1. For purposes of this section, the following terms shall mean:
(1) "Dispatchable power resource" , a source of electricity that is, under normal operating conditions, available for use on demand and that can have its power output adjusted according to market needs, except during routine maintenance and repair;
(2) "Electrical corporation" , the same as defined in section 386.020 , but shall not include an electrical corporation as described in subsection 2 of section 393.110 ;
(3) "Existing electric generating power plant" , a thermal power plant of over one hundred megawatts in nameplate capacity, a generating unit at a thermal power plant with a nameplate capacity of over one hundred megawatts, or two or more generating units at a thermal power plant with a combined nameplate capacity of over one hundred megawatts;
(4) "Regional transmission operator" , a regional transmission organization, independent system operator, or equivalent entity approved by the Federal Energy Regulatory Commission, or successor agency, that exercises functional control over electric transmission facilities located within this state;
(5) "Reliable electric generation" , electric generation meeting the accreditation requirements provided for in this section;
(6) "Unexpected or unplanned cause or event" , a natural disaster, physical sabotage, equipment failure or damage causing a forced prolonged outage, or an adverse decision of a court or a change in a state or federal law or regulation which causes the closure of an existing electric generating plant.
2. Prior to the closure of an existing electric generating power plant in Missouri if the closure occurs on or after January 1, 2026, and subject to subsection 3 of this section, an electrical corporation registered and doing business in this state shall first certify to the public service commission that such utility company has secured and placed on the electric grid an equal or greater amount of reliable electric generation as accredited power resources based on the regional transmission operator's resource accreditation for the reliable electric generation technology at issue with consideration of the electrical corporation's anticipated loss of load, if any. To determine if an equal or greater amount of reliable electric generation is being placed on the electric grid to replace the existing electric generating power plant that is to be closed, the electrical corporation shall compare the relevant regional transmission operator's average of the summer and winter accredited capacity for the generation technology of the to-be-closed existing electric generating power plant to the relevant regional transmission operator's average of the summer and winter accredited capacity for the generation technology of the replacement reliable electric generation with consideration of the electrical corporation's anticipated loss of load, if any. Such average of the summer and winter accredited capacity for the replacement reliable electric generation shall equal or exceed such average of the summer and winter accredited capacity for the existing electric generating plant that is to be closed with consideration of the electrical corporation's anticipated loss of load, if any. Dispatchable power resources shall comprise at least eighty percent of the average of the summer and winter accredited capacity of the replacement reliable electric generation.
3. With respect to the replacement reliable electric generation required by subsection 2 of this section, adequate electric transmission lines shall be in place and the replacement reliable electric generation shall be fully operational concurrently with the closure of the existing electric generating plant, except where some or all of the replacement reliable electric generation utilizes some or all of the interconnection facilities used by the existing electric generating power plant, or where the existing electric generating power plant is closed as a result of an unexpected or unplanned cause or event. In the event that some or all of the replacement reliable electric generation utilizes some or all of the interconnection facilities utilized by the existing electric generating power plant, then such replacement facilities shall be fully operational within one hundred eighty days of the closure of the existing electric generating power plant. In the event that the existing electric generating power plant is closed as a result of an unexpected or unplanned cause or event, then the following process shall apply:
(1) Within one hundred twenty days after the event causing the closure occurs, the electrical corporation shall file an application with the commission outlining its plan to install replacement reliable electric generation. The application shall specify the generation technology the electrical corporation proposes to be used for the replacement, its estimated cost, and shall demonstrate that the replacement reliable electric generation's average accredited capacity is equal to or greater than the average accredited capacity of the closed plant according to the process outlined in subsection 2 of this section. The application under this section shall be submitted to the commission prior to the electrical corporation's filing of an application to the commission under subsection 1 of section 393.170 . Within two hundred seventy days of the application's filing, the commission shall either approve or deny the electrical corporation's application.
(2) Promptly after issuance of the commission's order under subdivision (1) of this subsection, the electrical corporation shall proceed and use all reasonable efforts to procure, build, and place into operation the approved alternative reliable generation. During any periods allowed by this subsection where the replacement reliable electric generation is not fully operational by the time of the closure of the existing electric generating power plant, the electrical corporation shall use all reasonable efforts to contract for or otherwise acquire additional available firm generating capacity in a quantity necessary to meet the planning reserve margin requirement of the regional transmission operator in which the electrical corporation operates without reliance on such replacement reliable electric generation. At such time as such replacement reliable electric generation is fully operational, such additional available firm generating capacity shall no longer be required under this section. An electrical corporation shall not enter into a voluntary or negotiated settlement with a third party that requires closure of an existing electric generating plant unless the electrical corporation determines that such a settlement is in the best interest of its customers and would maintain electric reliability. Electrical corporations shall not enter into such a settlement in order to meet pollution reduction or other corporate or societal goals beyond those required by law.
4. (1) The average of the summer and winter accredited capacity of the replacement reliable electric generation determined in accordance with subsection 2 of this section shall be equal to or greater than the average summer and winter accredited capacity of the to-be-closed dispatchable existing electric generating power plant determined in accordance with subsection 2 of this section, using the regional transmission operator's resource accreditation as of the time of the electrical corporation's application to the commission under subsection 1 of section 393.170 with consideration of the electrical corporation's anticipated loss of load, if any.
(2) The commission may consider information regarding anticipated loss of load submitted by the electrical corporation to the pertinent regional transmission operator for purposes of its long-term resource plans. As part of its approval of the replacement reliable electric generation under subsection 1 of section 393.170 , the public service commission shall certify that the requirements of this subsection shall be met by the replacement reliable electric generation.
(3) If information is submitted to the commission that the electrical corporation has experienced a significant and long-term loss of load, pursuant to this section, the commission, prior to a review of potential replacement reliable electric generation under subsection 1 of section 393.170 , shall determine if the acquisition or construction of full replacement generation is in the public interest. If the commission determines that full replacement generation is not in the public interest, the requirements of subsection 2 of this section shall not apply.
5. Such reliable electric generation may be constructed in Missouri or in a state that neighbors Missouri, if the generation is connected to the electric grid of the regional transmission operator of which the electrical corporation is a member or is located in a neighboring regional transmission operator which also operates in Missouri and shares a seam with that member's regional transmission operator.
6. On or before the date that the new reliable electric generation is placed in service, the electrical corporation shall provide certification to the public service commission, the general assembly, and the governor that it has met the requirements of this section.
7. To the extent existing electric generating power plant capacity is replaced pursuant to this section, such capacity shall not be replaced by replacement resources under section 393.1705 .