Data Sheet

Wind
and Its
Uses
WHAT EFFECT DOES THE WIND HAVE
AND HOW IS IT MEASURED?
The wind can have many different effects — whether as a mild,
cooling breeze, as a powerful headwind that makes it hard to ride
your bike, or even as a hurricane ripping the roofs off of houses.
As long ago as 1806, the Irishman Sir Francis Beaufort had the
idea of using the observed effects of wind for a wind speed scale.
His scale is divided into 12 levels, and is the most commonly used
wind speed scale to this day. Even though he didn’t invent the 12
divisions, he popularized their use among British sailors, for
example. In his honor, the scale is therefore known as the
“Beaufort scale.”
To calculate wind speed from Beaufort wind speed (from 1 to 12),
you use the formula V = 0.836 × B
3/2
, with B standing for Beaufort
wind strength and V for wind velocity in m/s. This will be easier if
you know the complete Beaufort scale shown on the back cover
of this manual.
WHAT CREATES THE WIND?
The surface of the Earth is enveloped in an atmosphere. Because the
strength of the sun’s radiation is different in different regions of the
Earth, those different regions are heated to different degrees. High
temperatures cause warm air to rise and air pressure to drop. On the
other hand, low temperatures make cold air sink and air pressure rise.
This creates high and low pressure areas. As a reaction to this, air
particles will move from the high-pressure areas into low-pressure
areas until the air pressure evens out. This compensatory movement is
what we experience as wind.
CHECK IT OUT
Average Annual Wind Speeds in
the United States
at 100 Meters Above Ground
Source: NREL National Renewable
Energy Laboratory
Wind Speed
m/s
>10
9.5 - 10
9 - 9.5
8.5 - 9
8 - 8.5
7.5 - 8
7 - 7.5
6.5 - 7
6 - 6.5
5.5 - 6
5 - 5.5
4.5 - 5
4 - 4.5
<4
14