Certification questions

Data

• What should one consider when measuring the wind (speed and direction) at a mast?
• When analysing wind data what should one look for?

Orography

• Explain the concept of orography and its influence on the wind speed including the effects of (a) terrain elevation above sea level, (b) the roundedness / sharpness of hills and mountain tops and (c) orientation of mountain ridges relative to the wind direction.
• What is flow separation, at approximately what slopes does it occur, and how would WAsP predict wind speed in cases where flow separation occurs?
• Explain the RIX-concept, its background, interpretation and use.

Roughness

• What is roughness?
• What is an internal boundary layer?
• Describe the roughness classes and the effect of roughness.

Obstacles

• Describe the effect of obstacles including any special considerations.

Wakes

• What is a wind turbine wake and the effect of it on the production of a wind farm?

General

• Describe the wind atlas methodology.
• Describe the similarity principle.
• How is the annual energy production calculated?
• Describe the possible inaccuracies in a WAsP calculation.