Figure 1. An overview of the key topics in NORCOWE
Optimal wind farm site planning
Meteorology and oceanography
NORCOWE works to improve the knowledge of the offshore wind and ocean conditions – with focus on climatology and the marine (sea-air) boundary layer (MBL). This is done with modelling and observations. The models and new measurement techniques are being developed and are taken into use in order to improve our understanding of the marine boundary layer (WP1 and WP5).
One of the scientific focuses is to identify cost effective monitoring methods suitable to detect habitat change from offshore wind farms at high energy hard substrate seabed areas typical for the Norwegian coast (WP5).
Measurements and test facilities
NORCOWE provides infrastructure and expertise for measurements in the ocean and in the atmosphere. NORCOWE has bought a Stewart platform and equipment for turbulence measurements in ocean and atmosphere. Through the national project EFOWI the NORCOWE partners have access to well-equipped met/ocean buoys. Measurement campaigns are being conducted with EFOWI equipment. There have also been campaigns to test the LIDAR systems together with industry partners (WP1, WP3, WP4 and WP5).
Optimal wind farm design and optimal turbine design
This topic is addressed by modelling of wind turbine energy capture and wake. The goal is to do this with sufficient detail level and with sufficiently low computational cost to be included in wind farm and wind farm cluster simulations (WP4).
Figure 1. Production estimates for different positions of a turbine in a simplified wind farm.
NORCOWE develops the advanced CFD simulation software FLACS-Wind for offshore wind farms and clusters. FLACS-Wind will be available in NORCOWE spring 2011. Precise energy yield predictions for large scale offshore wind farm planning will be made possible though optimized software, parallel computing, improved turbulence modelling and turbine representations. There is improved modelling of flow in the marine environment together with easy geometry handling, simple simulation setup and extended GUI (WP4).
The work on power system integration is primarily concerned with optimizing the electrical system in large-scale offshore wind farms, as well as the connection of the farm to the electrical grid (WP4).
Dynamic analyses and innovative concepts (VAWT)
Unsteady aerodynamics plays an important role in the design of wind turbines. In order to achieve better designs in terms of performance reliability and costs, situations such as pitch steps, safety stops and yaw misalignment must be modelled correctly. One of the objectives in the dynamic analysis project is to assess the applicability of vortex codes for modelling of wind loads on wind turbine blades (WP2).
Vertical axis concepts (VAWT) may represent a superior solution over competing concepts as generators and gear systems might easily be moved down into controlled engine room environments. This will lower the centre of gravity, reducing size of the floater on optimizing overall design. Moreover, this represents a completely different installation, operation and maintenance concept as it will be based on principles developed by maritime industry for centuries (WP2).
Optimal wind farm operation
Optimal strategies to ensure the integrity of the offshore wind farm and at the same time reduce life-cycle cost are currently being developed. Nowcasting instrumentation, providing 2-120 s met/ocean predictions as control system input, is also a research topic in NORCOWE. Artificial Intelligence (AI) is being used in nowcasting modelling (WP3 and WP4).
Condition monitoring and maintenance
Measurement technology is developed for condition monitoring of offshore wind turbines, as input to condition-based maintenance. Early warnings and monitoring of faults may reduce costs dramatically in offshore operations. Such instrumentation may also provide input to control systems – in particular for fault-tolerant turbine control (operating a turbine with a damage/defect until next maintenance opportunity) (WP3).
Work is in progress on improved and simplified installation methods of monopoles. Heave compensation during installation and intervention is being addressed (WP3).