Actually I would like Generators as an option. Using biofuel actually is a green alternative, but basically I just dump planks into them. They give 750EU each, which means 3000 per piece of wood, which is quite nice compared to 4000EU of coal. I don't get why plain wood only gives 750, but Rubberwood (RP2) gives 3000^^ (at least it burns longer). Shouldn't vanilla-wood give 3000 too?
They don't give 3000 because rubber wood contains highly flammable resins which we can't quite extract yet with current technologies. They burn quite nicely though.