Most people just use Thermal or Fusion until you get to the two lategame paths - Energy Exchangers (powered by Solar in the midgame, and Ray Receivers later) and Artificial Suns.

When you can industrialize the entire universe some Dyson Sphere Program tips will help you get started on the task ahead. When you can visit every planet to extract resources, build machines ...

If there were some way to generate critical photons without the dyson sphere, like ray receivers could just generate them on their own (albeit at a slow rate) it'd be entirely unnecessary.