In this subchapter, "public utility" means and includes a private corporation that does business in this state and has the right of eminent domain, a municipality, or a state agency, authority, or subdivision engaged in the business of:
(1) generating, transmitting, or distributing electric energy to the public;
(2) producing, transmitting, or distributing natural or artificial gas to the public; or
(3) furnishing water to the public.