You may want to think about putting one around your entire house. Put 2-4 bat boxes or energy storage device of your choice (don't forget to hook them up to redstone for a turn off switch) hook up the energy sources to each other (with the wire that goes around your house) To compensate for energy loss, hook one of the energy sources up to some sort of energy generating device (of your choice) but make sure that you only have enough energy to compensate for the energy loss from the wires, otherwise both energy sources will fill up and won't function as an electric fence. (Also I'm not sure if this will work, I haven't touched on it much. Happy testing 
[Also... again I think it would be easier to just have a pole[made of wires] with a teslacoil on top infront of your door)