Wrong Roughness Used In Downscaling EmdConWx
Status: Closed - part of windPRO 3.0 Service Pack 3
Fixed in build: 633
For PARK-calculations using the Scaler to downscale the EMD-ConWx meso scale data we noticed a problem which is fixed in Service Pack 3. The problem is related to the downscaling method only and does not affect the use of the meso scale data as regular time series as for:
- Long-term-correlation via MCP
- creating a wind-index
In case the data is used for downscaling as time-varying PARK calculation, there is no impact on the results if
- … the data is used at an offshore-site
Onshore there is a minor impact if
- … the post calibration factors are determined based on reference WTGs or wind measurements at a similar hub height as the planned WTGs
Onshore there may be a significant impact if
- … the post calibration factors are determined based on reference WTGs or wind measurements at considerably different hub height as the planned WTGs
A considerable height difference would be a differnce of more than 15% between hub height and reference height.
We recommend installing windPRO 3.0 Service Pack 3 and inspecting the calculations at which a significant impact is expected. A new determination of post-calibration parameters must be part of any recalculation (also if only a minor influence is expected).
The degree of the impact is defined by the specific terrain and wind conditions of the site. In case you note considerable differences in your results we recommend inspecting also other projects at similar site conditions although only a minor impact would be expected according to the above systematic.
We apologize for the problem and are happy to answer upcoming questions. In case you already use the downscaling method of the EMD-ConWx data and would like to get more details concerning the problem, please contact us via the EMD Hotline Service support@emd.dk