Dyson Sphere Program has several ways of generating power. From the wind turbine you start with, to fusion generators, artificial stars and of course the Dyson Sphere itself. Some of these generators and your mech, Icarus, run on one or more different fuels. This page lists all fuels in the game and explains the stats they use.
Fuel stats
All fuels have two stats that tell you how good they are; Energy, and Fuel chamber gen.
Energy is the total energy each item contains. When used in you mech, the Mini Fusion Power Station and the Artificial Star this is the total energy it generates. Thermal Power Stations incur a 20% energy loss for all fuels it uses.
Fuel chamber gen. marks how efficiently your mech's Fuel Chamber is at converting the fuel. This only changes how fast energy is recharged, not how much total energy is produced. Note that coal with 0% is the only fuel that matches your Energy Circuit upgrade level. Both positive and negative percentages are relative to this. For instance; both a Hydrogen Fuel Rod and the 5 Hydrogen it requires to produce, contain a total of 40MJ, but the fuel rod has a Fuel chamber gen. of +200% instead of the +100% of regular hydrogen. Meaning you will use the fuel rod 50% faster than the regular hydrogen and also recover energy twice 50% faster. The final time a fuel lasts and your recovery speed depend on your Energy Circuit upgrade level. As this stat only affects your mech, processing hydrogen for use in the thermal power plant is a waste of resources.