Calibration Report of LiDAR unit “WLS7-436”

Abstract

Following an order of Massachusetts Clean Energy Center a calibration of a LiDAR of the type WindCube V2 by Leosphere (WLS7-436) against a met mast has been performed at a test site in the US. In this report the measurement results of the LiDAR device are compared to those from calibrated cup anemometers mounted on a met mast. The aim of this comparative assessment is to convey traceability to international standards of this particular LiDAR unit. The evaluation process is based on the IEC 61400-12-1 Ed. 2 Annex L [2]. This standard describes the calibration procedure of remote sensing devices in the frame of power curve measurements on wind turbines. However, this approach generally also applies in the field of wind resource assessment, under the recommendations of MEASNET [4]. The data of the LiDAR measurement (130 m, 125 m, 95 m and 60 m) have been compared with the measured met mast data at 4 different heights (130 m, 125 m, 94 m and 58 m) during a period of 36 days (2019.08.20 – 2019.09.25) for wind speed bins between 4 – 16 m/s and for the wind direction sector 67 – 354°. In addition, measurement results of the met mast and LiDAR unit have been compared in terms of turbulence intensity, wind direction and wind shear. UL was not involved in the installation of the instruments on the mast but has gathered all relevant information. However, UL was responsible for the installation of the LiDAR unit close to the mast. It is ensured that the results presented in this report have been measured in an unbiased manner, following the best practices and to the best knowledge of the participating persons.