No certificate of convenience and necessity shall be required under any provision of this act where the electricity is to be used exclusively in operations incident to the working of metalliferous mines and mining claims, mills, or reduction and smelting plants, and the transmission lines and distribution systems are owned by the consumer or where several consumers severally own their individual distribution systems and jointly own, in their own names or through a trustee, the transmission lines used in connection therewith and transmit such electricity, whether generated by themselves or procured from some other source, over such transmission lines and distribution systems without profit, and to be used for their private uses for the purposes aforesaid in places outside the limits of incorporated cities, towns and villages, and not for resale or public use, sale or distribution.