Using the Levenberg-Marquardt method to model anemometer data with lattice tower interference

Abstract

The use of boom-mounted anemometers attached to tubular or lattice-type towers is a standard method used by the wind energy industry for wind resource studies. The benefits afforded by already-existent structures should be considered prior to embarking on a wind resource assessment programme. If structures such as telecommunications towers and power transmission line pylons that are already extant at a candidate site could be used as measurement platforms, then this would avoid the expenses and waiting times associated with the procurement, installation and permitting procedures required to install new, dedicated wind monitoring masts in the field. Lattice towers invariably modify the local flow field in their immediate environs, thus influencing anemometer readings. Whilst it is paramount that the top level of such towers be utilized in order to collect representative wind speed samples that are comparatively uninfluenced by the tower structure, there is also a need for lower level measurements in cases where wind shear and other characteristics need to be established.