WAT 4 released

Monday 19 Oct 15

The Windfarm Assessment Tool (WAT) is a post-processor of results from WAsP and WAsP Engineering, supporting the site assessments of various IEC standards. The new release contains several new features. 

The Windfarm Assessment Tool (WAT) is for wind energy engineers: 

• Include effects of wind sector management, technical losses and uncertainty in windfarm production estimates 
• Check site suitability of a given wind turbine class 
• Make terrain assessments in preparations for power-performance measurements

The main feature of WAT is still the IEC 61400-1 site assessment based on combined results of WAsP and WAsP Engineering. It is possible to model ambient turbulence predictions by combination of observations at reference masts and predictions of conditions at turbine sites by WAsP Engineering. Users reported problems importing turbulence statistics in the prescribed format, but it is now possible to calculate these statistics within WAT by analysis of observed time series.

The WAT model for annual energy production (AEP) includes technical losses for sector management, turbine availability, losses in internal transmission lines and grid curtailment. AEP uncertainty is modelled by user-defined uncertainties on wind speeds, wind farm production or combinations of these. Technical losses and uncertainties are modelled in a non-linear way and the effects depend on each other. Power curves for individual turbines are optionally adapted to the local air density. Users who are interested in AEP estimates but not in site assessments, may import a WAsP workspace and avoid detailed calculations by WAsP Engineering.

The terrain and obstacles assessments for power performance measurements are enhanced and now support the IEC 61400-12-2 standard for measurements by nacelle anemometers. WAT can now run in a simplified mode for assessments related to power performance measurements only, and for this you no longer have to generate input by WAsP Engineering. The only information needed is terrain elevation plus turbine and obstacle geometry, which you edit from within WAT.

The user interface has been simplified and options are hidden when irrelevant. WAT is now distributed with sample data and has links to video tutorials on YouTube.

Access to WAT 4 results is included with a WAsP 11 licence. You will be able to install and try WAT without a WAsP licence, but results will be hidden. 

New features in WAT version 4 are

• A simplified user interface
• AEP uncertainty estimates
• AEP corrections for turbine availability and transmission power loss
• Import of WAsP projects for AEP calculations
• Power curve correction for local air density
• Turbulence statistics by observed time series
• Improved export and import of turbulence statistics
• Improved indication of neighbouring turbines in the sector management dialogue
• Transparent display of IEC 61400-12-1 performance measurement zones
• Improved accuracy when reading IEC 61400-12-1 measurement sectors from a WAT project file
• Support for IEC 61400-12-2 terrain and obstacle assessments
• IEC 61400-12-x assessment with no WAsP or WEng input
• Editor for obstacle geometry
• Corrected IEC 61400-1 terrain complexity plot
• Corrected IEC 61400-12-1 terrain assessment
• Corrected interpolation of WAsP/WEng site conditions

You can download the new WAT 4 version at our website. 

11 JULY 2020