(a) Unless the state corporation commission otherwise orders, no common carrier or public utility over which the commission has control shall make effective any changed rate, joint rate, toll, charge or classification or schedule of charges, or any rule or regulation or practice pertaining to the service or rates of such public utility or common carrier except by filing the same with the commission at least 30 days prior to the proposed effective date. The commission, for good cause, may allow such changed rate, joint rate, toll, charge or classification or schedule of charges, or rule or regulation or practice pertaining to the service or rates of any such public utility or common carrier to become effective on less than 30 days’ notice. If the commission allows a change to become effective on less than 30 days’ notice, the effective date of the allowed change shall be the date established in the commission order approving such change, or the date of the order if no effective date is otherwise established. Any such proposed change shall be shown by filing with the state corporation commission a schedule showing the changes, and such changes shall be plainly indicated by proper reference marks in amendments or supplements to existing tariffs, schedules or classifications, or in new issues thereof.

(b) Whenever any common carrier or public utility governed by the provisions of this act files with the state corporation commission a schedule showing the changes desired to be made and put in force by such public utility or common carrier, the commission either upon complaint or upon its own motion, may give notice and hold a hearing upon such proposed changes. Pending such hearing, the commission may suspend the operation of such schedule and defer the effective date of such change in rate, joint rate, toll, charge or classification or schedule of charges, or any rule or regulation or practice pertaining to the service or rates of any such public utility or common carrier by delivering to such public utility or common carrier a statement in writing of its reasons for such suspension.

(c) The commission shall not delay the effective date of the proposed change in rate, joint rate, toll, charge or classification or schedule of charges, or in any rule or regulation or practice pertaining to the service or rates of any such public utility or common carrier, more than 240 days beyond the date the public utility or common carrier filed its application requesting the proposed change. If the commission does not suspend the proposed schedule within 30 days of the date the same is filed by the public utility or common carrier, such proposed schedule shall be deemed approved by the commission and shall take effect on the proposed effective date. If the commission has not issued a final order on the proposed change in any rate, joint rate, toll, charge or classification or schedule of charges, or any rule or regulation or practice pertaining to the service or rates of any such public utility or common carrier, within 240 days after the carrier or utility files its application requesting the proposed change, then the schedule shall be deemed approved by the commission and the proposed change shall be effective immediately, except that:

(1) For purposes of the foregoing provisions regarding the period of time within which the commission shall act on an application, any amendment to an application for a proposed change in any rate, which increases the amount sought by the public utility or common carrier or substantially alters the facts used as a basis for such requested change of rate, shall, at the option of the commission, be deemed a new application and the 240-day period shall begin again from the date of the filing of the amendment;

(2) if hearings are in process before the commission on a proposed change requested by the public utility or common carrier on the last day of such 240-day period, such period shall be extended to the end of such hearings plus 20 days to allow the commission to prepare and issue its final order; and

(3) nothing in this subsection shall preclude the public utility or common carrier and the commission from agreeing to a waiver or an extension of the 240-day period.

(d) Except as provided in subsection (c), no change shall be made in any rate, toll, charge, classification or schedule of charges or joint rates, or in any rule or regulation or practice pertaining to the service or rates of any such public utility or common carrier, without the consent of the commission. Within 30 days after such changes have been authorized by the state corporation commission or become effective as provided in subsection (c), copies of all tariffs, schedules and classifications, and all rules and regulations, except those determined to be confidential under rules and regulations adopted by the commission, shall be filed in every station, office or depot of every such public utility and every common carrier in this state, for public inspection.

(e) Upon a showing by a public utility before the state corporation commission at a public hearing and a finding by the commission that such utility has invested in projects or systems that can be reasonably expected to produce energy from a renewable resource other than nuclear for the use of its customers, cause the conservation of energy used by its customers or bring about the more efficient use of energy by its customers, the commission may allow a return on such investment equal to an increment of from 0.5% to 2% plus an amount equal to the rate of return fixed for the utility’s other investment in property found by the commission to be used or required to be used in its services to the public. The commission may also allow such higher rate of return on investments by a public utility in experimental projects, such as load management devices, which it determines after public hearing to be reasonably designed to cause more efficient utilization of energy and in energy conservation programs or measures which it determines after public hearing provides a reduction in energy usage by its customers in a cost-effective manner.

(f) Whenever, after the effective date of this act, an electric public utility, a natural gas public utility or a combination thereof, files tariffs reflecting a surcharge on the utility’s bills for utility service designed to collect the annual increase in expense charged on its books and records for ad valorem taxes, such utility shall report annually to the state corporation commission the changes in expense charged for ad valorem taxes. For purposes of this section, such amounts charged to expense on the books and records of the utility may be estimated once the total property tax payment is known. If found necessary by the commission or the utility, the utility shall file tariffs which reflect the change as a revision to the surcharge. Upon a showing that the surcharge is applied to bills in a reasonable manner and is calculated to substantially collect the increase in ad valorem tax expense charged on the books and records of the utility, or reduce any existing surcharge based upon a decrease in ad valorem tax expense incurred on the books and records of the utility, the commission shall approve such tariffs within 30 days of the filing. Any over or under collection of the actual ad valorem tax increase charged to expense on the books of the utility shall be either credited or collected through the surcharge in subsequent periods. The establishment of a surcharge under this section shall not be deemed to be a rate increase for purposes of this act. The net effect of any surcharges established under this section shall be included by the commission in the establishment of base rates in any subsequent rate case filed by the utility.

(g) Except as to the time limits prescribed in subsection (c), proceedings under this section shall be conducted in accordance with the provisions of the Kansas administrative procedure act.

(h) In any general rate proceeding of an electric public utility serving more than 20,000 customers conducted pursuant to this section, the electric public utility shall evaluate and include in its application for a rate change an assessment of the following: (1) The regional rate competitiveness of the electric public utility’s current and proposed rates; and (2) the impact of the electric public utility’s current and proposed rates upon economic development within the state.