(a) The commission shall certify a power region if:
(1) a sufficient number of interconnected utilities in the power region fall under the operational control of an independent organization as described by § 39.151;
(2) the power region has a generally applicable tariff that guarantees open and nondiscriminatory access for all users to transmission and distribution facilities in the power region as provided by § 39.203; and
(3) no person owns and controls more than 20 percent of the installed generation capacity located in or capable of delivering electricity to a power region, as determined according to § 39.154.
(b) In determining whether a power region not entirely within the state meets the requirements of this section, the commission shall consider the extent to which the available transmission facilities limit the delivery of electricity from generators located outside the state to areas of the power region within the state.

(c) For a power region outside of ERCOT, the requirements of Subsection (a)(2) shall be deemed to have been met if power aggregating to approximately 50,000 megawatts can be delivered to the portion of the power region that is in this state through the payment of not more than one transmission tariff.
(d) For a power region outside of ERCOT, a power generation company that is affiliated with an electric utility may elect to demonstrate that it meets the requirements of Subsection (a)(3) by showing that it does not own and control more than 20 percent of the installed capacity in a geographic market that includes the power region, using the guidelines, standards, and methods adopted by the Federal Energy Regulatory Commission.
(e) In a power region outside of ERCOT, if customer choice is introduced before the requirements of Subsection (a) are met, an affiliated retail electric provider may not compete for retail customers in any area of the power region that is within this state and outside of the affiliated transmission and distribution utility’s certificated service area unless the affiliated power generation company makes a commitment to maintain and does maintain rates that are based on cost of service for any electric cooperative or municipally owned utility that was a wholesale customer on January 1, 1999, and was purchasing power at rates that were based on cost of service. This subsection requires a power generation company to sell power at rates that are based on cost of service, notwithstanding the expiration of a contract for that service, until the requirements of Subsection (a) are met.