The expense incurred in carrying out the provisions of sections 455.23 to 455.25 may be paid out of any money in the general fund of the city available for the purpose. If there is no money in such fund available, the bonds of the city may be issued under and pursuant to the provisions of chapter 475. The proposition of constructing a system of poles, wires and cables and the proposition to issue bonds therefor may be submitted at the same election.