curds and whey= power+heat

[Thehardway]

This is probably one of the best alternative energy processes  I have run across in a while. 

http://www.fairviewswisscheese.com/green-energy/

I grew up next to this cheese plant.  The farm I worked on provided milk to them.  neat to see where they have taken it.  Technology shows up in some strange places.  Not much going to waste here!

[Ianab]

In NZ the Whey ends up made into Vodka. Called Wheysky . It's worth more than Natural gas, do they run the plant on gas, and sell the vodka.   ;) :D

The other fats and proteins are generally processed out and recovered as they are themselves valuable, assuming you have the volume of milk to process.

Ian