Across
- 3. the perceptible natural movement of the air
- 4. organic matter used as a fuel
- 9. existing in finite quantity; not capable of being replenished
- 11. a black or brownish-black sedimentary rock formed from ancient plant matter
- 12. the sun's rays as a source of energy
- 13. a stock or supply that can be drawn on by a person in order to function effectively
- 14. relating to or denoting the generation of electricity using flowing water
- 16. discarded as worthless, defective, or of no use
- 17. convert into reusable material
- 18. flammable gas occurring naturally underground and used as fuel
Down
- 1. make smaller or less in amount, degree, or size
- 2. harnessing heat from within the Earth for energy
- 5. contaminate with harmful or poisonous substances
- 6. the action of using something again
- 7. a viscous liquid derived from petroleum, especially for use as a fuel
- 8. a source of energy that is not depleted by use
- 10. non-renewable energy sources that are formed from the remains of ancient plants and animals
- 15. the capacity to do work, in various forms like heat, light, motion, and electricity