The commission shall determine that portion of each existing electrical corporation’s retail rate effective on January 5, 2001, that is equal to the difference between the generation related component of the retail rate and the sum of the costs of the utility’s own generation, qualifying facility contracts, existing bilateral contracts, and ancillary services. That portion of the retail rate shall be known as the California Procurement Adjustment. The commission shall further determine the amount of the California Procurement Adjustment that is allocable to the power sold by the department. That amount shall be payable, by each electrical corporation, upon receipt by the electrical corporation of the revenues from its retail end use customers, to the department for deposit in the Department of Water Resources Electric Power Fund, established by Section 80200 of the Water Code. The amount determined pursuant to this subdivision shall be known as the Fixed Department of Water Resources Set-Aside.