What are possible power sources for satellites?

What happens to a ship when it runs out of power?

Many spacecrafts run out of electricity. Batteries and fuel cells can run out of fuel and RTG's can cease to provide enough heat to be effective. Solar panels can keep providing electrical power as long as the panels are functional and the ship is in the direct light of the Sun and close enough to the Sun to make enough power. But DS1 will travel far enough away from the Sun so that there is not enough electricity generated by the solar panels to power the ship adequately.

At this point, shipboard systems will begin to fail. Remote Agent, solar ion propulsion, and communications will all cease to function. The ship will not stop moving, but will continue traveling in the same direction and at the same speed unless it crashes into something, but will be unable to change course, do science, or communicate with Earth.

What are radioisotope thermoelectric generators (RTG's)?
What are batteries?
What are fuel cells?
Do solar panels wear out?
What will happen to DS1 after its done all of its objectives?

Why do solar panels become less useful the farther they get from the Sun?
What DS1's battery life?
How do objects in space travel?
What happens to a ship when its remote agent "dies?"

How much power does DS1 use? How much power does it produce?
What would happen if DS1 ran out of fuel?