Characteristics of the Wind - Wind Turbine Technology: Fundamental Concepts of Wind Turbine Engineering - page 470

Figure 8-2. Typical wind energy resource map using the wind power classes defined in
Table 1 to show estimated annual average wind power densities. [Elliott et al . 1986]

Table 8-1.
Wind Classification System based on Annual Average Wind Power Density 1

Wind
power
class

Annual average wind power density
(W/m 2 )

Equivalent mean wind speed (m/s)

10-m elevation 50-m elevation 10-m elevation 50-m elevation

1 0 - 100 0 - 200 0.0 - 4.4 0.0 - 5.6

2 100 - 150 200 - 300 4.4 - 5.1 5.6 - 6.4

3 150 - 200 300 - 400 5.1 - 5.6 6.4 - 7.0

4 200 - 250 400 - 500 5.6 - 6.0 7.0 - 7.5

5 250 - 300 500 - 600 6.0 - 6.4 7.5 - 8.0

6 300 - 400 600 - 800 6.4 - 7.0 8.0 - 8.8

7 400 - 1000 800 - 2000 7.0 - 9.4 8.8 - 11.9

1 A Rayleigh frequency distribution is assumed