Subject to the prior approval of the Board of Public Works, the Authority may issue bonds to refund any of its outstanding bonds, including the payment of: any redemption premium; and any interest accrued or that will accrue to the earliest or any subsequent date of redemption, purchase, or maturity of the bonds. For the public purpose of achieving a savings in the effective costs of debt service or alleviating impending or actual default, the Authority may issue refunding bonds directly or through a debt restructuring. The bonds authorized by this subsection may be issued in one or more series and in an amount in excess of that of the bonds to be refunded.