MODELED WIND RESOURCE DATA

Vortex uses a supercomputer cluster to run a non-linear flow model (WRF) that scales large atmospheric patterns (NCAR-NCEP, ECMWF, and NASA) down to fine spatial resolutions (SRTM), generating modeled wind resource data and global wind estimates suitable to be used where and when no measurements are yet available.

Current wind modellers on the market offer either pre-calculated products or specific studies on a consultancy basis. Pre-calculated modelled wind resource data need to cover the whole world and are therefore simpler than Vortex ones: lower resolutions, linear flow results, etc. Instead, Vortex has automated a full non-linear modelling chain down to the microscale. Each calculation is performed on-demand, only on the client’s area of interest and without a need for slow human interaction. Vortex is initialized by users, allowing direct interaction between the client’s PC and our computer cluster over the Internet. This approach is much faster (and its price more competitive) than consultancy and much more powerful than pre-calculated results of wind resource data or global wind estimates.

Vortex’s system core, WRF, is a sophisticated code that has been effectively employed to describe the physics and dynamics of atmospheric circulations with a significant degree of realism at a wide range of scales. WRF is neither a microscale nor large-scale model but is a one-in-all.

WRF accuracy is based on the ability to portray the different mechanisms that interact at each one of the relevant atmospheric scales. The WRF model is the result of years of development by the atmospheric research community combined with additional experience from the extended use for weather forecast applications and modeling wind resource data.

The usual truncation or simplification of the equations that control atmospheric movements of air masses is definitively small in WRF when compared to other lighter atmospheric codes. However, equally as relevant as this non-linear approach, is how the model includes other relevant factors such as radiation, thermal effects, and air-sea-land interactions. In this sense, WRF is a modular model that can be adapted for different applications depending on the scale of atmospheric movements, surface boundaries, and thermal characteristics of the air masses, ensuring high-quality modeled wind data and global wind estimates for each client’s area of interest.

For microscale applications, the WRF model poses a CFD algorithm based on the Large Eddy Simulation (LES) approach. When WRF is coupled to the LES model the result is commonly known as the WRF-LES model. This means that the simulation is run as usual, but the turbulence parameterisation is replaced by the LES model and hence turbulent eddies are resolved, providing high-resolution modeled wind data.

Vortex has improved the source code for its implementation for real simulations. This modified version of the model is the so-called Vortex-LES, capable of generating high-quality wind resource data and high-resolution wind estimates for microscale applications.

LES can mitigate uncertainty in offshore project wind resource assessment analysis by adding the possibility of simulating a virtual mast at any position on the wind turbines layout, generating high-resolution modeled wind data. Moreover, and in the context of the European offshore development, LES’s outstanding accurate representation of neutral stability conditions ensures more realistic wind resource data and high-resolution wind estimates of vertical profiles at sites across the North and Baltic Seas.