Generating Electricity

Question 1

What are the advantages of underground cables?

Answer 1

• Cannot be seen
• Not a hazard to aircraft
• Less likely to damaged by the weather

Question 2

What are the disadvantages of overhead cables?

Answer 2

• Higher risk of electric shock
• Can be damaged by weather
• Hazard to aircraft
• Can spoil the view

Question 3

What are the disadvantages of underground cables?

Answer 3

• Harder to access for repairs
  
  • Cost more to repair
• More expensive to repair
• Needs thicker cables
• Needs a cooling system
• Disruptive to land to install
• Needs electrical insulating

Question 4

What are the advantages and disadvantages of wind turbines?

Answer 4

Adv.
-Wind is a renewable resource
-They don't produce pollutants
Dis.
-Wind farms are noisy
-Don't run in low or high wind speeds (They are unreliable)

Question 5

What are the advantages and disadvantages of solar cells?

Answer 5

Adv.
-Renewable
-No fuel costs
-No pollutants produced
Dis.
-Expensive and inefficient
-Produce less at night/when its cloudy

Question 6

Evaluate geothermal energy.

Answer 6

Adv.
-Renewable
-Reliable
-No fuel costs
-No pollutants
Dis.
-Only a few locations where it is suitable

Question 7

What are the advantages of overhead cables?

Answer 7

• Easy to access for repairs
• Lower install costs than underground cables
• Air acts as an insulator
• Cooled by the air

Question 8

Why does the national grid use transformers?

Answer 8

The supply from the power station is stepped-up to 400,000V so that there is less energy lost as heat in the power lines.
It is stepped-down to 230V to be used by homes and business.

Question 9

Evaluate nuclear fission power stations.

Answer 9

Adv.
-Reliable
-Good for constant baseline power supply
-Don't produce CO2
Dis.
-Expensive to build and decommission
-Long decommission time
-Slow start-up times
-Slow to adjust output
-Produce radioactive waste