Comparison of WAsP and WEng

Different objectives

WAsP Engineering is complementary software to WAsP. The main WAsP objective is to estimate mean wind climate and wind energy resources, and the objective of WAsP Engineering (WEng) is to estimate wind conditions for turbine safety. WEng models extreme winds, tubulence, streamline inclination, and vertical wind-profile shear.

Different flow models

WAsP and WAsP Engineering apply two different linear flow models, which are based on the assumptions of neutral stability and moderate terrain inclination. The WAsP flow model (BZ) is formulated in a polar grid and operates with a Bessel function expansion. The WEng flow model (LINCOM) is formulated in a Cartesian grid and operates with Fourier expansions. LINCOM is not quite as fast as BZ, but on the other hand it is unneccesary to run it for every turbine site. BZ applies a uniform surface roughness over water whereas LINCOM applies a wind-speed dependent surface roughness known as Charnocks relation. This is because WEng is designed to model accurate extreme wind speeds where wind-speed dependence becomes significant.

Similar input

Input data for WAsP Engineering are prepared with familiar WAsP tools: the Map Editor provides terrain data and the Climate Analyst provides observed extreme wind data. Furthermore, WAsP Engineering reads turbine positions and obstacle list in WAsP format.

Familiar user interface

WAsP users will find that the WEng user interface has a familiar look and feel. The objects are stored in an object tree and turbine sites are shown in a map. You edit object properties, inspect detailed results and export the data by clicking on objects. Unlike in WAsP, you don't operate with wind distributions but with specific wind situations. Extreme wind climates are modelled as a colection of extreme winds from different directions.


In both WAsP and WEng calculations can be automated by scripts, which will do anything you normally do inside the programs and export the results in several formats including ASCII, HTML, XML, Words, and Excel. A collection of standard scripts are shipped with the installations and it is possible to write your own scripts. It is even possible to make scripts which call both programs and combine the results.