The powers conferred by this article shall be in addition and supplemental to the powers conferred by any other law. Bonds may be issued hereunder for the improvement of the electric plant of the City notwithstanding that any other law may provide for the issuance of bonds for like purposes and without regard to the requirements, restrictions, or procedural provisions contained in any other law. Any proceedings heretofore taken by the City relating to the subject matters of this article, whether or not commenced under any other law, may, at the option of the City Council, be discontinued and new proceedings instituted under this article. It shall not be necessary for the City proceeding under this article to obtain a certificate of convenience or necessity, franchise, license, permit, or other authorization or approval from any bureau, board, commission, or other instrumentality of the State of Vermont or the City in order to acquire or improve the electric plant or for the issuance of bonds in connection therewith hereunder.