Supplemental to any existing law on the subject, and in lieu of the issuance of general obligation bonds, or the levy of taxes upon property, as by law provided, any city or village within the State of Nebraska may construct, purchase, or otherwise acquire, maintain, extend, or enlarge, an electric light and power plant, distribution system, and transmission lines, and real and personal property needed or useful in connection therewith, and pay the cost thereof by pledging and hypothecating the revenue and earnings of any electric light and power plant, distribution system, and transmission lines, owned or to be owned by such city or village. In the exercise of the authority granted in this section, any such city or village may issue and sell revenue bonds or debentures and enter into such contracts in connection therewith as may be proper and necessary. Such revenue bonds or debentures shall be a lien only upon the revenue and earnings of the electric light and power plant, distribution system, and transmission lines owned or to be owned by such city or village. No revenue bonds shall be issued until thirty days' notice of the proposition relating thereto shall have been given by the governing body by publication once each week for three successive weeks in some legal newspaper published and of general circulation in such city or village, or if no such newspaper is published therein, then by posting in five or more public places therein. If, within thirty days after the last publication of such notice or posting thereof, a referendum petition signed by qualified electors of such city or village equal in number to at least twenty percent of the vote cast at the last general municipal election held therein shall be filed with the municipal clerk, such bonds shall not be issued until the issuance thereof has been approved by a vote of the electors of such municipality at any general or special municipal election. If a majority of the voters voting on the issue vote against issuing such bonds, the bonds shall not be issued. If no such petitions are filed, the bonds shall be issued at the expiration of such thirty-day period. No publication of notice shall be required when revenue bonds are issued solely for the maintenance, extension or enlargement of any electric generating plant, distribution system or transmission lines owned by such city or village. The provisions of this section shall not restrict or limit the power or authority in the issuance of any such revenue bonds, as authorized by any home rule charter duly adopted by the electors or any city pursuant to the Constitution of the State of Nebraska.