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GCSE Questions: Energy Sources

Q12.A small community of people live in an area in the mountains. The houses are not connected to the National Grid. The people plan to buy an electricity generating system that uses either the wind or the flowing water in a nearby river. Here is a sketch of where these people live.

 

(a) It would not be economical to connect the houses to the National Grid. Give one reason why.

Any one from:

high cost of installing overhead power lines or underground cables or pylons

high cost as (very) long cables needed

amount of electricity required is too low

not enough (surplus) electricity would be generated

[1 mark]

(b) Here is some information about the two electricity generation systems they could set up:

A wind turbine costs £50 000 to buy and install.

A hydroelectric generator costs £20 000 to buy and install.

The average power output from the wind turbine would be 10 kW.

The hydroelectric generator would produce a constant power output of 8 kW.

Compare the advantages and disadvantages of the two methods of generating electricity. Use your knowledge of energy sources as well as information given above in your answer.

 

This type of question is marked in two ways:

- the examiner looks for relevant points

- but also for a logical sequence...

It is not just a 'tick fest' - but a marker does look to see how many relevant points you have made, then considers how you have strung them together to put your answer into a 'level'

Level 3:

A clear comparison of advantages and disadvantages of each method
5 - 6 marks
Level 2:

At least one advantage and one disadvantage is stated for one method

and

a different advantage or disadvantage is stated for the other method
3 - 4 marks
Level 1:

At least one advantage or one disadvantage of either method
1 - 2 marks
Level 0:

No relevant information
0 marks

 

Examples of physics points that should be made in the response:

Advantages of both methods:
both renewable sources of energy
both have no fuel (cost)
both have very small (allow 'no') running costs
no carbon dioxide (greenhouse gases) produced, so carbon neutral and doesn't contribute to global warming		 Disadvantages of both methods
(may be) noisy
visual pollution
Advantages of wind:
higher average power output		 Disadvantages of wind:
higher (installation) cost
variable / unreliable power output
(may) kill birds / bats
Advantages of hydroelectric:
constant / reliable power (output)
lower (installation) cost		 Disadvantages of hydroelectric:
lower power output
(may) kill fish or (may) damage habitats
more difficult to set up (within river)

 

The examiners ignored payback time or time to build them - which rather surprised me as they had given you costs in the information and you would expect that they therefore expected you to go into implications if the costs involved - but there you go - that is examiners for you!

[6 marks]

(Total 7 marks)