Micrositing using rotor equivalent Wind speed: one step forward or aside?

Wind shear variation has been recognized as one of the main drivers for Power curve uncertainties. The rotor equivalent Wind speed (REWS) concept has been developed to address this issue and will be included in the upcoming release of the IEC 61400-12-1 standard. While this concept can be expected to reduce uncertainties related to Power curve measurements, the consequences for the uncertainty of subsequent energy yield assessments and micrositing studies are less clear