Renewable Energy - Wind Energy

Question 1

How much has wind capacity grown from 2008 to now?

Answer 1

100gW in 2008 and 830 in 2019

Question 2

How much wind capacity is onshore compared to offshore?

Answer 2

933% and 7%

Question 3

Capacity Additions

Answer 3

This is the adding-up of futher power generation through small-power projects like new generators.

Question 4

How much wind energy is in Asia?

Answer 4

41%

Question 5

How much global electricity does wind energy produce and how much by 2050?

Answer 5

Currently 6% by 2050 be 35%

Question 6

Why is offshore currently behind?

Answer 6

Developed much later, first farmi in Denmark in 1991.

Question 7

What do the International Renewable Energy Agency project tthe distribution of wind energy globally for onshore.

Answer 7

By 2050, 50% in Asia, 23% in NA and 10% in Europe

Question 8

What does a wind turbine do?

Answer 8

Converts kinetic energy into electricity, through turning of a turbine, rotational energy moving a shaft connected to a generator, producing electrical energy.

Question 9

What is the general mechanism of spin of a turbine?

Answer 9

Low pressure air on one side of the blade, pulling blade towards it generating lift.

Question 10

How do wind farms regulate under high winds?

Answer 10

Anemometer measures wind speed.

Question 11

Nacelle

Answer 11

Includes rotor hub, generator and gearbox, housing the components that transfer wind kinetic energy into mechanical energy to run the generator.

Question 12

What connects to the gearbox?

Answer 12

Wind turbines via a shaft.

Question 13

How do wind turbines optimise outputs under varying wind speeds?

Answer 13

Electrical components that alter balde angle.

Question 14

What is energy output determined by?

Answer 14

Third power of wind speed and to the square of swept area

Question 15

Swept area

Answer 15

The area of the circle created by the blades as they sweep through the air.

Question 16

Why is hub height important?

Answer 16

Wind increases the higher up

Question 17

What is an example of the importance of location for wind farms?

Answer 17

Coasts have higher amounts of winds, as do the poles compared to the equator.

Question 18

Why are floating offshore wind farms benefical?

Answer 18

They can be deployed in deep ocean

Question 19

What are the current proportions of a wind turbine?

Answer 19

50-200 meteres high and rotor diamets being about 110m(doubling from 50 in 2020)

Question 20

What is a trade off with increasing height?

Answer 20

With increasing height the turbine is subject to more turbulence, requiring stronger building materials.

Question 21

How much did doubling of rotor diamter increase capacity?

Answer 21

250%

Question 22

What is a downside of building wind farms in windy area?

Answer 22

You take up space in windy areas, thus must be in less windy areas.

Question 23

How can we adapt to building wind farms in less windy areas?

Answer 23

Increasing tower height, decreasing generator size proprotional to blade size for higher capacity utilization.

Question 24

What is a downside of decreasing generator size?

Answer 24

It means at higher wind speeds not all electricity is converted.

Question 25

What are some alternative ways to improve wind farm efficiency?

Answer 25

AI generation algorithmis to optimise placement of turbines

Question 26

How does installation cost differ from China and UK?

Answer 26

1170 per kW in China whilst 2030 kW in the UK

Question 27

Why do regional differences affect wind turbine costs?

Answer 27

Size of blades and towers require costly transports, as well as electrical production

Question 28

How much has wind turbine cost dropped since 2010?

Answer 28

22%

Question 29

What has caused decreased costs in wind utrbines?

Answer 29

Increasing learning rates and technological advancement, like larger generators and longer blades.

Question 30

Why is offshore wind three times more expensive?

Answer 30

Specialised ships for transport and grounding them, maintenance more difficult

Question 31

Levelised Cost of Electricity

Answer 31

This is the discounted lifetime cost of building/operating generation assets expressed as cost per unit of electricity genertaed

Question 32

How much is LCOE of offshore expected to decrease?

Answer 32

From $60 per MWH(2018) to $40 per MWh by 2030.

Question 33

What does offshore exceed in compared to onshore?

Answer 33

Higher capacity factors and steadier generation profiles.

Question 34

Why is LCOE a poor measurment of cost improvements?

Answer 34

It does not measure time value.

Question 35

Time value

Answer 35

The concept that a sum of something is worth more now than the same sum will be at a future date.

Question 36

Where are high potential zones for wind farms?

Answer 36

South America and New Zealand, as well as north and baltic seas

Question 37

Capacity Factor

Answer 37

The ratio of actual electrical energy output over a given period of time to the theoretical electrical energy.

Question 38

What is wind farm capacity in response to wind variation measured by?

Answer 38

Capacity factor.

Question 39

How does capacity factor compare in offshhore vs onshore?

Answer 39

35-65% in offshore whilst 30-40% onshore

Question 40

Why is energy variability an issue?

Answer 40

Off-peak energy demands must be met another way.

Question 41

Capacity Value

Answer 41

The amount of energy capacity something can replace without reducing energy securirty.

Question 42

What is an issue with offshore wind farms?

Answer 42

Grid integration.

Question 43

Water Electrolysis

Answer 43

Decompostion of chemicals by passing electrical currents through a liquid or solution containing ions.

Question 44

How can poor grid integration be overcome?

Answer 44

By powering of water electrolysis.