(a) Projection system for interaction of a Lambertian radiator with the black hole. The arrows represent radiation from the cold surface at temperature Tc directed to the black hole. The remaining surface at temperature TH interacts by radiation (not shown) with the hot sky. (b) Scheme of the thermodynamic system: the planet covered with the light concentration systems shown in (a) accepts high-energy photons (long arrows) from space and sends low-energy photons (short arrows) to the black hole.

Life is dependent on the income of energy with low entropy and the disposal of energy with high entropy. On Earth, the low-entropy energy is provided by solar radiation and the high-entropy energy is disposed of as infrared radiation emitted into cold space. Here, we turn the situation around and imagine the cosmic background radiation as the low-entropy source of energy for a planet orbiting a black hole into which the high-entropy energy is expelled. We estimate the power that can be produced by thermodynamic processes on such a planet, with a particular interest in planets orbiting a fast rotating Kerr black hole as in the science fiction movie Interstellar. We also briefly discuss a reverse Dyson sphere absorbing cosmic background radiation from the outside and dumping waste energy to a black hole inside.
read more at http://aapt.scitation.org/doi/full/10.1119/1.4966905