Information and Resources

The wind maps indicate that the ridge and mountain tops of the Ozark Mountains of northwestern Arkansas and the Ouachita Mountains of west-central Arkansas have the best wind resource in the state (see Figure 1 and Figure 2). The narrow east-west ridgelines of the Ouachita Mountains, in particular, are predicted to experience mean wind speeds at 50 m height of 7-9 m/s, and wind power densities of 400-800 W/m2 (NREL Class 4-6). Many, but not all, of these ridgelines are within the Ouachita National Forest. In the Ozarks, the ridgelines are not as well defined, and the wind resource is consequently less pronounced. Nevertheless, mean wind speeds at 50 m of 7-8 m/s are predicted on some mountain tops and short ridges, along with wind power densities of 400-500 W/m2 (Class 4). Some, but not all, of the windy spots are within the Ozark National Forest. Because of strong wind shear, much greater wind speeds and powers are predicted at the hub heights of modern turbines (80 to 100 m above ground). At such heights, mean speeds of 8-8.5 m/s in the Ozarks, and 8-10 m/s in the Ouachita Mountains, are expected to occur.

In low-lying regions of Arkansas, the wind resource is far more modest, with mean wind speeds at 50 m typically in the range of 4 m/s to 5.5 m/s, and wind power densities in the range of 70 W/m2 to 150 W/m2 (Class 1). This is caused by a combination of low elevation, moderate upper-air wind speeds, and high surface roughness created by extensive forest cover. An exception to the rule is extreme northeastern Arkansas, in the broad and flat flood plains formed by the Mississippi River and its tributaries, where the low surface roughness of open farmland permits the development of a somewhat better wind resource (predicted to be 5.5-6 m/s at 50 m, high Class 1 and low Class 2, rising to 6.5-7 m/s at 100 m).

Excerpted from Wind Resource Maps of Arkansas, by AWS Truewind, LLC for NREL in 2007.