Blackhole starlifting makes more sense to me than Dyson spheres (see section on star lifting): <a href="https://arxiv.org/abs/1104.4362" rel="nofollow">https://arxiv.org/abs/1104.4362</a><p>> Importantly, researchers have concluded that a thin accretion disk around a rotating black hole is the most efficient power source in the universe , a process up to ~50 times more efficient than nuclear fusion occurring in stars (e.g. Thorne 1974; Narayan and Quataert 2005). If any civilization is to climb the Kardashev scale, it would certainly at some point want to master that energetic source. We call such an endeavor black hole star lifting<p>Instead of a Dyson sphere, you're using a black hole (and apparent mastery of gravity) to leech energy directly from the sun.