SITING A WIND PROJECT - Wind Resource Assessment: A Practical Guide to Developing a Wind Project - page 23

competing criteria. For example, given the necessary inputs, a GIS could be queried
to find all sites outside defined exclusion zones and within a specified distance of
existing transmission lines, encompassing a contiguous area sufficiently large to sup-
port a wind project of a certain size, and with a specified minimum mean wind speed.
After some experimentation with the criteria, the analyst can usually hone in on a
“short list” of candidate sites meeting the developer's requirements.
The most useful geographic data to incorporate into a GIS during this phase typi-
cally include the following:

• wind resource maps
• topographic data (digital elevation or terrain model)
• land cover data (classified by vegetation type or use)
• water bodies
•

administrative boundaries

excluded areas (natural parks, military zones, urban areas, etc.)

•

buildings and other structures requiring setbacks

•

roads, railroads, and paths

•

transmission lines and substations

•

pipelines (natural gas, oil)

•

•

radar and airspace restrictions

competing or neighboring projects.

•

Appendix B lists some useful sources of global GIS data. Additional sources of
data for particular regions and countries may be available as well. In some cases,
the information can be digitized (converted to GIS format) from aerial or satellite
photographs.
A GIS cannot address every potential factor or concern, nor are the data inputs
always accurate. For these reasons, it is prudent to follow up a GIS-based site screening
with field visits, as described in Section 3.3.

3.2 REGIONAL WIND RESOURCE INFORMATION

Obtaining information about the wind resource in a region is a key step in the site-
selection process. Although usually insufficient by itself to determine a project's
feasibility, such information can suggest the range of performance to be expected
by wind projects that might be built in the region and can point toward potential sites.
Two common sources of regional wind resource information are wind resource maps
and publicly available wind measurements.

3.2.1 Wind Resource Maps
Regional wind resource maps can be a useful starting point for identifying attractive
wind project sites. Aside from allowing users to survey a large region at a glance,