms using proper control strategy has become an important issue for wind farm operators. However, the power transmitted to the onshore substation (OS) is not only related to the power production of each wind turbine (WT) but also the power losses...... and irregular shape wind farm are chosen for the case study. The proposed dispatch strategy is compared with two other control strategies. The simulation results show the effectiveness of the proposed strategy....

  12. Challenges in simulating coastal effects on an offshore wind farm

    DEFF Research Database (Denmark)

    van der Laan, Paul; Peña, Alfredo; Volker, Patrick

    2017-01-01

    The effect of a coastline on an offshore wind farm is investigated with a Reynolds-averaged Navier-Stokes (RANS) model. The trends of the RANS model compare relatively well with results from a mesoscale model and measurements of wind turbine power. In addition, challenges of modeling a large domain...

  13. OffshoreDC DC grids for integration of large scale wind power

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Endegnanew, Atsede Gualu; Stamatiou, Georgios

    The present report summarizes the main findings of the Nordic Energy Research project “DC grids for large scale integration of offshore wind power – OffshoreDC”. The project is been funded by Nordic Energy Research through the TFI programme and was active between 2011 and 2016. The overall...... objective of the project was to drive the development of the VSC based HVDC technology for future large scale offshore grids, supporting a standardised and commercial development of the technology, and improving the opportunities for the technology to support power system integration of large scale offshore...

  14. Cross-Wind Modal Properties of Offshore Wind Turbines Identified by Full Scale Testing

    DEFF Research Database (Denmark)

    Damgaard, Mads; Ibsen, Lars Bo; Andersen, Lars Vabbersgaard

    2013-01-01

    -2011, the paper evaluates the first natural frequency and modal damping of the structures. In addition, fitting of theoretical energy spectra to measured response spectra of operating turbines is presented as an alternative method of determining the system damping. Analyses show distinctly time-dependent cross......Cross-wind vibrations due to wave loading misaligned with wind turbulence are often a design driver for offshore wind turbine foundations. The phenomenon is characterised by increasing fatigue loads compared to the fore-aft fatigue and a small amount of system damping since almost no aerodynamic...

  15. Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

    Directory of Open Access Journals (Sweden)

    Rui Chang

    2015-01-01

    Full Text Available Using accurate inputs of wind speed is crucial in wind resource assessment, as predicted power is proportional to the wind speed cubed. This study outlines a methodology for combining multiple ocean satellite winds and winds from WRF simulations in order to acquire the accurate reconstructed offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS. The wind roses from the Navy Operational Global Atmospheric Prediction System (NOGAPS and ASCAT agree well with these observations from the corresponding in situ measurements. The statistical results comparing in situ wind speed and SAR-based (ASCAT-based wind speed for the whole co-located samples show a standard deviation (SD of 2.09 m/s (1.83 m/s and correlation coefficient of R 0.75 (0.80. When the offshore winds (i.e., winds directed from land to sea are excluded, the comparison results for wind speeds show an improvement of SD and R, indicating that the satellite data are more credible over the open ocean. Meanwhile, the validation of satellite winds against the same co-located mast observations shows a satisfactory level of accuracy which was similar for SAR and ASCAT winds. These satellite winds are then assimilated into the Weather Research and Forecasting (WRF Model by WRF Data Assimilation (WRFDA system. Finally, the wind resource statistics at 100 m height based on the reconstructed winds have been achieved over the study area, which fully combines the offshore wind information from multiple satellite data and numerical model. The findings presented here may be useful in future wind resource assessment based on satellite data.

  16. Cost and Benefit Analysis of VSC-HVDC Schemes for Offshore Wind Power Transmission

    Institute of Scientific and Technical Information of China (English)

    Sheng WANG; Chunmei FENG; An WEN; Jun LIANG

    2013-01-01

    Due to low load factors of wind power generation,it is possible to reduce transmission capacity to minimize the cost of transmission system construction.Two VSC-HVDC schemes for offshore wind farm,called the point to point (PTP) and DC mesh connections are compared in terms of the utilization of transmission system and its cost.A Weibull distribution is used for estimating offshore wind power generation,besides,the cross correlation between wind farms is considered.The wind energy curtailment is analyzed using the capacity output possibility table (COPT).The system power losses,costs of transmission investment and wind energy curtailment are also computed.A statistic model for the wind generation and transmission is built and simulated in MATLAB to validate the study.It is concluded that a DC mesh transmission can reduce the energy curtailment and power losses.Further benefit is achievable as the wind cross correlation between wind farms decreases.

  17. Offshore Wind Power Data

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Zeni, Lorenzo

    2012-01-01

    Wind power development scenarios are critical when trying to assess the impact of the demonstration at national and European level. The work described in this report had several objectives. The main objective was to prepare and deliver the proper input necessary for assessing the impact of Demo 4...

  18. The (R)evolution of China: Offshore Wind Diffusion

    DEFF Research Database (Denmark)

    Poulsen, Thomas; Hasager, Charlotte Bay

    2017-01-01

    This research presents an industry level gap analysis for Chinese offshore wind, which serves as a way to illuminate how China may fast track industry evolution. The research findings provide insight into how the Chinese government strongly and systematically decrees state-owned Chinese firms to ...

  19. Load Flow Analysis of Hybrid AC-DC Power System with Offshore Wind Power

    DEFF Research Database (Denmark)

    Dhua, Debasish; Huang, Shaojun; Wu, Qiuwei

    2017-01-01

    The offshore wind power has received immense attention because of higher wind speed and lower opposition for construction. A wide range of combinations of high-voltage ACDC transmission have been proposed for integrating offshore wind farms and long-distance power transmission. This paper...... is to model such hybrid AC-DC systems including the interfacing converters, which have several control parameters that can change the load flow of the hybrid systems. Then, the paper proposes a Load Flow algorithm based on the Newton-Raphson method, which covers three different section types...

  20. Evolution and Reduction of Scour around Offshore Wind Turbines

    Science.gov (United States)

    McGovern, David; Ilic, Suzana

    2010-05-01

    Evolution and Reduction of Scour around Offshore Wind Turbines In response to growing socio-economic and environmental demands, electricity generation through offshore wind turbine farms is a fast growing sector of the renewable energy market. Considerable numbers of offshore wind farms exist in the shallow continental shelf seas of the North-West Europe, with many more in the planning stages. Wind energy is harnessed by large rotating blades that drive an electricity generating turbine placed on top of a long cylindrical monopile that are driven into the sea-bed, well into the bed rock below the sediment. Offshore wind turbines are popular due to consistently higher wind speeds and lower visual impact than their onshore counter parts, but their construction and maintenance is not without its difficulties. The alteration of flow by the presence of the wind turbine monopile results in changes in sedimentary processes and morphology at its base. The increase in flow velocity and turbulence causes an amplification of bed shear stress and this can result in the creation of a large scour hole at the monopile base. Such a scour hole can adversely affect the structural integrity and hence longevity of the monopile. Changes to the sea bed caused by this may also locally affect the benthic habitat. We conducted an extensive series of rigid and mobile bed experiments to examine the process of scour under tidal currents. We also test the effectiveness of a flow-altering collared monopile in reducing scour. Firstly, we used Particle Image Velocimetry (PIV) and Acoustic Doppler Velocimetry (ADV) to visualise and analyse the flow and turbulence properties in the local flow around the monopile and collared monopile over a smooth rigid bed under tidal flow. The measured flow, turbulence and shear stress properties are related to mobile bed tests where a Seatek 5 MHz Ultrasonic Ranging system is used to identify the evolution of scour under reversing tidal currents. The tidal

  1. Fulfilment of Grid Code Obligations by Large Offshore Wind Farms Clusters Connected via HVDC Corridors

    OpenAIRE

    Attya, A.B.; Anaya-Lara, Olimpo; Ledesma, P.; Svendsen, Harald Georg

    2016-01-01

    - The foreseen high penetration levels of wind power will force the systems operators to apply restrictive constraints on wind power plants. The ability of offshore wind clusters, which are connected via HVDC, to fulfill the grid codes, especially those related to voltage stability is investigated. This came in the frame of a project to develop an integrated and practical tool to design offshore wind clusters (EERA-DTOC). The applied case studies examine the system stability during and aft...

  2. GIS-based approach for the evaluation of offshore wind power potential for Gujarat

    Science.gov (United States)

    Patel, Dhrumin; Nagababu, Garlapati; Radadia, Nishil; Parsana, Sohil; Sheth, Mohak; Sheth, Nisarg

    2018-05-01

    In the current global scenario, India is increasing its focus towards the methods to enrich the benefits of non-renewable energy sources as much as possible due to their key advantage of having low carbon footprint. India has already emerged as a key global player in on-shore wind energy and to achieve its annual wind energy production demand of 50 GWh, avenues other than current options have been researched on. Offshore wind energy has experienced remarkable growth worldwide but has not yet been harnessed sufficiently in India, despite addressing many of environmental and economic concerns. The present study focuses on offshore wind resource assessment on Indian exclusive economic zone (EEZ) around Gujarat region. The geographical information system (GIS) methodology has been used to develop maps of wind speed, power density and capacity factor maps. Further, careful consideration has been accorded for expulsion of marine protected areas, shipping transportation lines, fishing zones, and migratory bird movements. The resultant available area has been considered for annual energy production considering data from Siemens Wind Turbine 3.6. The results obtained shows that offshore wind energy can offset twice the annual energy demand of entire country with a potential energy production of more than 2580 TWh.

  3. Control and operation of wind turbine converters during faults in an offshore wind power plant grid with VSC-HVDC connection

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay; Teodorescu, Remus; Rodriguez, Pedro

    2011-01-01

    Voltage source converter (VSC) based high voltage dc (HVDC) transmission is an attractive technique for large offshore wind power plants, especially when long cable transmission is required for connection to the onshore grid. New multi-MW wind turbines are likely to be equipped with full scale...... converters to meet the stringent grid code requirements. In such a scenario, the offshore grid is terminated to the power electronic converters on all the ends. This paper presents a control scheme for the synchronization and control of the grid side converters (GSC) of the wind turbine generators (WTG......). Current limit control enables the GSC to sustain the fault currents during short circuits in the offshore wind collector system grid. However, power transmission is affected, and the fault has to be isolated. It can be resynchronized after the fault has been cleared and the breaker reclosed. Healthy WTG...

  4. Evaluation of offshore wind resources by scale of development

    DEFF Research Database (Denmark)

    Möller, Bernd; Hong, Lixuan; Lonsing, Reinhard

    -economic model operating in a geographical information systems (GIS) environment, which describes resources, costs and area constraints in a spatially explicit way, the relation between project size, location, costs and ownership is analysed. Two scenarios are presented, which describe a state......Offshore wind energy has developed rapidly in terms of turbine and project size, and currently undergoes a significant up-scaling to turbines and parks at greater distance to shore and deeper waters. Expectations to the positive effect of economies of scale on power production costs, however, have...... can be explained by deeper water, higher distance to shore, bottlenecks in supply or higher raw material costs. The present paper addresses the scale of offshore wind parks for Denmark and invites to reconsider the technological and institutional choices made. Based on a continuous resource...

  5. Evaluation of offshore wind resources by scale of development

    DEFF Research Database (Denmark)

    Möller, Bernd; Hong, Lixuan; Lonsing, Reinhard

    2012-01-01

    -economic model operating in a geographical information systems (GIS) environment, which describes resources, costs and area constraints in a spatially explicit way, the relation between project size, location, costs and ownership is analysed. Two scenarios are presented, which describe a state......Offshore wind energy has developed rapidly in terms of turbine and project size, and currently undergoes a significant up-scaling to turbines and parks at greater distance to shore and deeper waters. Expectations to the positive effect of economies of scale on power production costs, however, have...... can be explained by deeper water, higher distance to shore, bottlenecks in supply or higher raw material costs. The present paper addresses the scale of offshore wind parks for Denmark and invites to reconsider the technological and institutional choices made. Based on a continuous resource...

  6. Wind mapping offshore in coastal Mediterranean area using SAR images

    DEFF Research Database (Denmark)

    Calaudi, Rosamaria; Arena, Felice; Badger, Merete

    Satellite observations of the ocean surface from Synthetic Aperture Radars (SAR) provide information about the spatial wind variability over large areas. This is of special interest in the Mediterranean, where spatial wind information is only provided by sparse buoys, often with long periods...... of missing data. Here, we focus on evaluating the use of SAR for offshore wind mapping. Preliminary results from the analysis of SAR-based ocean winds in Mediterranean areas show interesting large scale wind flow features consistent with results from previous studies using numerical models and space borne...

  7. Potential Offshore Wind Energy Areas in California: An Assessment of Locations, Technology, and Costs

    Energy Technology Data Exchange (ETDEWEB)

    Musial, Walter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-12-01

    This report summarizes a study of possible offshore wind energy locations, technologies, and levelized cost of energy in the state of California between 2015 and 2030. The study was funded by the U.S. Department of the Interior's Bureau of Ocean Energy Management (BOEM), the federal agency responsible for regulating renewable energy development on the Outer Continental Shelf. It is based on reference wind energy areas where representative technology and performance characteristics were evaluated. These reference areas were identified as sites that were suitable to represent offshore wind cost and technology based on physical site conditions, wind resource quality, known existing site use, and proximity to necessary infrastructure. The purpose of this study is to assist energy policy decision-making by state utilities, independent system operators, state government officials and policymakers, BOEM, and its key stakeholders. The report is not intended to serve as a prescreening exercise for possible future offshore wind development.

  8. Conference 'onshore and offshore wind energy cost reduction: challenges and opportunities for the industry in France and in Germany'

    International Nuclear Information System (INIS)

    Abadie, Pierre-Marie; Hinsch, Thomas; Wallasch, Anna-Kathrin; Giese, Norbert; Guyet, Quentin; Lenhardt, Edouard; Beinke, Thies; Bodenstab, Marc; Wolff, Nicolas; Burkhardt, Claus; Lessmeister, Andreas L.

    2012-01-01

    The French-German office for Renewable energies (OFAEnR) organised a conference on cost reduction in onshore and offshore wind energy. In the framework of this French-German exchange of experience, about 140 participants exchanged views on the cost allocation in onshore wind energy projects, on their financing, and on the transport and logistics profitability challenges. Concrete examples of operating and maintenance cost reductions in offshore wind energy projects were presented as well. This document brings together the available presentations (slides) made during this event: 1 - Overview of France's onshore and offshore wind support policies (Pierre-Marie Abadie); 2 - Keynote: Framework conditions for cost reductions in the German wind energy sector (Thomas Hinsch); 3 - Cost of onshore wind energy projects in Germany - Status and experience feedback (Anna-Kathrin Wallasch); 4 - Crown estate's Offshore Wind Cost Reduction Pathways Study: how to transpose the conclusions to the German case (Norbert Giese); 5 - Combined Forces for Reliable Supply Chain - French-German Convergence of expertise: strategic partnerships for offshore projects implementation (Quentin Guyet, Edouard Lenhardt); 6 - Reducing costs of onshore and offshore wind energy. Mon2Sea research project - Real-time monitoring of transport and cargo handling of components for the offshore installation of wind turbines (Thies Beinke, Marc Bodenstab); 7 - expertise, Innovation and reduction of cost of energy: Vestas experience (Nicolas Wolff); 8 - Far-Offshore-Wind projects. Results of the First German Offshore Windpark alpha ventus (Claus Burkhardt); 9 - Maintenance for Offshore-Wind parks: examples and good practices for the future (Andreas L. Lessmeister)

  9. Environmental Risk Evaluation System (ERES) for Offshore Wind - Mock-Up of ERES, Fiscal Year 2010 Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Richard M.; Copping, Andrea E.; Van Cleve, Frances B.

    2010-11-01

    The Environmental Risk Evaluation System (ERES) has been created to set priorities among the environmental risks from offshore wind development. This report follows the conceptual design for ERES and shows what the system would look like, using a web interface created as part of a Knowledge Management System (KMS) for offshore wind. The KMS, called Zephyrus, and ERES for offshore wind, will be populated and made operational in a later phase of the project.

  10. Is the distribution and abundance of waterbirds altered in and around Danish Offshore wind farms?

    DEFF Research Database (Denmark)

    Petersen, Ib Krag

    programmes for Horns Rev 1 and the Nysted offshore wind farms were initiated, and after the erection of the turbines post-construction monitoring programmes were initiated. Data from these investigations will be touched upon. At Nysted offshore wind farm common eiders (Somateria mollissima) avoided flying...... and the near surroundings. Common scoters (Melanitta nigra) initially showed signs of avoidance, but in the spring of 2007 birds were seen in densities within the Horns Rev 1 wind farm that was equal to the densities found around the wind farm. Very recent findings from Horns Rev 2 indicate that this have......In 1999 a Danish demonstration programme concerning offshore wind farms was initiated. The aim was to evaluate environmental and technical aspects in relation to introducing these new structures at sea. Aarhus University was involved in ornithological investigations in that respect. Monitoring...

  11. December 8, 2000. Regional wind energy development. The offshore development potential: European perspectives; 8 decembre 2000. Developpement eolien regional. Le potentiel de developpement offshore: perspectives europeennes

    Energy Technology Data Exchange (ETDEWEB)

    Marcen Zunzarren, J.A. [Navarre Gvt., Dir. of national development and urbanism (Spain); O' Gallachoir, B. [Cork Univ., Dept. of civil engineering and Environment, Cork (Ireland); Vergnet, M. [Societe Vergnet SA, 45 - Ingret (France); Laumonier, Ch. [Centre Scientifique et Technique du Batiment, (CSTB), 75 - Paris (France); Donnat, J.M. [Agence Mediterraneenne de l' Environnement, Contribution du Conseil Regional au Developpement de l' Eolien en Languedoc-Roussillon, 34 - Montpellier (France); Stenvald Madsen, P. [Elsamprojekt A/S, Fredericia (Denmark); Thomas-Bourgneuf, G. [Direction du Service Maritime et de Navigation du Languedoc-Roussillon (France); Bonnefoi, S. [Cabinet Bonnefoi (France); Thoury, Ph. [Commission Environnement du Comite Regional des Peches Languedoc-Roussillon (France); Beutin, Ph. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France)

    2001-03-01

    This second day of colloquium was organized around two topics: the regional development of wind power and the feasibility of offshore wind farms in Europe. The regional aspect was illustrated with the presentation of the Spanish, Irish and French experience (programs, means, results, role of local authorities, public opinion). A round table was organized about the local environmental impacts of wind power development. The offshore aspect was illustrated with the presentation of projects in Denmark and France. The legal and fiscal aspects of offshore projects were considered too. (J.S.)

  12. Floating Offshore Wind in California: Gross Potential for Jobs and Economic Impacts from Two Future Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Speer, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States); Keyser, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-04-18

    Construction of the first offshore wind farm in the United States began in 2015, using fixed platform structures that are appropriate for shallow seafloors, like those located off of the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to anchor to the deeper seafloor if deployed off of the West Coast. To analyze the employment and economic potential for floating offshore wind along the West Coast, the Bureau of Ocean Energy Management (BOEM) has commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical, large-scale deployment scenarios for California: 16 GW of offshore wind by 2050 (Scenario A) and 10 GW of offshore wind by 2050 (Scenario B). The results of this analysis can be used to better understand the general scales of economic opportunities that could result from offshore wind development. Results show total state gross domestic product (GDP) impacts of $16.2 billion in Scenario B or $39.7 billion in Scenario A for construction; and $3.5 billion in Scenario B or $7.9 billion in Scenario A for the operations phases.

  13. Offshore oil and gas and offshore wind power - different in terms of safety.?; Offshore Oel and Gas und Offshore Wind - mit Sicherheit ''anders''.?

    Energy Technology Data Exchange (ETDEWEB)

    Weise, F.; Tatulinski, M. [DNV GL - Oil and Gas Germany, Hamburg (Germany)

    2014-07-01

    Safety standards in the oil and gas industry have risen to a high level over the past decades, driven in part by momentous accidents. Furthermore, an expanded framework has recently been defined through the new EU Offshore Safety Directive, which in Germany is still in the process of its transposition into national law. The installation of offshore wind farms in the North and Baltic Sea has within the shortest of time brought forth an entirely new branch of industry, most of whose players have no significant experience with offshore operations. One of the greatest challenges is the working environment, which is being approached in different ways by those involved. The supervisory authorities responsible are only just beginning to develop the competence required for their tasks, with the effect that regulations pertaining to onshore operations are often simply adopted as they are. This is in some cases impacting on the oil and gas industry, as is discussed in the present lecture. [German] Die Oel und Gas Industrie hat in den vergangen Jahrzehnten einen hohen Sicherheitsstandard entwickelt, teilweise getrieben durch signifikante Unfallereignisse. Aktuell wurde zudem mit der neuen EU-Offshore Richtlinie ein erweiterter Rahmen definiert, der sich in Deutschland noch in der gesetzgeberischen Umsetzung befindet. Durch die Installation von Offshore-Windparks in der Nord- und Ostsee ist innerhalb kuerzester Zeit zusaetzlich ein neuer Industriebereich entstanden, dessen Marktteilnehmer mehrheitlich nicht ueber signifikante Offshore-Erfahrung verfuegen. Insbesondere das Arbeitsumfeld stellt dabei eine Herausforderung dar, die von den Beteiligten unterschiedlich geloest wird. Ferner beginnen auch die verantwortlichen Aufsichtsbehoerden erst mit dem Aufbau entsprechender Kompetenzen, so dass vielfach auch Regelungen aus dem Onshore-Bereich uebertragen werden. Dies fuehrt teilweise zu Auswirkungen auf die Oel- und Gasindustrie, die im Rahmen dieses Vortrages diskutiert werden.

  14. GPS synchronisation of harmonic and transient measurements in offshore wind farms

    DEFF Research Database (Denmark)

    Kocewiak, Łukasz Hubert; Arana Aristi, Iván; Hjerrild, Jesper

    2012-01-01

    The GPS synchronization challenges during the development, construction and installation of a measurement system for multi-point, high-speed and long-term data logging is described in this paper. The presented measurement system was tested in a rough offshore environment at Avedøre Holme and Gunf......The GPS synchronization challenges during the development, construction and installation of a measurement system for multi-point, high-speed and long-term data logging is described in this paper. The presented measurement system was tested in a rough offshore environment at Avedøre Holme...... and Gunfleet Sands Offshore wind farms. The paper will describe the application of GPS technology in synchronised measurements carried out at Avedøre Holme and Gunfleet Sands wind farms. Different aspects of software development and hardware configuration in order to optimise measurement system reliability...

  15. Structural health and prognostics management for offshore wind turbines :

    Energy Technology Data Exchange (ETDEWEB)

    Myrent, Noah J.; Kusnick, Joshua F.; Barrett, Natalie C.; Adams, Douglas E.; Griffith, Daniel

    2013-04-01

    Operations and maintenance costs for offshore wind plants are significantly higher than the current costs for land-based (onshore) wind plants. One way to reduce these costs would be to implement a structural health and prognostic management (SHPM) system as part of a condition based maintenance paradigm with smart load management and utilize a state-based cost model to assess the economics associated with use of the SHPM system. To facilitate the development of such a system a multi-scale modeling approach developed in prior work is used to identify how the underlying physics of the system are affected by the presence of damage and faults, and how these changes manifest themselves in the operational response of a full turbine. This methodology was used to investigate two case studies: (1) the effects of rotor imbalance due to pitch error (aerodynamic imbalance) and mass imbalance and (2) disbond of the shear web; both on a 5-MW offshore wind turbine in the present report. Based on simulations of damage in the turbine model, the operational measurements that demonstrated the highest sensitivity to the damage/faults were the blade tip accelerations and local pitching moments for both imbalance and shear web disbond. The initial cost model provided a great deal of insight into the estimated savings in operations and maintenance costs due to the implementation of an effective SHPM system. The integration of the health monitoring information and O&M cost versus damage/fault severity information provides the initial steps to identify processes to reduce operations and maintenance costs for an offshore wind farm while increasing turbine availability, revenue, and overall profit.

  16. A Fuzzy-FMEA Risk Assessment Approach for Offshore Wind Turbines

    Directory of Open Access Journals (Sweden)

    M. Shafiee

    2013-01-01

    Full Text Available Failure Mode and Effects Analysis (FMEA has been extensively used by wind turbine assembly manufacturers for risk and reliability analysis. However, several limitations are associated with its implementation in offshore windfarms: (i the failure data gathered from SCADA system is often missing or unreliable, and hence, the assessment information of the three risk factors (i.e., severity, occurrence, and fault detection are mainly based onexperts’ knowledge; (ii it is rather difficult for experts to precisely evaluate the risk factors; (iii the relative importance among the risk factors is not taken into consideration, and hence, the results may not necessarily represent the true risk priorities; and etc. To overcome these drawbacks and improve the effectiveness of the traditional FMEA, we develop a fuzzy-FMEA approach for risk and failure mode analysis in offshore wind turbine systems. The information obtained from the experts is expressed using fuzzy linguistics terms, and a grey theory analysis is proposed to incorporate the relative importance of the riskfactors into the determination of risk priority of failure modes. The proposed approach is applied to an offshore wind turbine system with sixteen mechanical, electrical and auxiliary assemblies, and the results are compared with the traditional FMEA.

  17. Employees' perception on risk and risk management: evidence from Danish offshore wind industry

    DEFF Research Database (Denmark)

    Ahsan, Dewan

    in a mismatch between the experiences acquired by the supporting companies and the expectations the clients. It has been perceived that complicated project manuals (because of special and increased requirements from the clients) sometimes create more risk exposures. The employees identified that demand from......Production of electricity from offshore wind energy is receiving much priority in several develop and developing countries. Nevertheless, this industry is becoming more expensive and challenging due to various operational and policy related risks factors. Therefore, the aim of this paper...... is to provide empirical insight into risks in offshore wind industry as perceived by the workers and managers. The survey has been conducted with the employees who are working in several offshore wind industries in Denmark. It has been revealed that there is a lack of common standard which is resulting...

  18. Assessing the level of integration in the offshore wind industry value chain

    OpenAIRE

    Martinez-Neri, Ivan; Mikkelsen, Ole Stegmann; Stentoft, Jan

    2014-01-01

    The offshore wind industry (OWI) has experienced an explosive growth within the course of a decade and because of this rapid expansion, the industry has not had the opportunity to integrate well and be-come more efficient. The aim of this paper is to contribute to the understanding of the integration level of the offshore wind industry value chain. The work relies on a review of international peer-reviewed journals. The empirical basis of the paper is based on interviews with key players in t...

  19. Electrical Structure of Future Off-shore Wind Power Plant with a High Voltage Direct Current Power Transmission

    DEFF Research Database (Denmark)

    Sharma, Ranjan

    The increasing demand of electric power and the growing consciousness towards the changing climate has led to a rapid development of renewable energy in the recent years. Among all, wind energy has been the fastest growing energy source in the last decade. But the growing size of wind power plants......, better wind conditions at off-shore and the general demand to put them out of sight have all contributed to the installation of large wind power plants in off-shore condition. However, moving wind power plants far out in the off-shore comes with many associated problems. One of the main challenges...... is the transmission of power over long distance. Historically, the power transmission from off-shore wind power plants has been done via HVAC submarine cables. This provides a simple solution, but AC cables cannot be arbitrarily long. It is shown in the report that major issues with HVAC cable transmission system...

  20. Offshore and onshore wind turbine wake meandering studied in an ABL wind tunnel

    DEFF Research Database (Denmark)

    Barlas, Emre; Buckingham, Sophia; Glabeke, Gertjan

    2015-01-01

    Scaled wind turbine models have been installed in the VKI L1-B atmospheric boundary layer wind tunnel at offshore and onshore conditions. Time-resolved measurements were carried out with three component hot wire anemometry and stereo-PIV in the middle vertical plane of the wake up to eleven turbine...... diameter downstream. The results show an earlier wake recovery for the onshore case. The effect of inflow conditions and the wind turbine’s working conditions on wake meandering was investigated. Wake meandering was detected by hot wire anemometry through a low frequency peak in the turbulent power...

  1. Mapping Offshore Winds Around Iceland Using Satellite Synthetic Aperture Radar and Mesoscale Model Simulations

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Nawri, Nikolai

    2015-01-01

    effects, gap flow, coastal barrier jets, and atmospheric gravity waves are not only observed in SAR, but are also modeled well from HARMONIE. Offshore meteorological observations are not available, but wind speed and wind direction measurements from coastal meteorological masts are found to compare well...... to nearby offshore locations observed by SAR. More than 2500 SAR scenes from the Envisat ASAR wide swathmode are used for wind energy resource estimation. The wind energy potential observed from satellite SAR shows high values above 1000 Wm −2 in coastal regions in the south, east, and west, with lower...

  2. Aspects of structural health and condition monitoring of offshore wind turbines.

    Science.gov (United States)

    Antoniadou, I; Dervilis, N; Papatheou, E; Maguire, A E; Worden, K

    2015-02-28

    Wind power has expanded significantly over the past years, although reliability of wind turbine systems, especially of offshore wind turbines, has been many times unsatisfactory in the past. Wind turbine failures are equivalent to crucial financial losses. Therefore, creating and applying strategies that improve the reliability of their components is important for a successful implementation of such systems. Structural health monitoring (SHM) addresses these problems through the monitoring of parameters indicative of the state of the structure examined. Condition monitoring (CM), on the other hand, can be seen as a specialized area of the SHM community that aims at damage detection of, particularly, rotating machinery. The paper is divided into two parts: in the first part, advanced signal processing and machine learning methods are discussed for SHM and CM on wind turbine gearbox and blade damage detection examples. In the second part, an initial exploration of supervisor control and data acquisition systems data of an offshore wind farm is presented, and data-driven approaches are proposed for detecting abnormal behaviour of wind turbines. It is shown that the advanced signal processing methods discussed are effective and that it is important to adopt these SHM strategies in the wind energy sector.

  3. Aspects of structural health and condition monitoring of offshore wind turbines

    Science.gov (United States)

    Antoniadou, I.; Dervilis, N.; Papatheou, E.; Maguire, A. E.; Worden, K.

    2015-01-01

    Wind power has expanded significantly over the past years, although reliability of wind turbine systems, especially of offshore wind turbines, has been many times unsatisfactory in the past. Wind turbine failures are equivalent to crucial financial losses. Therefore, creating and applying strategies that improve the reliability of their components is important for a successful implementation of such systems. Structural health monitoring (SHM) addresses these problems through the monitoring of parameters indicative of the state of the structure examined. Condition monitoring (CM), on the other hand, can be seen as a specialized area of the SHM community that aims at damage detection of, particularly, rotating machinery. The paper is divided into two parts: in the first part, advanced signal processing and machine learning methods are discussed for SHM and CM on wind turbine gearbox and blade damage detection examples. In the second part, an initial exploration of supervisor control and data acquisition systems data of an offshore wind farm is presented, and data-driven approaches are proposed for detecting abnormal behaviour of wind turbines. It is shown that the advanced signal processing methods discussed are effective and that it is important to adopt these SHM strategies in the wind energy sector. PMID:25583864

  4. 78 FR 8190 - Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore North Carolina...

    Science.gov (United States)

    2013-02-05

    ...] Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore North Carolina--Call for... Commercial Leasing for Wind Power Offshore North Carolina (Call), published on December 13, 2012 (77 FR 7204). DATES: BOEM must receive your nomination describing your interest in obtaining a commercial wind lease...

  5. System Reliability for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Marquez-Dominguez, Sergio; Sørensen, John Dalsgaard

    2013-01-01

    E). In consequence, a rational treatment of uncertainties is done in order to assess the reliability of critical details in OWTs. Limit state equations are formulated for fatigue critical details which are not influenced by wake effects generated in offshore wind farms. Furthermore, typical bi-linear S-N curves...... are considered for reliability verification according to international design standards of OWTs. System effects become important for each substructure with many potential fatigue hot spots. Therefore, in this paper a framework for system effects is presented. This information can be e.g. no detection of cracks...... in inspections or measurements from condition monitoring systems. Finally, an example is established to illustrate the practical application of this framework for jacket type wind turbine substructure considering system effects....

  6. Contribution of VSC-HVDC to Frequency Regulation of Power Systems With Offshore Wind Generation

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2015-01-01

    to the onshore system grid through voltage-source converter-based–high voltage direct current (VSC-HVdc) transmission systems. Due to the decoupling of VSC-HVdc and signal transmission delay, offshore wind farms may not be able to respond to the onshore grid frequency excursion in time and, consequently......, the stability and security of the power system will be put at risk, especially for those with high wind penetration. This paper proposes a coordinated control scheme to allow VSC-HVdc link to contribute to the system frequency regulation by adjusting its dc-link voltage. By means of this approach, the dc...... capacitors of VSC-HVdc are controlled to absorb or release energy so as to provide frequency support. To further enhance the system frequency response, the frequency support from VSC-HVdc is also finely coordinated with that from offshore wind farm according to the latency of offshore wind farm responding...

  7. Bayesian based Diagnostic Model for Condition based Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Asgarpour, Masoud; Sørensen, John Dalsgaard

    2018-01-01

    Operation and maintenance costs are a major contributor to the Levelized Cost of Energy for electricity produced by offshore wind and can be significantly reduced if existing corrective actions are performed as efficiently as possible and if future corrective actions are avoided by performing...... sufficient preventive actions. This paper presents an applied and generic diagnostic model for fault detection and condition based maintenance of offshore wind components. The diagnostic model is based on two probabilistic matrices; first, a confidence matrix, representing the probability of detection using...... for a wind turbine component based on vibration, temperature, and oil particle fault detection methods. The last part of the paper will have a discussion of the case study results and present conclusions....

  8. Fatigue Reliability and Calibration of Fatigue Design Factors for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Dominguez, Sergio Marquez; Sørensen, John Dalsgaard

    2012-01-01

    Consequences of failure of offshore wind turbines (OWTs) are in general lower than consequences of failure of, e.g., oil & gas platforms. It is reasonable that lower fatigue design factors can be applied for fatigue design of OWTs when compared to other fixed offshore structures. Calibration...

  9. Effect of Geometric Uncertainties on the Aerodynamic Characteristic of Offshore Wind Turbine Blades

    International Nuclear Information System (INIS)

    Ernst, Benedikt; Schmitt, Henning; Seume, Jörg R

    2014-01-01

    Offshore wind turbines operate in a complex unsteady flow environment which causes unsteady aerodynamic loads. The unsteady flow environment is characterized by a high degree of uncertainty. In addition, geometry variations and material imperfections also cause uncertainties in the design process. Probabilistic design methods consider these uncertainties in order to reach acceptable reliability and safety levels for offshore wind turbines. Variations of the rotor blade geometry influence the aerodynamic loads which also affect the reliability of other wind turbine components. Therefore, the present paper is dealing with geometric uncertainties of the rotor blades. These can arise from manufacturing tolerances and operational wear of the blades. First, the effect of geometry variations of wind turbine airfoils on the lift and drag coefficients are investigated using a Latin hypercube sampling. Then, the resulting effects on the performance and the blade loads of an offshore wind turbine are analyzed. The variations of the airfoil geometry lead to a significant scatter of the lift and drag coefficients which also affects the damage-equivalent flapwise bending moments. In contrast to that, the effects on the power and the annual energy production are almost negligible with regard to the assumptions made

  10. State of the Offshore Wind Industry in Northern Europe. Lessons Learnt in the First Decade

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, F; Grassin, J; Crockford, A; Winkel, T; Ritzen, A; Folkerts, L

    2011-03-15

    The offshore wind industry has experienced rapid development over the past ten years and a supply chain is gradually developing towards maturity. Some regions and businesses have successfully taken advantage of this opportunity and have grown into centres for manufacturing, construction and servicing for the offshore wind energy industry. This has generated regional economic growth and jobs. The continued growth of offshore wind is set to provide a major contribution to reaching the EU 2020 CO2 reduction targets of North Sea countries. This is also a valuable opportunity for the development of a major industry that will contribute added economic value and increase potential for exports of leading technology to other regions. There are however, significant challenges to overcome. These relate to the rate at which projects must be realised, the corresponding growth rate in the supply chain and the scale of the investments required. Effective stakeholder management will be necessary to ensure an efficient acquisition of permits and approvals for projects. Clarity on a long-term policy outlook is also a precondition for the investments required in both supply chain and offshore wind projects. National and regional governments can play a key role in providing a solution to this, by being pro-active and enabling. This looks set to enable a progressive spiral of cost reduction and efficiency, allowing further growth of the offshore wind market.

  11. The effect of the 2010 Gulf oil spill on public attitudes toward offshore oil drilling and wind development

    International Nuclear Information System (INIS)

    Lilley, Jonathan; Firestone, Jeremy

    2013-01-01

    In April 2010, the Deepwater Horizon oil well exploded, releasing over four million barrels of oil into the Gulf of Mexico. This paper presents data from two national mail surveys undertaken in 2008 and 2010 that compare public attitudes to both offshore oil drilling and offshore wind development pre- and post-spill. The results show that while there was a drop in support for expanded drilling (from 66% in 2008 to 59% in 2010) the change was not significant. There was, however, a significant decrease in support for offshore drilling among coastal residents. There was a slight, non-significant increase in support for offshore wind development which remained significantly higher than support for offshore oil (80% in 2008 and 82% in 2010). Despite there being no significant change in overall support levels, there was a shift in the strength of feeling regarding offshore oil, with 80% of Americans either less supportive or more opposed to expanded drilling in 2010 than they were in 2008. -- Highlights: •We assess whether the Gulf oil spill affected attitudes to offshore energy. •Overall support for offshore wind (82%) was greater than for offshore oil (59%). •Support for expanded offshore oil drilling decreased but not significantly. •Support for offshore wind development increased slightly, again not significantly. •Although overall support levels did not change, the strength of feeling did

  12. Risk-Based Inspection and Maintenance Planning Optimization of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2009-01-01

    A risk-based inspection planning (RBI) approach applied to offshore wind turbines (OWT) is presented, based on RBI methodology developed in the last decades in the oil and gas industry. In wind farm (IWF) and single-alone locations are considered using a code-established turbulence models including...

  13. Probabilistic maximum-value wind prediction for offshore environments

    DEFF Research Database (Denmark)

    Staid, Andrea; Pinson, Pierre; Guikema, Seth D.

    2015-01-01

    statistical models to predict the full distribution of the maximum-value wind speeds in a 3 h interval. We take a detailed look at the performance of linear models, generalized additive models and multivariate adaptive regression splines models using meteorological covariates such as gust speed, wind speed......, convective available potential energy, Charnock, mean sea-level pressure and temperature, as given by the European Center for Medium-Range Weather Forecasts forecasts. The models are trained to predict the mean value of maximum wind speed, and the residuals from training the models are used to develop...... the full probabilistic distribution of maximum wind speed. Knowledge of the maximum wind speed for an offshore location within a given period can inform decision-making regarding turbine operations, planned maintenance operations and power grid scheduling in order to improve safety and reliability...

  14. Combined Optimization for Offshore Wind Turbine Micro Siting

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; N. Soltani, Mohsen

    2017-01-01

    In order to minimize the wake loss, wind turbines (WT) should be separated with large intervening spaces. However, this will incur an increase in the capital expenditure on electrical systems and even in the operation and maintenance costs. In order to realize a cost-effective wind farm......) algorithm is adopted to minimize the levelized production cost (LPC) of the wind farm. Simulation results are given for validating the proposed approach and comparison is made with results obtained using other methods. It is found that the proposed method can reduce the levelized production cost (LPC) by 5.......00% and increase the energy yields by 3.82% compared with the Norwegian centre for offshore wind energy (NORCOWE) reference wind farm layout. This is better than the traditional method which only achieves a 1.45% LPC reduction although it increases the energy yields by 3.95%....

  15. 77 FR 5545 - Commercial Leasing for Wind Power Development on the Outer Continental Shelf (OCS) Offshore...

    Science.gov (United States)

    2012-02-03

    ... development of the offshore wind energy industry, offshore wind energy projects, and associated supply chain... to chart a path forward to provide for reliable energy supplies at reasonable rates and increase the..., including endangered leatherback (Dermochelys coriacea), Kemp's ridley (Lepidochelys kempi) and green...

  16. WT-Bird. Bird collision recording for offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Wiggelinkhuizen, E.J.; Rademakers, L.W.M.M.; Barhorst, S.A.M. [ECN Wind Energy, Petten (Netherlands); Den Boon, H.J. [E-Connection Project, Bunnik (Netherlands); Dirksen, S. [Bureau Waardenburg, Culemborg (Netherlands); Schekkerman, H. [Alterra, Wageningen (Netherlands)

    2006-03-15

    A new method for registration of bird collisions has been developed using video cameras and microphones combined with event triggering by acoustic vibration measurement. Remote access to the recorded images and sounds makes it possible to count the number of collisions as well as to identify the species. Currently a prototype system is being tested on an offshore-scale land-based wind turbine using bird dummies. After these tests we planned to perform endurance tests on other land-based turbines under offshore-like conditions.

  17. Cost-efficient foundation structures for large offshore wind farms

    International Nuclear Information System (INIS)

    Birch, C.; Gormsen, C.; Lyngesen, S.; Rasmussen, J. L.; Juhl, H.

    1997-01-01

    This paper presents the results of the development of a cost-efficient foundation for large (1.5 MW) offshore wind farms at water depth of 5 to 11 m. Previously, medium sized wind turbines (500 kW) in Denmark have been installed offshore at water depths of approximately 5 m on concrete gravity foundations. The installation of larger turbines at greater depth does, however, hold great promise in terms of wind environment and environmental considerations. The costs of a traditional gravity foundation at these increased water depths is expected to be prohibitive, and the aim of the project has been to reduce the foundations costs in general. This paper describes the theoretical basis for the geotechnical and structural design of three alternative concepts and presents an optimised layout of each based on a research and development project. The basis has been a wind farm consisting of 100 turbines. The R and D project has been undertaken by the consulting engineers Nellemann, Nielsen and Rauschenberger A/S (Gravity foundation), LICengineering A/S (Mono pile) and Ramboell (Tripod) in co-operation with the Danish utility engineering companies Elkraft and Elsamprojekt A/S. The project was partly financed by the participants and by the Danish Energy Agency through their 1996 Energy Research Programme (EFP-96). (au) 18 refs

  18. Vibration-induced settlement of a slip-joint connection for offshore wind turbines

    NARCIS (Netherlands)

    Segeren, M.L.A.

    2018-01-01

    The majority of existing offshore wind turbines typically consist of a monopile foundation, a transition piece with a vertically positioned grouted connection, a turbine tower, and a turbine. Of the 2,653 offshore turbines that were installed by the end of 2015, 80 percent are supported by a

  19. European concerted action on offshore wind energy deployment: inventory and analysis of power transmission barriers in eight member states

    International Nuclear Information System (INIS)

    Woyte, Achim; Gardner, Paul; Snodin, Helen

    2007-01-01

    The European Concerted Action for Offshore Wind Energy Deployment (COD) was carried out by eight sea-bordering European Union member states, with the objective to remove not explicitly technical barriers to offshore wind energy. Within the COD, an inventory of relevant aspects affecting the grid integration of offshore wind energy on a large scale in the eight countries has been made. Collected data items for this inventory are national plans and prospects for offshore wind energy, information about the transmission system, possibilities for grid connection, aspects of the grid codes, balancing, connection and energy pricing. The comprehensive COD reports were published and presented in October 2005 during the Copenhagen Offshore wind conference. This paper provides a short description of the situation for each country. Thereafter, country-specific information is grouped based on geography and membership in a synchronous zone. Additionally, a view is developed on the desirable facilities for the trans-European exchange of power from large wind farms. Finally, we elaborate overall conclusions in order to arrive at generalized observations, recommendations for policy makers and issues that will emerge in the near future. As a general conclusion, many things need to be done on a technical level in order to integrate large amounts of offshore wind power into our power systems. However, none of these measures is technically unknown. Therefore, the feasibility of integrating large amounts of offshore wind power is mainly a question of finance and hence based on political decisions. (Author)

  20. Assessing environmental impacts of offshore wind farms: lessons learned and recommendations for the future.

    Science.gov (United States)

    Bailey, Helen; Brookes, Kate L; Thompson, Paul M

    2014-01-01

    Offshore wind power provides a valuable source of renewable energy that can help reduce carbon emissions. Technological advances are allowing higher capacity turbines to be installed and in deeper water, but there is still much that is unknown about the effects on the environment. Here we describe the lessons learned based on the recent literature and our experience with assessing impacts of offshore wind developments on marine mammals and seabirds, and make recommendations for future monitoring and assessment as interest in offshore wind energy grows around the world. The four key lessons learned that we discuss are: 1) Identifying the area over which biological effects may occur to inform baseline data collection and determining the connectivity between key populations and proposed wind energy sites, 2) The need to put impacts into a population level context to determine whether they are biologically significant, 3) Measuring responses to wind farm construction and operation to determine disturbance effects and avoidance responses, and 4) Learn from other industries to inform risk assessments and the effectiveness of mitigation measures. As the number and size of offshore wind developments increases, there will be a growing need to consider the population level consequences and cumulative impacts of these activities on marine species. Strategically targeted data collection and modeling aimed at answering questions for the consenting process will also allow regulators to make decisions based on the best available information, and achieve a balance between climate change targets and environmental legislation.

  1. The case for offshore wind farms, artificial reefs and sustainable tourism in the French mediterranean

    DEFF Research Database (Denmark)

    Westerberg, Vanja; Jacobsen, Jette Bredahl; Lifran, Robert

    2013-01-01

    As the French government strives to achieve their offshore renewable energy target, the impact of offshore wind farms on coastal tourism in the Languedoc Rousillon is now being questioned. To assess this issue, a choice experiment was undertaken to elicit tourist preferences for wind turbines...... attitudes towards compensatory policies. Two policy recommendations are suggested. First, everything else being equal, wind farms should be located no closer than 12 km from the shore. Second, and alternatively, a wind farm can be located from 5 km and outwards without a loss in tourism revenues...

  2. Five offshore wind farms by EDF, GDF Suez and Iberdrola. France; Vijf offshore windparken door EDF, GDF Suez en Iberdrola. Frankrijk

    Energy Technology Data Exchange (ETDEWEB)

    Polo-Leemreis, J. [TWA Netwerk, Paris (France)

    2012-02-15

    Five offshore wind farms are planned to be built off the Northwest coast of France. On 11 January 2012, three international consortia, led by the French businesses EDF EN (Energie Nouvelles), GDF Suez and the Spanish business Iberdrola, submitted their project proposals to this end. The French government highly values the contribution that offshore wind farms can make to the development of a new industrial sector. This would bring highly needed benefits to the French economy [Dutch] Voor de Noordwest-kust van Frankrijk moeten vijf offshore windparken komen. Op 11 januari 2012 hebben drie internationale consortia onder leiding van de Franse bedrijven EDF EN (Energies Nouvelles), GDF Suez en het Spaanse Iberdrola hun projectvoorstellen hiervoor ingediend. De Franse regering hecht veel waarde aan de bijdrage die offshore windparken kunnen leveren aan de ontwikkeling van een nieuwe industriele sector. De Franse economie zou dit goed kunnen gebruiken.

  3. Continuous spatial modelling to analyse planning and economic consequences of offshore wind energy

    International Nuclear Information System (INIS)

    Moeller, Bernd

    2011-01-01

    Offshore wind resources appear abundant, but technological, economic and planning issues significantly reduce the theoretical potential. While massive investments are anticipated and planners and developers are scouting for viable locations and consider risk and impact, few studies simultaneously address potentials and costs together with the consequences of proposed planning in an analytical and continuous manner and for larger areas at once. Consequences may be investments short of efficiency and equity, and failed planning routines. A spatial resource economic model for the Danish offshore waters is presented, used to analyse area constraints, technological risks, priorities for development and opportunity costs of maintaining competing area uses. The SCREAM-offshore wind model (Spatially Continuous Resource Economic Analysis Model) uses raster-based geographical information systems (GIS) and considers numerous geographical factors, technology and cost data as well as planning information. Novel elements are weighted visibility analysis and geographically recorded shipping movements as variable constraints. A number of scenarios have been described, which include restrictions of using offshore areas, as well as alternative uses such as conservation and tourism. The results comprise maps, tables and cost-supply curves for further resource economic assessment and policy analysis. A discussion of parameter variations exposes uncertainties of technology development, environmental protection as well as competing area uses and illustrates how such models might assist in ameliorating public planning, while procuring decision bases for the political process. The method can be adapted to different research questions, and is largely applicable in other parts of the world. - Research Highlights: → A model for the spatially continuous evaluation of offshore wind resources. → Assessment of spatial constraints, costs and resources for each location. → Planning tool for

  4. 75 FR 21653 - Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore Delaware-Request...

    Science.gov (United States)

    2010-04-26

    ... Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore Delaware--Request for Interest (RFI... proposal. In June 2008, Bluewater Wind Delaware LLC announced that it signed a 25-year power purchase agreement with Delmarva Power to sell up to 200 megawatts (MW) of power to the utility from an offshore wind...

  5. Dynamic analysis of a 5-MW tripod offshore wind turbine by considering fluid-structure interaction

    Science.gov (United States)

    Zhang, Li-wei; Li, Xin

    2017-10-01

    Fixed offshore wind turbines usually have large underwater supporting structures. The fluid influences the dynamic characteristics of the structure system. The dynamic model of a 5-MW tripod offshore wind turbine considering the pile-soil system and fluid structure interaction (FSI) is established, and the structural modes in air and in water are obtained by use of ANSYS. By comparing low-order natural frequencies and mode shapes, the influence of sea water on the free vibration characteristics of offshore wind turbine is analyzed. On basis of the above work, seismic responses under excitation by El-Centro waves are calculated by the time-history analysis method. The results reveal that the dynamic responses such as the lateral displacement of the foundation and the section bending moment of the tubular piles increase substantially under the influence of the added-mass and hydrodynamic pressure of sea water. The method and conclusions presented in this paper can provide a theoretical reference for structure design and analysis of offshore wind turbines fixed in deep seawater.

  6. A stakeholder analysis of divergent supply-chain trends for the European onshore and offshore wind installations

    International Nuclear Information System (INIS)

    Wüstemeyer, Christoph; Madlener, Reinhard; Bunn, Derek W.

    2015-01-01

    This paper provides a survey-based analysis of investment decisions and structural shifts related to onshore and offshore wind power supply chains. Insights on cost reductions are obtained from a detailed stakeholder survey conducted amongst the European wind power industry in 2012. Overall, a rather more optimistic view of the scope for cost reductions in offshore technology is presented than has previously been evident in empirical analysis. From the analysis we conclude that the wind power industry has experienced a decoupling process of the offshore supply chain from its onshore counterpart with diverging technological requirements. For policy-makers, it is essential to acknowledge that barriers to adoption and the consequent needs for subsidies among the players in the onshore and offshore supply chains seem to differ, and that a micro-level analysis of the innovations and risks involved at the various stages in the supply chain is necessary. - Highlights: • Survey-based analysis of supply chain trends in the European wind energy industry. • Study of technology adoption decisions, structural shifts, and cost projections. • Results reveal a decoupling process between onshore and offshore supply chains. • Possibilities to transfer knowledge from the onshore to the offshore product vary. • The divergent barriers to adoption need to be accounted for by policy-makers

  7. Extreme wind conditions for a Danish offshore site

    DEFF Research Database (Denmark)

    Hansen, Kurt S.

    2000-01-01

    This paper presents an analysis of extreme wind speed gust values measured at a shallow water offshore site and at a coastal onshore site in Denmark. An estimate of 50-year extreme values has been evaluated using a new statistical method. In addition a mean gust shape is determined, based on a la...

  8. Using the PROSA Method in Offshore Wind Farm Location Problems

    Directory of Open Access Journals (Sweden)

    Paweł Ziemba

    2017-11-01

    Full Text Available Wind is the most used renewable energy source (RES in the European Union and Poland. Due to the legal changes in the scope of RES in Poland, there are plans to develop offshore wind farms at the expense of onshore ones. On the other hand, the success of an offshore wind farm is primarily determined by its location. Therefore, the aim of this study is to select offshore wind farm locations in Poland, based on sustainability assessment, which is an inherent aspect of RES decision-making issues. To accomplish the objectives of this research, PROSA (PROMETHEE for Sustainability Assessment method, a new multi-criteria method is proposed. Like PROMETHEE (Preference Ranking Organization METHod for Enrichment Evaluation, PROSA is transparent for decision makers and is easy to use; moreover, it provides the analytical tools available in PROMETHEE, i.e., the sensitivity and GAIA (Geometrical Analysis for Interactive Assistance analyses. However, PROSA is characterized by a lower degree of criteria compensation than PROMETHEE. Thus, it adheres in a higher degree to the strong sustainability paradigm. The study also compared the solutions of the decision problem obtained with the use of PROSA and PROMETHEE methods. The compared methods demonstrated a high concurrence of the recommended decision-making variant of location selection, from methodological and practical points of view. At the same time, the conducted research allowed to confirm that the PROSA method recommends more sustainable decision-making variants, and that the ranking it builds is less sensitive to changes in criteria weights. Therefore, it is more stable than the PROMETHEE-based ranking.

  9. Power Transmission from Large Offshore Wind Farms

    DEFF Research Database (Denmark)

    Pedersen, Jørgen Kaas

    1999-01-01

    The major part of the coming wind farms in Denmark will be placed offshore. If the location is near a grid with a high short circuit level the power can be transmitted as AC.If the wind farm is far away from the grid and the grid perhaps has a low short circuit level, the best solution...... for transmitting the power can be by DC. At the moment it is possible to build self-commutating DC/AC-inverters up to about 150 kV. This paper will show a concept to a solution for a wind farm and a transmission system based on synchronous generators or a powerformer® with a rated voltage of 50 kV. The AC power...... will be rectified and boosted to a fixed DC voltage (e.g. 100 kV). The speed of the generator will be variable, depending of the wind but also controlled with the duty-cycle of the booster. In that way all wind turbines can be connected to the same DC bus and the cable to the inverter station connected to the AC...

  10. Offshore wind turbines and bird activity at Blyth

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    In 1996, a study was implemented to ultimately determine the impact of two 2MW wind turbines situated 900 metres offshore of the north-east of England. The turbines, with a hub height of 66 metres, began operation in December 2000. Earlier, similar studies were carried out on a row of wind turbines mounted on the harbour wall of the nearby town of Blyth. The report gives details of (i) total mortality and mortality due to the turbines; (ii) number of bird strikes; (iii) habitat displacement; (iv) feeding grounds; (v) flight routes and (vi) impact on bird populations of a nearby Site of Special Scientific Interest. The study was conducted by AMEC Wind Limited under contract to the DTI.

  11. Hierarchical Communication Network Architectures for Offshore Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2014-05-01

    Full Text Available Nowadays, large-scale wind power farms (WPFs bring new challenges for both electric systems and communication networks. Communication networks are an essential part of WPFs because they provide real-time control and monitoring of wind turbines from a remote location (local control center. However, different wind turbine applications have different requirements in terms of data volume, latency, bandwidth, QoS, etc. This paper proposes a hierarchical communication network architecture that consist of a turbine area network (TAN, farm area network (FAN, and control area network (CAN for offshore WPFs. The two types of offshore WPFs studied are small-scale WPFs close to the grid and medium-scale WPFs far from the grid. The wind turbines are modelled based on the logical nodes (LN concepts of the IEC 61400-25 standard. To keep pace with current developments in wind turbine technology, the network design takes into account the extension of the LNs for both the wind turbine foundation and meteorological measurements. The proposed hierarchical communication network is based on Switched Ethernet. Servers at the control center are used to store and process the data received from the WPF. The network architecture is modelled and evaluated via OPNET. We investigated the end-to-end (ETE delay for different WPF applications. The results are validated by comparing the amount of generated sensing data with that of received traffic at servers. The network performance is evaluated, analyzed and discussed in view of end-to-end (ETE delay for different link bandwidths.

  12. Impact of an offshore wind farm on wave conditions and shoreline development

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Kristensen, Sten Esbjørn; Deigaard, Rolf

    2014-01-01

    the shoreline’s sensitivity to the distance from the OWF to the shoreline was studied. The effect of the reduced wind speed inside and on the lee side of the offshore wind farm was incorporated in a parameterized way in a spectral wind wave model. The shoreline impact was studied with a one-line model....

  13. Voltage Feedback based Harmonic Compensation for an Offshore Wind Power Plant

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay K.; Lascu, Cristian; Teodorescu, Remus

    2016-01-01

    When an offshore wind power plant is connected to the grid, there is a risk of amplification of certain harmonics and appearance resonances at the point of connection due to the interaction between the grid network and the wind power plant network. Hence, the plant developer is obliged to maintain...

  14. Optimal support vessel and access system selection for offshore wind farms

    NARCIS (Netherlands)

    Asgarpour, M.; Serraris, J.W.; Ridder, E. de; Broek, J. van den; Bos, J.E.

    2016-01-01

    Operation and maintenance (O&M) costs contribute to a significant part of Cost of Energy produced by offshore wind. In order to reduce the O&M costs and to guarantee safety and wellbeing of the maintenance technicians, for each individual wind farm an optimal set of support vessels and access

  15. Risk-Based Operation and Maintenance of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

    2009-01-01

    For offshore wind turbines costs to operation and maintenance are substantial. This paper describes a risk-based lifecycle approach for optimal planning of operation and maintenance. The approach is based on pre-posterior Bayesian decision theory. Deterioration mechanisms such as fatigue, corrosion...

  16. Installation, Operation, and Maintenance Strategies to Reduce the Cost of Offshore Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Maples, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, G. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hand, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); van de Pietermen, R. [Energy Research Center of the Netherlands (Netherlands); Obdam, T. [Energy Research Center of the Netherlands (Netherlands)

    2013-07-01

    Currently, installation, operation, and maintenance (IO&M) costs contribute approximately 30% to the LCOE of offshore wind plants. To reduce LCOE while ensuring safety, this paper identifies principal cost drivers associated with IO&M and quantifies their impacts on LCOE. The paper identifies technology improvement opportunities and provides a basis for evaluating innovative engineering and scientific concepts developed subsequently to the study. Through the completion of a case study, an optimum IO&M strategy for a hypothetical offshore wind project is identified.

  17. One style to build them all: Corporate culture and innovation in the offshore wind industry

    International Nuclear Information System (INIS)

    Sovacool, Benjamin K.; Enevoldsen, Peter

    2015-01-01

    This study explores how Vestas and Siemens Wind Power manage technological innovation in the offshore wind power industry. It utilizes the concept of open and closed “research styles” to investigate how each company designs, constructs, and maintains offshore wind turbines. The article starts by summarizing three of the main innovation challenges facing the offshore wind sector—harsh conditions, capital intensity, and production bottlenecks—before it delves into the specific details about how Vestas and Siemens Wind Power approach turbine development. It divides this discussion into six distinct segments: resources and expenditures, stakeholder involvement and collaboration, testing and maintenance, control and knowledge management, adaptability of designs, and customization and marketing. The study finds that both Vestas and SWP, despite their corporate and cultural differences, utilize the same elements of closed and open styles. It lastly suggests that the notion of style itself may challenge certain assumptions held by scholars about managing the research and innovation process. - Highlights: • This study explores how Vestas and Siemens approach innovation in offshore wind turbine technology. • Open research styles are inclusive, participatory, cooperative, and flexible. • Closed research styles are exclusive, competitive, centralized, and rigid. • Interestingly, Vestas and Siemens use the same style to manage technological innovation. • They are closed when it comes to resources and expenditures and knowledge movement, but open in all other attributes.

  18. Development of a 5 MW reference gearbox for offshore wind turbines: 5 MW reference gearbox

    Energy Technology Data Exchange (ETDEWEB)

    Nejad, Amir Rasekhi [Norwegian Research Center for Offshore Wind Technology, Norwegian University of Science and Technology, Trondheim Norway; Center for Ships and Ocean Structures, Norwegian University of Science and Technology, Trondheim Norway; Guo, Yi [National Wind Technology Center, National Renewable Energy Laboratory, Golden Colorado USA; Gao, Zhen [Center for Ships and Ocean Structures, Norwegian University of Science and Technology, Trondheim Norway; Moan, Torgeir [Norwegian Research Center for Offshore Wind Technology, Norwegian University of Science and Technology, Trondheim Norway; Center for Ships and Ocean Structures, Norwegian University of Science and Technology, Trondheim Norway

    2015-07-27

    This paper presents detailed descriptions, modeling parameters and technical data of a 5MW high-speed gearbox developed for the National Renewable Energy Laboratory offshore 5MW baseline wind turbine. The main aim of this paper is to support the concept studies and research for large offshore wind turbines by providing a baseline gearbox model with detailed modeling parameters. This baseline gearbox follows the most conventional design types of those used in wind turbines. It is based on the four-point supports: two main bearings and two torque arms. The gearbox consists of three stages: two planetary and one parallel stage gears. The gear ratios among the stages are calculated in a way to obtain the minimum gearbox weight. The gearbox components are designed and selected based on the offshore wind turbine design codes and validated by comparison to the data available from large offshore wind turbine prototypes. All parameters required to establish the dynamic model of the gearbox are then provided. Moreover, a maintenance map indicating components with high to low probability of failure is shown. The 5 MW reference gearbox can be used as a baseline for research on wind turbine gearboxes and comparison studies. It can also be employed in global analysis tools to represent a more realistic model of a gearbox in a coupled analysis.

  19. Structural health and prognostics management for offshore wind turbines :

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, Daniel; Resor, Brian Ray; White, Jonathan Randall; Paquette, Joshua A.; Yoder, Nathanael C.

    2012-12-01

    Operations and maintenance costs for offshore wind plants are expected to be significantly higher than the current costs for onshore plants. One way in which these costs may be able to be reduced is through the use of a structural health and prognostic management system as part of a condition based maintenance paradigm with smart load management. To facilitate the creation of such a system a multiscale modeling approach has been developed to identify how the underlying physics of the system are affected by the presence of damage and how these changes manifest themselves in the operational response of a full turbine. The developed methodology was used to investigate the effects of a candidate blade damage feature, a trailing edge disbond, on a 5-MW offshore wind turbine and the measurements that demonstrated the highest sensitivity to the damage were the local pitching moments around the disbond. The multiscale method demonstrated that these changes were caused by a local decrease in the blades torsional stiffness due to the disbond, which also resulted in changes in the blades local strain field. Full turbine simulations were also used to demonstrate that derating the turbine power by as little as 5% could extend the fatigue life of a blade by as much as a factor of 3. The integration of the health monitoring information, conceptual repair cost versus damage size information, and this load management methodology provides an initial roadmap for reducing operations and maintenance costs for offshore wind farms while increasing turbine availability and overall profit.

  20. Stability analysis of offshore wind farm and marine current farm

    Science.gov (United States)

    Shawon, Mohammad Hasanuzzaman

    Renewable energy has been playing an important role to meet power demand and 'Green Energy' market is getting bigger platform all over the world in the last few years. Due to massive increase in the prices of fossil fuels along with global warming issues, energy harvesting from renewable energy sources has received considerable interest, nowadays, where extensive researches are going on to ensure optimum use of renewable sources. In order to meet the increasing demand of electricity and power, integration of renewable energy is getting highest priorities around the world. Wind is one of the most top growing renewable energy resources and wind power market penetration is expected to reach 3.35 percent by 2013 from its present market of about 240 GW. A wind energy system is the most environmental friendly, cost effective and safe among all renewable energy resources available. Another promising form of renewable energy is ocean energy which covers 70 % of the earth. Ocean energy can be tapped from waves, tides and thermal elements. Offshore Wind farm (OWF) has already become very popular for large scale wind power integration with the onshore grid. Recently, marine current farm (MCF) is also showing good potential to become mainstream energy sources and already successfully commissioned in United Kingdom. However, squirrel cage induction generator (SCIG) has the stability problem similar to synchronous generator especially during fault location to restore the electromagnetic torque. Series dynamic braking resistor (SDBR) has been known as a useful mean to stabilize fixed speed wind generator system. On the other hand, doubly fed induction generator (DFIG) has the capability of coupling the control of active and reactive power and to provide necessary reactive power demand during grid fault conditions. Series dynamic braking resistor (SDBR) can also be employed with DFIG to limit the rotor over current. An integration of wind and tidal energy represents a new

  1. Wave Run-Up on Cylindrical and Cone Shaped Foundations for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    De Vos, Leen; Frigaard, Peter; De Rouck, Julien

    2007-01-01

    During the last decade, several offshore wind-farms were built and offshore wind energy promises to be a suitable alternative to provide green energy. However, there are still some engineering challenges in placing the foundations of offshore wind turbines. For example, wave run-up and wave impacts....... The results show that the shape of the foundation substantially affects the maximum run-up level, increasing the expected run-up value. A new relationship between the wave climate (regular and irregular waves) and the run-up is suggested. For this, the velocity stagnation head theory is adjusted and second...... order Stokes equations are used to calculate the wave kinematics in the crest. The variation of the run-up around the pile is measured and it is found that the position with the lowest run-up level is located under 135°, while the run-up at that position amounts to approximately 40% to 50...

  2. The influence of waves on the offshore wind resource

    Energy Technology Data Exchange (ETDEWEB)

    Lange, B [Risoe National Lab., Roskilde (Denmark); Hoejstrup, J [NEG Micon, Randers (Denmark)

    1999-03-01

    With the growing interest in offshore wind resources, it has become increasingly important to establish and refine models for the interaction between wind and waves in order to obtain accurate models for the sea surface roughness. The simple Charnock relation that has been applied for open sea conditions does not work well in the shallow water near-coastal areas that are important for offshore wind energy. A model for the surface roughness of the sea has been developed based on this concept, using an expression for the Charnock constant as a function of wave age, and then relating the wave `age` to the distance to the nearest upwind coastline. The data used in developing these models originated partly from analysis of data from the Vindeby site, partly from previously published results. The scatter in the data material was considerable and consequently there is a need to test these models further by analysing data from sites exhibiting varying distances to the coast. Results from such analysis of recent data are presented for sites with distances to the coast varying from 10 km to several hundreds of km. The model shows a good agreement also with this data. (au)

  3. Assessment approaches to logistics for offshore wind energy installation

    NARCIS (Netherlands)

    Vis, Iris F.A.; Ursavas, Evrim

    2016-01-01

    Offshore wind farm installation planning is highly complex, due to the high dependency on weather and the oversized components that impose specific constraints in areas such as transportation and lifting. Currently, there is very little transparency vis-à-vis the logistics challenges in the

  4. The statistical prediction of offshore winds from land-based data for wind-energy applications

    DEFF Research Database (Denmark)

    Walmsley, J.L.; Barthelmie, R.J.; Burrows, W.R.

    2001-01-01

    Land-based meteorological measurements at two locations on the Danish coast are used to predict offshore wind speeds. Offshore wind-speed data are used only for developing the statistical prediction algorithms and for verification. As a first step, the two datasets were separated into nine...... percentile-based bins, with a minimum of 30 data records in each bin. Next, the records were randomly selected with approximately 70% of the data in each bin being used as a training set for development of the prediction algorithms, and the remaining 30% being reserved as a test set for evaluation purposes....... The binning procedure ensured that both training and test sets fairly represented the overall data distribution. To base the conclusions on firmer ground, five permutations of these training and test sets were created. Thus, all calculations were based on five cases, each one representing a different random...

  5. Dynamic performance of a novel offshore power system integrated with a wind farm

    DEFF Research Database (Denmark)

    Orlandini, Valentina; Pierobon, Leonardo; Schløer, Signe

    2016-01-01

    Offshore wind technology is rapidly developing and a wind farm can be integrated with offshore power stations. This paper considers as case study a futuristic platform powered by a wind farm and three combined cycle units consisting of a gas turbine and an ORC (organic Rankine cycle) module....... The first aim of this paper is to identify the maximum amount of wind power that can be integrated into the system, without compromising the electric grid balance. The stability of the grid is tested using a dynamic model of the power system based on first principles. Additionally, the dynamics...... of the system is compared with a simplified plant consisting of three gas turbines and a wind farm, in order to identify benefits of the installation of the ORC system. The maximum allowable wind power is 10 MW for a nominal platform load of 30 MW. The results show that the presence of the ORC system allows...

  6. Dynamic performance of a novel offshore power system integrated with a wind farm

    DEFF Research Database (Denmark)

    Orlandini, Valentina; Pierobon, Leonardo; Schløer, Signe

    2016-01-01

    of the system is compared with a simplified plant consisting of three gas turbines and a wind farm, in order to identify benefits of the installation of the ORC system. The maximum allowable wind power is 10 MW for a nominal platform load of 30 MW. The results show that the presence of the ORC system allows......Offshore wind technology is rapidly developing and a wind farm can be integrated with offshore power stations. This paper considers as case study a futuristic platform powered by a wind farm and three combined cycle units consisting of a gas turbine and an ORC (organic Rankine cycle) module....... The first aim of this paper is to identify the maximum amount of wind power that can be integrated into the system, without compromising the electric grid balance. The stability of the grid is tested using a dynamic model of the power system based on first principles. Additionally, the dynamics...

  7. Designing Offshore Super Grid for the Combined Operation of Offshore Wind Farms and Hydro Storage

    DEFF Research Database (Denmark)

    Grimaldi, Armando; Chen, Zhe; Chen, Peiyuan

    2009-01-01

    The European commission decided in 2008 to reduce the dependency of imported primary energy sources and to promote the use of renewable energy. In particular, many offshore wind farms are planned in the North Sea between 2020 and 2030. Furthermore, the recent blackouts in Europe have shown that i...

  8. Variable Frequency Operations of an Offshore Wind Power Plant with HVDC-VSC: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, V.; Singh, M.; Muljadi, E.

    2011-12-01

    In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated. Based on DOE study, wind power generation may reach 330 GW by 2030 at the level of penetration of 20% of the total energy production. From this amount of wind power, 54 GW of wind power will be generated at offshore wind power plants. The deployment of offshore wind power plants requires power transmission from the plant to the load center inland. Since this power transmission requires submarine cable, there is a need to use High-Voltage Direct Current (HVDC) transmission. Otherwise, if the power is transmitted via alternating current, the reactive power generated by the cable capacitance may cause an excessive over voltage in the middle of the transmission distance which requires unnecessary oversized cable voltage breakdown capability. The use of HVDC is usually required for transmission distance longer than 50 kilometers of submarine cables to be economical. The use of HVDC brings another advantage; it is capable of operating at variable frequency. The inland substation will be operated to 60 Hz synched with the grid, the offshore substation can be operated at variable frequency, thus allowing the wind power plant to be operated at constant Volt/Hz. In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated.

  9. The necessary distance between large wind farms offshore - study

    DEFF Research Database (Denmark)

    Frandsen, S.; Barthelmie, R.J.; Pryor, S.C.

    2005-01-01

    the new Storpark Analytical Model has been developed and evaluated. As it is often the need for offshore wind farms, the model handles a regular array-geometry with straight rows of wind turbines and equidistantspacing between units in each row and equidistant spacing between rows. Firstly, the case...... with the flow direction being parallel to rows in a rectangular geometry is considered by defining three flow regimes. Secondly, when the flow is not in line withthe main rows, solutions are found for the patterns of wind turbine units emerging corresponding to each wind direction. The model complex......A review of state of the art wake and boundary layer wind farms was conducted. The predictions made for wind recovery distances (that might be used to estimate optimal placing of neighbouring wind farms) range between 2 and 14 km. In order to model thelink between wakes and the boundary layer...

  10. Attitudes towards offshore wind farms-The role of beach visits on attitude and demographic and attitude relations

    International Nuclear Information System (INIS)

    Ladenburg, Jacob

    2010-01-01

    Presently, less than a handful of papers have analysed the attitude towards offshore wind farms in a population living in an area with offshore wind farms. This leaves the experience-based attitude and demographic relations analysis relatively unexplored. The present studies aims at covering some of that seemingly uncharted territory by analysing attitudes from a sample of more than 1000 respondents. Applying an Ordered Probit Model, the results show general positive attitudes towards offshore wind farms and that the attitude formation seems to be a function of the gender, income, level of education, visit frequency and type of visit to the beach and the view to on-land turbines from the residence. Interestingly and perhaps the most interesting results, the observed relations between demographics and attitude are found to be dependent on the type and frequency of usage of the beach among the respondents. Attitudes towards offshore wind farms and demographic associations are thus found to be more evident in the case that respondents do use not the beach for walking on a relatively frequent basis but much weaker if the respondent use the beach on a frequent basis. However, these results are sensitive to the type of beach usage. This suggests that attitude formation towards offshore wind farms appear to be dependent on a combination of the type and frequency of use of the beach. To the author's knowledge these findings are novel, as such relation has not yet been identified in the literature. As such, the results shed light on a new angle in both the literature focusing on the opposition formation towards wind power projects in general and offshore wind farms in particular.

  11. Material Composition of Bucket Foundation Transition Piece for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nezhentseva, Anastasia; Andersen, Lars; Ibsen, Lars Bo

    2010-01-01

    In Denmark, production of renewable energy is focused on offshore wind turbines, since they make little if any inconvenience for residents in inhabited areas. High requirements are placed on the installation of the foundations which can cost about 30% of the total cost of the wind turbine....... This paper deals with the transition piece for a relatively novel type of foundation, the so-called suction bucket (caisson), focusing on the design of a transition piece connecting the turbine column with a suction bucket used as a monopod foundation for an offshore wind turbine. Since the current design...... practice is limited to the use of steel-flange-reinforced shear panels for the transition piece—a production that requires extensive welding work—a desirable solution is to find a material that provides lower cost and easier manufacturing without compromising the strength and stiffness. The paper compares...

  12. Assessing Fatigue and Ultimate Load Uncertainty in Floating Offshore Wind Turbines Due to Varying Simulation Length

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, G.; Lackner, M.; Haid, L.; Matha, D.; Jonkman, J.; Robertson, A.

    2013-07-01

    With the push towards siting wind turbines farther offshore due to higher wind quality and less visibility, floating offshore wind turbines, which can be located in deep water, are becoming an economically attractive option. The International Electrotechnical Commission's (IEC) 61400-3 design standard covers fixed-bottom offshore wind turbines, but there are a number of new research questions that need to be answered to modify these standards so that they are applicable to floating wind turbines. One issue is the appropriate simulation length needed for floating turbines. This paper will discuss the results from a study assessing the impact of simulation length on the ultimate and fatigue loads of the structure, and will address uncertainties associated with changing the simulation length for the analyzed floating platform. Recommendations of required simulation length based on load uncertainty will be made and compared to current simulation length requirements.

  13. Development and Design of a Flexible Measurement System for Offshore Wind Farm

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz Hubert; Arana Aristi, Iván; Hjerrild, Jesper

    The development process of a flexible measurement system for multi-point, high-speed and long-term offshore data logging is described in this paper. This covers the complete design taking into account precise synchronisation, electromagnetic compatibility, software development and sensor...... calibration. The presented measurement set-up was tested in a rough offshore environment. Results from measurement campaigns at Avedøre and Gunfleet Sands offshore wind farms including synchronisation precision and accuracy, electromagnetic interference of power electronic devices are briefly presented....

  14. Development and Design of a Flexible Measurement System for Offshore Wind Farms

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz Hubert; Arana Aristi, Ivan; Hjerrild, Jesper

    2011-01-01

    The development process of a flexible measurement system for multi-point, high-speed and long-term offshore data logging is described in this paper. This covers the complete design taking into account precise synchronisation, electromagnetic compatibility, software development and sensor...... calibration. The presented measurement set-up was tested in a rough offshore environment. Results from measurement campaigns at Avedøre and Gunfleet Sands offshore wind farms including synchronisation precision and accuracy, electromagnetic interference of power electronic devices are briefly presented....

  15. Generation Ratio Availability Assessment of Electrical Systems for Offshore Wind Farms

    DEFF Research Database (Denmark)

    Zhao, Menghua; Chen, Zhe; Blaabjerg, Frede

    2007-01-01

    An availability index, Generation Ratio Availability (GRA), is proposed to evaluate the electrical system of offshore wind farms (OWF). The GRA is the probability that at least a certain percent of wind power could be transferred to the grid system through the concerned electrical system. The GRA....... Comprehensive studies have been conducted to investigate the influence of the network design, component parameters, and wind-speed regimes on the GRA. The analysis presented in this paper is useful for both future wind farm planning and existing OWF evaluation....

  16. A study of offshore wind HVDC system stability and control

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hanchao; Sun, Jian [Rensselaer Polytechnic Institute, Troy, NY (United States). Dept. of Electrical, Computer and Systems Engineering

    2011-07-01

    This work is concerned with the stability and control of ac power collection buses in offshore wind farms with high-voltage dc (HVDC) transmission connection to onshore power grid. The focus of the work is high-frequency interactions among the wind turbines, the ac collection bus and the filters, as well as the HVDC rectifier. Both voltage-source converter and line-commutated converter based HVDC systems are considered. To study high-frequency stability, particularly harmonic resonance in the ac bus, small-signal impedance models are developed for the wind inverters and the HVDC rectifier by using harmonic linearization techniques. An impedance-based stability criterion is applied to assess system stability in both positive- and negative-sequence domain. Small-signal stability conditions and requirements are developed from analytical impedance models. Detailed system-level simulation is used to validated the small-signal analysis. The goal of the study is to develop system design and control techniques that minimize the cost of the offshore infrastructure while guaranteeing system stability and power quality. (orig.)

  17. Offshore investments: Denmark shows the way

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    This article presents an overview of the use of wind power in Denmark and discusses the tremendous growth in the manufacture of wind turbines since 1981 with Denmark holding some 60% of the worlds' wind turbine market. The move to offshore wind farms is explained in terms of the shortage of land and the quality of the offshore wind, and details of the Tuno Knob pilot offshore wind farm are given. Offshore wind power in Europe, the challenges to offshore operations, the costs involved, environmental effects of the use of offshore wind, and the growing amount of wind power capacity are discussed

  18. Application of genetic algorithm in electrical system optimization for offshore wind farms

    DEFF Research Database (Denmark)

    Chen, Zhe; Zhao, M.; Blaabjerg, Frede

    2008-01-01

    Genetic Algorithm (GA) has been widely used in solving optimization problem in different areas. This paper illustrates the application of GA in the electrical system design for offshore wind farms, where the main components of a wind farm and key technical specifications are used as input...

  19. An Optimal Number-Dependent Preventive Maintenance Strategy for Offshore Wind Turbine Blades Considering Logistics

    Directory of Open Access Journals (Sweden)

    Mahmood Shafiee

    2013-01-01

    Full Text Available In offshore wind turbines, the blades are among the most critical and expensive components that suffer from different types of damage due to the harsh maritime environment and high load. The blade damages can be categorized into two types: the minor damage, which only causes a loss in wind capture without resulting in any turbine stoppage, and the major (catastrophic damage, which stops the wind turbine and can only be corrected by replacement. In this paper, we propose an optimal number-dependent preventive maintenance (NDPM strategy, in which a maintenance team is transported with an ordinary or expedited lead time to the offshore platform at the occurrence of the Nth minor damage or the first major damage, whichever comes first. The long-run expected cost of the maintenance strategy is derived, and the necessary conditions for an optimal solution are obtained. Finally, the proposed model is tested on real data collected from an offshore wind farm database. Also, a sensitivity analysis is conducted in order to evaluate the effect of changes in the model parameters on the optimal solution.

  20. AC-DC integrated load flow calculation for variable speed offshore wind farms

    DEFF Research Database (Denmark)

    Zhao, Menghua; Chen, Zhe; Blaabjerg, Frede

    2005-01-01

    This paper proposes a sequential AC-DC integrated load flow algorithm for variable speed offshore wind farms. In this algorithm, the variable frequency and the control strategy of variable speed wind turbine systems are considered. In addition, the losses of wind turbine systems and the losses...... of converters are also integrated into the load flow algorithm. As a general algorithm, it can be applied to different types of wind farm configurations, and the load flow is related to the wind speed....

  1. Frequency-domain characteristics of aerodynamic loads of offshore floating vertical axis wind turbines

    DEFF Research Database (Denmark)

    Borg, Michael; Collu, M.

    2015-01-01

    The re-emerging interest in vertical axis wind turbines for floating offshore applications has led to a need to investigate the relatively complex dynamics of such floating offshore structures. Through the use of a coupled model of dynamics this article investigates the frequency......-domain characteristics of floating vertical axis wind turbine aerodynamic loads. The impact of platform induced motion on aerodynamic loads is discussed in detail, with results indicating an increase in aerodynamic loads of several orders of magnitude over the range of frequencies usually containing significant wave...

  2. Comparison of alternative offshore wind farms and HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Bruns, M. [Technische Univ. Dresden (Germany); Lilje, P.; Poeller, M. [DIgSILENT GmbH, Gomaringen (Germany); Basteck, A. [Voith Turbo Wind GmbH und Co. KG, Crailsheim (Germany)

    2010-07-01

    This paper investigates the stability of offshore wind farms connected to the main power system via HVDC systems. Wind farms consisting of different ratios of directly connected synchronous machines and doubly-fed induction machines are considered. In addition, both conventional LCC- and VSC-type HVDC systems are considered. Furthermore, different control strategies are considered. Furthermore, different control strategies are considered for the VSC-based system, including constant frequency control and frequency regulation. The stability analysis is done by means of time-domain simulation. The maximum and minimum ratio of the two wind turbine technologies is found for each of the different HVDC systems. (orig.)

  3. Transients in VSC-HVDC connected offshore wind power plant

    DEFF Research Database (Denmark)

    El-Khatib, Walid Ziad; Schwartzberg, D.; Arana Aristi, I.

    2015-01-01

    The focus of this paper is transient phenomena in VSC-HVDC connected offshore wind power plants (WPPs). With the help of a case study modelled in PSCAD simulation software, energisation events are analysed in the time domain. A comparison with more well-known results obtained at energisation of AC...

  4. Archaeological Handbook for Establishing Offshore Wind Farms in Sweden. Lillgrund Pilot Project

    Energy Technology Data Exchange (ETDEWEB)

    Bengtsson, Boel [Bohuslaens Museum, Uddevalla (Sweden)

    2008-03-15

    The purpose of this handbook is to provide a structured guide for contractors interested in establishing offshore wind farms within Swedish territorial waters and its extended economical zone, in relation to Underwater Cultural Heritage (UCH). It is also applicable to UCH in inland waters. Therefore, this handbook seeks to provide information on; - The management structure of underwater/maritime cultural heritage in Sweden, including institutions and units with maritime antiquarian expertise, - The different types of archaeological remains that can be found around the Swedish coast - in offshore, coastal areas and on the foreshore - which can potentially be affected by offshore wind farm projects, - The laws that underwater archaeological remains are subject to - within the National Maritime Boundary as well as within the contiguous and exclusive economical zones - and the necessary archaeological investigations that need to be considered in order to avoid and/or protect the cultural heritage provided by those remains, - Archaeological standards and methods for assessing and evaluating the potential for finding archaeological remains under water, - The steps that need to be to considered during the planning process of establishing offshore wind farms, and how the contractor and archaeologist can work together in order to make the process more cost effective, and - Considerations for the future. Furthermore, this handbook includes a presentation of archaeological finds made during archaeological surveys in connection with the Lillgrund project. The handbook does not make references to any investigations that may be required in relation to land based archaeological sites other than those which are undertaken close to the shoreline (situated on the foreshore), nor does it consider the visual impact sea-based wind farms might have on cultural heritage

  5. The necessary distance between large wind farms offshore - study

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, S.; Barthelmie, R.; Pryor, S.; Rathmann, O.; Larsen, S.; Hoejstrup, J.; Nielsen, P.; Lybech Thoegersen, M.

    2004-08-01

    A review of state of the art wake and boundary layer wind farms was conducted. The predictions made for wind recovery distances (that might be used to estimate optimal placing of neighbouring wind farms) range between 2 and 14 km. In order to model the link between wakes and the boundary layer the new Storpark Analytical Model has been developed and evaluated. As it is often the need for offshore wind farms, the model handles a regular array-geometry with straight rows of wind turbines and equidistant spacing between units in each row and equidistant spacing between rows. Firstly, the case with the flow direction being parallel to rows in a rectangular geometry is considered by defining three flow regimes. Secondly, when the flow is not in line with the main rows, solutions are found for the patterns of wind turbine units emerging corresponding to each wind direction. The model complex will be adjusted and calibrated with measurements in the near future. (au)

  6. Seabird aggregative patterns: a new tool for offshore wind energy risk assessment.

    Science.gov (United States)

    Christel, Isadora; Certain, Grégoire; Cama, Albert; Vieites, David R; Ferrer, Xavier

    2013-01-15

    The emerging development of offshore wind energy has raised public concern over its impact on seabird communities. There is a need for an adequate methodology to determine its potential impacts on seabirds. Environmental Impact Assessments (EIAs) are mostly relying on a succession of plain density maps without integrated interpretation of seabird spatio-temporal variability. Using Taylor's power law coupled with mixed effect models, the spatio-temporal variability of species' distributions can be synthesized in a measure of the aggregation levels of individuals over time and space. Applying the method to a seabird aerial survey in the Ebro Delta, NW Mediterranean Sea, we were able to make an explicit distinction between transitional and feeding areas to define and map the potential impacts of an offshore wind farm project. We use the Ebro Delta study case to discuss the advantages of potential impacts maps over density maps, as well as to illustrate how these potential impact maps can be applied to inform on concern levels, optimal EIA design and monitoring in the assessment of local offshore wind energy projects. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Efficient preliminary floating offshore wind turbine design and testing methodologies and application to a concrete spar design

    OpenAIRE

    Matha, Denis; Sandner, Frank; Molins i Borrell, Climent; Campos Hortigüela, Alexis; Cheng, Po Wen

    2015-01-01

    The current key challenge in the floating offshore wind turbine industry and research is on designing economic floating systems that can compete with fixed-bottom offshore turbines in terms of levelized cost of energy. The preliminary platform design, as well as early experimental design assessments, are critical elements in the overall design process. In this contribution, a brief review of current floating offshore wind turbine platform pre-design and scaled testing methodologies is provide...

  8. Optimized Generator Designs for the DTU 10-MW Offshore Wind Turbine using GeneratorSE

    Energy Technology Data Exchange (ETDEWEB)

    Sethuraman, Latha; Maness, Michael; Dykes, Katherine

    2017-01-09

    Compared to land-based applications, offshore wind imposes challenges for the development of next generation wind turbine generator technology. Direct-drive generators are believed to offer high availability, efficiency, and reduced operation and maintenance requirements; however, previous research suggests difficulties in scaling to several megawatts or more in size. The resulting designs are excessively large and/or massive, which are major impediments to transportation logistics, especially for offshore applications. At the same time, geared wind turbines continue to sustain offshore market growth through relatively cheaper and lightweight generators. However, reliability issues associated with mechanical components in a geared system create significant operation and maintenance costs, and these costs make up a large portion of overall system costs offshore. Thus, direct-drive turbines are likely to outnumber their gear-driven counterparts for this market, and there is a need to review the costs or opportunities of building machines with different types of generators and examining their competitiveness at the sizes necessary for the next generation of offshore wind turbines. In this paper, we use GeneratorSE, the National Renewable Energy Laboratory's newly developed systems engineering generator sizing tool to estimate mass, efficiency, and the costs of different generator technologies satisfying the electromagnetic, structural, and basic thermal design requirements for application in a very large-scale offshore wind turbine such as the Technical University of Denmark's (DTU) 10-MW reference wind turbine. For the DTU reference wind turbine, we use the previously mentioned criteria to optimize a direct-drive, radial flux, permanent-magnet synchronous generator; a direct-drive electrically excited synchronous generator; a medium-speed permanent-magnet generator; and a high-speed, doubly-fed induction generator. Preliminary analysis of leveled costs of

  9. Design of Offshore Wind Turbine Support Structures: Selected topics in the field of geotechnical engineering

    DEFF Research Database (Denmark)

    Bakmar, Christian LeBlanc

    .D. thesis was to enable low-cost and low-risk support structures to be designed in order to improve the economic feasibility of future offshore wind farms. The research work was divided in the following four selected research topics in the field of geotechnical engineering, relating to the monopile......Breaking the dependence on fossil fuels offers many opportunities for strengthened competitiveness, technological development and progress. Offshore wind power is a domestic, sustainable and largely untapped energy resource that provides an alternative to fossil fuels, reduces carbon emissions......, and decreases the economic and supply risks associated with reliance on imported fuels. Today, the modern offshore wind turbine offers competitive production prices for renewable energy and is therefore a key technology in achieving the energy and climate goals of the future. The overall aim of this Ph...

  10. Coordinated Voltage Control in Offshore HVDC Connected Cluster of Wind Power Plants

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Rather, Zakir Hussain; Rimez, Johan

    2016-01-01

    This paper presents a coordinated voltage control scheme (CVCS) for a cluster of offshore wind power plants (OWPPs) connected to a VSC HVDC system. The primary control point of the proposed voltage control scheme is the introduced Pilot bus, which is having the highest short circuit capacity...... in the offshore AC grid. The developed CVCS comprehends an optimization algorithm, aiming for minimum active power losses in the offshore grid, to generate voltage reference to the Pilot bus. During steady state operation, the Pilot bus voltage is controlled by dispatching reactive power references to each wind...... turbine (WT) in the WPP cluster based on their available reactive power margin and network sensitivity based participation factors, which are derived from the dV/dQ sensitivity of a WT bus w.r.t the Pilot bus. This method leads to minimization of the risk of undesired effects, particularly overvoltage...

  11. The influence of humidity fluxes on offshore wind speed profiles

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Sempreviva, Anna Maria; Pryor, Sara

    2010-01-01

    extrapolation from lower measurements. With humid conditions and low mechanical turbulence offshore, deviations from the traditional logarithmic wind speed profile become significant and stability corrections are required. This research focuses on quantifying the effect of humidity fluxes on stability corrected...... wind speed profiles. The effect on wind speed profiles is found to be important in stable conditions where including humidity fluxes forces conditions towards neutral. Our results show that excluding humidity fluxes leads to average predicted wind speeds at 150 m from 10 m which are up to 4% higher...... than if humidity fluxes are included, and the results are not very sensitive to the method selected to estimate humidity fluxes....

  12. Future offshore sites for wind turbines - 2025; Denmark; Fremtidens havmoelleplaceringer - 2025

    Energy Technology Data Exchange (ETDEWEB)

    2007-04-15

    The committee has analysed 23 concrete siting possibilities at 7 main areas. The committee recommends that any extension of ocean wind farms is decided according to cost priorities. The selected sites for establishing offshore wind farms are: Djursland-Anholt in Kattegat, Horns Rev, Jammerbugten and off Ringkoebing in the North Sea, Store Middelgrund in Kattegat, and Kriegers Flak and Roenne Banke in the Baltic Sea. Wind data and power potential are presented for each of the selected sites. (ln)

  13. Natural frequency and vibration analysis of jacket type foundation for offshore wind power

    Science.gov (United States)

    Hung, Y.-C.; Chang, Y.-Y.; Chen, S.-Y.

    2017-12-01

    There are various types of foundation structure for offshore wind power, engineers may assess the condition of ocean at wind farm, and arrange the transportation, installation of each structure members, furthermore, considering the ability of manufacture steel structure as well, then make an optimum design. To design jacket offshore structure, unlike onshore cases, offshore structure also need to estimate the wave excitation effect. The aim of this paper is to study the difference of natural frequency between different kinds of structural stiffness and discuss the effect of different setting of boundary condition during analysis, besides, compare this value with the natural frequency of sea wave, in order to avoid the resonance effect. In this paper, the finite element analysis software ABAQUS is used to model and analyze the natural vibration behavior of the jacket structure.

  14. Load flow analysis for variable speed offshore wind farms

    DEFF Research Database (Denmark)

    Chen, Zhe; Zhao, Menghua; Blaabjerg, Frede

    2009-01-01

    factors such as the different wind farm configurations, the control of wind turbines and the power losses of pulse width modulation converters are considered. The DC/DC converter model is proposed and integrated into load flow algorithm by modifying the Jacobian matrix. Two iterative methods are proposed...... and integrated into the load flow algorithm: one takes into account the control strategy of converters and the other considers the power losses of converters. In addition, different types of variable speed wind turbine systems with different control methods are investigated. Finally, the method is demonstrated......A serial AC-DC integrated load flow algorithm for variable speed offshore wind farms is proposed. It divides the electrical system of a wind farm into several local networks, and different load flow methods are used for these local networks sequentially. This method is fast, more accurate, and many...

  15. Offshore Wind Power Plant Technology Catalogue - Components of wind power plants, AC collection systems and HVDC systems

    DEFF Research Database (Denmark)

    Das, Kaushik; Antonios Cutululis, Nicolaos

    2017-01-01

    Traditionally, Offshore Wind Power Plants (OWPPs) are connected through many com-ponents as shown in the figure 1. An OWPP consists of controllable, variable speed Wind Turbines (WTs). These WTs are connected through Medium Voltage (MV) sub-marine cables typically at voltage level of upto 33-66 k...... for the cables as well reduce the power losses through them....

  16. Efficient preliminary floating offshore wind turbine design and testing methodologies and application to a concrete spar design.

    Science.gov (United States)

    Matha, Denis; Sandner, Frank; Molins, Climent; Campos, Alexis; Cheng, Po Wen

    2015-02-28

    The current key challenge in the floating offshore wind turbine industry and research is on designing economic floating systems that can compete with fixed-bottom offshore turbines in terms of levelized cost of energy. The preliminary platform design, as well as early experimental design assessments, are critical elements in the overall design process. In this contribution, a brief review of current floating offshore wind turbine platform pre-design and scaled testing methodologies is provided, with a focus on their ability to accommodate the coupled dynamic behaviour of floating offshore wind systems. The exemplary design and testing methodology for a monolithic concrete spar platform as performed within the European KIC AFOSP project is presented. Results from the experimental tests compared to numerical simulations are presented and analysed and show very good agreement for relevant basic dynamic platform properties. Extreme and fatigue loads and cost analysis of the AFOSP system confirm the viability of the presented design process. In summary, the exemplary application of the reduced design and testing methodology for AFOSP confirms that it represents a viable procedure during pre-design of floating offshore wind turbine platforms. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  17. On the Effect of Offshore Wind Parks on Ocean Dynamics

    Science.gov (United States)

    Ludewig, E.; Pohlmann, T.

    2012-12-01

    Nowadays renewable energy resources play a key role in the energy supply discussion and especially an increasingly interest in wind energy induces intensified installations of wind parks. At this offshore wind energy gains in popularity in the course of higher and more consistent energy availability than over land. For example Germany's government adopted a national interurban offshore wind energy program comprising the construction of hundreds of wind turbines within Germany's Exclusive Economic Zone to ensure up to 50% of Germany's renewable energy supply. The large number of installation in coastal regions asks for analyzing the impact of offshore wind parks (OWPs) on the atmosphere and the ocean. As known from literature such wind parks excite also-called wake-effect and such an influence on the wind field in turn affects ocean circulation. To cover OWP's impact on ocean dynamics we evaluate model simulations using the Hamburg Shelf-Ocean-Model (HAMSOM). All simulations were driven with a wind forcing produced by the Mesoscale Atmosphere Model of the Hamburg University (METRAS) which has implemented wind turbines. Wind forcing data were generated in collaboration with and by courtesy of the Meteorological Institute of the University of Hamburg, Department Technical Meteorology, Numeric Modeling-METRAS. To evaluate dynamical changes forced by the OWP's wind wake-effect we did a sensitivity study with a theoretical setup of a virtual ocean of 60m depth with a flat bottom and a temperature and salinity stratification according to common North Sea's conditions. Here our results show that already a small OWP of 12 wind turbines, placed in an area of 4 km^2, lead to a complex change in ocean dynamics. Due to the wake-effect zones of upwelling and downwelling are formed within a minute after turning-on wind turbines. The evolving vertical cells have a size of around 15x15 kilometers with a vertical velocity in order of 10^-2 mm/sec influencing the dynamic of an area

  18. High-resolution computational algorithms for simulating offshore wind turbines and farms: Model development and validation

    Energy Technology Data Exchange (ETDEWEB)

    Calderer, Antoni [Univ. of Minnesota, Minneapolis, MN (United States); Yang, Xiaolei [Stony Brook Univ., NY (United States); Angelidis, Dionysios [Univ. of Minnesota, Minneapolis, MN (United States); Feist, Chris [Univ. of Minnesota, Minneapolis, MN (United States); Guala, Michele [Univ. of Minnesota, Minneapolis, MN (United States); Ruehl, Kelley [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Guo, Xin [Univ. of Minnesota, Minneapolis, MN (United States); Boomsma, Aaron [Univ. of Minnesota, Minneapolis, MN (United States); Shen, Lian [Univ. of Minnesota, Minneapolis, MN (United States); Sotiropoulos, Fotis [Stony Brook Univ., NY (United States)

    2015-10-30

    The present project involves the development of modeling and analysis design tools for assessing offshore wind turbine technologies. The computational tools developed herein are able to resolve the effects of the coupled interaction of atmospheric turbulence and ocean waves on aerodynamic performance and structural stability and reliability of offshore wind turbines and farms. Laboratory scale experiments have been carried out to derive data sets for validating the computational models.

  19. HVDC Connected Offshore Wind Power Plants: Review and Outlook of Current Research

    DEFF Research Database (Denmark)

    Glasdam, Jakob; Zeni, Lorenzo; Gryning, Mikkel

    2013-01-01

    This paper presents a state-of-the-art review on grid integration of large offshore wind power plants (OWPPs) using high voltage direct voltage (HVDC) for grid connection. The paper describes in detail selected challenges hereto and presents how DONG Energy Wind Power (DEWP) is addressing...... these challenges through three coordinated PhD projects in close collaboration with leading academia within the field. The overall goal of these projects is to acquire in-depth knowledge of relevant operating phenomena in the offshore OWPP grid, rich with power electronics devices (PEDs) such as the HVDC...... and the PED widely used in the wind turbine generators (WTGs). Challenges hereto include PED control system interaction (from a stability point of view), assessment of the quality of vendor supplied control systems and their robustness against e.g. short circuits and load rejection. Furthermore, the outcome...

  20. Offshore wind power. Market opportunities for the Norwegian supply industry, and regulatory framework needed to realize these opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Volden, G.; Bull-Berg, H.; Skjeret, F.; Finne, H.; Hofmann, M.

    2010-07-01

    Full text: Offshore wind power has received much attention these last few years, from governments, NGOs as well as energy companies. There are still huge technological challenges to overcome, especially concerning floating constructions on deep water, but offshore wind has a potential to become an important energy source in the future. The main objective of our study was to build more knowledge about market opportunities for the Norwegian supply industry, most of which is closely related to offshore oil and gas activities. We started by mapping and quantifying the parts of the supply industry that could be relevant to offshore wind, which is actually most of it. Then, through interviews and questionnaires, we asked potential suppliers about their attitude and strategies towards offshore wind. An over-whelming majority was optimistic about future markets internationally, whereas there was less belief in large-scale power production on the Norwegian shelf. Suppliers do not necessarily find the lack of a Norwegian 'home market' to be a barrier. However many of them expressed that the risk is high and it may be crucial to establish a national demo program, for supplier to test new technological solutions at low cost, gain references and develop industrial relations with other suppliers. We argue that being part of an industrial cluster may be a success criterion within offshore wind. By using Michael Porter's 'Diamond Model' we analyse Norway's inherent competitiveness as a potential host for an offshore wind cluster - with or without energy producers. Norway's most important advantage is the existing industrial environment, with a strong maritime sector and engineering companies with special competence in floating and fixed installations for the oil industry. Norway also has disadvantages; such as lack of traditions within wind power and wind turbine manufacturing, as well as high salaries and lack of engineers. So far it is also