No tax authorized by this article is imposed with respect to any transaction in interstate commerce or otherwise to the extent to which such business may not, under the constitution and statutes of the United States, be made subject to taxation by this state or any political subdivision thereof, nor shall any persons engaged in the business of distributing, supplying, furnishing, selling or transmitting electricity or using or consuming electricity acquired in a purchase at retail, be subject to taxation under the provisions of this article for such transactions as are or may become subject to taxation under the provisions of the "municipal retailers' occupation tax act" authorized by section 8-11-1 of the Illinois municipal code, as amended. (Ord. 0-10-11, 4-19-2010)