Wind farm

Wind Farm (or wind park) consists of several Wind Turbines joined into one system. Usually the Wind Farms are built near big energy consuming objects (cities, factories, etc.).

Forming the Wind Farms of Horizontal Axis Wind Turbines (HAWT) is preferrable only when the wind direction is known in advance and never changes (canyon, cutting in a forest, ec.). If the wind direction is not constant, then the application of Vertical Axis Wind Turbines (VAWT) will be more efficient.

The VAWT doesn't require the system of orientation on the wind in comparison with propellers. It means that do not have the reduction of efficiency whenthe wind changes its direction.

HAWT (traditional "propeller") occupies bigger volume as due to the orientation on wind the wind rotor forms a sort of sphere of bigger diameter than the diameter of cylinder formed by rotating blades of VAWT of the same power. I.e. HAWT creates bigger wind "shadow" behind itself then VAWT.



Wind rotors of the same diameter have bigger swept area and therefore generates more power:



HAWT has bigger diameter if compared with VAWT of the same power:



On the base of above mentioned features it is evident that on the same area more VAWTs than HAWTs can be arranged:



While arranging the Wind Farm (wind park) the Wind Turbines of any type would normally be placed on 10 diameters distance from each other. The reason is because the wind flow is reduced after passing through the first Turbine, but getting stronger moving towards to the next Turbine which stands in the "shadow" of the first one. Calculations and practice show that the wind flow has almost the same power as before the first Turbine.

When the property is valuable and Wind Turbines should be concentrated in the Wind Farm as much as possible,
the VAWTs are more preferrable than HAWTs because they can be built on the masts of different height. This opportunity allows the substantial increase of concentration of Turbines on limited area.

The application of VAWTs in Wind Farms is especially efficient when the alternators of all Turbines are located on the ground being connected with the upper wind rotor via long shaft. It reduces the expenses on montage, servicng and repairs. For instance the servicing of VAWT with bottom alternator design will cost 20% of servicing the HAWT of the same power.