The tower is used to get the wind turbine off the ground and into the air. A basic rule of thumb is that
‘the higher the tower then the more power the wind turbine can extract from the wind’.
A site assessment will discover which tower is needed for any particular site. The options include:
- Guyed Wire Tower
- Free Standing Monopole
- Lattice Tower
The site in question, the budget and the preference of the customer will dictate which type of tower will be used.
Guyed Wire Tower
A Guyed Wire Tower consists of a tower supported along its height by steel wire ropes which are anchored to the ground as in Fig. 1. The amount of guys needed depends on the height of the tower and the surrounding terrain.
Advantages
- Usually the least expensive type of tower
- Can be hinged at the base
- Small foundation
Disadvantages
- Has a large footprint
- Aesthetically unpleasing to some people
- Need relatively level terrain
- Only one guy wire needs to fail for entire tower to fail
Free Standing Monopole
A Free Standing Monopole tower is a self supporting tower that consists of just a single vertical tower structure. This type of tower needs to be strong and generally needs a large foundation. An example of a monopole tower in it lowered position can be seen in Fig.2 while Fig. 3 shows it in its upright position.
Advantages
- Can be hinged at the base with hydraulic ram
- More aesthetically pleasing than guyed wire tower
- Smaller footprint than the guyed wire tower
- Can be installed on uneven terrain
Disadvantages
- Large foundation needed
- Usually more expensive than a Guyed Wire Tower
Lattice Tower
Lattice towers are usually 3 or 4 sided structures made from bolted or welded angle iron or steel tube. Fig.4 shows a 4 sided lattice tower.
Advantages
- Smaller footprint than the guyed wire tower
- Can be installed on uneven terrain
Disadvantages
- Large foundation needed
- Usually more expensive than a Guyed Wire Tower
- Needs a crane for installation (unless a hinge is placed at the base)
- Has to be climbed for maintenance (unless a hinge is placed at the base)