Sea-Keeping Analysis of an Offshore Wind Farm Installation Vessel During the Jack-Up Process

2014 ◽  
Author(s):  
Philip H. Augener ◽  
Hannes Hatecke
Keyword(s):  
Wind Farm ◽  
Wind Farms ◽  
Weather Conditions ◽  
Offshore Wind ◽  
Shallow Waters ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
The North ◽  
The North Sea ◽  
Jack Up

Offshore wind farms are not planned in sheltered and shallow waters any longer. Especially in the North Sea there exist many approved offshore wind farm projects at water depth between 30 and 50 meters. In particular the installation process of these projects is strongly influenced by weather conditions and the sea-keeping capabilities of the installation vessels. For reliable planning of the entire project, not only the weather statistics, but also the vessel’s sea-keeping capabilities need to be known accurately. For this purpose different kinds of sea-keeping analyses can be conducted. In this paper a sea-keeping analysis is presented, where the focus is upon the jack-up process. For the numerical computation the sea-keeping code E4ROLLS is applied. The results of this sea-keeping analysis are operational limitations for the jack-up process, caused by two different criteria derived from jack-up classification requirements.

scholarly journals Stable Ships for Smooth Servicing of Offshore Wind Farms

2014 ◽  
pp. 179-183
Author(s):  
Matthew Shanley
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Wind Farms ◽  
Weather Conditions ◽  
Offshore Wind ◽  
Irish Sea ◽  
Offshore Wind Farms ◽  
The North ◽  
The North Sea ◽  
The Irish Sea

There is a rapid increase in the number of offshore wind farms in European waters to help meet renewable energy targets. Wind turbines are being installed in progressively more exposed areas of the North Sea and the Irish Sea, with the eventual aim of placing them in the Atlantic Ocean. As offshore wind farms require regular maintenance, being able to access the wind turbines during rough sea conditions is a key issue for profitable operation. The operation involves transferring personnel from the service ship to the wind turbine. The current wave height limit for this is 1.5 m, slightly less than 5 feet, increasing this results in significant savings over the lifetime of the wind farm. Each wind farm service ship has 12 maintenance crew. Imagine you are one waiting on port for the sea and weather conditions to be right so that you can head out to the wind ...

scholarly journals A Spatial Analysis of the Potentials for Offshore Wind Farm Locations in the North Sea Region: Challenges and Opportunities

2020 ◽  
Vol 9 (2) ◽  
pp. 96 ◽  
Author(s):  
Gusatu ◽  
Yamu ◽  
Zuidema ◽  
Faaij
Keyword(s):  
Protected Areas ◽  
North Sea ◽  
Water Depth ◽  
Wind Farm ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms ◽  
The North ◽  
Challenges And Opportunities ◽  
The North Sea

Over the last decade, the accelerated transition towards cleaner means of producing energy has been clearly prioritised by the European Union through large-scale planned deployment of wind farms in the North Sea. From a spatial planning perspective, this has not been a straight-forward process, due to substantial spatial conflicts with the traditional users of the sea, especially with fisheries and protected areas. In this article, we examine the availability of offshore space for wind farm deployment, from a transnational perspective, while taking into account different options for the management of the maritime area through four scenarios. We applied a mixed-method approach, combining expert knowledge and document analysis with the spatial visualisation of existing and future maritime spatial claims. Our calculations clearly indicate a low availability of suitable locations for offshore wind in the proximity of the shore and in shallow waters, even when considering its multi-use with fisheries and protected areas. However, the areas within 100 km from shore and with a water depth above –120 m attract greater opportunities for both single use (only offshore wind farms) and multi-use (mainly with fisheries), from an integrated planning perspective. On the other hand, the decrease of energy targets combined with sectoral planning result in clear limitations to suitable areas for offshore wind farms, indicating the necessity to consider areas with a water depth below –120 m and further than 100 km from shore. Therefore, despite the increased costs of maintenance and design adaptation, the multi-use of space can be a solution for more sustainable, stakeholder-engaged and cost-effective options in the energy deployment process. This paper identifies potential pathways, as well as challenges and opportunities for future offshore space management with the aim of achieving the 2050 renewable energy targets.

scholarly journals The Relation between Migratory Activity of Pipistrellus Bats at Sea and Weather Conditions Offers Possibilities to Reduce Offshore Wind Farm Effects

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3457
Author(s):  
Robin Brabant ◽  
Yves Laurent ◽  
Bob Jonge Poerink ◽  
Steven Degraer
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Negative Relationship ◽  
Wind Farms ◽  
Weather Conditions ◽  
Seasonal Migration ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
Migratory Activity

Bats undertaking seasonal migration between summer roosts and wintering areas can cross large areas of open sea. Given the known impact of onshore wind turbines on bats, concerns were raised on whether offshore wind farms pose risks to bats. Better comprehension of the phenology and weather conditions of offshore bat migration are considered as research priorities for bat conservation and provide a scientific basis for mitigating the impact of offshore wind turbines on bats. This study investigated the weather conditions linked to the migratory activity of Pipistrellus bats at multiple near- and offshore locations in the Belgian part of the North Sea. We found a positive relationship between migratory activity and ambient temperature and atmospheric pressure and a negative relationship with wind speed. The activity was highest with a wind direction between NE and SE, which may favor offshore migration towards the UK. Further, we found a clear negative relationship between the number of detections and the distance from the coast. At the nearshore survey location, the number of detections was up to 24 times higher compared to the offshore locations. Our results can support mitigation strategies to reduce offshore wind farm effects on bats and offer guidance in the siting process of new offshore wind farms.

scholarly journals Temporal patterns in offshore bird abundance during the breeding season at the Dutch North Sea coast

2021 ◽  
Vol 168 (10) ◽  
Author(s):  
Jens A. van Erp ◽  
E. Emiel van Loon ◽  
Kees J. Camphuysen ◽  
Judy Shamoun-Baranes
Keyword(s):  
Breeding Season ◽  
North Sea ◽  
Wind Farm ◽  
Wind Farms ◽  
Offshore Wind ◽  
Bird Abundance ◽  
Offshore Wind Farms ◽  
The North ◽  
The North Sea

AbstractThe expanding development of offshore wind farms brings a growing concern about the human impact on seabirds. To assess this impact a better understanding of offshore bird abundance is needed. The aim of this study was to investigate offshore bird abundance in the breeding season and model the effect of temporally predictable environmental variables. We used a bird radar, situated at the edge of a wind farm (52.427827° N, 4.185345° E), to record hourly aerial bird abundance at the North Sea near the Dutch coast between May 1st and July 15th in 2019 and 2020, of which 1879 h (51.5%) were analysed. The effect of sun azimuth, week in the breeding season, and astronomic tide was evaluated using generalized additive modelling. Sun azimuth and week in the breeding season had a modest and statistically significant (p < 0.001) effect on bird abundance, while astronomic tide did not. Hourly predicted abundance peaked after sunrise and before sunset, and abundance increased throughout the breeding season until the end of June, after which it decreased slightly. Though these effects were significant, a large portion of variance in hourly abundance remained unexplained. The high variability in bird abundance at scales ranging from hours up to weeks emphasizes the need for long-term and continuous data which radar technology can provide.

Modelling Installation and Construction of Offshore Wind Farms

2014 ◽  
Author(s):  
Florian Stempinski ◽  
Sebastian Wenzel ◽  
Jan Lüking ◽  
Luigi Martens ◽  
Mahboubeh Hortamani
Keyword(s):  
Wind Energy ◽  
Winter Season ◽  
Wind Farms ◽  
Weather Conditions ◽  
Offshore Wind ◽  
Soil Conditions ◽  
Offshore Wind Farms ◽  
The North ◽  
Heavy Lift ◽  
The North Sea

While the offshore climate in the North Sea bears a great potential for the exploitation of reliable and powerful wind energy it poses a challenge for the constructors of offshore wind farms. Large heavy lift jack-up vessels (HLJV) are employed to transport the components of the wind energy converters to the offshore location. After a preloading and jacking procedure, subsea lifts of tripod foundations weighing up to 950tons as well as tower and nacelle installations at large heights need to be undertaken. As typical offshore wind farms consist of 80 or more separate wind turbines the installation works are conducted in a serial manner — often through the winter season. Thus, many critical offshore operations are conducted consecutively on the basis of daily or weekly weather reports. These operations cannot rely on optimal weather conditions therefore planning and engineering has to cover appropriate wind and wave conditions taking into account contingencies for uncertainties in the reliability of weather windows as well as in the soil conditions. This paper shows how the weather criteria derived from numerical seakeeping and structural simulations are taken into a project simulation model covering 90 separate serial installations. Based on hindcast re-analyses installation simulations are conducted in multi-seasonal weather scenarios. This enables the quantification of the suitability of a particular marine spread and its associated installation processes in combination. The risk profile of weather related delays are derived.

scholarly journals The use of 'ecological risk' for assessing effects of human activities: An example including eutrophication and offshore wind farm construction in the north sea

2008 ◽  
Vol 5 ◽  
pp. 1-20 ◽  
Author(s):  
Corinna Nunneri ◽  
Hermann Josef Lenhart ◽  
Benjamin Burkhard ◽  
Franciscus Colijn ◽  
Felix Müller ◽  
...  
Keyword(s):  
Ecological Risk ◽  
Wind Farm ◽  
Ecological Integrity ◽  
Wind Farms ◽  
Well Being ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Offshore Wind Farms ◽  
The North ◽  
Use Of Resources

This paper takes the move from the uncertainty surrounding ecosystem thresholds and addresses the issue of ecosystem-state assessment by means of ecological integrity indicators and 'ecological risk'. The concept of 'ecological risk' gives a measure of the likelihood of ecosystem failure to provide the level of natural ecological goods and services expected/desired by human societies. As a consequence of human pressures (use of resources and discharge into the environment), ecosystem thresholds can be breached thus resulting in major threats to human health, safety and well-being. In this study we apply the concept of 'ecological risk' to two case-studies in the German exclusive economic zone: eutrophication and construction of offshore wind farms. The effects of different future scenarios for single-uses upon ecosystem integrity are analysed as well as the effects of one combined scenario. We conclude that in the short term construction of offshore wind farms can influence some processes to a much larger degree than eutrophication, however, combined impacts deriving from eutrophication and offshore wind farm construction need a more detailed analysis. Due to non-linear ecosystem processes, effects of combined or multiple uses of marine resources in terms of 'ecological risk', cannot be extrapolated from single-use scenarios.

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

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

An Investigation into the Motion Behaviour of a Wind Farm Mothership

2015 ◽  
Author(s):  
Blanca Peña ◽  
Erik P. ter Brake ◽  
Kyriakos Moschonas
Keyword(s):  
Numerical Simulations ◽  
Wind Farm ◽  
Wind Farms ◽  
Weather Conditions ◽  
Offshore Wind ◽  
Financial Benefit ◽  
Offshore Wind Farms ◽  
Motion Characteristics ◽  
Vessel Motion ◽  
Motion Behavior

A number of UK Round Three offshore wind farms are located relatively far from the coast making crew transfer to the sites time consuming, more prone to interruption by weather conditions and increasingly costly. In order to optimize the functionality of a permanent accommodation vessel, Houlder has developed a dedicated Accommodation and Maintenance Wind Farm vessel based on an oil & gas work-over vessel that has been successfully deployed for many years. The Accommodation and Maintenance (A&M) Wind Farm vessel is designed to provide an infield base for Marine Wind Farm operation. The A&M vessel is designed for high operability when it comes to crew access and performance of maintenance and repair of wind turbine components in its workshops. Also general comfort on board is of high regard. As such, the seakeeping behavior of the unit is of great importance. In this publication, the seakeeping behavior is presented on the basis of numerical simulations using 3D diffraction software. The first design iteration is driven by achieving high maneuverability and good motion characteristics for operational up-time and personnel comfort on board the vessel. Model test data of the original work-over vessel has been used to validate and calibrate the numerical simulations. On this basis, parametric studies can be performed to fine-tune a potential new hull form. In turn, this could reduce the number of required physical model tests providing a potential financial benefit and optimized delivery schedule. The vessel motion behavior was tested against the acceptability criteria and crew comfort guidelines of motion behavior for a North Sea environment.

Wind wake effects of large offshore wind farms, an underrated impact on the marine ecosystem?

2020 ◽  
Author(s):  
Corinna Schrum ◽  
Naveed Akhtar ◽  
Nils Christiansen ◽  
Jeff Carpenter ◽  
Ute Daewel ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Sea ◽  
Large Scale ◽  
Spatial Scales ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Farms ◽  
The North ◽  
The North Sea ◽  
Ocean Hydrodynamics

&lt;p&gt;The North Sea is a world-wide hot-spot in offshore wind energy production and installed capacity is rapidly increasing. Current and potential future developments raise concerns about the implications for the environment and ecosystem. Offshore wind farms change the physical environment across scales in various ways, which have the potential to modify biogeochemical fluxes and ecosystem structure. The foundations of wind farms cause oceanic wakes and sediment fluxes into the water column. Oceanic wakes have spatial scales of about O(1km) and structure local ecosystems within and in the vicinity of wind farms. Spatially larger effects can be expected from wind deficits and atmospheric boundary layer turbulence arising from wind farms. Wind disturbances extend often over muliple tenths of kilometer and are detectable as large scale wind wakes. Moreover, boundary layer disturbances have the potential to change the local weather conditions and foster e.g. local cloud development. The atmospheric changes in turn changes ocean circulation and turbulence on the same large spatial scales and modulate ocean nutrient fluxes. The latter directly influences biological productivity and food web structure. These cascading effects from atmosphere to ocean hydrodynamics, biogeochemistry and foodwebs are likely underrated while assessing potential and risks of offshore wind.&lt;/p&gt;&lt;p&gt;We present latest evidence for local to regional environmental impacts, with a focus on wind wakes and discuss results from observations, remote sensing and modelling.&amp;#160; Using a suite of coupled atmosphere, ocean hydrodynamic and biogeochemistry models, we quantify the impact of large-scale offshore wind farms in the North Sea. The local and regional meteorological effects are studied using the regional climate model COSMO-CLM and the coupled ocean hydrodynamics-ecosystem model ECOSMO is used to study the consequent effects on ocean hydrodynamics and ocean productivity. Both models operate at a horizontal resolution of 2km.&lt;/p&gt;

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