Given that no sunlight can penetrate Europa's ice shell, what would be the type of energy that could make some form of europan life possible?

life in europa is possible due to chemical energy, surface and ocean intracts with one another and give off chemical energy.

Explanation:

the ocean in europa is in contact with the underlying rocky mantle and at high temperatures, its rocks and water interact. oxidization and reduction in which molecules give off and accept electrons occur in it and in deep ocean, when chemically reduction vent fluids interacts with oxygen containing seawater to produce energy that can support micro-organisms and animals.