Good locations for utility scale wind development must have fast, steady, nonturbulent winds, and they must be near transmission lines. The Amercian Wind Energy Association (AWEA) has developed a fact sheet, "Ten Steps to Developing a Wind Farm", to include certain siting criteria. Below are the four essential siting requirements.
- Wind speed. A site must have a minimum annual average wind speed in the neighborhood of 11-13 miles per hour to be considered. Wind farm sites are typically pre-selected using a wind atlas (http://rredc.nrel.gov/wind/pubs/atlas). Once potential sites are identified, local winds are monitored for a year or more before wind turbines are constructed. Wind power density (WPD) is the yardstick used to select locations for wind energy development.
- Access to interconnectivity and distribution. One of the most important factors in turbine siting is access to interconnectivity options that allow the delivery of energy produced to the end consumer. This includes transmission and distribution lines and substations. Wind developers are reluctant to build where transmission lines do not yet exist or where capacity is weak.
- Land area. About two acres of land is needed for each wind turbine. With most farms being built today, a minimum of 50 turbines are constructed, requiring a total land mass of 100 acres. In addition to the acreage needed to site the turbines, sufficient land is needed to adequately space the turbines.
- Environmental factors. Danger to birds and bats has been a concern in some locations. Environmental studies must be done before construction to determine the potential impact. Developers perform an avian risk assessment to evaluate the risk of collision for birds and bats and avoid high traffic areas.