(a) An electric utility is allowed to recover all of its net, verifiable, nonmitigable stranded costs incurred in purchasing power and providing electric generation service.
(b)(1) Recovery of retail stranded costs by an electric utility shall be from all existing or future retail customers, including the facilities, premises, and loads of those retail customers, within the utility’s geographical certificated service area as it existed on May 1, 1999. A retail customer may not avoid stranded cost recovery charges by switching to new on-site generation except as provided by § 39.262(k). For purposes of this subchapter, “new on-site generation” means electric generation capacity greater than 10 megawatts capable of being lawfully delivered to the site without use of utility distribution or transmission facilities and which was not, on or before December 31, 1999, either:
(A) a fully operational facility; or
(B) a project supported by substantially complete filings for all necessary site-specific environmental permits under the rules of the Texas Natural Resource Conservation Commission in effect at the time of filing.
(2) If a customer commences taking energy from new on-site generation which materially reduces the customer’s use of energy delivered through the utility’s facilities, the customer shall pay an amount each month computed by multiplying the output of the on-site generation by the new sum of competition transition charges under § 39.201 and transition charges under Subchapter G which are in effect during that month. Payment shall be made to the utility, its successors, an assignee, or other collection agent responsible for collecting the competition transition charges and transition charges and shall be collected in addition to the competition transition charges and transition charges applicable to energy actually delivered to the customer through the utility’s facilities.

(c) In multiply certificated areas, a retail customer may not avoid stranded cost recovery charges by switching to another electric utility, electric cooperative, or municipally owned utility after May 1, 1999. A customer in a multiply certificated service area that requested to switch providers on or before May 1, 1999, or was not taking service from an electric utility on May 1, 1999, and does not do so after that date is not responsible for paying retail stranded costs of that utility.
(d) An electric utility shall pursue commercially reasonable means to reduce its potential stranded costs, including good faith attempts to renegotiate above-cost fuel and purchased power contracts or the exercise of normal business practices to protect the value of its assets. The commission shall consider the utility’s efforts under this subsection when determining the amount of the utility’s stranded costs; provided, however, that nothing in this section authorizes the commission to substitute its judgment for a market valuation of generation assets determined under Sections 39.262(h) and (i).