With the introduction of a solution to allow the standalone use of wind lidar ZX 300 in complex terrain, Deutsche WindGuard has made a successful start to 2021. The new “ZX Complex Flow Solver” (ZX CFS) is the result of a joint development with the leading computational wind engineering organization ZephyScience, supported by lidar OEM ZX Lidars. Fully based on computational fluid dynamics (CFD), ZX CFS identifies, quantifies and resolves the relative differences between lidar and cup anemometer measurements witnessed in complex terrain.
“Deutsche WindGuard has been supporting lidar applications since 2004,” says Johannes Cordes, Wind and Data Analyst at Deutsche WindGuard’s Wind Resource Assessment team. “While stand-alone lidar measurements in flat terrain have already had a high acceptance in the past, we see the particular challenges of stand-alone measurements in complex terrain well addressed and appropriately treated with the ZX CFS application. The design and structure of this service provides the best available solution for bankable wind resource and energy yield assessment based on stand-alone lidar in complex terrain.”
In complex, non-benign terrain, the assumption of homogeneous flow conditions within the measurement volume introduces differences between lidar and cup anemometer. The Complex Flow Solver algorithm developed by Deutsche WindGuard is optimized for ZX Lidars’ wind field reconstruction. Incorporating results from a high-resolution CFD model, it derives a set of conversion factors. Applied to the volume-based wind data from Continuous Wave Lidar ZX 300, which samples 50 measurements points per second, these conversion factors produce single point measurements equivalent to those of a cup anemometer installed at the same location.
ZX CFS even provides guidance on where to install the lidar initially to achieve the lowest possible uncertainties. Cloud computing delivers fast, transparent and accurate results.
Uncertainties associated to inhomogeneous flow conditions within the measurement volume according to IEC 61400-12-1 Ed. 2 (2017) L.4.5 can thus be reduced significantly. This widens the usability of ZX 300 wind lidar standalone deployments for wind resource assessments in complex terrain with no additional onsite met mast.