Yep.

Things falling towards a black hole have an extraordinary amount of energy. Something free falling towards one would pick up a vast amount of speed before crossing the event horizon. Which means if it smacks into anything that event is going to be energetic. If something actually is orbiting, it needs to change speed a lot to drop below the ISCO (innermost stable circular orbit). And that is also an energetic process.

So while nothing can escape the black hole itself, the system around it can have a lot of energy to spare that make accreting black holes some of the brightest objects in the universe. As well as photons they can also produce impressive jets of matter. Nobody has ever doubted that there is plenty energy to spare to make the jets, but the mechanism has been a bit of a mystery.