You mean https://en.wikipedia.org/wiki/Penrose_process https://en.wikipedia.org/wiki/Penrose_process - it doesn't look like it is very efficient or effective, a

You mean https://en.wikipedia.org/wiki/Penrose_process https://en.wikipedia.org/wiki/Penrose_process - it doesn't look like it is very efficient or effective, and you'd have to get so close to the black hole that you'd be shredded to get anything at all.