1. The electric utility of the city is a business, and it shall be operated in a businesslike manner. An electric utility fund is hereby established, and the electric utility shall be operated from this fund, separate from the general fund of the city;
2. An accounting system for the electric utility shall be established within the general accounting system of the city. The accounting system shall be so set up and operated as to reflect the financial condition of the utility and its income and expense; and a balance sheet and statement of income and expense (profit and loss) shall be made annually and as often as the council may require;
3. The electric utility shall be duly compensated for all supplies, materials, equipment and services (including electric current at regular rates) which it furnishes either to other units of the city government or to others; and all income of the electric utility shall be credited to the electric utility fund;
4. The electric utility shall be duly charged for all supplies, materials, equipment and services which are furnished to it either by other units of the city government or by others; and all expenses of the electric utility shall be charged against the electric utility fund. Among the expenses shall be an amount reasonably reflecting the actual depreciation of the properties of the utility during that accounting period. Also among the expenses shall be an amount equal to the interest earned during that period on any bonds the proceeds of which were used for the electric utility, and that amount shall be paid or transferred into the sinking fund to pay the interest on bonds or into the general fund. The council may make a reasonable estimate of all taxes of all kinds which the electric utility would pay if it were privately owned and operated, and may provide that a contribution in lieu of taxes of the estimated amount be charged against the electric utility as an expense, and the contribution in lieu of taxes be paid into the general fund or into the sinking fund; and
5. With exception of the contribution in lieu of taxes and the payment or transfer of an amount equal to the interest earned during that period on any bonds the proceeds of which were used for the electric utility, no contribution from net income (profit) or surplus, nor any other contribution or transfer from the electric utility fund may be made to the general fund or to any other fund of the city until an amount or amounts sufficient to meet sinking fund requirement for the fiscal year for principal and interest of outstanding bonds the proceeds of which were used for the electric utility, have been paid from the electric utility fund into the sinking fund.