1 IC2 EU is 4 RF, this is the official ratio, as 10 RF makes 1 BC MJ which is 2.5 IC2 EU. This has been negotiated back in ye olden days between people who had to convert Power.
The ridiculous part is, the way I handled balance is I took all the Fuel values of things like Buildcraft Fuel or MFR Bio Fuel, converted them to the highest probable EU value, and then just gave that insane value as a Fuel Value for my Generators.
So the various GT6 Generators are always the most efficient way to use your other Mods Fuels. Oh and ofcourse I balanced all my Stuff around those ridiculous Values, so it is always balanced for me, and all the other Mods are getting way more power than they originally intended.
Pretty sure this is called Power Creep and it definitely is already too insane to care about it, unless you make it even worse. XD