Assessment of the wind shear

Assessment of the wind shear

Site: 200 MW project in Morocco

Issue to be resolved:

The existing wind measurements with masts only cover a small part of the height range of the rotors of the planned wind turbines. The course of the wind speed above the masts is therefore unknown. This results in a significant uncertainty of the energy prediction and a difference between the results of different experts.

Solution: Wind measurement with Sodar over several months

Results:

• The wind shear across the entire heigt range of the rotor is very homogenous.
• The main cause for the difference in the results between the existing wind resource assessments could be resolved.
• The total uncertainty of the energy prediction for the entire project was reduced by about 1 %.
• The data availability of the Sodar instrument at the site was very good.
• The results of the verification of the Sodar instrument performed in North Germany are valid for the Moroccan site.
• The parabolic sound reflectors should be cleaned from sand about every two months.
• Operation of the instrument by local personnel was possible without problems.