Across
- 3. Energy from tides
- 6. Heat energy from the Earth's interior
- 9. Gas used as a cleaner fossil fuel
- 10. Energy from the sun
- 12. Liquid fossil fuel used as fuel.
- 13. Energy from burning coal
- 14. Energy from flowing rivers
Down
- 1. Fuel from ancient plant matter
- 2. Fuel derived from plants or animals
- 4. Energy from waves
- 5. Power generated by falling water
- 7. Power from moving water
- 8. Renewable fuel made from organic materials
- 9. Energy from splitting atoms
- 11. Energy from the wind