They say that being sucked into a blackhole will kill you instantly, but if you could some how survive the trip you would move at the speed of light or faster. So you might not need a power source if there was a way to reflect off the pull off a blackhole. Still there's the problem with infinite mass and our fragile little bodies.

As you're being pulled into a blackhole time moves slower and slower and everything outside would look as if it were speeding by faster and faster. Would be kind of interesting to spend 1 minute in a blackhole. Time would be extremely slow, but when you came out it would be like 100 years later.

Sounds to me if we could someday harness this power, that moving forward in time will be possible. Moving into the past will definately be harder and i cant see that happening.