When considering whether or not wind energy is applicable in your
location, an accurate wind map can be an invaluable resource.
One place to start is with some of the national and regional level
wind maps available through the site provided by the National
Renewable Energy Lab (NREL) at
This site offers both a national wind resource assessment of the United States and high-resolution wind data. The national wind resource assessment was created for the U.S. Department of Energy in 1986 by the Pacific Northwest Laboratory and is documented in the
Wind Energy Resource Atlas of the United States, October 1986. This national wind resource data provides an estimate of the annual average wind resource for the United States.
The wind resource assessment was based on surface wind data, coastal
marine area data, and upper-air data, where applicable.
Here is an example from the NREL site of a national wind map
showing the Average Annual Wind Power for the US.
National and regional wind maps can give you the big picture but if you
really want to understand what is going on locally you need a state
and local wind map. The NREL site has wind maps for most individual
states. In addition, many state energy departments or
commissions provide state and local wind maps via the Web. Below
is an example of a state level wind map for California provided by the
California Energy Commission.
When reviewing wind maps it is helpful to see if you can find maps
which show not just average wind speeds but seasonal wind speeds.
The wind speed can vary dramatically by season in many locations.
This is especially important to know if you are living off-the-grid
and would be relying on wind or a combination of wind and solar to
provide your power. If the wind doesn't blow much in winter and
you are relying on it for energy it is good to know up front.
The good news is that wind and solar energy tend to be inversely
related and often the worst season for solar is the best season for
wind. By looking at seasonal maps for both wind and solar you
can determine if this is true in your location.
Another factor to take into consideration when looking at wind
maps is the altitude. Some wind maps provide wind speeds at
higher elevations which may not reflect ground speeds. Remember,
a good rule of thumb is that the wind at ground level needs to be
between 7-9 miles per hour if you are going to have sufficient power.