Subject: Where is the energy coming from?

Given, in a system the sum of matter and energy does not change.  Where is the source 
of energy in the following system?  As Europa orbits Jupiter, it gets deformed by the 
enormous gravitational forces (tides), this kneading of its thick, icy surface (?60km) would 
create sufficient friction to heat the core (electromagnetic energy) and possibly have 
some of the ice liquify. The question is, if energy is apparently created, where is it sucked 
from? Would the orbit be affected (decaying)?

Re: Where is the energy coming from?