SECTION 3D. municipal electric systems — authorized indebtedness. Notwithstanding the limitations and requirements of Section 3, Article VIII, of the Constitution of the State of Idaho, any city owning a municipal electric system may:
(a) acquire, construct, install and equip electric generating, transmission and distribution facilities for the purpose of supplying electricity to customers located within the service area of each system established by law and for the purpose of paying the cost thereof, may issue revenue bonds with the assent of a majority of the qualified electors voting at an election held as provided by law; and
(b) incur indebtedness or liability under agreements to purchase, share, exchange or transmit wholesale electricity for the use and benefit of customers located within such service area;
provided that any revenue bonds, indebtedness or liability shall be payable solely from the rates, charges or revenues derived from the municipal electric system and shall not be secured by the full faith and credit or the taxing power of the city, the state or any political subdivision.