Nature has already fashioned mega-masers in clouds near galactic black holes, and therefore radiation pumping by artificial means may not be so difficult to set up, say the authors.
A consortium of super-civilizations might pool resources to build a chain of power stations encircling the black hole. It would be the heart of a robust and fault-tolerant energy grid connecting numerous worlds like a fantasy scene out of the film "Tron."
However, I think it is more likely that a federation of expanding space colonies, spawned from a single mother civilization, would work together to maintain their viability. This wouldn't run into the thorny question of how two or more independent but similarly co-evolved species manage to contact each other and work out a practical energy infrastructure.
But could we detect evidence of such a mega-engineering project?