I actually thought about that too, but couldn't find any arguments why zombies should fear lightbulb :P but the idea is not about the zombies but it to be a game element. As far s the zombies spawning, they should spawn only not directly into the village/town and come into the town area when the power goes down either way someone turns it off from the plant or the resources end or the plant itself needs repairing. That way coming into the town and leaving the town requires caution 'cos there's zombies around it. As far as the game element goes the simple idea is "Control the power, control the area!". You need resources to create power, you need to maintain the plant, you can turn the electricity on and off from the plant. I had a simple situation in mind when i posted my idea. Player or rather a group controls one powerplant, they see that some other group enters that area. they let them enter the town, then switch on the lights so zombies would see them as in daylight and then attack and then the other way around when approaching an area you see it's lit up then you can assume there's someone controlling the power you can then try to gain the control to yourself or do other things or whatnot... It would mainly be just to enhance the night play...'cos during the daytime in the server you would only need power for charging equipment. That's why in my opinion it shouldn't be overly complicated.