The National Grid

Question 1

What does the National Grid do?

Answer 1

Takes electrical energy from power stations to where it is needed in homes and industry

Question 2

What does the National Grid enable?

Answer 2

Energy to be generated anywhere on the grid and be supplied anywhere else on the grid

Question 3

To transmit the huge amount of power needed, you either need a ____ ____ or a ____ ____

Answer 3

To transmit the huge amount of power needed, you either need a high voltage or a high current

Question 4

What is the problem with using a high current to transmit electrical energy around the grid?

Answer 4

A lot of the energy is lost as heat energy in the cables

Question 5

So why do we use a high voltage?

Answer 5

It is much cheaper _{(as you lose less energy via heat in cables)} to use a boost the voltage up really high ^{(400 000 V)} and keep the current very low

Question 6

What is used to get the voltage to 400 000 V to transmit power?

(2)

Answer 6

1. Tranformers
2. Pylons with huge insulators

Question 7

Using pylons with huge insulators is still ____ than keeping the ____ ____

Answer 7

Using pylons with huge insulators is still cheaper than keeping the current high

Question 8

What does the ‘step-up- transformer do and why?

Answer 8

Increases the voltage and decreases the current for efficient transmission

Question 9

What does the ‘step-down’ transformer do and why?

Answer 9

Decreases the voltage and increases the current to make the energy safe and usable