According to Geology.com's web-article Active Volcanoes of Our Solar System, there are several volcanically active regions in the solar system asides from the Earth. In particular, the satellites Europa and Ganymede (Jupiter), Enceladus and Titan (Saturn) and Triton (Neptune) exhibit a type of volcanism known as cryovolcanism.
Cryovolcanism is defined by NASA as:
Eruption of water or other liquid or vapor-phase volatiles (collectively referred to as "cryomagma"), together with gas-driven solid fragments, onto the surface of a planet or moon due to internal heating.
Has there been any research that investigates how viable cryovolcanism would be as a power source to a future colony?
How does the energy output of cryovolcanoes compare to 'normal' magmatic volcanoes?
Note: I have read the thread What types of sustainable energy are available beyond Mars? and are looking at cryovolcanism in particular