Wind turbine notes

Wind turbines

Wind turbines convert wind into electrical energy.
And the amount of electrical energy produced depends on wind speeds.

A measure of wind energy available is called the Wind Power Density.

Types of turbines:
 There are horizontal and vertical axis wind turbines.
 The horizontal ones are used the most and are most effective.
Extra:
 Horizontal axis wind turbines have the main rotor shaft
 and electrical generator at the top of a tower.

 Vertical axis wind turbines have the main rotor shaft
 arranged vertically. An advantage of this is that the arrangement of the turbine does not
 need to be pointed into the wind to be effective

Design and construction:
Overall:
 Aerodynamic modeling is used to determine the optimum tower height,
 control systems, number of blades and blade shape.
Rotor blades:
 Materials that are usually used for the rotor blades in wind turbines
 are composites, as they tend to have a high stiffness, high strength,
 high fatigue resistance, and low weight.
  Most used resins used for these composites include polyester and epoxy.
  And glass and carbon fibers have been used as reinforcing material.
What they exist of:
-The tower
-The rotor
-The blades
-The pitch
-Low-speed shaft
-Brake
-Gear box
-Generator
-High speed shaft
-Yaw drive
-Yaw moter
-Controller
-Anemometer
-Wind vane
-Nacelle

Efficiency:
  Betz's law gives the maximal achievable extraction of
  wind power by a wind turbine as 59.3%
  of the total kinetic energy of the air flowing through the turbine

Placements:
 Wind turbines are placed on land but are also placed in the sea or ocean, called
 offshore windmills. And there are also floating wind turbines.