(a) All transmission and distribution utilities shall provide transmission service at wholesale under Subchapter A, Chapter 35. In addition, on and after January 1, 2002, a transmission and distribution utility shall provide transmission or distribution service, or both, at retail to an electric utility, a retail electric provider, a municipally owned utility, an electric cooperative, or an end-use customer at rates, terms of access, and conditions that are comparable to those that apply to the transmission and distribution utility and its affiliates. A municipally owned utility offering customer choice or an electric cooperative offering customer choice shall likewise provide transmission or distribution service, or both, at retail to all such entities in accordance with the commission’s rules applicable to terms and conditions of access and at rates adopted in accordance with Sections 40.055(a)(1) and 41.055(1), respectively.
(b) When necessary to serve a wholesale customer an electric utility, an electric cooperative that has not opted for customer choice, or a municipally owned utility that has not opted for customer choice shall provide wholesale transmission service at distribution voltage. A customer of a municipally owned utility that has not opted for customer choice or of an electric cooperative that has not opted for customer choice may not claim the status of a wholesale customer or be designated as a wholesale customer if the customer is being or has been served under a retail rate schedule of the municipally owned utility or electric cooperative.

(c) On or before January 1, 2002, the commission shall establish for all retail electric utilities offering customer choice reasonable and comparable terms and conditions, in accordance with § 39.201, that comply with Subsection (a) for open access on distribution facilities and shall establish, for all retail electric utilities offering customer choice other than municipally owned utilities and electric cooperatives, reasonable and comparable rates for open access on distribution facilities.
(d) The terms of access, conditions, and rates established under Subsection (c) shall be comparable to the terms of access, conditions, and rates that the electric utility applies to itself or its affiliates. The rules shall also provide that all ancillary services provided by the utility to itself or its affiliates are also available to third parties on request on a nondiscriminatory basis.
(e) The commission may require an electric utility or a transmission and distribution utility to construct or enlarge facilities to ensure safe and reliable service for the state’s electric markets and to reduce transmission constraints within ERCOT in a cost-effective manner where the constraints are such that they are not being resolved through Chapter 37 or the ERCOT transmission planning process. In any proceeding brought under Chapter 37, an electric utility or transmission and distribution utility ordered to construct or enlarge facilities under this subchapter need not prove that the construction ordered is necessary for the service, accommodation, convenience, or safety of the public and need not address the factors listed in Sections 37.056(c)(1)-(3) and (4)(E). Notwithstanding any other law, including § 37.057, in any proceeding brought under Chapter 37 by an electric utility or a transmission and distribution utility related to an application for a certificate of public convenience and necessity to construct or enlarge transmission or transmission-related facilities under this subsection, the commission shall issue a final order before the 181st day after the date the application is filed with the commission. If the commission does not issue a final order before that date, the application is approved.
(f) The commission’s rules must be consistent with the standards of this title and may not be contrary to an applicable decision, rule, or policy statement of a federal regulatory agency having jurisdiction.
(g) Each power region shall have generally applicable tariffs approved by the commission or a federal regulatory agency having jurisdiction that guarantees open and nondiscriminatory access as required by § 39.152. This subsection may not be deemed to vest in the commission power to set or approve distribution access rates of a municipally owned utility or an electric cooperative that has adopted customer choice.
(h) A customer in a multiply certificated service area may switch its retail distribution service provider among certificated retail electric utilities only by disconnecting from the facilities of one retail electric utility and connecting to the facilities of another retail electric utility.
(i) The commission, in cooperation with transmission and distribution utilities and the ERCOT independent system operator, shall study whether existing transmission and distribution planning processes are sufficient to provide adequate infrastructure for seawater desalination projects. If the commission determines that statutory changes are needed to ensure that adequate infrastructure is developed for projects of that kind, the commission shall include recommendations in the report required by § 12.203.