energy from the wind

Question 1

what is the main mechanism used for extracting energy from the wind

Answer 1

a wind turbine

Question 2

what does V.A.W.T and H.A.W.T stand for, and explain their meaning

Answer 2

VAWT stands for a vertical axis wind turbine, which rotates its blades upon a vertical axis. these machines can harness wind energy from any direction.
HAWT stands for a horizontal wind turbine. these are the more commonly used turbines. they spin their blades along a horizontal axis and will typically have at least 3 blades.

Question 3

Before modern day mechanisms, give an example of how we utilised the wind before the industrial revolution

Answer 3

milling grain (wind mills)

Question 4

list the main part of a basic wind turbine

Answer 4

blades 
rotor
low-speed shaft
gearbox
high-speed shaft
generator
nacelle/casing

Question 5

explain the purpose of a pitch system

Answer 5

the purpose of a pitch system is to allow rotation of the blades along a separate axis to their spinning. the blades will be able to rotate along a vertical axis while spinning to allow the most optimum wind to be hitting the blades as well as decrease the amount of wind hitting the turbine blades while there are rough winds.

Question 6

explain the purpose of a YAW mechanism

Answer 6

a YAW mechanism can be broken up into 2 components:
1. YAW drive
2.YAW motor
3. controller (anemometer and wind vane.
the purpose of this mechanism is to allow the wind turbine to rotate in order to always be facing the oncoming wind, increasing effectiveness and energy generation. this is done when the controller detects from the wind devices from which direction the wind is coming from, and controllers the motor to rotate the turbine to that direction.

Question 7

list thefactors that determine a wind turbines energy production

Answer 7

1. size and amount of rotor blades
2. the speed of the wind
3. the efficiency of the wind turbine system
4. the location of the turbine
5. the turbines design(hub height)

Question 8

explain what is meant by the Betz limit

Answer 8

in 1928 Albert Betz identified that the maximum amount of energy that can be extracted from the wind and converted to other forms is 59.3%. this is due to loss of energy, for example heat and sound.

Question 9

explain the equation:
power = 1/2 x P x A x V(cubed)
P = \_\_\_\_\_\_\_\_\_\_\_
A = \_\_\_\_\_\_\_\_\_\_\_
V = \_\_\_\_\_\_\_\_\_\_\_

Answer 9

P = density of the air Kg/m(cubed)
A = swept area of the blades (PI x R(squared))  M(squared) 
V = velocity of the wind M/s