Rigs don't have Power Grid or CPU fitting requirements, but instead require calibration, a rig-specific fitting resource. All ships have 400 calibration points, except for pirate faction ships which have 350. A Tech 1 rig requires between 50 and 250 calibration points, with Tech 2 variants requiring 50% more calibration than their Tech 1 equivalents.They also are destroyed when you repackage the ship (often required for our haulers).