1. The commission shall, in consultation with the department, prescribe by rule a portfolio requirement for all electric utilities to generate or purchase electricity generated from renewable energy resources. Such portfolio requirement shall provide that electricity from renewable energy resources shall constitute the following portions of each electric utility's sales:
(1) No less than two percent for calendar years 2011 through 2013;
(2) No less than five percent for calendar years 2014 through 2017;
(3) No less than ten percent for calendar years 2018 through 2020; and
(4) No less than fifteen percent in each calendar year beginning in 2021.
2. (1) This subsection applies to electric utilities with more than two hundred fifty thousand but less than one million retail customers in Missouri as of the end of the calendar year 2024.
(2) Energy meeting the criteria of the renewable energy portfolio requirements set forth in subsection 1 of this section that is generated from renewable energy resources and contracted for by an accelerated renewable buyer shall:
(a) Have all associated renewable energy certificates retired by the accelerated renewable buyer, or on their behalf, and the certificates shall not be used to meet the electric utility's portfolio requirements pursuant to subsection 1 of this section;
(b) Be excluded from the total electric utility's sales used to determine the portfolio requirements pursuant to subsection 1 of this section; and
(c) Be used to offset all or a portion of its electric load for purposes of determining compliance with the portfolio requirements pursuant to subsection 1 of this section.
(3) The accelerated renewable buyer shall be exempt from any renewable energy standard compliance costs as may be established by the utility and approved by the commission, based on the amount of renewable energy certificates retired pursuant to this subsection in proportion to the accelerated renewable buyer's total electric energy consumption, on an annual basis.
(4) An "accelerated renewable buyer" means a customer of an electric utility, with an aggregate load over eighty average megawatts, that enters into a contract or contracts to obtain:
(a) Renewable energy certificates from renewable energy resources as defined in section 393.1025 ; or
(b) Energy and renewable energy certificates from solar or wind generation resources located within the Southwest Power Pool region and initially placed in commercial operation after January 1, 2020, including any contract with the electric utility for such generation resources that does not allocate to or recover from any other customer of the utility the cost of such resources.
(5) Each electric utility shall certify, and verify as necessary, to the commission that the accelerated renewable buyer has satisfied the exemption requirements of this subsection for each year, or an accelerated renewable buyer may choose to certify satisfaction of this exemption by reporting to the commission individually.
(6) The commission may promulgate such rules and regulations as may be necessary to implement the provisions of this subsection. Any rule or portion of a rule, as that term is defined in section 536.010 , that is created under the authority delegated in this section shall become effective only if it complies with and is subject to all of the provisions of chapter 536 and, if applicable, section 536.028 . This section and chapter 536 are nonseverable and if any of the powers vested with the general assembly pursuant to chapter 536 to review, to delay the effective date, or to disapprove and annul a rule are subsequently held unconstitutional, then the grant of rulemaking authority and any rule proposed or adopted after August 28, 2025, shall be invalid and void.
(7) Nothing in this section shall be construed as imposing or authorizing the imposition of any reporting, regulatory, or financial burden on an accelerated renewable buyer.
3. The commission, in consultation with the department and within one year of November 4, 2008, shall select a program for tracking and verifying the trading of renewable energy credits. An unused credit may exist for up to three years from the date of its creation. A credit may be used only once to comply with sections 393.1020 to 393.1030 and may not also be used to satisfy any similar nonfederal requirement. An electric utility may not use a credit derived from a green pricing program. Certificates from net-metered sources shall initially be owned by the customer-generator. The commission, except where the department is specified, shall make whatever rules are necessary to enforce the renewable energy standard. Such rules shall include:
(1) A maximum average retail rate increase of one percent determined by estimating and comparing the electric utility's cost of compliance with least-cost renewable generation and the cost of continuing to generate or purchase electricity from entirely nonrenewable sources, taking into proper account future environmental regulatory risk including the risk of greenhouse gas regulation. Notwithstanding the foregoing, until June 30, 2020, if the maximum average retail rate increase would be less than or equal to one percent if an electric utility's investment in solar-related projects initiated, owned or operated by the electric utility is ignored for purposes of calculating the increase, then additional solar rebates shall be paid and included in rates in an amount up to the amount that would produce a retail rate increase equal to the difference between a one percent retail rate increase and the retail rate increase calculated when ignoring an electric utility's investment in solar-related projects initiated, owned, or operated by the electric utility. Notwithstanding any provision to the contrary in this section, even if the payment of additional solar rebates will produce a maximum average retail rate increase of greater than one percent when an electric utility's investment in solar-related projects initiated, owned or operated by the electric utility are included in the calculation, the additional solar rebate costs shall be included in the prudently incurred costs to be recovered as contemplated by subdivision (4) of this subsection;
(2) Penalties of at least twice the average market value of renewable energy credits for the compliance period for failure to meet the targets of subsection 1 of this section. An electric utility will be excused if it proves to the commission that failure was due to events beyond its reasonable control that could not have been reasonably mitigated, or that the maximum average retail rate increase has been reached. Penalties shall not be recovered from customers. Amounts forfeited under this section shall be remitted to the department to purchase renewable energy credits needed for compliance. Any excess forfeited revenues shall be used by the division of energy solely for renewable energy and energy efficiency projects;
(3) Provisions for an annual report to be filed by each electric utility in a format sufficient to document its progress in meeting the targets;
(4) Provision for recovery outside the context of a regular rate case of prudently incurred costs and the pass-through of benefits to customers of any savings achieved by an electrical corporation in meeting the requirements of this section.
4. As provided for in this section, except for those electrical corporations that qualify for an exemption under section 393.1050 , each electric utility shall make available to its retail customers a solar rebate for new or expanded solar electric systems sited on customers' premises, up to a maximum of twenty-five kilowatts per system, measured in direct current that were confirmed by the electric utility to have become operational in compliance with the provisions of section 386.890 . The solar rebates shall be two dollars per watt for systems becoming operational on or before June 30, 2014; one dollar and fifty cents per watt for systems becoming operational between July 1, 2014, and June 30, 2015; one dollar per watt for systems becoming operational between July 1, 2015, and June 30, 2016; fifty cents per watt for systems becoming operational between July 1, 2016, and June 30, 2017; fifty cents per watt for systems becoming operational between July 1, 2017, and June 30, 2019; twenty-five cents per watt for systems becoming operational between July 1, 2019, and June 30, 2020; and zero cents per watt for systems becoming operational after June 30, 2020. An electric utility may, through its tariffs, require applications for rebates to be submitted up to one hundred eighty-two days prior to the June thirtieth operational date. Nothing in this section shall prevent an electrical corporation from offering rebates after July 1, 2020, through an approved tariff. If the electric utility determines the maximum average retail rate increase provided for in subdivision (1) of subsection 3 of this section will be reached in any calendar year, the electric utility shall be entitled to cease paying rebates to the extent necessary to avoid exceeding the maximum average retail rate increase if the electrical corporation files with the commission to suspend its rebate tariff for the remainder of that calendar year at least sixty days prior to the change taking effect. The filing with the commission to suspend the electrical corporation's rebate tariff shall include the calculation reflecting that the maximum average retail rate increase will be reached and supporting documentation reflecting that the maximum average retail rate increase will be reached. The commission shall rule on the suspension filing within sixty days of the date it is filed. If the commission determines that the maximum average retail rate increase will be reached, the commission shall approve the tariff suspension. The electric utility shall continue to process and pay applicable solar rebates until a final commission ruling; however, if the continued payment causes the electric utility to pay rebates that cause it to exceed the maximum average retail rate increase, the expenditures shall be considered prudently incurred costs as contemplated by subdivision (4) of subsection 3 of this section and shall be recoverable as such by the electric utility. As a condition of receiving a rebate, customers shall transfer to the electric utility all right, title, and interest in and to the renewable energy credits associated with the new or expanded solar electric system that qualified the customer for the solar rebate for a period of ten years from the date the electric utility confirmed that the solar electric system was installed and operational.
5. The department shall, in consultation with the commission, establish by rule a certification process for electricity generated from renewable resources and used to fulfill the requirements of subsection 1 of this section. Certification criteria for renewable energy generation shall be determined by factors that include fuel type, technology, and the environmental impacts of the generating facility. Renewable energy facilities shall not cause undue adverse air, water, or land use impacts, including impacts associated with the gathering of generation feedstocks. If any amount of fossil fuel is used with renewable energy resources, only the portion of electrical output attributable to renewable energy resources shall be used to fulfill the portfolio requirements.
6. In carrying out the provisions of this section, the commission and the department shall include methane generated from the anaerobic digestion of farm animal waste and thermal depolymerization or pyrolysis for converting waste material to energy as renewable energy resources for purposes of this section.
7. The commission shall have the authority to promulgate rules for the implementation of this section, but only to the extent such rules are consistent with, and do not delay the implementation of, the provisions of this section. Any rule or portion of a rule, as that term is defined in section 536.010 , that is created under the authority delegated in this section shall become effective only if it complies with and is subject to all of the provisions of chapter 536 and, if applicable, section 536.028 . This section and chapter 536 are nonseverable and if any of the powers vested with the general assembly pursuant to chapter 536 to review, to delay the effective date, or to disapprove and annul a rule are subsequently held unconstitutional, then the grant of rulemaking authority and any rule proposed or adopted after August 28, 2013, shall be invalid and void.