in IC2-exp there is now what we call the semifluid generator its like the thermal generator but accepts fuels from the forge fluid dictionary.
fuels such as Biogas (MFR), Ethanol (forestry), Liquified coal (TE3), Fuel (BC), Oil (BC) and then there's UE's Mekanism and Atomic Science which produces MJ, RF and EU (despite producing their own power system) ... the machines accept EU,MJ and RF