Tex. Utilities Code § 39.1593

(a) The commission shall direct the independent organization certified under Section 39.151 for the ERCOT power region to evaluate with input from a technical advisory committee established under the bylaws of the independent organization that includes market participants whether allocating the costs of ancillary and reliability services, including those procured under Section 39.159, as added by Chapter 426 (S.B. 3), Acts of the 87th Legislature, Regular Session, 2021, using a methodology described by Subsection (b) would result in a net savings to consumers in the ERCOT power region compared to allocating all costs of ancillary and reliability services to load to ensure reliability.

(b) The commission shall evaluate whether to allocate the cost of ancillary and reliability services:

(1) on a semiannual basis among electric generation facilities and load-serving entities in proportion to their contribution to unreliability during the times of highest reliability risk due to low operating reserves by season, as determined by the commission based on a number of hours adopted by the commission for that season; or

(2) using another method identified by the commission.

(c) The evaluation must:

(1) use historical ancillary and reliability services data;

(2) consider the causes for ancillary services deployments; and

(3) consider the design, procurement, and cost allocation of ancillary services required by Section 35.004(h).

(d) Not later than December 1, 2026, the commission shall submit a report on the evaluation to the legislature.