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.

Dyson Sphere Program oil To get hydrogen in Dyson Sphere Program, you need to upgrade your tech tree to unlock the ability to build an oil extractor and refinery.

A calculator can be of significant assistance in working out relevant Dyson Sphere Program ratios, so this quickfire guide will briefly explain how they work, and the best calculator to use.

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.