It's the inverse square law that bites you here as the same amount of energy gets stretched out into a larger sphere as it travels outwards (at earth the energy is 1.4kW for a square meter, when going outwards, this square meter gets stretched)
Double the distance and you get 1/4th the energy.
Saturn is 9AU or 9 times as far as earth; 1/81th the energy. (1400 / 9^2 = 17, so math checks out; roughly)
We're quite lucky to be close enough for solar energy to be a viable source of energy.
If solar energy were not viable, Hacker News posts might be written by technologically inclined chemoautotrophs hacking in the basement of their hydrothermal vent.
https://en.wikipedia.org/wiki/Chemosynthesis
Double the distance and you get 1/4th the energy.
Saturn is 9AU or 9 times as far as earth; 1/81th the energy. (1400 / 9^2 = 17, so math checks out; roughly)
We're quite lucky to be close enough for solar energy to be a viable source of energy.
[*]: https://en.wikipedia.org/wiki/Inverse-square_law