The incorporation of Reanalysis data into the wind energy resource assessment methodology used at the National Renewable Energy Laboratory (NREL) has helped to increase the quality of its maps and atlases. The most useful aspect of Reanalysis has been to identify the various wind energy climates that may be present in a study area. Some of the factors used in identifying a particular wind climate include the seasonal distribution of the wind resource, the prevailing direction(s) of the wind, and the vertical profile of wind speed and power. The last feature is valuable for recognizing low-level jets, an important factor in many regions with significant wind resource.

NREL uses 40 years of the sigma level Reanalysis data in its methodology with emphasis on the wind data from the five levels closest to the surface. These data give an overview of the regional wind characteristics from the surface to about 700 m above the ground. The analysis of the low-level Reanalysis data is most valuable for identifying wind energy climates for topographic regions without complex terrain. This technique has been especially useful for wind mapping projects on the broad plains of the Midwestern United States and central and eastern Mongolia