# A new tidal barrage is proposed for a coastal region to generate electricity as a renewable energy resource. Describe how the tidal barrage generates electricity and explain one advantage and one disadvantage of using tidal energy compared with using fossil fuels.

> OCR GCSE Physics A: Gateway Science (J249) — P6.1 Energy resources · Describe · 4 marks

> A coastal council is considering replacing a small coal-fired power station with a tidal barrage. The coal-fired power station burns coal to release thermal energy, which heats water to produce steam that turns turbines connected to generators.

## Mark scheme (4 marks)

1. Wave/tidal action directly turns turbines (in the barrage) to generate electricity
2. Tidal energy is a renewable energy resource / can be replenished whilst it is being used (whereas fossil fuels are non-renewable / finite)
3. Advantage: tidal energy does not produce carbon dioxide / greenhouse gases / does not cause air pollution when generating electricity (whereas burning fossil fuels does)
4. Disadvantage: tidal energy is not always available / depends on tides so electricity cannot be generated continuously / at all times (whereas a fossil fuel power station can generate on demand)

## Key terms

- [renewable energy resource](https://www.gradenine.co.uk/glossary/renewable-energy-resource)
- [tidal](https://www.gradenine.co.uk/glossary/tidal)

## Related

- [Revision notes for OCR GCSE Physics A: Gateway Science (J249)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/a-new-tidal-barrage-is-proposed-ff1ad188) · Published by Druglandscape Ltd.