Recommendation for re-working IEC 61400-12-2 standard concerning uncertainty components using spinner anemometry. PTP Deliverable D.7.4

Spinner anemometry is used to measure traceable and calibrated wind speed, yaw misalignment and inflow angle. Free wind speed may be estimated by application of a spinner wind speed transfer function on the spinner anemometer measurements. The latter are used in power performance measurements according to the standard IEC 61400-12-2 on use of nacelle anemometry. This document presents the adaptations required in the standard to estimate the corresponding uncertainties arising from the use of spinner anemometry and the spinner transfer function, which is analogous to the nacelle transfer function. The adaptations are required due to the differences between the spinner and nacelle anemometry, which consists typically of a cup or sonic anemometer mounted on the nacelle behind the rotor. The adaptation refers directly to tables on the standard and is based on experience gained from the PTP in several wind farms in different terrain types (offshore, flat and complex terrain).

The Performance Transparency Project (PTP) was sponsored by EUDP under the name “Large Spinner Anemometer Performance Demonstration Project” with the EUDP Journal number: 64016-0059.