(1) In any multiyear rate plan proposed by a natural gas company or combination utility, the company may propose a merger into a single rate base of its regulated gas operations with its operation of a thermal energy network. The commission may approve the merger of gas and thermal energy rate bases if the commission finds that such a merger is in the public interest.

(2) For a natural gas company or combination utility that has merged gas and thermal energy rate bases, the natural gas company or combination utility must monetize benefits received from any applicable federal and state tax and other incentives for the benefit of customers. These benefits must be separately accounted for and amortized on a schedule designed to mitigate the rate impacts to customers after the rate bases are combined. These credits may not be used for any other purpose, unless directed by the commission.