Combining renewable energy portfolios

(a) An electric utility company and its electric utility affiliates may aggregate their renewable portfolios to achieve the renewable portfolio standard. (b) If an electric utility company and its electric utility affiliates aggregate their renewable portfolios to achieve the renewable portfolio standard, the public utilities commission may distribute, apportion, or allocate the costs and expenses of all or any portion of the respective renewable portfolios among the electric utility company, its electric utility affiliates, and their respective ratepayers, as is reasonable under the circumstances. (c) An electric utility company may recover, through an automatic rate adjustment clause, the electric utility company's revenue requirement resulting from the distribution, apportionment, or allocation of the costs and expenses of the renewable portfolios of the electric utility company and its electric utility affiliates. (d) To provide for timely recovery of the revenue requirement under subsection (c), the commission may establish a separate automatic rate adjustment clause, or approve the use of a previously approved automatic rate adjustment clause, without a rate case filing. The use of the automatic rate adjustment clause to recover the revenue requirement shall be allowed to continue until the revenue requirement is incorporated in rates in the respective electric utility company's rate case.