Figure 1 shows a large wind farm off the coast of the UK
The mean power output of the wind farm is 696 MW, which is enough power for 580 000 homes.
i- Calculate the mean power needed for 1 home.
Give your answer in watts.
[2 marks]
SOLUTION
To calculate the mean power needed for 1 home, let us divide the total power output of the wind farm by total number of homes to which electricity is supplied.
Don’t forget to change mega watts (MW) to watts (W). Take the help from the following table.
Prefix | Meaning |
Giga (G) | |
Mega (M) | |
Kilo (k) | |
Deci (d) | |
Centi (c) | |
Milli (m) | |
Micro ( | |
Nano (n) |
On one day the demand for electricity in the UK was 34 000 MW.
ii- Suggest two reasons why wind power was not able to meet this demand.
[2 marks]
SOLUTION
(Here you may write the challenges/disadvantages of wind turbine that are logically alligned to the question’s need.)
Since wind power is unreliable, the mean power output at that day might not have been enough to meet the demand.
Wind might have been too light that little power was produced.
Uk don’t have enough wind turbine to meet the demand.
(You may pick any two reasons.)
Some of the energy from the wind used to rotate a wind turbine is wasted.
An engineer oils the mechanical parts of a wind turbine.
iii- Explain how oiling would affect the efficiency of the wind turbine.
[3 marks]
SOLUTION
Oiling reduces friction as a result less energy is wasted in the form of heat. This makes a larger proportion of energy to be useful. Hence, increasing the efficiency.
(An Increase in useful power output causes increase in useful power input. As the formula of efficiency is
In most homes in the UK there are many different electrical devices.
iv- Explain why people should be encouraged to use energy efficient electrical devices.
[2 marks]
SOLUTION
So that their is less wastage of energy.
To minimize the energy demand.
(Remember, energy efficient electrical devices would waste less energy; as a result, there is greater proportion of useful output energy.)
