Cal. Rev. & Tax. Code § 40062

The return filed by an electric utility shall show the number of kilowatt-hours of electrical energy sold to consumers in this state for which billing was first made during that quarter that are due and required to be collected for all such billings. The return shall further show the number of kilowatt-hours of electrical energy purchased by the electric utility during the calendar quarter and the number of kilowatt-hours of electrical energy generated by such electric utility during such period. Such return shall also set forth the number of kilowatt-hours consumed during such period by the electric utility for its own use and consumption and such other information as the board deems necessary for the proper administration of this part.