Rates charged by a company for service pursuant to a franchise granted hereunder shall be fair and reasonable and designed to meet all necessary costs of service, including a fair rate of return on the net valuation of its properties devoted thereto, under efficient and economical management. In no event shall rates charged by a company franchised hereunder exceed the corresponding residential or commercial rate charged by the city to customers of its own energy services department by more than fifteen percent (15%). A company accepting a franchise hereunder acknowledges that the city establishes just, reasonable and compensatory electric rates for its own system, and that the use of their rates as a base for determining a fair rate of return to a franchised company is an appropriate method for setting maximum rates. A company shall have no authority to charge and collect rates in excess of such limits, and rates so established shall not be changed or modified except as rates charged by the city for its own utility services may be changed or modified. In the event a franchised company receives refunds or rebates from the city or any other wholesale supplier of electricity, the company shall pass on to its customers such refunds or any savings resulting therefrom. (Ord. 1-2-1986; amd. 2003 Code)