Well first you'll need to setup a working reactor. It's usually best to hook up glass fibre wires to the bottom of the reactor through the floor so you can cover the entire reactor in water. With those wires, connect them to a storage space. Preferably you'll be hooking them up to numerous MFSUs. You can then hook up ELECTRCAL engines added by forestry to convert EUs to BCE (forgot the name of BC energy :\). You can hook up the electrical engines on the line leading straight out of the reactor towards the MFSUs, you do not need to us transformers at all. At least it worked that way in MC 1.1 IC2, haven't tried it in the latest Dev build.