An Introduction to Wind Power Classes
Wind power is the amount of energy available in a given area due to the wind speeds at a given height. Wind speed is measured in meters per second (m/s) or miles per hour (mph). Wind power is divided into eight classes ranging from 0 – 7 on a wind map. A wind map is a map with colored areas that indicate the potential wind speeds at various heights. In Pennsylvania elevation directly relates to wind speed and therefore wind power.
Wind power classes of 1 or 2 are generally suitable for a small wind project. Small wind refers to turbines with blades of 4 to 8 feet in length with enough power output to power a single home. These require only moderate wind speeds. Wind power classes from 3 and above are those that can produce enough energy to make the installation of a mid to large scale wind turbine economically feasible. Mid to large scale wind turbines have blades of 30 to 100+ feet in length with enough power output for 40 – 600 homes. These require much faster and more consistent wind speeds.
The Renewable Energy Center is looking to place data collection towers within those wind power classes of 3 and above. The map shows Class 2 wind and Class 3 and above.
Table 1
Wind Power Classes
|
Wind Power Class
|
Wind Speed (m/s)
|
Wind Speed (mph)
|
Feasible Project Type
|
|
<5.6
|
<12.5
|
|
2
|
5.6 - 6.4
|
12.5 - 14.3
|
Small Wind
|
3
|
6.4 - 7.0
|
14.3 - 15.7
|
Community and Commercial
Wind
|
4
|
7.0 - 7.5
|
15.7 - 16.8
|
5
|
7.5 - 8.0
|
16.8 - 17.9
|
6
|
8.0 - 8.8
|
17.9 - 19.7
|
7
|
> 8.8
|
>19.7
|