I had this idea quite some time ago, but something just kicked it back into my consciousness.
Space, at least relatively near a star, is both very hot and very cold at the same time.
Imagine a spaceships with ion drives.
Couldn't there be a way to make water into steam using the heat from the Sun and then condense it in a shadowed area of the system. The steam generated starts flowing through circular tubes turning turbines and generating electricity. After that it flows into the condesing zone and warms up and keeps the water there above freezing and it also pushes it into the evaporation zone and the cycle repeats.
It seems a little like a perpetual machine, but it isn't since the Sun provides the energy and the system can't be completely frictionless.
It's also sounds a bit simple, but if it were possible it might be as complex as a steam locomotive or at least as a steam powered car from the 20s.
The advantage would be that as long as you can hold water and be in relatively close range to a star you would have a reliable source of electricity in a more compact form than that of solar panels and could act as a backup. It may even be the main source of power in places where asteroids are mined and a lot of dust is present and can cover the solar panels. This way you avoid exotic or radioactive ways of making electricity Water would be relatively easy to find on celestial bodies.
Some disadvantages are that if a micro meterorite or something damages your system and you lose the water you lose the power too. You also can't have your ship stationed completely in shadow for a lengthy period of time. This might be mitigated by having enough electricity stored in batteries which can keep the system warm enough and the engines powered until you exit the shadow.
This is just an idea I had. Some of you out there might have more understanging of mechanisms and physics or have some interesting thoughts and I would like to know what you guys thing of such a system. Would it be doable?
Listening to: Some weird noises coming from my neighbours.....
Reading: the internets
Watching: the internets