Across
- 5. a resource that is free and won't ever run out
- 6. an energy that can be reused
- 7. using less energy but getting the same results as if it was normal
- 8. form of power produced by the natural rise and fall of tides
- 9. an energy powered by wind
- 10. energy made out of things that were once living.
Down
- 1. Hydrogen fuel cells produce electricity by combining hydrogen and oxygen atoms
- 2. an energy that is created out of flowing water.
- 3. energy powered by the sun
- 4. energy that takes longer time to restore