The premise is simple you need power systems and yet you can't generate it on your own. The world will have several different types of run down power generation (Coal plant, Nuclear, hydroelectric, Etc.). You will have to seek them out and build your infrastructure around it. You can play singleplayer however I'm building it with community building in mind. In my head on servers many little cities will crop up with people living in together or at least in proximity. If you have input for this pack go ahead and suggest them here.