What Makes A Good Wind Site

Tuesday, May 19th, 2009

To assess the feasibility of installing a wind turbine on a site, several factors have to be considered:

• Wind speed
• Topography and accessibility
• Surface roughness
• Distance to transmission lines

Wind Speed

Wind speed is the most important factor in choosing a turbine site. Small increases in wind speeds make a significant difference in power output. A wind turbine at a 16-mph site can produce over 50% more electricity than the same turbine at a 13-mph site.

Topography and accessibility

Good wind sites are generally higher than the surrounding areas. Steep hills and cliffs can create wind turbulence that reduces energy output and leads to higher maintenance costs, while gradually sloping hills can increase wind speeds. Sites also need to accommodate access roads for construction and maintenance equipment.

Surface roughness

Tall obstacles such as buildings and trees can slow the speed of wind and create turbulence at low altitudes. Siting turbines in open fields or in the ocean reduces the effect of surface turbulence, while taller towers can be used to get turbine blades above turbulent areas.

Distance to transmission lines

In the case of commercial wind turbines, generated electricity must be fed into the electrical grid. Proximity and access to transmission lines are key; building new transmission lines can be very costly.