Be wary of allowing a firefight to break out in the vicinity if you wish to claim them intact. Small Scouts yield a maximum of one power source, while larger ships can yield up to four. UFO Power Sources can be recovered following successful UFO landing and crash site missions involving all classes of alien ships.
The Elerium core must be the key to its amazing efficiency. This power cell is apparently capable of generating enough energy to power the alien craft and its requisite systems.
