Page 300 - Handbook of Energy Engineering Calculations

FIGURE 7 Variation of mean annual free-air wind velocity and
3
total available wind power per unit area (= ½ ρ V ) with altitude in New
England. (Mechanical Engineering.)

To understand how the proposed scheme will extract energy from the
wind, consider the following: The motion of air generates a pull in the rope
that holds the kite. This pull is a function of both the angle of attack of the

kite and the kite area normal to the wind direction, and by varying any of
these we can vary the pull on the rope. On the surface of the earth, this rope
will be suitably connected to an energy system which will convert the
variation in developed force on the rope to the rotational energy of a rotor.

Whenever a period of calm occurs, the kite will tend to lose its altitude.
One solution to this difficulty is to fill the empty spaces in the kite with
helium gas such that the upward pull from the helium gas will balance the