These are advanced shielding generators that consume a huge amount of energy. They require 5 city sized Shield generators at different parts of the planet to ensure they can cover the planet. The shield emitters must have 4 Fusion plants or 2 Antimatter Plants to generate the amount of power. They consume 200 gW of power per minute to shield the planet. They protect the planet from over 300 Heavy Cruisers ensuring these structures are intact. Fortress worlds also known as Citadels have four to five of these layers as well as multiple layers of Planetary Rings.