(1) Every rate made, demanded, or received by any natural gas public utility shall be just and reasonable. Rates shall not be unreasonably preferential or discriminatory and shall be reasonably consistent in application to a class of ratepayers. Rates negotiated with agricultural ratepayers and high-volume ratepayers in conformity with the State Natural Gas Regulation Act shall not be considered discriminatory.
(2) No jurisdictional utility shall, as to rates or terms and conditions of service, make or grant any unreasonable preference or advantage to any person or subject any person to any unreasonable prejudice or disadvantage.
(3) The commission, in the exercise of its power and duty to determine just and reasonable rates for natural gas public utilities, shall give due consideration to the public need for adequate, efficient, and reasonable natural gas service and to the need of the jurisdictional utility for revenue sufficient to enable it to meet the cost of furnishing the service, including adequate provisions for depreciation of its utility property used and useful in rendering service to the public, and to earn a fair and reasonable return upon the investment in such property.
(4) Cost of service shall include operating expenses and a fair and reasonable return on rate base, less appropriate credits.
(5) In determining a fair and reasonable return on the rate base of a jurisdictional utility, a rate-of-return percentage shall be employed that is representative of the utility's weighted average cost of capital including, but not limited to, long-term debt, preferred stock, and common equity capital.
(6) The rate base of the jurisdictional utility shall consist of the utility's property, used and useful in providing utility service, including the applicable investment in utility plant, less accumulated depreciation and amortization, allowance for working capital, such other items as may be reasonably included, and reasonable allocations of common property, less such investment as may be reasonably attributed to other than investor-supplied capital unless such deduction is otherwise prohibited by law.
(7) Operating expenses shall consist of expenses prudently incurred to provide natural gas service including (a) a reasonable allocation of common expenses as authorized and limited by section 66-1819 and (b) the quantity and type of purchased services regulated by the Federal Energy Regulatory Commission.
(8) In determining the cost of service, the Public Service Commission shall give effect to all costs and allocations as reflected in the rate schedules approved by the Federal Energy Regulatory Commission.
(9) The Public Service Commission may include in a jurisdictional utility's rate base the full or partial value of stranded investment which was prudently incurred when the investment actually was, or reasonably was expected to be, used and useful in providing service to ratepayers and was stranded due to changes in regulation or other circumstances reasonably beyond the utility's control and subject to any reasonable obligation of the utility to mitigate the cost.
(10) Subsidization is prohibited. For purposes of this subsection, subsidization means the establishment of rates to be collected from a ratepayer or class of ratepayers of a jurisdictional utility that (a) include costs that properly are includable in rates charged to other ratepayers or classes of ratepayers of the utility, or other persons, firms, companies, or corporations doing business with the jurisdictional utility, (b) exclude costs that properly are includable in rates charged to such ratepayers or classes of ratepayers, or (c) include costs that properly are chargeable or allocable to a nonregulated private enterprise engaged in by such jurisdictional utility.