Development of a collision impact indicator to integrate in the life cycle assessment of offshore wind farms

Aiming at the disadvantages of the construction and management of offshore wind farm in china, a smart energy management cloud platform(SEMCP) based on big data and cloud computing technology is put forward, which integrates the structure, equipment, Management and operation of offshore wind farm effectively, improves the utilization efficiency and overall planning of wind power, and establishes the communication channels of managers at all Levels. Reduce the operation and maintenance cost of offshore wind farm, improve management Efficiency. The scheme is designed from the aspects of design goal, design content, equipment selection, topological structure and so on, and it is highly operational. Although the scheme is based on the design of a offshore wind farm in our company, its basic principles and construction ideas are universal and can be easily extended to other offshore wind farm Construction.

The increasing numbers of offshore wind farm (OWF) projects question the impacts of such infrastructures on the social-ecological system (SES) in which they are to be constructed. Some answers can be given using qualitative modeling and loop analysis. We used participatory modeling to co-construct a qualitative model of the socio-ecosystem together with stakeholders of the APPEAL project. The goal of the project was to evaluate the potential impacts of the pilot OWF in the Groix–Belle-île region. Then, loop analysis was used to study the characteristics of the SES created by the setting-up of an OWF. We focused on the impacts of SES variables on each other by evaluating their effects through direct and indirect pathways. Pleasure boating appeared as one of the SES components prone to suffer from the OWF construction, whereas industrial tourism was likely to benefit from it. This article presents the methodology used to obtain such results, for it to be used in spatial planning or in citizen-science processes.

Since 2007, China’s offshore wind farm construction has developed rapidly, with more than 50 projects under construction and under construction. The operation period of offshore wind farms has a far-reaching impact on the ship traffic pattern in coastal traffic-intensive waters, and the poor compatibility of sea resources has a fragmented and three-dimensional exclusive impact on the use of sea areas, which makes the navigation conditions in nearby waters more complex. At present, there is no universally binding international convention or technical standard for ship navigation safety in offshore wind farm waters at home and abroad, which leads to the lack of unification of several important aspects of standards for offshore wind farm design and construction.For example, the requirements for channel distance, anti-collision requirements, setting standards for navigation marks and warning signs, pollution prevention management, emergency disposal and subsequent abandonment are not uniform. This paper focuses on the analysis of anti-collision measures between ship and wind turbine foundation from the perspective of navigation safety during the operation of offshore wind farm, and takes the No.6 offshore wind farm project in Zhoushan Putuo as an example to discuss.

In all European countries with shallow coastal waters and strong mean wind speed at the coast the planning and construction of offshore wind farms is on the way and large parts of the North Sea and the Baltic are under investigation as to whether they are suitable for offshore parks. In this paper it is demonstrated how satellite images taken by spaceborne radar sensors can be used to determine mesoscale wind fields and thus help in the task of planning offshore wind farms. High resolution SAR images acquired by the European remote sensing satellite ERS 2 are presented which show single wind turbines (Fig. 1). The derivation of high resolution wind fields from SAR images is explained and comparisons with numerical models are presented.

Offshore wind power is one of the most popular renewable sources of energy. However, there are many challenges during the design, construction and operation of offshore wind farms. One of these challenges is the stability of offshore wind turbines. The main loads on the foundations of wind turbines are from the environment (wind and wave) and there are other loads arising due to their operations (known as rotor frequency loads-1P and blade passing loads-2P/3P). All these 4 loads are unique in terms of magnitude, number of cycles and the strain they apply to the supporting soil. Furthermore, due to innovation in turbine technology, the sizes of turbines also increased few folds (3MW to 12MW) in a span of about 5 years and these large turbines need customised foundations. Due to the attractiveness of this new technology and the reduction of LCOE (Levelized Cost of Energy), offshore wind turbines are also sited not only in deeper waters but also in seismic areas and other disaster-prone areas (typhoon and hurricane). Any new foundation must be validated using scaled model tests (i.e. study of Technology Readiness Level) to satisfy the industry requirements. This thesis developed techniques for scaled model testing to study different aspects of long-term performance of foundations. The novel testing methodology and apparatus is based on understanding of the loads on the foundations. The apparatus consists of two eccentrically loaded gears which can be customised to apply cycloid loads. The apparatus can be easily upscaled to study bigger models and is very simple to assemble and operate. The apparatus can also apply millions of cycles of loading of different amplitude and frequency which is representative of a real wind turbine. Results from scaled model tests on few types of foundations are presented and they revealed interesting Soil-Structure Interaction. In a wind turbine system, long term performance is mainly governed by the SSI and this thesis summarised the limited field observations reported in the literature and compared with the laboratory observations. One of the scientific challenges is the prediction of long-term performance of these relatively new and novel technologies. While scaled model tests can identify the physics, this is not a practical tool for routine design as it is difficult to create model tests for each of the sites. As a result, this thesis aimed to link the understanding of SSI to element testing of soil. This will allow to use the recovered sample from offshore wind farm location to carry laboratory tests to obtain design parameter. This thesis proposed a simple method to obtain the strain level in the soil which is beneficial for planning offshore Site Investigation. Offshore wind turbines are currently designed for 25 to 30 tars and the number of cycles of loading are in the range of 100 million. This thesis presented data from element testing of soil where up to 50,000 cycles of loading were applied. The general trends of behaviour were noted, and it was observed that the soil behaviour was attaining a steady state. All the above helped to understand some SSI aspects of offshore wind turbines. Future work is also suggested

Purpose: to develop proposals for ensuring industrial safety in the wind energy sector and practical recommendations for organising the work of employees to prevent accidents. Methods: the materials presented in the article are the result of using special research methods – methods of collecting, summarising information, critical analysis and forecasting. Results: the research has shown that wind energy is considered one of the most reliable sources for increasing renewable energy production in the world. However, there are risks that need to be taken into account during the construction and maintenance of offshore wind farms in Ukraine to ensure the safest possible working conditions for workers. The article the causes of accidents at offshore wind farms. The basic principles of ensuring technological safety in the field of renewable energy are formulated. Practical recommendations for ensuring the safety analyses y of workers in the wind energy industry are proposed. Scientific novelty: Ukraine’s wind energy network faces a lack of flexibility in the energy system. A scientific justification for the development of offshore wind energy in Ukraine was carried out, taking into account the experience of world countries in the operation of installations, measures to eliminate accidents at the stage of occurrence, the implementation of measures to eliminate and prevent accidents and avoid recurrence of violations. The need for regulatory and legal regulation of offshore wind farms is extremely important. Practical significance: the proposals will improve the level of labour safety and reduce the risk of accidents in the wind energy sector. The use of the experience of implementing a systematic approach and principles of managing complex processes in ensuring safety at offshore wind farms in the world will allow identifying the most important risks and focus efforts on their avoidance, prevention or reduction during the construction and operation of offshore wind farms in Ukrainian territorial seas. Keywords: technogenic safety, wind energy, offshore wind farms, risk, accident.

The climate crisis is driving a rapid increase in size and number of offshore wind farms to reduce carbon emissions from electricity generation. However, there are concerns about the potential impact of offshore wind farms on the marine environment. Seabirds are considered to be at risk of being displaced from preferred foraging habitat, by construction and operation of offshore wind farms, resulting in reduced energy intake or elevated energetic costs and consequent decreases in survival and/or productivity. Typically, displacement or avoidance behaviour is assessed by comparing abundance and spatial distributions of seabirds before and after an offshore wind farm is constructed. However, seabird distributions are highly variable through time and space and so discerning a change in distribution caused by an offshore wind farm from other environmental variables can be challenging. We present a new method that controls for temporal variation by examining the location of individual seabirds relative to turbines. Mean seabird density at different distances from individual turbines (0-400m) was calculated from data collected on a total of 12 digital aerial surveys of the Beatrice Offshore Wind Farm (UK), in May-August in 2019 and 2021. Mean densities of common guillemot (Uria aalge), razorbill (Alca torda), Atlantic puffin (Fratercula arctica) and black-legged kittiwake (Rissa tridactyla), both flying and sat on the water, were calculated. If the presence of turbines had no effect on seabird distribution, there should be no relationship between distance from turbine and seabird density. This was tested by simulating a relocation of turbines, relative to seabird distribution, and recalculating seabird density over 0-400m from simulated turbine locations. This was repeated to generate a bootstrapped distribution of expected densities against which observed density was compared. If displacement was occurring, mean observed density close to turbines would be significantly lower than expected density, derived from the bootstrap distribution. Overall, observed mean density did not differ significantly from expected density, i.e. no displacement effect was detected. There was a slight tendency for guillemot and razorbill, when sat on the water, to be at higher densities than expected, near turbines, suggestive of possible attraction to turbines, and for flying birds to be at lower densities than expected, near turbines, suggestive of possible avoidance. No flying razorbills were recorded within 100m of turbines but sample sizes were small. Kittiwake tended to show no avoidance or attraction behaviour, although flying kittiwake density was slightly lower than expected at 200m from turbines. Puffins sat on the water were recorded in densities similar to the expected density. Overall, no effect of turbine rotor speed was found, i.e. birds were not more likely to be displaced/avoid turbines at higher or lower rotor speeds. The results of the turbine relocation analysis gave a more consistent and more easily interpreted assessment of displacement/avoidance behaviour than the typical approaches of comparing abundance and seabird distribution through time. We strongly encourage application of this new approach to post-construction spatial distribution data from other offshore wind farms, to build the evidence base on the effects of offshore wind farms on seabirds.

Human activities are increasing in the marine environment causing underwater noise. The most intense source of underwater noise is pile driving during construction of offshore wind farms. This might disturb marine mammals, such as the harbour porpoise. Therefore, measures to prevent and mitigate underwater noise are necessary.In order to be effective such measures should be regulated. However, regulators have to demonstrate and assess the applicability, efficiency and effectiveness of mitigation measures. This requires scientific knowledge on the impact of underwater noise while the normative aspects of noise mitigation have to be considered.Since 2008, operators have to comply with limits for pile driving noise during the construction of offshore wind farms in Germany. Since 2011, they have to use technical noise abatement systems. The Federal Maritime and Hydrographic Agency (BSH) approves offshore wind farms and monitors underwater noise in the German Exclusive Economic Zone (EEZ).Since 2017, BSH operates the expert tool MarinEARS, which includes the scientific basis for regulating underwater noise. The data shows that the regulations have been successful in the recent years. Underwater noise affected less than 10 percent of the German EEZ at any time, including adjacent nature conservation areas.Here, BSH outlines a step-wise approach to establish a regulatory framework for pile driving noise and to implement mitigation measures in practice. It highlights the successful cooperation between science, authorities and industry in recent years to minimise the impact of underwater noise on the marine environment.These lessons learnt from addressing underwater noise from the construction of offshore wind farms, are currently being transferred to underwater noise from e.g. shipping and the operation of offshore wind farms. Furthermore, the EU issued for the first time thresholds to limit underwater noise in European waters in 2022.BSH plays also a crucial role in the development of European threshold values and the standardised evaluation of underwater noise. This is important for making the assessment of underwater noise comparable and reproducible. In this way, common goals for the protection and sustainable use of the seas can be set in the future.

Abstract: With the increase in global investments in offshore wind energy and the rapid implementation of wind technologies in hazardous deep water environments, operational inspection of wind turbines and related infrastructure plays an important role in the safe and efficient operation of offshore wind farms. In recent years, much attention has been paid to the use of unmanned aerial vehicles (UAVs) and remotely piloted unmanned aerial vehicles (RPAs) commonly referred to as "drones" for remote inspection of renewable energy infrastructure, i.e. photovoltaic farms and onshore wind farms. Drones have significant potential also in in offshore wind energy. Inspection with drones allows for to reduce not only the number of flight operations (involvement of aircraft and flight crews) and the transport of personnel carrying out the maintenance and repair of offshore wind turbines. With drones is possible carry the equipment transported for hazardous inspection work. The involvement of UAVs also reduces the plant downtime needed to detect faults and collect diagnostic information from the entire wind farm. The benefits of inspection technology in the offshore wind energy industry based on drones are confirmed by the previous tests, and the prospect of offshore energy development encourages further work with the use of UAVs. At the same time, it should be borne in mind that any unexpected failure of the drone system during its mission may interrupt control works (during inspections), and thus reduce the electricity generated by wind turbines. The article presents the potential of drones in the process of inspecting wind farms, including offshore wind farms, presents examples of UAV models used for inspections, indicates methods of conducting inspections with the use of drones and highlights a significant reduction in the costs of the operation of offshore wind farms as a result of limiting the use of manned aviation (helicopters and flight crews) and the elimination of the risk associated with the involvement of personnel to perform inspections of wind farms at sea. The potential of unmanned floating platforms as part of cooperation with UAV in the process of inspecting offshore wind farms was also indicated. Keywords: wind energy, offshore, drones, wind farms, drone inspections, maritime inspections, marine aviation, offshore, offshore wind energy, safety air operations, risk analysis

Extensive expansion in offshore wind energy takes place these years in European waters, with North America following. Concern has been about possible conflicts with marine ecosystems, including marine mammals. During the last 10 years, several impact studies have been conducted during construction and first years of operation of wind farms in Europe and general conclusions begin to emerge. Pronounced effects (deterrence of animals) during construction have been observed in most cases. In particular, pile driving of steel monopiles for foundations has repeatedly been demonstrated to affect porpoise behavior at great distance and effects on seal haul‐out behavior has been observed in a single case. Controlled exposure studies have confirmed the results and demonstrated reactions to pile driving impact noise at levels around 140 re. 1 μPa. Effects of operation are far less pronounced and range from negative (deterrence) over neutral, to positive (attraction). Noise levels from operating turbines are very low, however, and it is unlikely that deterrence can be attributed to the noise. In general, there appears to be little conflict between marine mammals and operating offshore wind farms, but there is reason for continued attention to the construction phase, in particular, regarding pile driving operations.

Offshore wind power generation represents a chance to supply energy in a more sustainable way; however, the ecological risks associated with the construction and operation of offshore wind farms are still largely unknown. This paper uses the concept of ecological risk for analysing ecological changes during construction of offshore wind farms. “Ecological risk” is defined as the potentially reduced ability of providing ecosystem services. The ERSEM ecosystem model allows assessing ecological risk based on a number of selected variables (integrity indicators) and under the assumption that increased suspended matter concentration during construction of wind farms affects ecosystem functioning. We conclude that ecological risk is adequate to describe the effects of wind farm constructions, although the computation procedure still needs to be refined and the choice of indicators further optimised. In this context, the choice of indicators available in modelling as well as in monitoring time-series may offer the way forward.

Since the beginning of the 2000’, the French government ambition was to have an offshore wind production formed 40% of the renewable electricity in 2030. Three calls tenders of Offshore Wind Farms (OWFs) construction have been pronounced since 2011. However, no offshore wind farm (OWF) had been constructed at the end of 2017 due to long administrative procedures and numerous appeals in justice, at French and European levels. Nevertheless, several studies have been enterprised to identify the environmental conditions and ecosystem functioning in selected sites before OWF implantations. However, these studies are generally focused on the conservation of some species or groups of species, and there is no holistic study on the effects of the construction and operation of OWF on an ecosystem taken as a whole. In 2017, a complete and integrated view of the ecosystem of two future OWF sites of the eastern English Channel (Courseulles-sur-Mer and Dieppe-Le Treport) was developed to model the marine ecosystems before OWF implementation and to simulate reef effects due to new spatial occupation of maritime territory. Results contribute to a better knowledge of the impacts of the OWFs on the functioning of marine ecosystems. They also allow to define recommendations for environmental managers and industry in terms of monitoring the effects of marine renewable energy (MRE), not only locally but also on other sites, at national and European levels.

The construction of offshore wind farms in Northern Europe commenced in the early nineties. In the beginning, only minor test offshore wind farms were built, but from 2002 and onwards, large-scale offshore wind farms have been erected. Construction and operation experiences from these wind farms are now being collected, and this paper discusses construction and operation experiences obtained from selected offshore wind farms. Differences and similarities between the wind industry and the oil and gas industry are discussed with a view to raising the awareness of this new and growing industry among market players in the oil and gas industry. Current status and plans in Europe [1] In the European Union (EU) the development of wind power is very impressive. Over the past five years, 30% of all newly installed electricity generating capacity has been wind power. The installed capacity is now 40.5 GW, and the generated power is enough to supply 21 million households. However, wind power still only covers 2.8% of the total European electricity demand. Only 680 MW of the above-mentioned 40.5 GW capacity are installed off shore. Recent projections of the future development suggest that by 2030 the installed capacity may reach 300 GW of which 150 GW are expected to be installed off shore. Whether the targets for offshore wind power will be met depends crucially on technology development, grid infrastructure and the existence of political incentives to encourage investments. A renewables target of at least 20% of EU energy by 2020 will be a significant driving force behind this development. It will only be possible to meet this target with a strong contribution from wind power. Another driving force behind the wind power development is the increase in fossil fuel prices. Current status and plans in Denmark [2] Denmark has been and is still a frontrunner in the development of on- and offshore wind energy. Only in Denmark, Spain, Germany and Ireland does wind power cover more than 5% of the electricity demand. In Denmark, the actual figure is close to 20%. The installed capacity is 3100 MW of which 420 MW are located off shore (two large-scale wind farms contribute 325 MW). Recent wind farm developments have been located off shore, and future plans aim to expand offshore wind power event further. Currently, investment decisions to erect two offshore wind farms of 200 MW each are in the pipeline. Challenges going off shore The main reasons for going off shore are access to large energy resources and potentially less complicated planning processes. Although the wind resources are vast, the investment in foundations and electrical infrastructure (cables and substations) are dramatically higher than for onshore wind farms, and operation costs increase as well. At first glance, the planning process, including the environmental statements, seems to be easier off shore, but experience shows that there are many stakeholders in the offshore areas, who make the offshore process as difficult as the onshore process.

Life cycle cost (LCC) considerations are of increasing importance to offshore wind farm operators and their insurers to undertake long-term profitable investments and to make electricity generation more price-competitive. This paper presents a cost breakdown structure (CBS) and develops a whole life cost (WLC) analysis framework for offshore wind farms throughout their life span (∼25 years). A combined multivariate regression/neural network approach is developed to identify key cost drivers and evaluate all the costs associated with five phases of offshore wind projects, namely pre-development and consenting (P&C), production and acquisition (P&A), installation and commissioning (I&C), operation and maintenance (O&M) and decommissioning and disposal (D&D). Several critical factors such as geographical location and meteorological conditions, rated power and capacity factor of wind turbines, reliability of sub-systems and availability and accessibility of transportation means are taken into account in cost calculations. The O&M costs (including the cost of renewal and replacement, cost of lost production, cost of skilled maintenance labour and logistics cost) are assessed using the data available in failure databases (e.g. fault logs and O&M reports) and the data supplied by inspection agencies. A net present value (NPV) approach is used to quantify the current value of future cash flows, and then, a bottom-up estimate of the overall cost is obtained. The proposed model is tested on an offshore 500-MW baseline wind farm project, and the results are compared to experimental ones reported in the literature. Our results indicate that the capital cost of wind turbines and their installation costs account for the largest proportion of WLC, followed by the O&M costs. A sensitivity analysis is also conducted to identify those factors having the greatest impact on levelized cost of energy (LCOE). The installed capacity of a wind farm, distance from shore and fault detection capability of the condition monitoring system are identified as parameters with significant influence on LCOE. Since the service lifetime of a wind farm is relatively long, a small change in interest rate leads to a large variation in the project’s total cost. The presented models not only assist stakeholders in evaluating the performance of ongoing projects but also help the wind farm developers reduce their costs in the medium–long term.

Before piling of offshore wind farm foundations, acoustic harassment devices (AHDs) are used to drive harbor porpoises out of the area where they could suffer injuries. Until 2017, a combination of pingers and seal scarer devices (usually SPL = 174-193 dB re 1 μPa (rms) @ 1m at 1 to 20 kHz depending on the device) was prescribed for mitigation purposes in Germany. However, seal scarers led to decreased porpoise detection rates in much larger distances than intended, when 750 m is usually rendered sufficient to avoid injuries. Therefore, devices specifically designed for mitigation purposes were developed and are prescribed since then. These acoustic porpoise deterrents (APDs; e.g. FaunaGuard Porpoise Module; SPL = 172 dB re 1 μPa (rms) @ 1m at 60 to 150 kHz) aim to keep the animals away from offshore construction sites but should not lead to large-scale disturbance as caused by a seal scarer. Although project-specific evaluations indicated that APDs are effective, a cross-project analysis and a comparison with data from previous piling procedures employing seal scarers were still pending. The present study aimed to fill this gap. Between March 2018 and April 2019, harbor porpoise detection rates were monitored acoustically in four offshore wind farm projects using CPODs before, during and after piling at different distances up to 10 km from piling. APD operation led to a significant decrease in detection rates in the vicinity of the device, indicating the displacement of the animals from a small-scale area. Depending on the wind farm, detection rates during APD operation decreased by 30 to 100% at 750 m distance compared to 6 hours before APD operation. Furthermore, reduced detection rates during APD operation were only observed up to about 2.5 km distance even when the APD was switched on for over 40 minutes. Given that the extent of disturbance to harbor porpoises is lower when using an acoustic porpoise deterrent compared to the seal scarer, we consider that preferential use of an acoustic porpoise deterrent is an improvement to mitigation strategies and an important step forward to a less harmful piling procedure.