So here is a spoiler, dont read if you want to figure it out on your own. The turbine is used to open the doors that need power, just set it by them. That way you dont have to pay to open the front door. There are 3 pieces needed. On the garage level there are 2 pieces, they make a zombie shield. Use just like a riot shield. On the farm there are 3 pieces that turn the power on. Thats as far as i got. I keep missing the bus as i am just exploring still.