Power Generating Units are exactly what the name implies - a medium sized power generator. You can usually find them around industrial areas or hangars and are commonly used as power supply for small camps; X-wings and Y-wings carry one in case of emergency landing. They have no artificial intelligence and therefore won't attack you, but beware of them in the middle of a fight becuase a stray laser or misplaced detonator can have a disastrous (or beneficial) effect. The generators are very unstable and will explode with only a slight amount of provocation.

Suggested Method of Attack - If you're moving into an area you suspect holds enemy troops, try to take out the PGUs before you enter the area if you can. Rolling a TD into the room can not only remove the possibility of your being damaged by the PGU in a firefight, but the resulting explosion may also take care of the troops in the room. Beware around these things because while you may be careful your enemies might not care so much.