I thought of something I would like to get tested, just to see what would happen. It involves setting up multiple Lightning Rods (lets say 20-100+) in a Mystcraft World of endless lightning (caused by multiple Dragon Egg Siphons, where multiple dragon eggs are allowed), near every Lightning Rod, which are at least x blocks away from each other (where x is the amount of blocks where two lightning rods would not interfere with each other, with chunk loaders, and connected to each rod is an inter-dimensional storage unit to see how much eu per miunte is produced. The rod block would be placed on layer 2 on a flatland world, with the iron fence itself going up to built height. The idea here is to increase the chance of lightning hitting a lightning rod, since it seems normally, it can be about once every couple minutes. If it would even work, with enough rods, one could theoretically (maybe?) get several multiples of 25 million eu per minute.
This would be done in creative mode, and, I would think, would be the most expensive and best (not in terms of time, nearly output as a whole) eu generator possible in the game for some packs (I am not familiar at all with Ultimate).
It seems the weakest link with this is the lightning itself, because even if the flux causes lightning (which itself is not likely), the lightning still has to touch the rod, which is even less likely. It seems this would not work, even theoretically, unless there were 1000+ rods, and somehow all the chunks stayed loaded :l.