There is created a public body corporate and politic to be known as the Municipal Electric Authority of Georgia, which shall be a public corporation of the State of Georgia and shall have a perpetual existence. This authority, however, shall not be a state institution nor a department or agency of the state but shall be an instrumentality of the state, a mere creature of the state, having distinct corporate entity and being exempt from Article 2 of Chapter 17 of Title 50. The authority shall have its principal office in Fulton County, and its legal situs or residence for the purpose of this article shall be Fulton County.