A tidal power station uses the movement of seawater to generate electricity. Explain how a tidal power station generates electricity and transfers it to consumers via the National Grid.

Eduqas GCSE Physics — 1.2 Generating electricity · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Tidal power stations are built in estuaries where large volumes of seawater flow in and out with the tides. The UK has some of the largest tidal ranges in the world.

Model answer (4 marks)

A tidal power station uses the movement of seawater to drive a turbine.
The turbine turns a generator, which converts the mechanical energy into electrical energy.
The electricity is stepped up by a transformer to a high voltage.
The high‑voltage electricity is then transmitted through power cables to the National Grid, where it is distributed to consumers.

Examiner tips

  • Use the exact sequence: seawater → turbine → generator → transformer → high‑voltage transmission
  • Mention the purpose of stepping up voltage: to reduce energy loss

Common mistakes

  • Confusing the direction of flow (turbine drives generator, not vice‑versa)
  • Omitting the transformer step or the reason for high‑voltage transmission

Mark scheme (4 marks)

  1. The movement/flow of seawater drives (rotates) a turbine
  2. The turbine drives a generator which produces electricity
  3. A transformer increases (steps up) the voltage before transmission along power cables
  4. Electricity is transmitted at very high voltage to reduce energy loss, making transmission more efficient

Key terms in this question

National Grid

Related

More Generating electricity questions

▶ Try answering this question with AI marking (free) →