Section 62-6-14 - Valuation by the commissionA. When in the exercise of its powers and jurisdiction it is necessary for the commission to consider or ascertain the valuation of the properties or business of a public utility, or make any other determination involved in the fixing or setting of rates for a utility, the commission shall give due consideration to the history and development of the property and business of the particular public utility, to the original cost thereof, to the cost of reproduction as a going concern, to the revenues, investment and expenses of the utility in this state and otherwise subject to the commission's jurisdiction, to construction work in progress and to other elements of value and rate-making formulae and methods recognized by the laws of the land for rate-making purposes. B. For the purpose of making such valuation or determinations, the members of the commission and its duly authorized agents and employees shall at all reasonable times have free access to the property, accounts, records and memoranda of the utility whose property and rights are being valued, and the utility shall aid and cooperate with the commission and its duly authorized agents and employees to the fullest degree for the purpose of facilitating the investigation. C. In making any determination involving the rates or service of a utility, the commission may change its past practices or procedures, provided that substantial evidence on the record justifies such a change. D. The commission shall set rates based on a test period that the commission determines best reflects the conditions to be experienced during the period when the rates determined by the commission take effect. If a future test period is proposed, the commission shall give due consideration that the future test period may best reflect those conditions. E. Upon a request to include construction work in progress in the rate base, the commission shall grant the request only upon a finding that a project's costs are reasonable. The commission shall not include the associated allowance for funds used during construction in income. The projects for which the commission shall grant a request include environmental improvement projects and generation and transmission investments for which the utility has obtained a certificate of public convenience and necessity; provided that the projects are anticipated to be in service no later than five months after the end of a utility's test period, but in no event later than twenty-four months after the filing date of a utility's rate proceeding. Laws 1941, ch. 84, § 26; 1941 Comp., § 72-514; 1953 Comp., § 68-5-14; Laws 1983, ch. 250, § 2; 2009, ch. 113, § 2.