Notwithstanding any other provision of law, no electric membership corporation shall be authorized or empowered to furnish service inside the corporate limits of any municipality except:(1) If it is already furnishing service therein on March 29, 1973, or if its lines become annexed, including annexation that may be caused by the merger, consolidation, or any other combination of a then existing municipality and one or more other geographically defined political subdivisions, if the resulting political subdivision constitutes a municipality as defined in Code Section 46-3-3, or if its lines become included in a wholly new municipality, in any of which events the other relevant Code sections of this part shall apply and prevail;(2) To extend and furnish service initially inside a municipality the population of which at the time of such initial service is 1,500 or less, but not inconsistently with the other Code sections of this part; or(3) Notwithstanding paragraphs (1) and (2) of this Code section, if the municipality and all electric suppliers then furnishing service inside such municipality or furnishing electric service to the municipality at wholesale so consent.