A new process for the pragmatic choice of wind models in complex terrain – quantification of "skill score" and "cost"

In wind energy, the accuracy of the estimation of the wind resource has an enormous effect on the expected rate of return of a project. Due to the complex nature of the weather and of the wind flow over the earth’s surface, it can be very challenging to measure and model the wind resource correctly. For a given project, the modeller is faced with a difficult choice of a wide range of simulation tools with varying accuracies and costs. If this choice is made incorrectly, either many resources are wasted in needless high accuracy simulations, or the rate of return is incorrect and investors risk losing large amounts of money. As there are currently no guidelines or tools available to the modeller to help with this choice, it is usually left to gut feeling – and this can be catastrophic for investors or acquirers of wind parks.

In this project, a decision tool is being developed to help modellers choose the most appropriate model for a particular wind energy related project. This involves firstly applying various simulation tools from WAsP (Wind Atlas Analysis and Application Model), RANS-CFD (Reynolds-Averaged Navier-Stokes Computational Fluid Dynamics), Detached Eddy Simulations (DES), and Large Eddy Simulations (LES) to the Lattice Boltzmann Method (LBM) to a range of test sites, defining appropriate comparison metrics and developing a draft process. Relevant comparison metrics include factors relating to the "skill" or accuracy of the model as well as those relating to its "cost" or complexity. In a second step, the simulation tools will be applied to a demonstration site in order to validate, demonstrate and improve the decision process.

The goal of the work in the presentation is to investigate appropriate comparison metrics for the decision process by applying simulations carried out on the Bolund experiment blind comparison set-up.