Institut für Energietechnik (IET)


With our state-of-the-art expert knowledge and industry experience we can offer you the following support:

  • CFD simulations of wind turbines and wind farms in complex terrain.
  • Measurements in our open winid tunnel.
  • Technical support for the installation of small wind turbines.

 Some examples of our projects are shown below.

CFD simulations

In order to find viable locations for carrying out wind turbine prototype tests, we have assessed a range of sites in the area of Rapperswil using online topographical data (, wind measurements and CFD simulations. Wind speed and direction measurements were carried out at 10 m and 15 m with a INENSUS Aelog 3 system. The following sites have been investigated:

  • Halsegg, Sattel SZ
  • Sonnenberg, Rothenthurm SZ
  • Farneralp, Wald ZH / Goldingen SG 
  • Maienfeld, GR

We have also simulated the flow around Vertical Axis Wind Turbine, as shown below, where the resultant force in the direction of rotation is called FT and the resultant force tangentially to the direction of rotation is called FN.

Measurements in our open wind tunnel

Our open wind tunnel was originally built for the optimisation of Vertical Axis Wind Turbines (VAWTs), in which we have tested a VAWT model with a H-rotor and 3D-printed blades. The basis of the wind tunnel is a wind machine with a diameter of 1.5 m, which has a maximum volume flow rate of 100,000 and a maximum wind speed of 90 km/h.

Small wind turbines

In order to assess the potential energy production of a small wind turbine, we can carry out power measurements with a "wind flower", which is an easy-to-install, efficient, quiet and attractive-looking wind turbine with a diameter of 2 m and a rated power of 1 kW that can be connected to the grid. Power measurements over one year with the wind flower allow you to establish the potential electricity production of a larger wind turbine installed at the site.

You organise the site and the necessary paperwork. We carry out a professional power measurement at your site.

We look forward to hearing from you!


Dr. Sarah Barber
Oberseestrasse 10
CH-8640 Rapperswil SG
+41 (0)55 222 42 62