If you’re enjoying this list, check out 25 Cleanest Cities In The World. While cold fusion is still hypothetical, there have been several predictions for technology throughout the years. Check out 25 Cleanest Cities In The World. Photos: 24. CODIGO82/wikimedia commons, 22. Geoffrey.landis at English Wikipedia, 21. Fundy/wikimedia commons, 19. Activ Solar via Flickr, 18. Arto Alanenpaa/wikimedia commons, 17. Bruno Cordioli via Flickr, 16. Valcenteu/wikimedia commons, 15. NuScale/wikimedia commons, 13. Toby Hudson/wikimedia commons, 12. Stranman84/wikimedia commons, 11. afloresm via Flickr, 10. Carnegie Wave Energy Limited/wikimedia commons, 8. Claus Ableiter/wikimedia commons, 7. Norbert Nagel/wikimedia commons, 6. James Grellier/wikimedia commons, 5. Jusdafax/wikimedia commons, 4. Bob Ford via geographic.org.uk, 3. Theresa Knott/wikimedia commons, 2. mycobond via Flickr