Wind Turbine
Towers & Types and Height
The wind turbine tower is an
important element of any wind system (except in the experimental
urban micro-wind systems. Wind speed increases
sharply with the tower height, and that causes a major increase
in the electricity produced by the system.
The same small turbine can
increase its power by 30% or more if the height of its tower is
30m/100 feet instead of 18m/60 feet.
Mega turbine towers
 The mega turbines towers of the wind farms
are made of tubular steel, and are rather standardized, though
their height also depends on specific site conditions.
In the case of the
Texan Snyder Wind project in Scurry County, the 21 Vestas V90 3.0 megawatt wind turbines are mounted
on 345 feet
towers - and that because
local
wind conditions are best at that height.
That's a record, but usually the towers and the turbines are
intrinsically linked, and the height and diameter of the tower
depend largely on the size and capacity of the turbine.
Micro turbine towers
As expected, micro turbines dispense complex
or tall towers. Towers are most of the time just a mere pipe of 2” diameter
or less.
Small turbine towers
The case of other small wind systems (more than a
1KW) is less simple, with several types of towers and different heights
and configurations: guyed towers and the non-guyed
towers, cylindrical/pipe and lattice configurations.
A small wind tower should be
mounted...
- far enough from any obstructions and
on the top or on consistently
windy side of hills:
see Wind turbines Location
- with enough room to raise and lower the tower for maintenance
and stabilization.
 Guyed
small cylindrical Towers
Many small wind turbines use narrow pole towers (pipe, tubing)
supported by guy wires. It’s a cheap solution, though with some
potential disadvantages: they are
not usually climbable for inspections or repairs, and require
more land than self-supporting towers, due to the guy wires.
Non-guyed cilyndrical towers
Non-guyed tilt-up/cylindrical towers use pipe or tubing and a
self-supporting design. They do not use guy wires and have a
small footprint. These towers can include climbing pegs but are
a relatively expensive type of tower.
 Lattice configuration
Lattice towers use welded steel profiles and are a cheap and
tested solution (a lattice tower requires half as much material
as tubular freely standing towers). Most lattice towers aren’t
guyed, but there are also guyed configurations: three legged
lattice structures suspended on all three sides by guy wires.
They are usually climbable.
How to calculate the optimum height of a small wind tower
The height of a small turbine tower should take into account
the height of the surrounding obstacles: to attain
maximum efficiency the height of the tower should allow the
bottom of the turbine blades to be 10
meter (30 feet) or more above the top of any obstacle within 100
meters/300 feet of the tower.
But the tower height depends also on the turbine model and
on its characteristics. Towers and wind turbines are often
supplied together, and manufacturers demand their turbines to be
mounted on towers with sufficient height.
Height of the tower and local and state rules
Local rules may impose height restrictions to a wind tower:
there are in some cases rules imposing maximums of 30 or 40
feet / 9-12 meters, which may have a negative impact on the electric power
generated by the wind turbine. Just pay attention to local rules.
See also:
Basics on Wind electric generators
Wind Maps and data
Stand alone systems
On-grid systems
Net metering
Turbines
Power and size
Landowners and onshore wind farms
Return to
Energy-Savings Home Page
|
