ZephIR Lidar has announced that its ZephIR 300, has been successfully verified against a fully IEC compliant met mast at the Lelystad Test Site (The Netherlands). The verification, carried out by Ecofys WTTS in parallel with three other ZephIRs, deems that ZephIR 300 “is suitable for field measurements as a replacement of cup anemometers in flat terrain.”
The 81 metres MM02/03 mast is equipped with cup anemometers at heights of 40 metres, 60 metres and 81 metres. It also has vanes at heights of 76 metres and 79.5 metres for wind direction measurement. The ZephIR 300 was collecting wind data at 40 metres, 60 metres and 80 metres between 19th March 2013 and 11th April 2013. The results show “consistent, highly-correlated measurements with slopes near unity,” said Ecofys’ official report. It continued: “The calculated uncertainty in the lidar wind speed measurements is … in line with high quality anemometry. The calculated uncertainty tables can be used directly in wind resource assessments, together with the classification uncertainty and site-specific uncertainty components.” It also states that “the lidar measurements were also validated against the NORSEWInD (Northern Seas Wind Index Database) criteria which stipulate thresholds for the quality of the correlation. The lidar meets the majority of the NORSEWInD criteria … The overall high correlations and excellent linear regression fit indicate that the lidar is functioning properly with high accuracy.” ZephIR 300 was also found to be insensitive to external conditions: “Sensitivity tests of the wind speed deviation revealed that the wind speed deviation shows no significant linear correlation to external conditions: vertical wind speed, horizontal wind speed, turbulence intensity or rain. This indicates that the lidar is relatively insensitive to these factors.”
