ok, so this is in part a poke of fun at everyone suggesting lightning rods. But my reply to that very topic spawned an idea... no measly lightning rod feeding EU storage, but the ElectroVitalyzer!
Picture a contraption that Frankenstein himself would be proud of, which uses as input the constituent parts of creatures - and when struck by lightning, it brings those pieces TO LIFE so they can serve as your minions/underlings/cannon fodder!
You could use rotting flesh as a base for all the recipies, with the 2nd ingredient providing the type: say, arrows for a pet Skeleton, gunpowder for a Creeper minion, and suchlike.
If this ever gets built - I'll post a tribute video in full Rocky Horror Picture Show drag.
Seriously, who doesn't want their own Zombie army?