Required information needed to run wind assessment in Wasp 11

[guidogr]

Hello,

I am working on a thesis related to wind energy and I am about to request a WasP 11 student license. Given that this type of license is temporary I am here to ask if the information I have is enough to run my analysis using the software.

Right now I have:

- Wind speed and direction records of the areas in study.
- SRTM3 elevation maps (already converted to .map).

Is this information enough? I would like to have all the information needed before the start date for the license is set so I would be grateful if you can comment.

Best regards,

Guido.

[Niels Gylling Mortensen]

Hi Guido,
You will also need
- a land cover / roughness map of the area(s)
- wind turbine power and thrust curves if you want to calculate yields
- maybe, information about nearby sheltering obstacles
You could take a look in these course notes to see what you need and what you need to do:
http://orbit.dtu.dk/en/publications/wind-resource-assessment-using-the-wasp-software-dtu-wind-energy-e0135(259e26f3-1828-4e3f-9c37-17de375cd057).html

Best regards,
Niels

[guidogr]

Niels,

I forgot to mention that I have the power curve of the selected wind turbine.

I have been reading the course notes but I am not sure if I fully understand how to generate the land cover / roughness map. Could you help me with this step?

What I understood is that I need to find a digital land cover map or a paper one if I want to digitize it myself. If this is the kind of map that I have in mind, this map shows the limits between areas with different type of land cover and the description of each land cover. Once I have the digital map I have to add each individual roughness length value for each digitized area.

Here I am not sure how to continue. I thought about entering the roughness values based on the roughness classes of the European Wind Atlas using the land cover description in the map to decide which roughness class best suits each area. Is this correct? Are there land cover maps where the roughness length value is already specified in the map?

Best regards,

Guido.

[kedx3mmn]

how do you create a land cover / roughness map of the area(s). I am not able to create one.

I am under the impression that the SRTM maps includes the roughness / land cover. Since it has the elevation lines. I tried to draw obstacles with the help of Google earth and miserably failed. Is there an easy way to do that? Thank you

[Duncan]

SRTM is orographic (elevation) only. There is no roughness information from that radar survey of the world.

To prepare a roughness map, you could digitise the change lines yourself in WAsP Map Editor, or you could take a land use classes map and use some kind of table to interpret those classes into roughness lengths. Programs like Global Mapper support this kind of interpretation.

Obstacles are another matter completely. WAsP 11 only accepts obstacles with polar coordinates. You can use the obstacle group editor inside WAsP to add information about them.

Duncan.

[gtaklis]

can Wasp create a HTML report and open in another browser than IE ?

[gtaklis]

using Wasp 8.4 IE 11 and Windows 10 64bit error during report

Script control reported the error:
could not launch a browser to display the HTML document

The last execution line attempt was for line number: 221, which reads:

Builder.LaunchInBrowser

[Niels Gylling Mortensen]

Dear gtaklis,
It is difficult to provide any advice for this combination of software; WAsP 8.4 has not been supported for about 10 years now.
Best regards,
Niels

[Niels Gylling Mortensen]

SRTM is orographic (elevation) only. There is no roughness information from that radar survey of the world.

True, but information on land and water surfaces has been added to the SRTM database. So, if you construct an elevation map from SRTM data using the Map Editor, the map will contain roughness change lines at the coastlines, lakes, large rivers etc. Roughness of the water areas will be 0 m (zero m), and roughness of the land areas is specified by the user. You can then add more land cover classes to this map using the Map Editor, or Google Earth.

Best regards,
Niels

[Manasi]

Hello,

Like Guidogr I too am now preparing for my thesis, and before requesting for the education license, I'm doing some homework to save time. I have downloaded the SRTM files and am now digitizing the maps for roughness.

1 - Could I please check if it is possible to combine these two maps in Map Editor or should I wait till I have access to WAsP to combine them?

Additionally, I have read N.G.Mortensen's reply above indicating that power and thrust curves/coefficients are required to calculate the yield--I managed to get the power curves.

2-I have been rather unsuccessful in retrieving thrust coefficients--is there any work around this as commercial manufacturers of wind turbines are not readily parting with this information. I plan to calculate the wake loss in order to calculate the WAsP Net Production of Wind Farm.