Except as otherwise provided by this act, the Authority may acquire all real or personal property that it deems necessary for carrying out the purposes of this act, whether in fee simple absolute or a lesser interest, by condemnation and the exercise of the power of eminent domain in the manner and by like proceedings as provided by general law with respect to condemnation. The Authority shall never have power of eminent domain with respect to any real or personal property or interest therein at the time owned or leased by any person as part of a system, whether existing, under construction or being planned, or facilities for the generation, transmission, production or distribution of electrical power. The authority of the Authority to acquire real or personal property by condemnation or the exercise of the power of eminent domain shall be a continuing power, and no exercise thereof shall exhaust it.