Thank you for the fast reply!
My control variable is seeing how much one piece of coal generates in the generator. On default it generates 4,000.
This is the section in the config which I discovered that enables you to edit the energy output:
Base energy generation factors - increase for higher energy yield.
[balance / energy / generator]
generator = 1.0
geothermal = 1.0
water = 1.0
solar = 1.0
wind = 1.0
nuclear = 1.0
semiFluidOil = 1.0
semiFluidFuel = 1.0
semiFluidBiomass = 1.0
semiFluidBioethanol = 1.0
semiFluidBiogas = 1.0
Stirling = 1.0
Kinetic = 1.0
radioisotope = 1.0
By changing the generator to 0.1, the generator outputs 400, which makes sense (One decimal spot). However, you cannot add anymore decimal spots. For example I've tried 0.09 to 0.07 and it does not bring down the energy output any further.