Wind Classes for Wind Maps
Each wind power class should span two power densities. For example, Wind Power Class = 3 represents the Wind Power Density range between 150 W/m2 and 200 W/m2. The offset cells in the first column attempt to illustrate this concept. Please note that the wind speed classes are taken at 30 m (100 ft), instead of the usual 10 m (33 ft).
Wind Power Class* | 10 m (33 ft) | 50 m (164 ft) | ||
Wind Power Density (W/m2) | Speed (b) m/s (mph) | Wind Power Density (W/m2) | Speed (b) m/s (mph) | |
1 | 0 | 0 | 0 | 0 |
100 | 4.4 (9.8) | 200 | 5.6 (12.5) | |
2 | ||||
150 | 5.1 (11.5) | 300 | 6.4 (14.3) | |
3 | ||||
200 | 5.6 (12.5) | 400 | 7.0 (15.7) | |
4 | ||||
250 | 6.0 (13.4) | 500 | 7.5 (16.8) | |
5 | ||||
300 | 6.4 (14.3) | 600 | 8.0 (17.9) | |
6 | ||||
400 | 7.0 (15.7) | 800 | 8.8 (19.7) | |
7 | ||||
1000 | 9.4 (21.1) | 2000 | 11.9 (26.6) |
(a) Vertical extrapolation of wind speed based on the 1/7 power law.
(b) Mean wind speed is based on Rayleigh speed distribution of equivalent mean wind power density. Wind speed is for standard sea-level conditions.