Recycling of aluminium can save 95% of the energy. Be careful, sometimes tins will mix into the aluminium collection. They are easy to remove by using a magnet, as aluminium is not magnetic.
Solution 1: Compacting the cans
Solution 2: Melting aluminium
Useful Links
http://alu.ch/f/portrait_zweck.php
Documentaries
Tout sur l’aluminium (french)