Niels Gylling Mortensen

Hi Andrés, You can also explore the wind profile at a site by using scripts in WAsP: Insert a turbine site, select it, and then choose Tools > Utility scripts > ... to see what scripts are readily available. This way of doing it is described further in these course notes. Hope this helps, Niels

The Map Editor can use different grid formats to make WAsP maps. Look in the File > Import menu of the software and the help file. I personally use Surfer to make maps for WAsP, but the Map Editor can do more than most think. Hope this helps, Niels

Hi Inés, The Climate Analyst is not trying to recreate 2013 for you; it's a simple case of the software not 'lifting the pen' when drawing the entire time trace. If you have a look at the Generation report for the OWC, you can see that the 2013 data were not included. Hope this helps, Niels

Hi vob, There is no such thing as a stupid question ;-) I agree that the WAsP help file describes the default 12-sector setup only when it comes to RSF/WRG files. This is not a limitation of the software. The limitation is 36 10-degree sectors in the OWC and therefore also in the results. WAsP 12 will happily export 36-sector resource grids to RSF files. Thanks for your question; we'll update the help file accordingly in the next version. Best regards, Niels

Hi Jenny, I have WAsP 12.5.8 installed too and I can open and view the Palette Gallery by navigating to Tools > Options > Resource grids > ... The default palette files seem to be installed in C:\Program Files (x86)\WAsP\Samples\PaletteFiles.zip, but the software still points to "...\Documents\WAsP samples\Palette files" and can import files from here. The help file seems not to be updated on this point, sorry. Finally, I have no problems synchronizing to Google Earth Pro 7.3.3.7786, which is the version I use. Seems to me your WAsP installation is somehow not in order; have you tried to reinstall the software? Best regards, Niels

Dear CA1, I totally agree, but unfortunately we still have not implemented anything like this in WAsP for Windows. You can get some information from, say, the Global Wind Atlas 3 which can show typical yearly, monthly and daily variations of the wind resource. Best regards, Niels

Dear Pedro, No, only if you specify an obstacle member of the hierarchy. The mast itself will provide some flow distortion and 'shelter', but that is not treated at all by the obstacle model. However, you can insert User corrections in the hierarchy, if you have information about such effects.

Dear user, I have not heard of any references to this. I use the Map Editor myself on a regular basis and have not experienced any conflicts so far. If we hear of such conflicts we will of course try to solve them, but it is hard to guarantee that there could not (ever) be any conflicts. - Our general recommendation with WAsP software is to use the latest published version on our web site, unless you want to replicate an old project exactly. Hope this helps, Niels

Dear Irving, From version 12.3, WAsP will calculate a wake-reduced mean wind speed for every turbine site. I have not used this feature myself yet, but you might find it useful for your project when evaluating the influence of the turbines on the mast. The wake losses from different turbines, with different power/thrust curves and different hub heights (HH) can be modeled in WAsP. Hope this helps, Niels

Dear Pedro, I have not heard of similar studies and have not done any such studies myself. With the climatological nature of WAsP, we usually recommend to try tweak the average heat fluxes over land and water (WAsP 12 > GWC window > Profile model tab). This can work quite well, see e.g. https://orbit.dtu.dk/en/publications/wind-atlas-for-south-africa-wasa-observational-wind-atlas-for-10--4. Best regards, Niels PS. Adjusting for stability is after you have done all other adjustments, checked the maps, checked for obstacles, etc.

Dear Vinh Le Thanh, You are right: the roughness map is important in this case, so I will try to give you a few more hints: 1. The size (radius) of the map should be = 100 times your mast height and then some. So, for an 80 m mast, the radius should be, say, 8000 m + 50% = 12 km. The total map is then approx. 25 km by 25 km with the mast in the centre. 2. The most important roughness change is the coastline, i.e. from water (z_0 = 0 m) to land. If you download and use an SRTM elevation map in the Map Editor, this comes with the coastline already. 3. You need to generalise the land cover (roughness map) in order for the work to be practical. So, there is maybe not so many land cover classes (e.g. from south to north): the sea, marsh areas along the coast, farmland with few houses, farmland with many houses. For wind directions where a lot of the wind comes from, you can try to detail the land cover description and see if it changes the results. But you cannot specify each and every house, of course, but may specify an area of houses along a road. 4. How to digitise is described in this report http://orbit.dtu.dk/en/publications/wind-resource-assessment-using-the-wasp-software-dtu-wind-energy-e0135(259e26f3-1828-4e3f-9c37-17de375cd057).html Hope this helps, Niels

Dear Map Editor user, If you could share the area you are trying to download, I would be happy to try and reproduce the error. You can send the information to waspsupport@dtu.dk or nimo@dtu.dk. Best regards, Niels WAsP Support

Dear Seenu, Unfortunately, there is no "site (url) that identifies the level of error or deviation at each stage of WAsP’s calculation". There are some results reported in the literature, e.g. the CREYAP exercises and elsewhere; and the entire uncertainty question is the focus if an IEC working group at the moment. Best regards, Niels

Dear Seenu, I cannot help you with this question, but would have to refer you to the open literature. WindEurope made a series of test some years back that investigated uncertainties in power curves and wind farm modelling (Google 'CREYAP exercises'). Hope this helps... Best regards, Niels

Dear Seenu, We have addressed this problem in WAsP 12, which is able to estimate the air density at any turbine height (anywhere on planet earth) and extrapolate the power curve data to this air density. Before WAsP 12, we would have to do this calculation manually or ask the manufacturer of the turbine for data at the given air density. Best regards, Niels

Dear Roella, The wind turbine editor is not really meant for the design of wind turbine generators, more like a tool for handling power and thrust curves of existing or modelled turbines and providing the data files to WAsP. Best regards, Niels

Dear D. Bachai, Yes, WAsP can only handle rectangular boxes for obstacles, so you have to find a 'box size' to represent the circular obstacle. If you experiment a little with this, you will probably find that the 40-m anemometer is not influenced significantly by the obstacle (40 m being way higher than three times the 6-m water tank). The 10-m level will be influenced, but because of the proximity of the water tank, the obstacle model may not give realistic result. Your experimental setup would require a different type of modelling to obtain reliable results -- and even then it would still be difficult... Best regards, Niels

Dear D. Bachai, See http://www.wasptechnical.dk/forum/viewtopic.php?id=1006. Best regards, Niels

Dear D. Bachai, No, I have never heard of a minimum width threshold for water bodies, but one could make a small case study to explore this. However, I am quite sure that small meter-wide channels will not have any significant effect for a sizeable wind mast or wind turbine. The recommended roughness for water bodies is always 0 m in WAsP. However, in your case I would suggest a low land roughness for your rice fields, see e.g. http://agrometeorologia.it/documenti/Rivista2015_1/estimation_of_zero_plane_displacement_height_and_aerodynamic_roughness_length_on_rice_fields.pdf Best regards, Niels

Dear Caglar, This is a tricky one, since we use the mast measurements to adjust the heat flux parameters for the site (most often only the average or offset value). There is no simple way of relating the WAsP values to what would have been measured at the site, and there is also no simple relation to modelled heat flux values. Could you not find some period(s) of data where you could look at the wind profiles? My general experience is, that the default heat fluxes work quite well in most cases, but not knowing anything about your site this is not very helpful... Anybody else in your region who might have some experience? Best regards, Niels

Dear matt, Have you updated your software to the latest version? http://www.wasp.dk/Download/WAsP12-Suite-Installer Best regards, Niels

Dear Tutitaka, We cannot help you unless we get to see the file. Maybe you can mail it to waspsupport@dtu.dk so we can have a look? Best regards, Niels

Dear WAsP user, The two traditional ways of making roughness maps is 1) by digitising in the Map Editor using a background map image, or 2) by digitising in Google Earth and then edit the lines in the Map Editor. Both methods are described in these course notes http://orbit.dtu.dk/en/publications/wind-resource-assessment-using-the-wasp-software-dtu-wind-energy-e0135(259e26f3-1828-4e3f-9c37-17de375cd057).html (Appendix C). Map Editor 11 can further vectorise raster land cover data and make them into roughness maps (File > Import > Grid maps). I have used Globcover raster data to make roughness maps this way. In the next Map Editor 12, there will be an additional option to download GlobCover and Corine land cover maps and change them into roughness maps. Best regards, Niels WAsP support

Dear André, I am not sure what went wrong, but would suggest that you first make the map using the Map Editor (File > Import > SRTM ver.2 database). After that, you can add more roughness areas as described in these notes http://orbit.dtu.dk/en/publications/wind-resource-assessment-using-the-wasp-software-dtu-wind-energy-e0135(259e26f3-1828-4e3f-9c37-17de375cd057).html. Look in Appendix D for more information. Best regards, Niels

Dear ysga, Here are a some brief comments to your post: Adding a met. station: we recommend you use the Climate Analyst instead. Remember the geographical coordinates of the anemometer, and export in the *.omwc format for best results. Map for WAsP: once you have the SRTM elevation contour and land/sea roughness map, you can add more roughness areas using Google Earth or a scanned paper map. Procedures are described in these course notes: http://orbit.dtu.dk/en/publications/wind-resource-assessment-using-the-wasp-software-dtu-wind-energy-e0135(259e26f3-1828-4e3f-9c37-17de375cd057).html Obstacle group: model most cities and towns as roughness areas. The obstacle model is only used for situations where the mast is closer than 50 obstacle heights and lower than 3 obstacle heights in relation to the obstacle. So this is a fairly local effect. Wind turbine: you can have information on turbines from the manufacturer or the internet. Also, there are some turbine power and thrust curves in the WAsP library. WAsP cannot calculate these specifications, you must know them from somewhere else. My best piece of advice for now is to study the course notes mentioned above carefully; they contain quite a bit of information and links to other sources. Good luck with your thesis! Best regards, Niels WAsP support