ENDOW (efficient development of offshore wind farms): modelling wake and boundary layer interactions

While experience gained through the offshore wind energy projects currently operating is valuable, a major uncertainty in estimating power production lies in the prediction of the dynamic links between the atmosphere and wind turbines in offshore regimes. The objective of the ENDOW project was to evaluate, enhance and interface wake and boundary layer models for utilization offshore. The project resulted in a significant advance in the state of the art in both wake and marine boundary layer models, leading to improved prediction of wind speed and turbulence profiles within large offshore wind farms. Use of new databases from existing offshore wind farms and detailed wake profiles collected using sodar provided a unique opportunity to undertake the first comprehensive evaluation of wake models in the offshore environment. The results of wake model performance in different wind speed, stability and roughness conditions relative to observations provided criteria for their improvement. Mesoscale model simulations were used to evaluate the impact of thermal flows, roughness and topography on offshore wind speeds. The model hierarchy developed under ENDOW forms the basis of design tools for use by wind energy developers and turbine manufacturers to optimize power output from offshore wind farms through minimized wake effects and optimal grid connections. The design tools are being built onto existing regional‐scale models and wind farm design software which was developed with EU funding and is in use currently by wind energy developers. Copyright © 2004 John Wiley & Sons, Ltd.     

Ecological and economic cost-benefit analysis of offshore wind energy

Wind energy has experienced dramatic growth over the past decade. A small fraction of this growth has occurred offshore, but as the best wind resources become developed onshore, there is increasing interest in the development of offshore winds. Like any form of power production, offshore wind energy has both positive and negative impacts. The potential negative impacts have stimulated a great deal of opposition to the first offshore wind power proposals in the U.S. and have delayed the development of the first offshore wind farm in the U.S. Here we discuss the costs and benefits of offshore wind relative to onshore wind power and conventional electricity production. We review cost estimates for offshore wind power and compare these to estimates for onshore wind and conventional power. We develop empirical cost functions for offshore wind based on publicly reported projects from 2000 to 2008, and describe the limitations of the analysis. We use this analysis to inform a discussion of the tradeoffs between conventional, onshore and offshore wind energy usage.     

中欧海上风电产业发展比较

相对于陆地风能,海上风能资源丰富,发电产能大,海上风电将是最有可能大规模发展的能源资源之一。欧洲是世界发展海上风力发电的先驱,从1991年至2009年,欧洲建设完成并投入运营的共有38个海上风电场,装机容量达到2056MW,其中一半以上的海上风电场是近5年建成的。欧洲海上风电产业拥有先进的核心技术,海上风电场正朝着大规模、深水化、离岸化方向发展,目前正处于示范阶段向商业扩展阶段的过渡时期。而我国虽然拥有丰富的海上风能资源,但海上风电产业的发展却比较缓慢,目前还处于研发阶段和示范阶段的过渡期,海上风电技术仍然面临着核心技术缺失、行业标准混乱、研发能力不足等问题。我国海上风电产业发展面临的主要问题包括:缺乏统筹;产能过剩、质量不高;难以盈利;缺少标准、无法推广等。为促进我国海上风电产业的发展,政府应进一步细化海上风能开发的有关规定,完善政策体系,统筹产业发展,采取多种措施推进政策具体落实;充分发挥市场作用,构建海上风电产品认证检测体系;提升核心技术含量,提高产品技术水平和工艺水平;加快培养专业人才。     

Offshore wind power in the US: Regulatory issues and models for regulation

The first offshore wind farm became operational in 1991 in Vindeby, Denmark. By 2008, large offshore wind farms had been built in Denmark, the UK, the Netherlands, Ireland, and Sweden with a total capacity of 1200 MW. Offshore wind farms have the potential to generate a significant fraction of US electrical consumption, but the US currently lacks offshore wind farms and is still developing a regulatory system. At the state level only Texas has a leasing system for offshore wind. Since all offshore land is the property of the state and cannot be legally developed without a lease from the government, these absences have stalled development. We review and compare regulatory and leasing systems developed in Europe and the US to inform a discussion of the major issues associated with the development of an offshore leasing and regulatory system. We focus on the tradeoffs between encouraging a sustainable energy source and ensuring environmental protection and public compensation. We conclude that there are likely multiple effective methods of regulation.     

The economics of offshore wind

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.     

Shifting towards offshore wind energy—Recent activity and future development

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.     

Offshore wind energy in the world context

The interest for the exploitation of the offshore wind energy is growing in Europe, where man land use is very high resulting in strong limitation to the installation of onshore wind farms. The today offshore operating wind power is 12 MW, with two wind farms in Denmark and one in Netherlands; it starts to be significant (0.6%) in terms of the onshore power, 2000 MW in Europe.In the world the onshore installed wind power is exceeding 4000 MW, but not so much up to now has been done on the offshore area outside Europe.The European four years experience on the prototypical offshore wind farms looks significantly promising and suggests to promote a similar approach in many densely populated coastal countries in the world with high electricity demand.Results of studies are presented on the offshore wind potential in the European countries and of the tentative evaluation for the Mediterranean basin, and the seas of USA and China. A review is made of the offshore applications, particularly for the Nothern European seas.Economy and environmental trends are illustrated in parallel to those of maturing offshore technology. It is suggested to prepare an action plan to promote the development of the offshore applications in the world context.     

Auction designs for allocating wind energy leases on the U.S. outer continentalshelf

The anticipated expansion of offshore wind energy in the U.S. has been the subject of considerable legislative effort. The Energy Policy Act (EPAct) of 2005 and the Outer Continental Shelf Lands Act (OSCLA) detail the criteria the federal government must follow when allocating leases for offshore wind farms. The Bureau of Ocean Energy Management (BOEM) provides primary federal oversight to offshore wind in federal waters, and in 2009 they released their formal management guidelines going forward. This research examines lease allocation methods BOEM may use, as well as several promising alternatives, through the lens of the mandated criteria set forth by OSCLA and the EPAct of 2005. We find significant variation between allocation methods in terms of how well they meet each of the criteria. Price-based allocations will have difficulty in meeting criteria while also accounting for the immature status of the offshore wind energy industry. Instead, a multiple factor approach which includes non-monetary considerations may be a more appropriate way to balance federal mandates and industryneeds.     

Offshore wind power policy and planning in Sweden

The main objective of this paper is to analyze the role of policy support schemes and planning systems for inducing offshore wind power development in Sweden. Specifically, it highlights the different types of economic, political and planning-related conditions that face offshore wind power investors in Sweden, and provides brief comparisons to the corresponding investment conditions in Denmark, Norway and the UK. The analysis shows that in Sweden existing policy incentives are generally too weak to promote a significant development of offshore wind power, and the paper provides a discussion about a number of political and economic aspects on the choice between different support schemes for offshore wind in the country. Swedish permitting and planning procedures, though, appear favorable to such a development, not the least in comparison to the corresponding processes in the other major offshore wind countries in Europe (e.g., the UK). On a general level the paper illustrates that the success and failure stories of national offshore wind policies and institutions cannot be easily transferred across country borders, and the analysis shows that both the political and the legal frameworks governing the investment situation for offshore wind farms in Denmark, Norway, Sweden and the UK differ significantly.     

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

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.     

Offshore wind energy policy for India—Key factors to be considered

Indian Economy is growing at a healthy pace during the last few years. To sustain this growth, power sector needs to build additional generation capacity. However, continued dependence on fossil fuels to power the growth of electricity generation capacity, is hardly sustainable. Renewable Energy source forms a miniscule portion (25 GW,∼12%) of India's overall power generation 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 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 literature survey, to identify 21 building blocks of a successful offshore wind energy policy initiative adopted by select European countries, which have been classified under 5 broad categories—Government support, Fiscal and quota based incentives, Availability of local expertise, Capital for investments and Building an enabling ecosystem, which can be leveraged by India to articulate its own offshore wind energy policy.     

生态系统理念在海上风电项目管理中的应用研究

  [目的]  中国海上风电行业已迈入快速发展期,如何创新项目开发管理模式,有效应对海上风电造价高、界面多、工期长等问题,实现成本降低、效能提升,是推动海上风电行业健康快速发展的重要保障。  [方法]  通过将生态系统理念应用到海上风电场项目开发建设和运营管理中,探索构建海上风电场生态系统,以搭建风电场神经网络为核心,提高整体关联效能,实现最优开发目标;利用层次分析法对系统影响因子权重进行定量分析。  [结果]  通过海上风电场生态系统的构建,使海上风电场具备信息快速的收集、存储、共享、分析和反馈调节功能,降本增效,提升风电场稳定性。  [结论]  生态系统的引入为海上风电项目的开发管理和提供了新的思路,借助人工智能技术等前沿科技的发展,海上风电场生态系统也将不断完善和广泛应用。     

Food-energy-environment trilemma: Policy impacts on farmland use and biofuel industry development

We present a game-theoretic model to analyze the role of two major biofuel policies in the U.S., namely mandates and subsidies, and their implications to biofuel industry development. By characterizing the farmers' land use decision (land allocation among food, energy, and reservation) and biofuel firm's mandate compliance strategy (whether to comply with the mandate or not), we identify the complementarity roles of mandate and subsidy. We further illustrate the impact of coordination in the two policy instruments; lack of coordination may result in excessive biofuel mandate in the early stage of industry development, while it may lead to insufficient mandate during the matured stage. With a case study based on the U.S. Midwest, we address recent trends in the U.S. biofuel industry and further discuss related policy insights.     

欧盟风电产业的发展及对我国的启示

欧洲风电发展取得了很大的成就,建立了世界最大的风电市场和产业,制定和实施了有效的支持政策,促进了风电技术的迅速发展和成本的持续下降,风电开始在欧洲成为主要的替代能源.文章介绍了欧洲风电技术、产业和市场发展状况及趋势;实施强制上网、价格激励、税收优惠、资源普查、电网建设等政策的经验,提出了我国具有世界最重要的风电潜在市场,应该借鉴欧洲经验,加快在完善价格体系、风机标准化和检测、资源普查、电网建设等方面的工作步伐,支持我国风电产业的发展.     

An investigation into the potential barriers facing the development of offshore wind energy in Scotland: Case study – Firth of Forth offshore wind farm

The Scottish Executive has set ambitious targets of achieving 100% of electricity from renewable sources by 2020. As Scotland has the best offshore wind resources in Europe, the development of this energy source is crucial for reaching these targets. However, the development of offshore wind raises a number of issues related to economic viability, grid connection and public acceptability. This paper investigates these areas in greater depth, using a case study of the Firth of Forth offshore wind farm, in order to determine if these barriers can be overcome in time to make a valuable contribution to 2020 targets. Through interviews with relevant stakeholders, it emerged that there are various obstacles which are impeding progress in offshore wind development in Scotland. It became evident that stakeholder opposition, an inadequate renewable energy support mechanism, and the insufficient grid infrastructure off the Scottish coast are posing barriers, and hindering development. It became apparent that in order to overcome these barriers, a number of changes need to take place. A more inclusive approach to stakeholder engagement is required, which facilitates the sharing of knowledge. In order to improve the economic viability of offshore wind in Scotland, adopting a new mechanism which reduces risk and provides developers and investors with more certainty, would be more effective in encouraging offshore wind development. Finally, in order to overcome the most significant barrier, the grid, a more integrated and collaborative approach is required, which will share the burden of responsibility between the developer, Ofgem, and the National Grid.     

The offshore trend: Structural changes in the wind power sector

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.     

海上风电场设施技术规范综述

  [目的]  文章旨在推动我国海上风电场设施技术规范的建立健全。  [方法]  指出了我国海上风电场建设中存在的问题,总结了国内外海上风电场设施规范标准,介绍了中国船级社对海上风电场设施技术规范的探索及成效。  [结果]  尽管国内海上风电的发展迅猛,但配套的海上风电场设施技术规范并没有及时跟进,更没有形成从设计、建造、安装、运维直至弃置的全生命周期技术规范体系;尽管欧洲拥有较为成熟的海上风电规范体系,但并不能完全照搬使用,如结构设计的LRFD方法,其分项系数与海域的环境条件和可靠性指标相关,适用于欧洲海域的分项系数并不适用于中国海域。  [结论]  因此,国内海上风电场技术规范体系的建立,需要业界共同努力、多方协作。传统的海洋工程专业应在该领域发挥更大的作用。中国船级社多年在海上风电领域的研究和积累,可为构建国内海上风电场设施技术规范体系提供借鉴和参考。     

A framework for data integration of offshore wind farms

Operation and maintenance play an important role in maximizing the yield and minimizing the downtime of wind turbines, especially offshore wind farms where access can be difficult due to harsh weather conditions for long periods. It contributes up to 25–30% to the cost of energy generation. Improved operation and maintenance (O&M) practices are likely to reduce the cost of wind energy and increase safety. In order to optimize the O&M, the importance of data exchange and knowledge sharing within the offshore wind industry must be realized. With more data available, it is possible to make better decisions, and thereby improve the recovery rates and reduce the operational costs. This article describes the development of a framework for data integration to optimize the remote operations of offshore wind farms.     

以设计为龙头的海上风电工程总承包项目管理研究

[目的]为应对平价上网阶段下海上风电行业发展的巨大挑战,推动海上风电产业可持续健康发展,[方法]基于我国多个以设计为龙头的总承包模式建设的海上风电项目,分析工程总承包模式在电力工程中的应用,提出海上风电工程总承包管理当前特有的挑战与对策,从宏观上总结平价上网阶段下以设计为龙头的海上风电工程总承包管理的主要优势.[结果]...     

Offshore wind energy prospects

In last two years offshore wind energy is becoming a focal point of national and non national organizations 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 is shallow waters 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 Netherland, Denmark using large size wind turbine (1–2 MW). In 1997 an offshore proposal was supported in Netherland 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 the European offshore wind programs with trends in technology, economics and siting effects.