Greenhouse gas emissions from electricity generated by offshore wind farms

For wind power generation offshore sites offer significantly better wind conditions compared to onshore. At the same time, the demand for raw materials and therefore the related environmental impacts increase due to technically more demanding wind energy converters and additional components (e.g. substructure) for the balance of plant. Additionally, due to environmental concerns offshore wind farms will be sited farshore (i.e. in deep water) in the future having a significant impact on the operation and maintenance efforts (O&M). Against this background the goal of this analysis is an assessment of the specific GHG (greenhouse gas) emissions as a function of the site conditions, the wind mill technology and the O&M necessities. Therefore, a representative offshore wind farm is defined and subjected to a detailed LCA (life cycle assessment). Based on parameter variations and modifications within the technical and logistical system, promising configurations regarding GHG emissions are determined for different site conditions. Results show, that all parameters related to the energy yield have a distinctive impact on the specific GHG emissions, whereas the distance to shore and the water depth affect the results marginally. By utilizing the given improvement potentials GHG emissions of electricity from offshore wind farms are comparable to those achieved onshore.     

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.     

Visual impact assessment of offshore wind farms and prior experience

Energy planners have shifted their attention towards offshore wind power generation and the decision is supported by the public in general, which in the literature has a positive attitude towards offshore wind generation. However, globally only a few offshore wind farms are operating. As more wind farms start operating and more people become experienced with especially the visual impacts from offshore wind farms, the public positive attitude could change if the experienced impacts are different from the initially perceived visual interference. Using a binary logit model, the present paper investigates the relation between different levels of prior experience with visual disamenities from offshore wind farms and perception of visual impacts from offshore wind farms. The differences in prior experience are systematically controlled for sampling respondents living in the areas close to the large scale offshore wind farms Nysted and Horns Rev and by sampling the a group of respondents representing the Danish population, which has little experience with offshore wind farms. Compared to previous results in the literature, the present paper finds that perception of wind power generation is influenced by prior experience. More specifically, the results show that people with experience from offshore wind farms located far from the coast have a significant more positive perception of the visual impacts from offshore wind farms than people with experience from wind farms located closer to the coast. These results are noteworthy on two levels. First of all, the results show that perceptions of offshore wind generation are systematically significantly influenced by prior experience with offshore wind farms. Secondly, and in a policy context, the results indicate that the future acceptance of future offshore wind farms is not independent of the location of existing and new offshore wind farms. This poses for caution in relation to locating offshore wind farms too close to the coast.     

Offshore renewable energy exploitation strategies in remote areas by power-to-gas and power-to-liquid conversion

Chemical storage of electric energy is recognised as a potential solution to improve the penetration of renewable energy. The coupling of renewable power production with offshore oil & gas exploitation by converting electricity into synthetic fuels represents an opportunity to valorize renewables in remote areas in an energy transition panorama. The present study aims at a comparison of alternative power-to-gas and power-to-liquid strategies for the conversion of offshore wind power into different chemical energy vectors (hydrogen, synthetic natural gas and methanol), taking advantage of conventional offshore oil & gas infrastructures for energy conversion and synthetic fuel transportation. A set of technical, economic, environmental and profitability performance indicators was defined to allow the comparison. A case study in the North Sea was analysed. The results showed that electrolyzers capacity and offshore-onshore distance play an important role on economic indicators. Sensitivity analysis was carried out to test the robustness of the results.     

A macro-level decision analysis of wind power as a solution for sustainable energy in the USA

This study aims to quantify the socio-economic and environmental impacts of producing electricity by wind power plants for the US electricity mix. To accomplish this goal, all direct and supply chain-related impacts of different onshore and offshore wind turbines are quantified using a hybrid economic input-output-based triple bottom line (TBL) life cycle assessment model. Furthermore, considering TBL sustainability implications of each onshore and offshore wind energy technology, a multi-criteria decision-making tool which is coupled with Monte Carlo simulation is utilised to find the optimal choice of onshore and offshore wind energy. The analysis results indicate that V90-3.0 MW wind turbines have lower impacts than V80-3.0 MW for both socio-economic and environmental indicators. The Monte Carlo simulation results reveal that when environmental issues are more important than socio-economic impacts, V90-3.0 MW offshore is selected among the alternatives.     

海上风电场对鸟类的影响及其危害预防

[目的]风能作为公认的最成熟的可再生能源技术之一,近年来发展迅速.中国在近年开发了大量的海上风电项目.但风电场对环境,尤其是对鸟类的影响引发了人们大量的担忧和研究.在碳达峰实现之前,我国的海上风能产业将持续增长,需要全面了解风电场对鸟类的影响.[方法]通过总结现有研究,对海上风电场引起的鸟类问题进行了综述,并讨论了可将...     

State and local economic impacts from wind energy projects: Texas case study

This paper uses the Jobs and Economic Development Impacts (JEDI) model to estimate economic impacts from 1398 MW of wind power development in four counties in west Texas. Project-specific impacts are estimated at the local level (i.e., within a 100-mile radius around the wind farms) and at the state level. The primary economic policy question addressed is how investment in wind energy affects the state and local communities where the wind farms are built. During the four-year construction phase approximately 4100 FTE (full time equivalents) jobs were supported with turbine and supply chain impacts accounting for 58% of all jobs generated. Total lifetime economic activity to the state from the projects equated to more than $1.8 billion, or $1.3 million per MW of installed capacity. The total economic activity to the local communities was also substantial, equating to nearly $730 million over the assumed 20-year life cycle of the farms, or $0.52 million per MW of installed capacity. Given the current level of impacts observed, and the potential for increased impacts via greater utilization of instate manufacturing capacity and the development of trained wind industry specific laborers, Texas appears to be well positioned to see increasing impacts from continued wind development.     

Life cycle assessment of a floating offshore wind turbine

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.     

GHG emissions and energy performance of offshore wind power

This paper presents specific life cycle GHG emissions from wind power generation from six different 5 MW offshore wind turbine conceptual designs. In addition, the energy performance, expressed by the energy indicators Energy Payback Ratio (EPR) Energy Payback Time (EPT), is calculated for each of the concepts.There are currently few LCA studies in existence which analyse offshore wind turbines with rated power as great as 5 MW. The results, therefore, give valuable additional environmental information concerning large offshore wind power. The resulting GHG emissions vary between 18 and 31.4 g CO₂-equivalents per kWh while the energy performance, assessed as EPR and EPT, varies between 7.5 and 12.9, and 1.6 and 2.7 years, respectively. The relatively large ranges in GHG emissions and energy performance are chiefly the result of the differing steel masses required for the analysed platforms. One major conclusion from this study is that specific platform/foundation steel masses are important for the overall GHG emissions relating to offshore wind power. Other parameters of importance when comparing the environmental performance of offshore wind concepts are the lifetime of the turbines, wind conditions, distance to shore, and installation and decommissioning activities.Even though the GHG emissions from wind power vary to a relatively large degree, wind power can fully compete with other low GHG emission electricity technologies, such as nuclear, photovoltaic and hydro power.     

Nuclear power and the environment: comparative assessment of environmental and health impacts of electricity-generating systems

This paper deals with comparative assessment of the environmental and health impacts of nuclear and other electricity-generation systems. The study includes normal operations and accidents in the full energy chain analysis. The comparison of environmental impacts arising from the waste-management cycles associated with non-emission waste are also discussed. Nuclear power, while economically feasible and meeting 17% of the world's demand for electricity, is almost free of the air polluting gases that threaten the global climate. Comparing nuclear power with other sources for electricity generation in terms of their associated environmental releases of pollutant such as SO₂, NOX, CO₂, CH₄ and radioisotopes, taking into account the full fuel chains of supply option, nuclear power will help to reduce environmental degradation due to electricity generation activities. In view of CO₂ emission, the ranking order commences with hydro, followed by nuclear, wind and photovoltaic power plants. CO₂ emissions from a nuclear power plant are by two orders of magnitude lower than those of fossil-fuelled power plants. A consequent risk comparison between different energy sources has to include all phases of the whole energy cycle. Coal mine accidents have resulted in several 1000 acute deaths over the years. Then came hydropower, also resulting in many catastrophes and loss of human lives, followed by the oil and gas energy industries, last in the list is commercial nuclear energy, which has had a “bad” press because of the Chernobyl accident, resulting officially in 31 acute fatalities, and at least 145 latent fatalities. The paper offers some findings and conclusions on the role of nuclear power in protecting the global environment.     

Wind energy development and its environmental impact: A review

Wind energy, commonly recognized to be a clean and environmentally friendly renewable energy resource that can reduce our dependency on fossil fuels, has developed rapidly in recent years. Its mature technology and comparatively low cost make it promising as an important primary energy source in the future. However, there are potential environmental impacts due to the installation and operation of the wind turbines that cannot be ignored. This paper aims to provide an overview of world wind energy scenarios, the current status of wind turbine development, development trends of offshore wind farms, and the environmental and climatic impact of wind farms. The wake effect of wind turbines and modeling studies regarding this effect are also reviewed.     

Onshore wind power development in China: Challenges behind a successful story

Wind energy utilization, especially onshore grid-connected wind power generation, has a history of 30 years in China. With the increasing attention to renewable energy development in recent years, wind energy has become the focus of academic research and policy-making. While the potential and advantages of wind energy are widely recognized, many questions regarding the effectiveness of policies and performances of current practices remain unanswered. This paper takes Inner Mongolia, the province that has the most abundant wind energy resources in China, as a case to assess the performance of Chinese onshore wind power projects, focusing on the institutional setting, economic and technological performance, as well as environmental and social impacts. Results show that China is experiencing a rapid growth in wind power generation, which brings China great environmental, energy security and social benefits. However, for a full development of wind energy in China a number of barriers need to be removed: high generation cost, low on-grid price, and stagnating development of domestic manufacture. These findings lead to three policy recommendations.     

Environmental issues associated with wind energy – A review

Recognized as one of the most mature renewable energy technologies, wind energy has been developing rapidly in recent years. Many countries have shown interest in utilizing wind power, but they are concerned about the environmental impacts of the wind farms. The continuous growth of the wind energy industry in many parts of the world, especially in some developing countries and ecologically vulnerable regions, necessitates a comprehensive understanding of wind farm induced environmental impacts. The environmental issues caused by wind farms were reviewed in this paper by summarizing existing studies. Available mitigation measures to minimize these adverse environmental impacts were discussed in this document. The intention of this paper is to provide state-of-the-art knowledge about environmental issues associated with wind energy development as well as strategies to mitigate environmental impacts to wind energy planners and developers.     

Assessing the life cycle environmental impacts of wind power: A review of present knowledge and research needs

We critically review present knowledge of the life cycle environmental impacts of wind power. We find that the current body of life cycle assessments (LCA) of wind power provides a fairly good overall understanding of fossil energy use and associated pollution; our survey of results that appear in existing literature give mean values (± standard deviation) of, e.g., 0.060 (±0.058) kW h energy used and 19 (±13) g CO₂e emitted per kW h electricity, suggesting good environmental performance vis-à-vis fossil-based power. Total emissions of onshore and offshore wind farms are comparable. The bulk of emissions generally occur in the production of components; onshore, the wind turbine dominates, while offshore, the substructure becomes relatively more important. Strong positive effects of scale are present in the lower end of the turbine size spectrum, but there is no clear evidence for such effects for MW-sized units. We identify weaknesses and gaps in knowledge that future research may address. This includes poorly understood impacts in categories of toxicity and resource depletion, lack of empirical basis for assumptions about replacement of parts, and apparent lack of detailed considerations of offshore operations for wind farms in ocean waters. We argue that applications of the avoided burden method to model recycling benefits generally lack transparency and may be inconsistent. Assumed capacity factor values are generally higher than current mean realized values. Finally, we discuss the need for LCA research to move beyond unit-based assessments in order to address temporal aspects and the scale of impacts.     

一体化理念在国内海上风电开发建设上的应用探究

可再生能源作为日益严峻的能源问题和因此导致的环境问题的重要解决措施之一,受到世界各国的重视,海上风电作为可再生能源的新兴领域和重要组成部分得到了推广和发展。将多个领域中成功应用的一体化设计理念引入到海上风电场前期、风机选型、风机基础与风电机组设计、建设期、运营期的各个环节,分析了国内海上风电场成本降低和突破效益瓶颈的可行性。研究表明:一体化理念应用于海上风电项目前期核准、设计、施工建设、运营维护等全生命周期中,大幅降低了风电场成本,并提高了风电场的抗风险能力。     

Offshore wind farm site selection study around Jeju Island,South Korea

This study suggests strategies for conducting an offshore wind farm site selection and evaluates feasible offshore wind farm sites in the coastal areas of Jeju Island, South Korea. The site selection criteria are classified into four categories: energy resources and economics, conservation areas and landscape protection, human activities, and the marine environment and marine ecology. We used marine spatial techniques from GIS and the investigated resources available in the country. The results indicate that offshore wind farms can be located along a wide range of the eastern and western coasts of Jeju Island, considering energy resources and economics only. However, when considering the four categories presented in this study, the number of feasible offshore wind farm sites was significantly less than when only energy resources and economics were considered. The data and analysis presented in this study will be useful for the offshore wind farm site selection around Jeju Island, and it will also contribute to minimizing the environmental impacts and reducing the social conflicts between stakeholders.     

Life cycle assessment of H2 generation with high temperature electrolysis

Water electrolysis is a well-established process for hydrogen production but requires efficiency improvements to reduce costs. High temperature electrolysis (HTE) as a means to higher efficiency was advanced in the EU project RelHY. Through Life Cycle Assessment (LCA), also the environmental performance of five HTE-based hydrogen production systems was evaluated: operation with power and steam from a nuclear plant, continuous and intermittent operation with wind power and water, intermittent operation with natural gas or biogas reforming as back-up. Large scale natural gas reforming (NGR) was used as a reference. The LCA aims to identifying environmental hotspots of HTE plants and comparing their operation. The results show that stack manufacturing has the strongest impact during construction of the HTE plant while the impacts during H₂ production are largely due to power supply. All HTE variants studied lead to less life cycle CO₂-equivalent emissions than NGR. However, only the wind powered HTE variants without back-up use less energy than NGR. The other impacts and flows show different patterns. The results and limitations of the study are discussed.     

The quantification of the embodied impacts of construction projects on energy,environment, and society based on I–O LCA

With rapid social development and large-scale construction of infrastructure in China, construction projects have become one of the driving forces for the national economy, whose energy consumption, environmental emissions, and social impacts are significant. To completely understand the role of construction projects in Chinese society, this study developed input–output life-cycle assessment models based on 2002, 2005, and 2007 economic benchmarks. Inventory indicators included 10 types of energy, 7 kinds of environmental emissions, and 7 kinds of social impacts. Results show that embodied energy of construction projects in China accounts for 25–30% of total energy consumption; embodied SO₂ emissions are being controlled, and the intensities of embodied NO_x and CO₂ have been reduced. However, given that the construction sector related employment is 17% of the total employment in China, the accidents and fatalities related to the construction sector are significant and represent approximately 50% of the national total. The embodied human and capital investments in science and technology (ST) increased from 2002 to 2007. The embodied full time equivalent (FTE) of each ST person also increased while the personal ST funding and intramural expenditures decreased. This might result from the time lag between RD activities and large-scale implementation.     

广东海上风电岩土勘察船只平台技术研究

[目的]随着国家能源结构的加速演变,海上风电将进入快速稳定开发期.目前,国内多个省份近岸海上风电开发已接近完成,海上风电逐步向近海深水区开发并将大规模发展.近海深水区海上风电对海洋岩土勘察技术的要求更高,海洋岩土勘察船只和设备要求趋于专业化.国内大型专业海洋岩土勘察平台数量有限,其主要服务于国家海洋资源勘探和科考工作,...     

The impact of climate change on the European energy system

Climate change can affect the economy via many different channels in many different sectors. The POLES global energy model has been modified to widen the coverage of climate change impacts on the European energy system. The impacts considered are changes in heating and cooling demand in the residential and services sector, changes in the efficiency of thermal power plants, and changes in hydro, wind (both on- and off-shore) and solar PV electricity output. Results of the impacts of six scenarios on the European energy system are presented, and the implications for European energy security and energy imports are presented.Main findings include: demand side impacts (heating and cooling in the residential and services sector) are larger than supply side impacts; power generation from fossil-fuel and nuclear sources decreases and renewable energy increases; and impacts are larger in Southern Europe than in Northern Europe.There remain many more climate change impacts on the energy sector that cannot currently be captured due to a variety of issues including: lack of climate data, difficulties translating climate data into energy-system-relevant data, lack of detail in energy system models where climate impacts act. This paper does not attempt to provide an exhaustive analysis of climate change impacts in the energy sector, it is rather another step towards an increasing coverage of possible impacts.