Design of an Extra-Tall Mast Above Blade-Tip Heights for Wind Resource Assessments Across Complex Terrain Regions

Abstract

Wind energy predictions for many rural, complex terrain regions are based solely on large-scale meteorological models that may poorly characterize the local resource. Changes in government policies, energy economics, and wind technologies suggest that the best wind resources across such a complex terrain region in southeast Ohio may be economically viable. The wind energy and assessment visualization (WEAV) assessment approach is a meso-scale strategy to locate the best resource in a marginal wind region. The measurement component is described here. Wind characteristics measurements on a communications tower at six heights up to 240 m, are being acquired. This data will be input into a complex-terrain wind simulator with terrain information to model the wind resource across approximately 2000 square miles (5200 km2). Advantages of the WEAV assessment strategy include explicit measurement of wind shear and velocities, long-term characterization of the free stream velocity field, and evaluation of a much larger assessment region. Included is a description of, the motivation for and advantages of this approach, details of the design, installation, and challenges of an extra-tall tower wind measurements, and a discussion of the economics of both Class 2 wind (∼250 W/m2) and the WEAV assessment approach compared with conventional wind assessments.