Nitinol
 

Nitinol is one Eco cool metal that I would like to hear more of

Here's a Video on it , its old but informative !

https://www.youtube.com/watch?v=oKmYqUSDch8

I Imagine a Nitinol generator using a AC's waste heat could be turned to power and fed back to the AC reducing its power consumption

https://www.youtube.com/watch?v=8-dCIkJAjyM

Just saw your nitinol post- fasinating!
did you ever figure why it didn't take off after such a great start?