Rotor: Sometimes called the hub, this is used to connect the blades to the gear box and
power generation train within the nacelle.
Nacelle: an enclosure which contains the electrical and mechanical components, namely
the gear box, the brake, the speed and direction monitor, the yaw mechanism and the
generator.
i) Gearbox: Many turbines have a gearbox that increases the rotational speed of the
shaft to match the required rotation speed of the generator/alternator.
Some smaller turbines (under 10 KW) use direct drive generators that
do not require a gearbox.
ii) Generator: Wind turbines typically have an AC generator (housed in the nacelle)
that converts the mechanical energy from the wind turbine’s rotation
into electrical energy. Synchronous generators require less rotational
speed than asynchronous ones and thus are often operated without
gearbox even in bigger wind turbines.
Tower: Towers are usually tubular steel structures (about 80 m/260 feet high) which
support the rotor and nacelle. It also raises the rotor high in the air where the blades are
exposed to stronger winds. They consist of several sections of varying heights. The
tower sits on a reinforced concrete foundation, so that it is well fixed onto the ground.
Blades: The modern rotor blades are made of composite materials, making them light
but durable. Blades are often made of fiberglass, reinforced with polyester or woodepoxy.
Vacuum resin infusion is a new material which is gaining popularity among
manufacturers. Most wind turbines have three blades. Blades are generally 30 to 50
meters (100 to 165 feet) long, with the most common size around 40 meters (130 feet).
Blades typically represent approximately 22% of the value of a wind turbine.
Transformer: The electricity generated by wind turbines must be delivered to the
electrical grid. In order to do this, the voltage needs to be stepped up for energy
transmission. There is usually, at least, one large transformer that is shipped with a wind
turbine project and is considered a critical component especially for DSU and operational
BI.