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Calculating wind speed
at your nominated site is the first step in the process
of determining if wind power will work for you. The wind
maps linked here offer a very generalized picture of windspeeds.
To really guage windspeed for any specific site and tower
height, a higher degree of accuracy is called for. Temporary
towers and anenometers are required with good data-logging.
To capture all the seasonal variety in wind/weather patterns,
12 months of record keeping is usually afforded. Combined
with known general conditions and historical weather stations'
data from the area, an investment-grade site assessment
can be created with confidence.
The chart below shows how wind speeds
are categorized by the U.S. Department of Energy, and appear
on the NREL wind maps below.
| Classes of wind
power density at 10 m and 50 ma |
| |
10 m (33 ft) |
50 m (164 ft) |
| Class |
Wind Power Density (W/m2) |
Speed b m/s
(mph) |
Wind Power Density (W/m2) |
Speed b m/s
(mph) |
| 1 |
0 - 100 |
0 - 4.4 (9.8) |
0 - 200 |
0 - 5.6 (12.5) |
| 2 |
100 - 150 |
4.4 (9.8) - 5.1 (11.5) |
200 - 300 |
5.6 (12.5) - 6.4 (14/3) |
| 3 |
150 - 200 |
5.1 (11.5) - 5.6 (12.5) |
300 - 400 |
6.4 (14.3) - 7.0 (15.7) |
| 4 |
200 - 250 |
5.6 (12.5) - 6.4 (14.3) |
400 - 600 |
7.0 (15.7) - 7.5 (16.8) |
| 5 |
250 - 300 |
6.0 (13.4) - 6.4 (14.3) |
500 - 600 |
7.5 (16.8) - 8.0 (17.9) |
| 6 |
300 - 400 |
6.4 (14.3) - 7.0 (15.7) |
600 - 800 |
8.0 (17.9) - 8.8 (19.7) |
| 7 |
400 - 1000 |
7.0 (15.7) - 9.4 (21.1) |
800 - 2000 |
8.8 (19.7) - 11.9 (26.6) |
a: Vertical extrapolation
of wind speed based on the 1/7 power law.
b: Mean wind speed is based on Rayleigh speed distribution
of equivalent mean wind power density. Wind speed
is for standard sea-level conditions.
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List of Maps
All links are to the NREL Website
|
| Articles with maps
|
| U.S. Wind Maps
|
| Analyzed Annual and Seasonal Average Wind Resource
Maps
|
Gridded Wind Resource, Certainty Rating, and Areal
Distribution Maps
- 2-6
Annual average wind resource estimates in the
contiguous United States
- 2-7 Certainty rating of the wind resource estimates in
the contiguous United States
- 2-8
Certainty rating of the wind resource estimates
for areas with Class 3 or higher wind power in
the contiguous United States
- 2-9
Certainty rating of the wind resource estimates
for areas with Class 4 or higher wind power in
the contiguous United States
- 2-10 Percent of the land area estimated to have Class
3 or higher wind power in the contiguous United
States
- 2-11 Percent of the land area estimated to have a Class
4 or higher wind power in the contiguous United
States
- 2-12 Winter wind resource estimates in the contiguous
United States
- 2-13
Spring wind resource estimates in the contiguous
United States
- 2-14
Summer wind resource estimates in the contiguous
United States
- 2-15
Autumn wind resource estimates in the contiguous
United States
- 2-16
Annual average wind resource estimates in Alaska,
Hawaii, Puerto Rico, and Virgin Islands
- 2-17
Certainty rating of wind resource estimates in
Alaska, Hawaii, Puerto Rico, and Virgin Islands
- 2-18
Certainty rating of the wind resource estimates
for areas with Class 3 or higher wind power in
Alaska, Hawaii, Puerto Rico, and Virgin Islands
- 2-19
Certainty rating of the wind resource estimates
for areas with Class 4 or higher wind power in
Alaska, Hawaii, Puerto Rico, and Virgin Islands
- 2-20 Percent of the land area estimated to have Class
3 or higher wind power in Alaska, Hawaii, Puerto
Rico, and Virgin Islands
- 2-21 Percent of the land area estimated to have Class
4 or higher wind power in Alaska, Hawaii, Puerto
Rico, and Virgin Islands
- 2-22 Winter wind resource estimates in Alaska, Hawaii,
Puerto Rico, and Virgin Islands
- 2-23
Spring wind resource estimates in Alaska, Hawaii,
Puerto Rico, and Virgin Islands
- 2-24
Summer wind resource estimates in Alaska, Hawaii,
Puerto Rico, and Virgin Islands
- 2-25
Autumn wind resource estimates in Alaska, Hawaii,
Puerto Rico, and Virgin Islands
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| Regional summaries of wind resource estimates
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| Northwest Region
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| North Central Region
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| Great Lakes Region
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| Northeast Region
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| East Central Region
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| Southeast Region
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| South Central Region
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| Southern Rocky Mountain Region
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| Southwest Region
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| Alaska
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| Hawaii and the Pacific Islands
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| Puerto Rico and the Virgin Islands
|
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