Tex. Utilities Code § 36.001: AUTHORIZATION TO ESTABLISH AND REGULATE RATES.

(a) The regulatory authority may establish and regulate rates of an electric utility and may adopt rules for determining:

(1) the classification of customers and services; and

(2) the applicability of rates.

(b) A rule or order of the regulatory authority may not conflict with a ruling of a federal regulatory body.

Acts 1997, 75th Leg., ch. 166, Sec. 1, eff. Sept. 1, 1997.