Alternative Technical and Market Solutions

Alternative Technical and Market Solutions

The potential for capturing wind power is huge, although the wind resource varies by location. A reasonably high and reliable source of wind is needed to make the use of this technology viable. Many potential sites cannot be developed on environmental grounds, objections often being voiced to the location of wind towers close to residences.

1. 
   Rotor: It is consisted of three blades, mounted on a hub. Typical rotor diameters are 80 90 metres for today’s larger machines. Blades are usually made from Glass Reinforced Plastic (GRP) and incorporate lightning protection measures.
   
2. 
   Nacelle: The “box” within which the main components are housed and home to the gearbox, generator and transformer as well as some of the control electronics.
   
3. 
   Gearbox: It converts the rotational speed of the rotor (typically 10-20 rpm) to 1500 rpm for the generator. Some turbine designs avoid a gearbox by using direct drive.
   
4. 
   Generator: It converts rotational movement to electrical energy
   
5. 
   Transformer: It converts electricity from 415 V or 690 V to 11 kV or 35 kV for transmission down the tower. The transformer can also be housed separately within the tower, or be absent where an external transformer serves more than one turbine.
   
6. 
   Tower: Made usually out of steel, a cylinder supporting the nacelle and rotor. Typical tower heights are 60-80 metres. Cables run down the tower taking the electricity from the generator at the top, into the ground and then onto a connection point to the grid. Lifts or ladders allow maintenance crew to access the nacelle.
   
7. 
   Base: A concrete base, typically 15 metres x 15 metres x 1 metres which acts as the foundation for the structure.
   

Wind towers have increased substantially in size over time, which has brought down the cost of wind power generation As illustrated in Figure 52, in the early days of modern wind power in the 1980s, turbine rotors were typically 20 metres in diameter and had a capacity of 20-60 kW. Ten years later, the machines had a capacity of 500 kW. Today offshore turbines can reach up to 5 MW or more, spanning 120 metres. The average size of onshore turbines is smaller, but units of 2.5-3.0 MW are now common. Manufacturers such as General Electric state that 10 MW units may be commercially available in as little as five years.