Bergen Offshore Wind Centre (BOW)

Project overview - Bergen Offshore Wind Centre (BOW)

Here you will find an overview and project description of the offshore wind related projects at Bergen Offshore Wind Centre (BOW), University of Bergen

måleutstyr for vind med jorder og hus i bakgrunnen
OBLO instrumentation Kirstin Frøysa/UiB
Illustration of the HIPERWind project
Mostafa Bakhoday Paskyabi

Main content

CONWIND: Research on smart operation control technologies for offshore windfarms (led by NORCE)

Conwind is a Norwegian-Chinese collaborative project on offshore wind technologies. The project is lead by NORCE and have partners from both former Norwegian research centers for environmentally friendly energy (FME) on offshore wind: NORCOWE and NOWITECH. 

The University of Bergen/Bergen Offshore Wind Centre (BOW) leads work package 1 on wind prediction (nowcasting) and wind farm control. 

Project period: January 2020 - December 2022

Contact at Bergen Offshore Wind Centre (BOW): Mostafa Bakhoday-Paskyabi

COTUR (Measuring COherence and TURbulence with lidars)

COTUR (Measuring COherence and TURbulence with lidars) is a joint reserach project under the lead of NORCE (former CMR) with the Geophysical Institute of the University of Bergen, the University of Stavanger, and Equinor as partners. Main goal is the investigation of coherence in the turbulent wind field at scales that are relevant for state-of-the-art offshore wind turbines, with rotor diameters of beyond 150 m. Core of the campaign is the deployment of three scanning lidar systems (Leosphere WindCube 100S) in a triangular setup that are operated synchronized.

Project period: January 2019 - March 2020

Read more: Measuring the wind

Contacts: Joachim Reuder and Martin Flügge

Estimation and Prevention of Erosion on Off-Shore Wind Turbine Blades

Erosion of wind turbine blades due to hydrometeors (e.g. rain droplets, graupel pellets, or hail stones) is a major challenge and cost factor for the operation of wind turbines, as it reduces the power output (due to a negative impact on the aerodynamics of the blades) and increases the costs for maintenance and repair (due to a considerable reduction in lifetime of the blades). The size distribution of rain droplets and the probability of occurrence of graupel and hail offshore is poorly monitored and understood, leading to a crucial knowledge gap with respect to estimation and prediction of blade erosion for a given off-shore site.

The project has three closely related objectives:

The first objective is to develop realistic erosion test requirements for off-shore wind turbine blades, based on a climatology of hydrometeor size distributions and the probability of occurrence of situations with high erosion potential due to large droplets, graupel and hail.  For this purpose we will use, among others, a unique 6-year data set of rain droplet size distributions from the Norwegian coast in Bergen, measured by the Geophysics Institute by a vertically-pointing Micro Rain Radar (MRR). This data set is at the moment the best available proxy for offshore conditions off the Norwegian coast.  We will then apply our new test requirements on material samples from selected wind turbine blades This data set can also be used to identify synoptic situations with high erosion damage potential, where a temporary reduction of the rotational speed could prevent most of the damage.

The second objective is to create a least erosion map for the North Sea which can be used to identify potential new wind farm sites that will exhibit low erosion conditions.

The third and final objective is to develop a new protective coating made of nano-diamonds for the leading edge on wind turbine blades. For this we will use a recent nano-diamond coating facility developed at the IFT Nanophysics group. Material samples with the new coating will also be subjected to our erosion test requirements. The project, which is set to run for three years, is an interdisciplinary cooperation between the Nanophysics group at the Institute for Physics and Technology lead by PI Prof. Bodil Holst, and the group of Experimental Meteorology at the Geophysics Institute, lead by CO-PI Professor Joachim Reuder. For experimental erosion tests we collaborate with the world leading group in the field, DTU Wind Energy, lead by Dr. Charlotte Bay Hasager.

Contacts: Bodil Holst and Joachim Reuder

Highly advanced Probabilistic design and enhanced Reliability methods for high-value, cost efficient offshore WIND (HIPERWind)

Significant cost savings in offshore wind industry can be achieved through the technological advancements as well as comprehensive knowledge of environmental conditions. and physical processes relevant for the operation of large offshore wind farms can deliver significant cost savings to wind farm. HIPERWind aims therefore to decrease the cost of energy from offshore wind turbines by at least 9% through reduction of risk and uncertainty. HIPERWind aims at using a sophisticated numerical model chain of different fidelity, highly advanced probabilistic design, and enhanced reliability methods to optimize the offshore farm operating strategy. Further, to enhance the reliability prediction, and improve state of the art in the wind energy design. UiB is responsible for WP2on multiscale modelling of the wind field. A major part of the work starts in March 2021. However, since December 2020, UiB has contributed to WP1 with data collection and processing to be used in WP2 as well as uncertainty assessments in other WPs. Part of a report and two sets of lidar-based datasets were processed for these tasks.

We have developed several modelling/processing tools for conducting multiscale modelling of the wind field in the offshore wind park area. We have developed a constrained turbulence box model and started to apply a module for WRF model to better account for the sea surface roughness length in the presence of waves. The COAWST coupled system was compiled and run in our high-performance computing system. In 2021 two researchers will be hired UiB for this project. 

Contact: Mostafa.Bakhoday-Paskyabi@uib.no

Large Eddy Simulation Modelling of Offshore Wind Farms Under the Influence of Varying Atmospheric Stability and Sea-State Conditions

To understand the air-flow inside a wind farm and thus be able to optimize layout as well as operation of the wind farm, advanced numerical tools, capable to resolve a wide range of time and spatial scales, are needed. The coupling of the various scales needs, however, a careful nesting scheme as well as comperhensive understanding of influential physical and structural processes. UiB has a considerable instrument park for measurements of the wind and wave conditions in front and inside a wind farm. A large amount of observational (offshore) data acquired by UiB will then provide a framework to improve the accuracy/performance of numerical CFD tools by developing, for example, new sets of parameterisations for different processes and their interactions with turbines/farm.

The “ Parallelized Large-Eddy Simulation Model” (PALM) model system 6.0 is a state-of-the-art LES code suitable for offshore wind farm applications, modified to incoorporate effects of wind turbines through a rotating actuator disk. PALM can be considered to be the most comprehensive LES code in the world, including embedded models to represent complex terrain and topography, the ocean surface (and interaction with the oceanic mixed layer), Lagrangian particle transport, and both offline nesting to large-scale models (e.g. COSMO is available and the coupling of PALM to the WRF model is under progress), as well as online self-nesting. Building upon very close cooperation with the PALM developer group at University of Hannover in this project will ensure rapid build-up of a very competent LES group focusing on the application of PALM to study the offshore wind farms under the influence of different processs such as varying atmospheric stability and sea-state conditions. One of challenging and important applications of the developed LES tool, will be tailored to the study of the importance of meandering wake on the power production of wind turbines and the structural loads, in particular for floating wind turbine applications.

The proposal is organized in three work packages that will focus on addressing the scientific questions and a work package to management and dissemination:

WP0. Management and dissemination.

WP1. Data collection and model configurations.

WP2. Develop wave model coupled with PALM.

WP3. Validation.

Contact: Mostafa Bakhoday-Paskyabi

Marine geological sea bottom surveys for offshore wind farms

This project deals with how geological information can contribute to a better understanding of moorings of offshore wind farms. The project is a collaboration between Department of Earth Science, Bergen Offshore Wind Centre and Equinor. The project is organized around a PhD-project and is based on geological and geophysical data from areas where offshore wind farms are planned. New data will also be acquired as part of the project.

Contact: Haflidi Haflidason and Christian Haug Eide


Large Offshore Wind Turbines (LOWT): Structural design accounting for non-neutral wind conditions

The project has a total volume of 14MNOK and is funded with 12 MNOK via the NFR FRIPRO program. It is coordinated by UiS, with UiB, SINTEF Energy and SINTEF industry as partners. 

LOWT will develop new knowledge and models to improve the design basis for large floating wind turbines (>12MW) in freewind and wake conditions. Observations from Hywind Scotland have shown that the thermal stratification of the atmosphere can substantially affect the structural response of a wind turbine to the incoming turbulent flow.

The first objective is to use wind data from several offshore sites to characterize the wind field in non-neutral atmospheric conditions. The project will use high-frequency wind data combined with a brand new remote sensing dataset (COTUR). In the COTUR campaign, the incoming flow over the ocean was recorded, both within and above the surface layer, thus providing new insight on the applicability surface-layer scaling to model the turbulent wind loads on LOWT. This unique dataset will be analyzed for the first time to indicate whether the turbulence models used in the standards, which mainly relies on surface-layer scaling are appropriate or not. The final output will be to recommend a suitable wind and coherence model for in non-neutral conditions as input to free wind aero-elastic simulations and DWM models offshore. 

The second objective is to validate the simulated wind turbine response using full scale data from offshore wind farms (Alpha Ventus, Sheringham Shoal, and Zefyros/Hywind Demo). The validated simulation tools will then be used to quantify the effect of non-neutral atmospheric conditions on future LOWT (>12MW) to ensure safe and cost-effective design in the next generation of offshore wind farms in Norway and beyond. 

The final focus of the project is wake simulations of LOWT in non-neutral conditions using DWM model. High-fidelity CFD simulations will be used to include variable velocity shear in the DWM method and validate the wake meandering in non-neutral conditions. The non-neutral wind spectra and coherence from the data analysis work will be used as input for the DWM simulations. 

Contact: joachim.reuder@uib.no