Supply and demand
2 marks · EasyElectricity generation must match supply to demand at all times.
Name two factors that affect the demand for electricity throughout a typical day.
Describe one way the National Grid prepares for predictable changes in demand.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Time of day; weather (e.g., temperature); events (e.g., sporting events)
(b) The National Grid predicts demand and schedules power stations to be ready to supply power at times when demand is likely to go up.
Common mistakes: Sunlight for a; No planning by grid for b
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Names two valid factors affecting demand
B2 (b) · 1 mark · Describes that the grid plans ahead and schedules stations
Worked solution
a) For example, demand rises in the morning and evening, or during cold weather. b) The grid can schedule quick-response stations to come online at peak times.