If there are Force/Shield Fields they need to work close to the same way the Power Gens do, by taking instead 4-8 corners and linking them together, allowing players to make a Wall, or around important functions on a ship a Cube. Of course i would have ot say it should be similar to Cloaking, and radar Jammers that the use of them uses a Constant power supply not as much as others, but would need a good bit if it is hit by Weapons (or could be linked to shields in damage obsortion) but still needs to pull a constant power supply to function to keep the game balanced.
Best wat to put is by making a 4 block corner or 3 block (depending on Cube and wall types) that once linked would need a Centeral \"Shield Core\" type block that if destroyed would cause the Force/Shield Field to be lowered, but can also be turned on and off through the \"Shield Core\" allowing you to take in Friendly ships, and keep out Unfriendly. (A Protection grid/system)