Ala. Code § 41-10-501

The authority may, from time to time, sell and issue its refunding bonds, without limitation as to principal amount, for the purpose of refunding any matured or unmatured bonds of the authority at the time outstanding and paying any premiums necessary to be paid to redeem any such bonds so to be refunded and all expenses incurred in connection therewith. Such refunding bonds shall be subrogated and entitled to all priorities, rights, and pledges to which the bonds refunded thereby were entitled.