Nobody (sane) is talking about putting nuclear reactors on Satellites in close Earth orbit so we don't have to worry about them generating heat. They've got solar panels that move some of the solar energy they absorb to a central location which presents problems in moving the waste heat back out so that spot doesn't get too hot. But that doesn't change the overall equilibrium temperature.
I'm not sure if you're being serious or not? Any use of power turns useful work into heat (conservation of energy and all that), which raises the temperature of the satellite, until radiative cooling can equalize within incoming heat (solar irradiation).
You’re ignoring where the power comes from. Unless you take it up there with you (eg. nuclear material) it has to come from the sun, so you can’t use or emit more energy than the sun hit you with. You can move it around in space and time, but you can’t get on average hotter than a lump of rock in the same spot.