Cal. Rev. & Tax. Code § 24303

Any grant made in any taxable year by the Secretary of the Treasury under Section 1603 of the American Recovery and Reinvestment Tax Act of 2009 (Public Law 111-5) to a person that places in service specified energy property shall not be includable in the gross income or the alternative minimum taxable income of the taxpayer, but shall be taken into account in determining the basis of the property to which that grant relates, except that the basis of that property shall be reduced using rules prescribed under Section 50(c) of the Internal Revenue Code in the same manner as a credit allowed under Section 48(a) of the Internal Revenue Code, and adjusted in accordance with rules applied by the Secretary of the Treasury under Section 1603(f) of the American Recovery and Reinvestment Tax Act of 2009 (Public Law 111-5).