Wind Resource - Wind Energy: Renewable Energy and the Environment - page 54

South Dakota - Wind Resource Map

104° 102° 100° 98°

46°

46°

1

3

Aberdeen

2

Watertown

Pierre

Huron

Brookings

9

4 44°

44°

Rapid City

5

Mitchell

Sioux Falls

6

8

7

Ya nkton

Indian
Reservations
1
2
3
4
5
6
7
8
9

N Wind Power Classification

Wind speed a
at 50 m
m/s

Wind speed a
at 50 m
mph

Wind
power
class

Resource
potential

Wind power
density at 50 m
W/m 2

Meteorological station with wind data
City or town Standing Rock

Cheyenne River
LakeTraverse
Lower Brule
Crow Creek
Pine Ridge
Rosebud
Ya nkton
Flandreau

50 0 50 100 Kilometers

2
4
5
6
7

Marginal
Fair
Good
Excellent
Outstanding
Superb

200-300
300-400
400-500
500-600
600-800
800-1600

5.6-6.4
6.4-7.0
7.0-7.5
7.5-8.0
8.0-8.8
8.8-11.1

12.5-14.3
14.3-15.7
15.7-16.8
16.8-17.9
17.9-19.7
19.7-24.8

Transmission Line
Voltage
69 Kilovolts
115 Kilovolts
230 Kilovolts
345 Kilovolts

25 0 25 50 75 Miles

U.S. Department of Energy
National Renewable Energy Laboratory

a Wind speeds are based on a Weibull k value of 2.0

FIGURE 4.2 Wind power map for South Dakota using terrain enhancement. (Image from NREL. With
permission.)

Now all of this information has been placed online and the maps are in a digital format ( Figure 4.1 ) .
The National Wind Technology Center (NWTC), National Renewable Energy Laboratory (NREL),
is updating the wind maps for states using terrain modeling, and maps have been completed for a
number of states (Figure 4.2). The procedure uses actual data for verification. Information and data
on wind resources are available at the NWTC [7], and digital wind maps for the United States are
available from Wind Powering America [8].
New computer tools and technical analyses, which use satellite, weather balloon, and meteo-
rological tower data, are being used to create better maps for assessing the wind power potential.
Geographic Information Systems (GIS) provide wind maps with selected overlays, for example,
transmission lines, roads, parks, and wildlife areas, etc., to assist in wind resource assessment. The
higher resolution of these maps (1 km) provides better assessment for possible location of wind
farms and has also shown higher-class winds in areas where none were thought to exist. The wind
maps for the Northwest region [9] and Texas [10] have online interactive features to zoom in on
local areas.
NWTC had a program of collecting data on tall towers, up to 100 m. The data from the thirteen
tall towers in the Central Plains show that wind speeds and, of course, wind power potential con-
tinue to increase with height. Because wind speed increases with height, some regions with class 2
winds, which were presumed to have little potential for wind farms, have now become viable if they
are close to large load centers. Three years of met data from the two tall tower sites in Texas and five
years of met data from sixteen met sites in Texas and one met site in New Mexico are available to
the public [11]. Some met data from the General Land Office, Texas, are also available.