Thanks for playing! When you place a generator you are given 20 energy as long as that generator stays on the map. I hope that answers your question.
I'd also wanted some way for the tower info to be shown, but couldn't find a good place in the UI for it, without it being messy, but I might go back and add it if this game is well received.
Originally the idea was that certain buildings would cost more energy depending on how powerful they were, so you'd have to build up energy to place the better ones. The issue with this is that without any choice of which building you place, you just get generators whenever your energy is low.
Right now it basically just adds extra delay between placing better towers.
