| Wind Power Class* |
Height = 10 m (33 ft) | Height = 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. To maintain the same power density, speed increases 3%/1000 m (5%/5000 ft) elevation.
*WEB NOTE: 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.