Regulatory Matters	3 Months Ended
Mar. 31, 2024
Regulated Operations [Abstract]
Regulatory Matters	REGULATORY MATTERS RATE-RELATED INFORMATION The NCUC, PSCSC, FPSC, IURC, PUCO, TPUC and KPSC approve rates for retail electric and natural gas services within their states. The FERC approves rates for electric sales to wholesale customers served under cost-based rates (excluding Ohio and Indiana), as well as sales of transmission service. The FERC also regulates certification and siting of new interstate natural gas pipeline projects. For open regulatory matters, unless otherwise noted, the Subsidiary Registrants and Duke Energy Kentucky cannot predict the outcome or ultimate resolution of their respective matters. Duke Energy Carolinas and Duke Energy Progress Nuclear Station Subsequent License Renewal On June 7, 2021, Duke Energy Carolinas filed a subsequent license renewal (SLR) application for the Oconee Nuclear Station (ONS) with the U.S. Nuclear Regulatory Commission (NRC) to renew ONS’s operating license for an additional 20 years. The SLR would extend operations of the facility from 60 to 80 years. The current licenses for units 1 and 2 expire in 2033 and the license for unit 3 expires in 2034. By a Federal Register Notice dated July 28, 2021, the NRC provided a 60-day comment period for persons whose interest may be affected by the issuance of a subsequent renewed license for ONS to file a request for a hearing and a petition for leave to intervene. On September 27, 2021, Beyond Nuclear and Sierra Club (Petitioners) filed a Hearing Request and Petition to Intervene (Hearing Request) and a Petition for Waiver. The Hearing Request proposed three contentions and claimed that Duke Energy Carolinas did not satisfy the National Environmental Policy Act (NEPA) of 1969, as amended, or the NRC’s NEPA-implementing regulations. Following Duke Energy Carolinas' answer and the Petitioners' reply, on February 11, 2022, the Atomic Safety and Licensing Board (ASLB) issued its decision on the Hearing Request and found that the Petitioners failed to establish that the proposed contentions are litigable. The ASLB also denied the Petitioners' Petition for Waiver and terminated the proceeding. On February 24, 2022, the NRC issued a decision in the SLR appeal related to Florida Power and Light's Turkey Point nuclear generating station in Florida. The NRC ruled that the NRC’s license renewal Generic Environmental Impact Statement (GEIS) does not apply to SLR because the GEIS does not address SLR. The decision overturned a 2020 NRC decision that found the GEIS applies to SLR. Although Turkey Point is not owned or operated by a Duke Energy Registrant, the NRC’s order applies to all SLR applicants, including ONS. The NRC order also indicated no subsequent renewed licenses will be issued until the NRC staff has completed an adequate NEPA review for each application. On April 5, 2022, the NRC approved a 24-month rulemaking plan that will enable the NRC staff to complete an adequate NEPA review. Although an SLR applicant may wait until the rulemaking is completed, the NRC also noted that an applicant may submit a supplement to its environmental report providing information on environmental impacts during the SLR period prior to the rulemaking being completed. On November 7, 2022, Duke Energy Carolinas submitted a supplement to its environmental report addressing environmental impacts during the SLR period. On September 14, 2023, the NRC posted on its website that the issuance of the GEIS will now be issued in August 2024 instead of May 2024 due to the volume and technical complexity of the comments received. On March 6, 2024, the NRC staff submitted the rulemaking, which included the updated GEIS, to the NRC. On December 19, 2022, the NRC published a notice in the Federal Register that the NRC will conduct a limited scoping process to gather additional information necessary to prepare an environmental impact statement (EIS) to evaluate the environmental impacts at ONS during the SLR period. The NRC received comments from the EPA and the Petitioners and these comments identify 18 potential impacts that should be considered by the NRC in the EIS, which include, but are not limited to, climate change and flooding, environmental justice, severe accidents, and external events. On February 8, 2024, the NRC issued the Oconee site-specific draft EIS. The NRC and EPA published the notice for the public to submit comments on the ONS site-specific draft EIS. On April 29, 2024, the petitioners filed a hearing request. The request proposed three contentions and claimed that the ONS site-specific draft EIS is inadequate to satisfy the requirements of NEPA and the NRC’s NEPA-implementing regulations. Duke Energy Carolinas' deadline to respond to any such requests was extended to May 31, 2024. On December 19, 2022, the NRC issued the Safety Evaluation Report (SER) for the safety portion of the SLR application. The NRC determined Duke Energy Carolinas met the requirements of the applicable regulations and identified actions that have been taken or will be taken to manage the effects of aging and address time-limited analyses. Duke Energy Carolinas and the NRC met with the Advisory Committee on Reactor Safeguards (ACRS) on February 2, 2023, to discuss issues regarding the SER and SLR application. On February 25, 2023, the ACRS issued a report to the NRC on the safety aspects of the ONS SLR application, which concluded that the established programs and commitments made by Duke Energy Carolinas to manage age-related degradation provide confidence that ONS can be operated in accordance with its current licensing basis for the subsequent period of extended operation without undue risk to the health and safety of the public and the SLR application for ONS should be approved. Although the NRC’s GEIS applicability decision has delayed completion of the SLR proceeding, Duke Energy Carolinas does not believe it changes the probability that the ONS subsequent renewed licenses will ultimately be issued, although Duke Energy Carolinas cannot guarantee the outcome of the license application process. Duke Energy Carolinas and Duke Energy Progress intend to seek renewal of operating licenses and 20-year license extensions for all of their nuclear stations. Accordingly, new depreciation rates were implemented for all of the nuclear facilities during the second quarter of 2021. Duke Energy Carolinas 2023 North Carolina Rate Case On January 19, 2023, Duke Energy Carolinas filed a PBR application with the NCUC to request an increase in base rate retail revenues. The PBR Application included a Multiyear rate plan (MYRP) to recover projected capital investments during the three-year MYRP period. In addition to the MYRP, the PBR Application included an Earnings Sharing Mechanism, Residential Decoupling Mechanism and Performance Incentive Mechanisms (PIMS) as required by HB 951. The application as originally filed requested an overall retail revenue increase of $501 million in Year 1, $172 million in Year 2 and $150 million in Year 3, for a combined total of $823 million, or 15.7%, by early 2026. The rate increase is driven primarily by transmission and distribution investments since the last rate case and projected in the MYRP, as well as investments in energy storage and solar assets included in the MYRP consistent with the Carolinas Carbon Plan (Carbon Plan). On August 22, 2023, Duke Energy Carolinas filed with the NCUC a partial settlement with the Public Staff in connection with its PBR application. The partial settlement included, among other things, agreement on a substantial portion of the North Carolina retail rate base for the historic base case of approximately $19.5 billion and all of the capital projects and related costs to be included in the three-year MYRP, including $4.6 billion (North Carolina retail allocation) projected to go in service over the MYRP period. Additionally, the partial settlement included agreement, with certain adjustments, on depreciation rates, the recovery of grid improvement plan costs and PIMs, Tracking Metrics and the Residential Decoupling Mechanism under the PBR application. On August 28, 2023, Duke Energy Carolinas filed with the NCUC a second partial settlement with the Public Staff resolving additional issues, including the future treatment of nuclear production tax credits related to the Inflation Reduction Act, through a stand-alone rider that will provide the benefits to customers beginning January 1, 2025. On December 15, 2023, the NCUC issued an order approving Duke Energy Carolinas' PBR Application, as modified by the partial settlements and the order, including an overall retail revenue increase of $436 million in Year 1, $174 million in Year 2 and $158 million in Year 3, for a combined total of $768 million. The order established an ROE of 10.1% based upon an equity ratio of 53% and approved, with certain adjustments, depreciation rates and the recovery of grid improvement plan costs and certain deferred COVID-related costs. Additionally, the Residential Decoupling Mechanism and PIMs were approved as requested under the PBR Application and revised by the partial settlements. Duke Energy Carolinas implemented interim rates, subject to refund, on September 1, 2023. New revised Year 1 rates and the residential decoupling were implemented on January 15, 2024. On February 13, 2024, a number of parties filed Notices of Appeal of the December 15, 2023, NCUC order. Notices of Appeal were filed by the Carolina Industrial Group for Fair Utility Rates (CIGFUR) III, a collection of various electric membership corporations (collectively, the EMCs), and the North Carolina Attorney General’s Office (the AGO). CIGFUR III and the EMCs appealed the interclass subsidy reduction percentage and the Transmission Cost Allocation stipulation. In addition, CIGFUR III appealed the NCUC’s elimination of the equal percentage fuel cost allocation methodology. The AGO appealed several issues including the authorized ROE and certain rate design and accounting matters. On March 1, 2024, Carolina Utility Customers Association, Inc. appealed several issues, including the authorized ROE and certain rate design and accounting matters. 2024 South Carolina Rate Case On January 4, 2024, Duke Energy Carolinas filed a rate case with the PSCSC to request a net increase in annual retail revenues of 11.4%, or approximately $239 million, in the first two years, and an additional overall increase of about 4.1%, or approximately $84 million additional revenue, after the first two years. The requested increases, if approved, would result in an overall average 15.5% increase in annual retail revenues, or approximately $323 million, prior to mitigation efforts. Duke Energy Carolinas requested an ROE of 10.5% with an equity ratio of 53%. To mitigate the rate increase, Duke Energy Carolinas has proposed to accelerate the return of remaining federal unprotected EDIT balances to customers over two years. This offset reduces the impact to customers in the first two years to the effective net increase of 11.4% after which the credit for EDIT balances expire. Duke Energy Carolinas has requested the revised rates to be effective no later than August 1, 2024. Intervenor testimony and Duke Energy Carolinas' rebuttal testimony were filed in April 2024. The evidentiary hearing is scheduled to commence on May 20, 2024. Marshall Combustion Turbines CPCN On March 14, 2024, Duke Energy Carolinas filed with the NCUC an application to construct and operate two hydrogen-capable advanced-class simple-cycle combustion turbines (CTs) at the site of the existing Marshall Steam Station. The two new CTs – totaling approximately 850 MW – will enable the retirement of Marshall coal units 1 and 2 and provide incremental capacity to support system capacity needs and expanded flexibility to support integration of renewables. Pending regulatory approvals, construction is planned to start in 2026, and the CTs are targeted to be placed into service by the end of 2028. As part of the application, Duke Energy Carolinas noted that Construction Work in Progress for the proposed facility will accrue AFUDC and will not be in rate base, resulting in no impact on Duke Energy Carolinas' North Carolina retail revenue requirement during the construction period. The 2029 North Carolina retail revenue requirement for the proposed facility is estimated to be $104 million, representing an approximate average retail rate increase of 2.2% across all classes. Duke Energy Progress 2022 North Carolina Rate Case On October 6, 2022, Duke Energy Progress filed a PBR application with the NCUC to request an increase in base rate retail revenues. The rate request before the NCUC included an MYRP to recover projected capital investments during the three-year MYRP period. In addition to the MYRP, the PBR Application included an Earnings Sharing Mechanism, Residential Decoupling Mechanism and PIMs as required by HB 951. The overall retail revenue increase as originally filed would have been $326 million in Year 1, $151 million in Year 2 and $138 million in Year 3, for a combined total of $615 million, by late 2025. The rate increase is driven primarily by transmission and distribution investments since the last rate case and projected in the MYRP, as well as investments in energy storage and solar assets included in the MYRP consistent with the Carbon Plan. On April 26, 2023, Duke Energy Progress filed with the NCUC a partial settlement with Public Staff, which included agreement on many aspects of Duke Energy Progress' three-year MYRP proposal. In May 2023, CIGFUR II joined this partial settlement and Public Staff and CIGFUR II filed a separate settlement reaching agreement on PIMs, Tracking Metrics and the Residential Decoupling Mechanism under the PBR application. On August 18, 2023, the NCUC issued an order approving Duke Energy Progress' PBR Application, as modified by the partial settlements and the order, including an overall retail revenue increase of $233 million in Year 1, $126 million in Year 2 and $135 million in Year 3, for a combined total of $494 million. Key aspects of the order include the approval of North Carolina retail rate base for the historic base case of approximately $12.2 billion and capital projects and related costs to be included in the three-year MYRP, including $3.5 billion (North Carolina retail allocation) projected to go in service over the MYRP period. The order established an ROE of 9.8% based upon an equity ratio of 53% and approved, with certain adjustments, depreciation rates and the recovery of grid improvement plan costs and certain deferred COVID-related costs. Additionally, the Residential Decoupling Mechanism and PIMs were approved as requested under the PBR Application and revised by the partial settlements. Duke Energy Progress implemented interim rates, subject to refund, on June 1, 2023, and implemented revised Year 1 rates and the residential decoupling on October 1, 2023. On October 17, 2023, CIGFUR II and Haywood Electric Membership Corporation each filed a Notice of Appeal of the August 18, 2023 NCUC order. Both parties are appealing certain matters that do not impact the overall revenue requirement in the rate case. Specifically, they appealed the interclass subsidy reduction percentage, and CIGFUR II also appealed the Customer Assistance Program and the equal percentage fuel cost allocation methodology. On November 6, 2023, the AGO filed a Notice of Cross Appeal of the NCUC's determination regarding the exclusion of electric vehicle revenue from the residential decoupling mechanism. On November 9, 2023, Duke Energy Progress, the Public Staff, CIGFUR II, and a number of other parties reached a settlement pursuant to which CIGFUR II agreed not to pursue its appeal of the Customer Assistance Program. 2023 South Carolina Storm Securitization On May 31, 2023, Duke Energy Progress filed a petition with the PSCSC requesting authorization for the financing of Duke Energy Progress' storm recovery costs through securitization due to storm recovery activities required as a result of the following storms: Pax, Ulysses, Matthew, Florence, Michael, Dorian, Izzy and Jasper. On September 8, 2023, Duke Energy Progress filed a comprehensive settlement agreement with all parties on all cost recovery issues raised in the storm securitization proceeding. The evidentiary hearing occurred in early September 2023. On September 20, 2023, the PSCSC approved the comprehensive settlement agreement and on October 13, 2023, the PSCSC issued its financing order. The storm recovery bonds of $177 million were issued by Duke Energy Progress on April 25, 2024. Duke Energy Progress implemented storm recovery charges effective May 1, 2024. See notes 6 and 12 for more information. Person County Combined Cycle CPCN On March 28, 2024, Duke Energy Progress filed with the NCUC its application to construct and operate a 1,360 MW hydrogen-capable, advanced-class combined-cycle generating facility (CC) in Person County at the site of the existing Roxboro Plant. Subject to negotiation of final contractual terms, the new Roxboro CC will be co-owned with the North Carolina Electric Membership Corporation (NCEMC), with Duke Energy Progress owning approximately 1,135 MW and NCEMC owning the remaining 225 MW. Pending regulatory approvals, construction is planned to start in 2026, with the CC targeted to be placed in service by the end of 2028. The CC will allow for the retirement of Roxboro’s coal-fired units 1 and 4. As part of the application, Duke Energy Progress noted that the recovery of Construction Work in Progress during the construction period for the proposed facility may be pursued in a future rate case. The 2029 North Carolina retail revenue requirement for the proposed facility is estimated to be $98 million, representing an approximate average retail rate increase of 2.6% across all classes. Duke Energy Florida 2021 Settlement Agreement On January 14, 2021, Duke Energy Florida filed a Settlement Agreement (the “2021 Settlement”) with the FPSC. The parties to the 2021 Settlement include Duke Energy Florida, the Office of Public Counsel (OPC), the Florida Industrial Power Users Group, White Springs Agricultural Chemicals, Inc. d/b/a PCS Phosphate and NUCOR Steel Florida, Inc. (collectively, the “Parties”). Pursuant to the 2021 Settlement, the Parties agreed to a base rate stay-out provision that expires year-end 2024; however, Duke Energy Florida is allowed an increase to its base rates of an incremental $67 million in 2022, $49 million in 2023 and $79 million in 2024, subject to adjustment in the event of tax reform during the years 2021, 2022 and 2023. The Parties also agreed to an ROE band of 8.85% to 10.85% with a midpoint of 9.85% based upon an equity ratio of 53%. The ROE band can be increased by 25 basis points if the average 30-year U.S. Treasury rate increases 50 basis points or more over a six-month period in which case the midpoint ROE would rise from 9.85% to 10.10%. On July 25, 2022, this provision was triggered. Duke Energy Florida filed a petition with the FPSC on August 12, 2022, to increase the ROE effective August 2022 with a base rate increase effective January 1, 2023. The FPSC approved this request on October 4, 2022. The 2021 Settlement Agreement also provided that Duke Energy Florida will be able to retain $173 million of the expected Department of Energy (DOE) award from its lawsuit to recover spent nuclear fuel to mitigate customer rates over the term of the 2021 Settlement. In return, Duke Energy Florida is permitted to recognize the $173 million into earnings through the approved settlement period. Duke Energy Florida settled the DOE lawsuit and received payment of approximately $180 million on June 15, 2022, of which the retail portion was approximately $154 million. The 2021 Settlement authorizes Duke Energy Florida to collect the difference between $173 million and the $154 million retail portion of the amount received through the capacity cost recovery clause. As of March 31, 2024, Duke Energy Florida has recognized $149 million into earnings, including $8 million and $54 million recognized during the three months ended March 31, 2024, and 2023, respectively. The remaining $24 million is expected to be recognized in 2024. The 2021 Settlement also contained a provision to recover or flow back the effects of tax law changes. As a result of the IRA enacted on August 16, 2022, Duke Energy Florida is eligible for PTCs associated with solar facilities placed in service beginning in January 2022. Duke Energy Florida filed a petition with the FPSC on October 17, 2022, to reduce base rates effective January 1, 2023, by $56 million to flow back the expected 2023 PTCs and to flow back the expected 2022 PTCs via an adjustment to the capacity cost recovery clause. On December 14, 2022, the FPSC issued an order approving Duke Energy Florida's petition. In addition to these terms, the 2021 Settlement contained provisions related to the accelerated depreciation of Crystal River Units 4-5, the approval of approximately $1 billion in future investments in new cost-effective solar power, the implementation of a new Electric Vehicle Charging Station Program and the deferral and recovery of costs in connection with the implementation of Duke Energy Florida’s Vision Florida program, which explores various emerging non-carbon emitting generation technology, distributed technologies and resiliency projects, among other things. The 2021 Settlement also resolved remaining unrecovered storm costs for Hurricane Michael and Hurricane Dorian. The FPSC approved the 2021 Settlement on May 4, 2021, issuing an order on June 4, 2021. Revised customer rates became effective January 1, 2022, with subsequent base rate increases effective January 1, 2023, and January 1, 2024. Clean Energy Connection On July 1, 2020, Duke Energy Florida petitioned the FPSC for approval of a voluntary solar program consisting of 10 new solar generating facilities with combined capacity of approximately 750 MW. The program allows participants to support cost-effective solar development in Florida by paying a subscription fee based on per kilowatt subscriptions and receiving a credit on their bill based on the actual generation associated with their portion of the solar portfolio. The estimated cost of the 10 new solar generation facilities is approximately $1 billion and the projects are expected to be completed by the end of 2024. This investment is included in base rates offset by the revenue from the subscription fees and the credits will be included for recovery in the fuel cost recovery clause. The FPSC approved the program in January 2021. On February 24, 2021, the League of United Latin American Citizens (LULAC) filed a notice of appeal of the FPSC’s order approving the Clean Energy Connection to the Supreme Court of Florida. The Supreme Court of Florida heard oral arguments in the appeal on February 9, 2022. On May 27, 2022, the Supreme Court of Florida issued an order remanding the case back to the FPSC so that the FPSC can amend its order to better address some of the arguments raised by LULAC. On September 23, 2022, the FPSC issued a revised order and submitted it on September 26, 2022, to the Supreme Court of Florida. The Supreme Court of Florida requested that the parties file supplemental briefs regarding the revised order, which were filed February 6, 2023. LULAC has filed a request for Oral Argument on the issues discussed in the supplemental briefs, but the court has yet to rule on that request. The FPSC approval order remains in effect pending the outcome of the appeal. Storm Protection Plan On April 11, 2022, Duke Energy Florida filed a Storm Protection Plan for approval with the FPSC. The plan, which covers investments for the 2023-2032 time frame, reflects approximately $7 billion of capital investment in transmission and distribution meant to strengthen its infrastructure, reduce outage times associated with extreme weather events, reduce restoration costs and improve overall service reliability. The evidentiary hearing began on August 2, 2022. On October 4, 2022, the FPSC voted to approve Duke Energy Florida’s plan with one modification to remove the transmission loop radially fed program, representing a reduction of approximately $80 million over the 10-year period starting in 2025. On December 9, 2022, the OPC filed a notice of appeal of this order to the Florida Supreme Court. The OPC's initial brief was filed on April 18, 2023. Duke Energy Florida filed its answer brief on July 17, 2023. The OPC's reply brief was filed on October 16, 2023. The Florida Supreme Court heard oral arguments on February 7, 2024. Hurricanes Ian and Idalia On September 28, 2022, much of Duke Energy Florida’s service territory was impacted by Hurricane Ian, which caused significant damage resulting in more than 1.1 million outages. After depleting any existing storm reserves, which were approximately $107 million before Hurricane Ian, Duke Energy Florida is permitted to petition the FPSC for recovery of additional incremental operation and maintenance costs resulting from the storm and to replenish the retail customer storm reserve to approximately $132 million. Duke Energy Florida filed its petition for cost recovery of various storms, including Hurricane Ian, and replenishment of the storm reserve on January 23, 2023, seeking recovery of $442 million, for recovery over 12 months beginning with the first billing cycle in April 2023. On March 7, 2023, the FPSC approved this request for interim recovery, subject to refund, and ordered Duke Energy Florida to file documentation of the total actual storm costs, once known. Duke Energy Florida filed documentation evidencing its total actual storm costs of $431 million on September 29, 2023. The FPSC will hold a final hearing to determine the prudence of these costs on May 21 and 22, 2024. On August 30, 2023, Hurricane Idalia made landfall on Florida’s gulf coast, causing damage and impacting more than 200,000 customers across Duke Energy Florida's service territory. On October 16, 2023, Duke Energy Florida requested to combine the $92 million retail portion of the deferred estimated Hurricane Idalia costs with $74 million of costs projected to be collected after December 31, 2023, under the existing approved storm cost recovery and storm surcharge. This $74 million of costs relates primarily to the approved ongoing replenishment of the storm reserves. At its December 5, 2023 Agenda Conference, the FPSC approved recovery of the total $166 million over 12 months beginning with its first billing cycle in January 2024, replacing the previously approved storm cost recovery and storm surcharge, and ordered Duke Energy Florida to file documentation of the total actual Idalia related storm costs, once known. Revised rates were effective January 1, 2024. 2024 Florida Rate Case On April 2, 2024, Duke Energy Florida filed a formal request for new base rates with the FPSC. Duke Energy Florida has proposed a three-year rate plan that would begin in January 2025, once its current base rate settlement agreement concludes at the end of 2024. Duke Energy Florida proposed multiyear rate increases that use the projected 12-month periods ending December 31, 2025, 2026, and 2027 as the test years, with adjusted rates to be effective with the first billing period of January 2025, 2026, and 2027, respectively. Duke Energy Florida requested additional base rate revenue requirements of approximately $593 million in 2025, $98 million in 2026 and $129 million in 2027, representing an average annual increase in revenue requirements of approximately 4% over 2025 through 2027. Duke Energy Florida requested an ROE midpoint at 11.15% and an equity ratio of 53%. A final hearing on this request is scheduled to begin on August 12, 2024. Duke Energy Ohio Duke Energy Ohio Electric Base Rate Case Duke Energy Ohio filed with the PUCO an electric distribution base rate case application on October 1, 2021, with supporting testimony filed on October 15, 2021, requesting an increase in electric distribution base rates of approximately $55 million. On September 19, 2022, Duke Energy Ohio filed a Stipulation and Recommendation with the PUCO, which includes an increase in overall electric distribution base rates of approximately $23 million with an equity ratio of 50.5% and an ROE of 9.5%. The stipulation is among all but one party to the proceeding. The PUCO issued an order on December 14, 2022, approving the Stipulation without material modification. Rates went into effect on January 3, 2023. The Ohio Consumers' Counsel filed an application for rehearing on January 13, 2023, arguing the Stipulation was unreasonable, discriminatory, and denied OCC due process. On March 20, 2024, the PUCO issued its Second Entry on Rehearing, denying OCC's rehearing application. OCC has 60 days to seek an appeal. Duke Energy Ohio Natural Gas Base Rate Case Duke Energy Ohio filed with the PUCO a natural gas base rate case application on June 30, 2022, with supporting testimony filed on July 14, 2022, requesting an increase in natural gas base rates of approximately $49 million. The drivers for this case are capital invested since Duke Energy Ohio's last natural gas base rate case in 2012. Duke Energy Ohio also sought to adjust the caps on its CEP rider. On April 28, 2023, Duke Energy Ohio filed a stipulation with all parties to the case except the OCC. In the stipulation, the parties agreed to approximately $32 million in revenue increases with an equity ratio of 52.32% and an ROE of 9.6%, and adjustments to the CEP Rider caps. The stipulation was opposed by the OCC at an evidentiary hearing that concluded on May 24, 2023. On November 1, 2023, PUCO issued an order approving the stipulation as filed. New rates went into effect November 1, 2023. On December 1, 2023, the OCC filed an application for rehearing. On December 13, 2023, the PUCO granted OCC's application for rehearing for further consideration of issues raised. Duke Energy Ohio Electric Security Plan On April 1, 2024, Duke Energy Ohio filed with the PUCO a request for an Electric Security Plan (ESP). The ESP application proposes a three-year term from June 1, 2025 through May 31, 2028 and includes continuation of market-based customer rates through competitive procurement processes for generation and continuation and expansion of existing rider mechanisms. Duke Energy Ohio is proposing a new rider mechanism relating to electric distribution infrastructure modernization programs, which may be enabled by and partially funded through federal or state funding opportunities, future battery storage projects, and two proposed electric vehicle programs. Additional proposed new rider mechanisms are related to solar for all investments for low-income and disadvantaged communities, low-income senior citizen bill assistance, and energy efficiency and demand-side management programs. Duke Energy Kentucky Electric Base Rate Case On December 1, 2022, Duke Energy Kentucky filed a rate case with the KPSC requesting an annualized increase in electric base rates of approximately $75 million. The request for rate increase was driven by capital investments to strengthen the electricity generation and delivery systems along with adjusted depreciation rates for the East Bend and Woodsdale Combustion Turbine (CT) generation stations. Duke Energy Kentucky also requested approval for new programs and tariff updates, including a voluntary community-based renewable subscription program and two electric vehicle charging programs. The KPSC issued an order on October 12, 2023, including a $48 million increase in base revenues, an ROE of 9.75% for electric base rates and 9.65% for electric riders and an equity ratio of 52.145%. New rates went into effect October 13, 2023. The Company's request to align the depreciation rates of East Bend with a 2035 retirement date was denied and the KPSC ordered depreciation rates with a 2041 retirement date for the unit. The KPSC did approve the request to align the depreciation rates of Woodsdale CT with a 2040 retirement date and denied the voluntary community-based renewable subscription program and the two electric vehicle charging programs. On November 1, 2023, Duke Energy Kentucky filed for rehearing requesting certain matters be reconsidered by the KPSC. On November 21, 2023, KPSC granted in part and denied in part the Company's request for rehearing. On February 15, 2024, the KPSC issued a briefing schedule for the rehearing process. The briefing concluded on April 1, 2024, and the matter was submitted for decision on April 2, 2024. On December 14, 2023, Duke Energy Kentucky filed an appeal with the Franklin County Circuit Court on certain matters for which the KPSC denied rehearing, specifically as it relates to including decommissioning costs in depreciation rates for East Bend and Woodsdale. On January 8, 2024, answers to the appeal were filed by the KPSC, Kentucky Attorney General, and the Kentucky Broadband & Cable Association. On April 11, 2024, the Franklin County Circuit Court approved a briefing schedule with Duke Energy Kentucky's initial brief due June 26, 2024, appellee briefs due September 24, 2024, and Duke Energy Kentucky's reply brief due November 8, 2024. Duke Energy Indiana Indiana Coal Ash Recovery In Duke Energy Indiana’s 2019 rate case, the IURC opened a subdocket for post-2018 coal ash related expenditures. Duke Energy Indiana filed testimony on April 15, 2020, in the coal ash subdocket requesting recovery for the post-2018 coal ash basin closure costs for plans that have been approved by the Indiana Department of Environmental Management (IDEM) as well as continuing deferral, with carrying costs, on the balance. On November 3, 2021, the IURC issued an order allowing recovery for post-2018 coal ash basin closure costs for the plans that have been approved by IDEM, as well as continuing deferral, with carrying costs, on the balance. The OUCC and the Duke Industrial Group appealed. The Indiana Court of Appeals issued its opinion on February 21, 2023, reversing the IURC's order to the extent that it allowed Duke Energy Indiana to recover federally mandated costs incurred prior to the IURC's November 3, 2021 order. In addition, the court found that any costs incurred pre-petition to determine federally mandated compliance options were not specifically authorized by the statute and should also be disallowed. In the second quarter of 2023, Duke Energy Indiana filed its proposal to remove from rates certain costs incurred prior to the IURC's November 3, 2021 order date. On September 20, 2023, the commission approved the Company's proposal to remove the costs from its rates and assessed simple interest of the refunds of 4.71%, beginning from when the costs were initially recovered from customers. Duke Energy Indiana seeks to recover the pre-order costs denied by the Indiana Court of Appeals and certain future coal ash closure costs as part of depreciation costs in the 2024 Indiana Rate Case. Duke Energy Indiana filed a new petition under the amended version of the federal mandate statute for additional post-2018 coal ash closure costs for the remaining basins not included in the Indiana coal ash recovery case from 2020. An evidentiary hearing was held on January 25, 2024. TDSIC 2.0 On November 23, 2021, Duke Energy Indiana filed for approval of the Transmission, Distribution, Storage Improvement Charge 2.0 investment plan for 2023-2028 (TDSIC 2.0). On June 15, 2022, the IURC approved, without modification, TDSIC 2.0, which includes approximately $2 billion in transmission and distribution investments selected to improve customer reliability, harden and improve resiliency of the grid, enable expansion of renewable and distributed energy projects and encourage economic development. In addition, the IURC set up a subdocket to consider a targeted economic development project, which the IURC approved on March 2, 2022. On July 15, 2022, the OUCC filed a notice of appeal to the Indiana Court of Appeals in Duke Energy Indiana’s TDSIC 2.0 proceeding. An appellant brief was filed on October 28, 2022, and Duke Energy Indiana filed its responsive brief on December 28, 2022. The Indiana Court of Appeals issued its opinion on March 9, 2023, affirming the IURC’s order in its entirety. The Duke Industrial Group filed a petition to transfer to the Indiana Supreme Court. The Indiana Supreme Court granted transfer and held an oral argument on September 28, 2023. 2024 Indiana Rate Case On April 4, 2024, Duke Energy Indiana filed an application with the IURC for a rate increase of $492 million, representing an overall average bill increase of approximately 16.2%, which, if approved, would be added to retail customer bills in two steps, approximately 11.7% in 2025 and approximately 4.5% in 2026. Duke Energy Indiana requested an ROE of 10.5% with an equity ratio of 53%. The rate increase is driven by $1.6 billion in investments made since the last general rate case filed in 2019 in order to reliably serve customers, improve resiliency of the system, and advance environmental sustainability. An evidentiary hearing is scheduled to begin August 29, 2024. Piedmont 2024 North Carolina Rate Case On April 1, 2024, Piedmont filed an application with the NCUC for a rate increase for retail customers of approximately $159 million, which represents a 12.5% increase in retail revenues. Piedmont requested an ROE of 10.5% with an equity ratio of 53%. The rate increase is driven by significant infrastructure upgrade investments since the last general rate case, offset by lower fixed natural gas costs and remaining federal and state tax reform savings to be received by customers. Approximately 40% of the plant additions being rolled into rate base are categories of plant investment that are covered under the IMR mechanism, which was originally approved as part of the 2013 North Carolina Rate Case. Piedmont plans to implement revised interim rates by November 1, 2024.

The NCUC, PSCSC, FPSC, IURC, PUCO, TPUC and KPSC approve rates for retail electric and natural gas services within their states. The FERC approves rates for electric sales to wholesale customers served under cost-based rates (excluding Ohio and Indiana), as well as sales of transmission service. The FERC also regulates certification and siting of new interstate natural gas pipeline projects. For open regulatory matters, unless otherwise noted, the Subsidiary Registrants and Duke Energy Kentucky cannot predict the outcome or ultimate resolution of their respective matters.

On June 7, 2021, Duke Energy Carolinas filed a subsequent license renewal (SLR) application for the Oconee Nuclear Station (ONS) with the U.S. Nuclear Regulatory Commission (NRC) to renew ONS’s operating license for an additional 20 years. The SLR would extend operations of the facility from 60 to 80 years. The current licenses for units 1 and 2 expire in 2033 and the license for unit 3 expires in 2034. By a Federal Register Notice dated July 28, 2021, the NRC provided a 60-day comment period for persons whose interest may be affected by the issuance of a subsequent renewed license for ONS to file a request for a hearing and a petition for leave to intervene. On September 27, 2021, Beyond Nuclear and Sierra Club (Petitioners) filed a Hearing Request and Petition to Intervene (Hearing Request) and a Petition for Waiver. The Hearing Request proposed three contentions and claimed that Duke Energy Carolinas did not satisfy the National Environmental Policy Act (NEPA) of 1969, as amended, or the NRC’s NEPA-implementing regulations. Following Duke Energy Carolinas' answer and the Petitioners' reply, on February 11, 2022, the Atomic Safety and Licensing Board (ASLB) issued its decision on the Hearing Request and found that the Petitioners failed to establish that the proposed contentions are litigable. The ASLB also denied the Petitioners' Petition for Waiver and terminated the proceeding.

On February 24, 2022, the NRC issued a decision in the SLR appeal related to Florida Power and Light's Turkey Point nuclear generating station in Florida. The NRC ruled that the NRC’s license renewal Generic Environmental Impact Statement (GEIS) does not apply to SLR because the GEIS does not address SLR. The decision overturned a 2020 NRC decision that found the GEIS applies to SLR. Although Turkey Point is not owned or operated by a Duke Energy Registrant, the NRC’s order applies to all SLR applicants, including ONS. The NRC order also indicated no subsequent renewed licenses will be issued until the NRC staff has completed an adequate NEPA review for each application. On April 5, 2022, the NRC approved a 24-month rulemaking plan that will enable the NRC staff to complete an adequate NEPA review. Although an SLR applicant may wait until the rulemaking is completed, the NRC also noted that an applicant may submit a supplement to its environmental report providing information on environmental impacts during the SLR period prior to the rulemaking being completed. On November 7, 2022, Duke Energy Carolinas submitted a supplement to its environmental report addressing environmental impacts during the SLR period. On September 14, 2023, the NRC posted on its website that the issuance of the GEIS will now be issued in August 2024 instead of May 2024 due to the volume and technical complexity of the comments received. On March 6, 2024, the NRC staff submitted the rulemaking, which included the updated GEIS, to the NRC.

On December 19, 2022, the NRC published a notice in the Federal Register that the NRC will conduct a limited scoping process to gather additional information necessary to prepare an environmental impact statement (EIS) to evaluate the environmental impacts at ONS during the SLR period. The NRC received comments from the EPA and the Petitioners and these comments identify 18 potential impacts that should be considered by the NRC in the EIS, which include, but are not limited to, climate change and flooding, environmental justice, severe accidents, and external events. On February 8, 2024, the NRC issued the Oconee site-specific draft EIS. The NRC and EPA published the notice for the public to submit comments on the ONS site-specific draft EIS. On April 29, 2024, the petitioners filed a hearing request. The request proposed three contentions and claimed that the ONS site-specific draft EIS is inadequate to satisfy the requirements of NEPA and the NRC’s NEPA-implementing regulations. Duke Energy Carolinas' deadline to respond to any such requests was extended to May 31, 2024.

On December 19, 2022, the NRC issued the Safety Evaluation Report (SER) for the safety portion of the SLR application. The NRC determined Duke Energy Carolinas met the requirements of the applicable regulations and identified actions that have been taken or will be taken to manage the effects of aging and address time-limited analyses. Duke Energy Carolinas and the NRC met with the Advisory Committee on Reactor Safeguards (ACRS) on February 2, 2023, to discuss issues regarding the SER and SLR application. On February 25, 2023, the ACRS issued a report to the NRC on the safety aspects of the ONS SLR application, which concluded that the established programs and commitments made by Duke Energy Carolinas to manage age-related degradation provide confidence that ONS can be operated in accordance with its current licensing basis for the subsequent period of extended operation without undue risk to the health and safety of the public and the SLR application for ONS should be approved.

On January 19, 2023, Duke Energy Carolinas filed a PBR application with the NCUC to request an increase in base rate retail revenues. The PBR Application included a Multiyear rate plan (MYRP) to recover projected capital investments during the three-year MYRP period. In addition to the MYRP, the PBR Application included an Earnings Sharing Mechanism, Residential Decoupling Mechanism and Performance Incentive Mechanisms (PIMS) as required by HB 951. The application as originally filed requested an overall retail revenue increase of $501 million in Year 1, $172 million in Year 2 and $150 million in Year 3, for a combined total of $823 million, or 15.7%, by early 2026. The rate increase is driven primarily by transmission and distribution investments since the last rate case and projected in the MYRP, as well as investments in energy storage and solar assets included in the MYRP consistent with the Carolinas Carbon Plan (Carbon Plan).

On August 22, 2023, Duke Energy Carolinas filed with the NCUC a partial settlement with the Public Staff in connection with its PBR application. The partial settlement included, among other things, agreement on a substantial portion of the North Carolina retail rate base for the historic base case of approximately $19.5 billion and all of the capital projects and related costs to be included in the three-year MYRP, including $4.6 billion (North Carolina retail allocation) projected to go in service over the MYRP period. Additionally, the partial settlement included agreement, with certain adjustments, on depreciation rates, the recovery of grid improvement plan costs and PIMs, Tracking Metrics and the Residential Decoupling Mechanism under the PBR application. On August 28, 2023, Duke Energy Carolinas filed with the NCUC a second partial settlement with the Public Staff resolving additional issues, including the future treatment of nuclear production tax credits related to the Inflation Reduction Act, through a stand-alone rider that will provide the benefits to customers beginning January 1, 2025.

On December 15, 2023, the NCUC issued an order approving Duke Energy Carolinas' PBR Application, as modified by the partial settlements and the order, including an overall retail revenue increase of $436 million in Year 1, $174 million in Year 2 and $158 million in Year 3, for a combined total of $768 million. The order established an ROE of 10.1% based upon an equity ratio of 53% and approved, with certain adjustments, depreciation rates and the recovery of grid improvement plan costs and certain deferred COVID-related costs. Additionally, the Residential Decoupling Mechanism and PIMs were approved as requested under the PBR Application and revised by the partial settlements. Duke Energy Carolinas implemented interim rates, subject to refund, on September 1, 2023. New revised Year 1 rates and the residential decoupling were implemented on January 15, 2024.

On February 13, 2024, a number of parties filed Notices of Appeal of the December 15, 2023, NCUC order. Notices of Appeal were filed by the Carolina Industrial Group for Fair Utility Rates (CIGFUR) III, a collection of various electric membership corporations (collectively, the EMCs), and the North Carolina Attorney General’s Office (the AGO). CIGFUR III and the EMCs appealed the interclass subsidy reduction percentage and the Transmission Cost Allocation stipulation. In addition, CIGFUR III appealed the NCUC’s elimination of the equal percentage fuel cost allocation methodology. The AGO appealed several issues including the authorized ROE and certain rate design and accounting matters. On March 1, 2024, Carolina Utility Customers Association, Inc. appealed several issues, including the authorized ROE and certain rate design and accounting matters.

On January 4, 2024, Duke Energy Carolinas filed a rate case with the PSCSC to request a net increase in annual retail revenues of 11.4%, or approximately $239 million, in the first two years, and an additional overall increase of about 4.1%, or approximately $84 million additional revenue, after the first two years. The requested increases, if approved, would result in an overall average 15.5% increase in annual retail revenues, or approximately $323 million, prior to mitigation efforts. Duke Energy Carolinas requested an ROE of 10.5% with an equity ratio of 53%. To mitigate the rate increase, Duke Energy Carolinas has proposed to accelerate the return of remaining federal unprotected EDIT balances to customers over two years. This offset reduces the impact to customers in the first two years to the effective net increase of 11.4% after which the credit for EDIT balances expire. Duke Energy Carolinas has requested the revised rates to be effective no later than August 1, 2024. Intervenor testimony and Duke Energy Carolinas' rebuttal testimony were filed in April 2024. The evidentiary hearing is scheduled to commence on May 20, 2024.

On March 14, 2024, Duke Energy Carolinas filed with the NCUC an application to construct and operate two hydrogen-capable advanced-class simple-cycle combustion turbines (CTs) at the site of the existing Marshall Steam Station. The two new CTs – totaling approximately 850 MW – will enable the retirement of Marshall coal units 1 and 2 and provide incremental capacity to support system capacity needs and expanded flexibility to support integration of renewables. Pending regulatory approvals, construction is planned to start in 2026, and the CTs are targeted to be placed into service by the end of 2028. As part of the application, Duke Energy Carolinas noted that Construction Work in Progress for the proposed facility will accrue AFUDC and will not be in rate base, resulting in no impact on Duke Energy Carolinas' North Carolina retail revenue requirement during the construction period. The 2029 North Carolina retail revenue requirement for the proposed facility is estimated to be $104 million, representing an approximate average retail rate increase of 2.2% across all classes.

On October 6, 2022, Duke Energy Progress filed a PBR application with the NCUC to request an increase in base rate retail revenues. The rate request before the NCUC included an MYRP to recover projected capital investments during the three-year MYRP period. In addition to the MYRP, the PBR Application included an Earnings Sharing Mechanism, Residential Decoupling Mechanism and PIMs as required by HB 951. The overall retail revenue increase as originally filed would have been $326 million in Year 1, $151 million in Year 2 and $138 million in Year 3, for a combined total of $615 million, by late 2025. The rate increase is driven primarily by transmission and distribution investments since the last rate case and projected in the MYRP, as well as investments in energy storage and solar assets included in the MYRP consistent with the Carbon Plan.

On April 26, 2023, Duke Energy Progress filed with the NCUC a partial settlement with Public Staff, which included agreement on many aspects of Duke Energy Progress' three-year MYRP proposal. In May 2023, CIGFUR II joined this partial settlement and Public Staff and CIGFUR II filed a separate settlement reaching agreement on PIMs, Tracking Metrics and the Residential Decoupling Mechanism under the PBR application.

On August 18, 2023, the NCUC issued an order approving Duke Energy Progress' PBR Application, as modified by the partial settlements and the order, including an overall retail revenue increase of $233 million in Year 1, $126 million in Year 2 and $135 million in Year 3, for a combined total of $494 million. Key aspects of the order include the approval of North Carolina retail rate base for the historic base case of approximately $12.2 billion and capital projects and related costs to be included in the three-year MYRP, including $3.5 billion (North Carolina retail allocation) projected to go in service over the MYRP period. The order established an ROE of 9.8% based upon an equity ratio of 53% and approved, with certain adjustments, depreciation rates and the recovery of grid improvement plan costs and certain deferred COVID-related costs. Additionally, the Residential Decoupling Mechanism and PIMs were approved as requested under the PBR Application and revised by the partial settlements. Duke Energy Progress implemented interim rates, subject to refund, on June 1, 2023, and implemented revised Year 1 rates and the residential decoupling on October 1, 2023.

On October 17, 2023, CIGFUR II and Haywood Electric Membership Corporation each filed a Notice of Appeal of the August 18, 2023 NCUC order. Both parties are appealing certain matters that do not impact the overall revenue requirement in the rate case. Specifically, they appealed the interclass subsidy reduction percentage, and CIGFUR II also appealed the Customer Assistance Program and the equal percentage fuel cost allocation methodology. On November 6, 2023, the AGO filed a Notice of Cross Appeal of the NCUC's determination regarding the exclusion of electric vehicle revenue from the residential decoupling mechanism. On November 9, 2023, Duke Energy Progress, the Public Staff, CIGFUR II, and a number of other parties reached a settlement pursuant to which CIGFUR II agreed not to pursue its appeal of the Customer Assistance Program.

On May 31, 2023, Duke Energy Progress filed a petition with the PSCSC requesting authorization for the financing of Duke Energy Progress' storm recovery costs through securitization due to storm recovery activities required as a result of the following storms: Pax, Ulysses, Matthew, Florence, Michael, Dorian, Izzy and Jasper. On September 8, 2023, Duke Energy Progress filed a comprehensive settlement agreement with all parties on all cost recovery issues raised in the storm securitization proceeding.

The evidentiary hearing occurred in early September 2023. On September 20, 2023, the PSCSC approved the comprehensive settlement agreement and on October 13, 2023, the PSCSC issued its financing order. The storm recovery bonds of $177 million were issued by Duke Energy Progress on April 25, 2024. Duke Energy Progress implemented storm recovery charges effective May 1, 2024. See notes 6 and 12 for more information.

On March 28, 2024, Duke Energy Progress filed with the NCUC its application to construct and operate a 1,360 MW hydrogen-capable, advanced-class combined-cycle generating facility (CC) in Person County at the site of the existing Roxboro Plant. Subject to negotiation of final contractual terms, the new Roxboro CC will be co-owned with the North Carolina Electric Membership Corporation (NCEMC), with Duke Energy Progress owning approximately 1,135 MW and NCEMC owning the remaining 225 MW. Pending regulatory approvals, construction is planned to start in 2026, with the CC targeted to be placed in service by the end of 2028. The CC will allow for the retirement of Roxboro’s coal-fired units 1 and 4. As part of the application, Duke Energy Progress noted that the recovery of Construction Work in Progress during the construction period for the proposed facility may be pursued in a future rate case. The 2029 North Carolina retail revenue requirement for the proposed facility is estimated to be $98 million, representing an approximate average retail rate increase of 2.6% across all classes.

Pursuant to the 2021 Settlement, the Parties agreed to a base rate stay-out provision that expires year-end 2024; however, Duke Energy Florida is allowed an increase to its base rates of an incremental $67 million in 2022, $49 million in 2023 and $79 million in 2024, subject to adjustment in the event of tax reform during the years 2021, 2022 and 2023. The Parties also agreed to an ROE band of 8.85% to 10.85% with a midpoint of 9.85% based upon an equity ratio of 53%. The ROE band can be increased by 25 basis points if the average 30-year U.S. Treasury rate increases 50 basis points or more over a six-month period in which case the midpoint ROE would rise from 9.85% to 10.10%. On July 25, 2022, this provision was triggered. Duke Energy Florida filed a petition with the FPSC on August 12, 2022, to increase the ROE effective August 2022 with a base rate increase effective January 1, 2023. The FPSC approved this request on October 4, 2022. The 2021 Settlement Agreement also provided that Duke Energy Florida will be able to retain $173 million of the expected Department of Energy (DOE) award from its lawsuit to recover spent nuclear fuel to mitigate customer rates over the term of the 2021 Settlement. In return, Duke Energy Florida is permitted to recognize the $173 million into earnings through the approved settlement period. Duke Energy Florida settled the DOE lawsuit and received payment of approximately $180 million on June 15, 2022, of which the retail portion was approximately $154 million. The 2021 Settlement authorizes Duke Energy Florida to collect the difference between $173 million and the $154 million retail portion of the amount received through the capacity cost recovery clause. As of March 31, 2024, Duke Energy Florida has recognized $149 million into earnings, including $8 million and $54 million recognized during the three months ended March 31, 2024, and 2023, respectively. The remaining $24 million is expected to be recognized in 2024.

The 2021 Settlement also contained a provision to recover or flow back the effects of tax law changes. As a result of the IRA enacted on August 16, 2022, Duke Energy Florida is eligible for PTCs associated with solar facilities placed in service beginning in January 2022. Duke Energy Florida filed a petition with the FPSC on October 17, 2022, to reduce base rates effective January 1, 2023, by $56 million to flow back the expected 2023 PTCs and to flow back the expected 2022 PTCs via an adjustment to the capacity cost recovery clause. On December 14, 2022, the FPSC issued an order approving Duke Energy Florida's petition.

In addition to these terms, the 2021 Settlement contained provisions related to the accelerated depreciation of Crystal River Units 4-5, the approval of approximately $1 billion in future investments in new cost-effective solar power, the implementation of a new Electric Vehicle Charging Station Program and the deferral and recovery of costs in connection with the implementation of Duke Energy Florida’s Vision Florida program, which explores various emerging non-carbon emitting generation technology, distributed technologies and resiliency projects, among other things. The 2021 Settlement also resolved remaining unrecovered storm costs for Hurricane Michael and Hurricane Dorian.

On July 1, 2020, Duke Energy Florida petitioned the FPSC for approval of a voluntary solar program consisting of 10 new solar generating facilities with combined capacity of approximately 750 MW. The program allows participants to support cost-effective solar development in Florida by paying a subscription fee based on per kilowatt subscriptions and receiving a credit on their bill based on the actual generation associated with their portion of the solar portfolio. The estimated cost of the 10 new solar generation facilities is approximately $1 billion and the projects are expected to be completed by the end of 2024. This investment is included in base rates offset by the revenue from the subscription fees and the credits will be included for recovery in the fuel cost recovery clause. The FPSC approved the program in January 2021.

On February 24, 2021, the League of United Latin American Citizens (LULAC) filed a notice of appeal of the FPSC’s order approving the Clean Energy Connection to the Supreme Court of Florida. The Supreme Court of Florida heard oral arguments in the appeal on February 9, 2022. On May 27, 2022, the Supreme Court of Florida issued an order remanding the case back to the FPSC so that the FPSC can amend its order to better address some of the arguments raised by LULAC. On September 23, 2022, the FPSC issued a revised order and submitted it on September 26, 2022, to the Supreme Court of Florida. The Supreme Court of Florida requested that the parties file supplemental briefs regarding the revised order, which were filed February 6, 2023. LULAC has filed a request for Oral Argument on the issues discussed in the supplemental briefs, but the court has yet to rule on that request. The FPSC approval order remains in effect pending the outcome of the appeal.

On April 11, 2022, Duke Energy Florida filed a Storm Protection Plan for approval with the FPSC. The plan, which covers investments for the 2023-2032 time frame, reflects approximately $7 billion of capital investment in transmission and distribution meant to strengthen its infrastructure, reduce outage times associated with extreme weather events, reduce restoration costs and improve overall service reliability. The evidentiary hearing began on August 2, 2022. On October 4, 2022, the FPSC voted to approve Duke Energy Florida’s plan with one modification to remove the transmission loop radially fed program, representing a reduction of approximately $80 million over the 10-year period starting in 2025. On December 9, 2022, the OPC filed a notice of appeal of this order to the Florida Supreme Court. The OPC's initial brief was filed on April 18, 2023. Duke Energy Florida filed its answer brief on July 17, 2023. The OPC's reply brief was filed on October 16, 2023. The Florida Supreme Court heard oral arguments on February 7, 2024.

On September 28, 2022, much of Duke Energy Florida’s service territory was impacted by Hurricane Ian, which caused significant damage resulting in more than 1.1 million outages. After depleting any existing storm reserves, which were approximately $107 million before Hurricane Ian, Duke Energy Florida is permitted to petition the FPSC for recovery of additional incremental operation and maintenance costs resulting from the storm and to replenish the retail customer storm reserve to approximately $132 million. Duke Energy Florida filed its petition for cost recovery of various storms, including Hurricane Ian, and replenishment of the storm reserve on January 23, 2023, seeking recovery of $442 million, for recovery over 12 months beginning with the first billing cycle in April 2023. On March 7, 2023, the FPSC approved this request for interim recovery, subject to refund, and ordered Duke Energy Florida to file documentation of the total actual storm costs, once known. Duke Energy Florida filed documentation evidencing its total actual storm costs of $431 million on September 29, 2023. The FPSC will hold a final hearing to determine the prudence of these costs on May 21 and 22, 2024.

On August 30, 2023, Hurricane Idalia made landfall on Florida’s gulf coast, causing damage and impacting more than 200,000 customers across Duke Energy Florida's service territory. On October 16, 2023, Duke Energy Florida requested to combine the $92 million retail portion of the deferred estimated Hurricane Idalia costs with $74 million of costs projected to be collected after December 31, 2023, under the existing approved storm cost recovery and storm surcharge. This $74 million of costs relates primarily to the approved ongoing replenishment of the storm reserves. At its December 5, 2023 Agenda Conference, the FPSC approved recovery of the total $166 million over 12 months beginning with its first billing cycle in January 2024, replacing the previously approved storm cost recovery and storm surcharge, and ordered Duke Energy Florida to file documentation of the total actual Idalia related storm costs, once known. Revised rates were effective January 1, 2024.

On April 2, 2024, Duke Energy Florida filed a formal request for new base rates with the FPSC. Duke Energy Florida has proposed a three-year rate plan that would begin in January 2025, once its current base rate settlement agreement concludes at the end of 2024. Duke Energy Florida proposed multiyear rate increases that use the projected 12-month periods ending December 31, 2025, 2026, and 2027 as the test years, with adjusted rates to be effective with the first billing period of January 2025, 2026, and 2027, respectively. Duke Energy Florida requested additional base rate revenue requirements of approximately $593 million in 2025, $98 million in 2026 and $129 million in 2027, representing an average annual increase in revenue requirements of approximately 4% over 2025 through 2027. Duke Energy Florida requested an ROE midpoint at 11.15% and an equity ratio of 53%. A final hearing on this request is scheduled to begin on August 12, 2024.

Duke Energy Ohio filed with the PUCO an electric distribution base rate case application on October 1, 2021, with supporting testimony filed on October 15, 2021, requesting an increase in electric distribution base rates of approximately $55 million. On September 19, 2022, Duke Energy Ohio filed a Stipulation and Recommendation with the PUCO, which includes an increase in overall electric distribution base rates of approximately $23 million with an equity ratio of 50.5% and an ROE of 9.5%. The stipulation is among all but one party to the proceeding. The PUCO issued an order on December 14, 2022, approving the Stipulation without material modification. Rates went into effect on January 3, 2023. The Ohio Consumers' Counsel filed an application for rehearing on January 13, 2023, arguing the Stipulation was unreasonable, discriminatory, and denied OCC due process. On March 20, 2024, the PUCO issued its Second Entry on Rehearing, denying OCC's rehearing application. OCC has 60 days to seek an appeal.

Duke Energy Ohio filed with the PUCO a natural gas base rate case application on June 30, 2022, with supporting testimony filed on July 14, 2022, requesting an increase in natural gas base rates of approximately $49 million. The drivers for this case are capital invested since Duke Energy Ohio's last natural gas base rate case in 2012. Duke Energy Ohio also sought to adjust the caps on its CEP rider. On April 28, 2023, Duke Energy Ohio filed a stipulation with all parties to the case except the OCC. In the stipulation, the parties agreed to approximately $32 million in revenue increases with an equity ratio of 52.32% and an ROE of 9.6%, and adjustments to the CEP Rider caps. The stipulation was opposed by the OCC at an evidentiary hearing that concluded on May 24, 2023. On November 1, 2023, PUCO issued an order approving the stipulation as filed. New rates went into effect November 1, 2023. On December 1, 2023, the OCC filed an application for rehearing. On December 13, 2023, the PUCO granted OCC's application for rehearing for further consideration of issues raised.

On April 1, 2024, Duke Energy Ohio filed with the PUCO a request for an Electric Security Plan (ESP). The ESP application proposes a three-year term from June 1, 2025 through May 31, 2028 and includes continuation of market-based customer rates through competitive procurement processes for generation and continuation and expansion of existing rider mechanisms. Duke Energy Ohio is proposing a new rider mechanism relating to electric distribution infrastructure modernization programs, which may be enabled by and partially funded through federal or state funding opportunities, future battery storage projects, and two proposed electric vehicle programs. Additional proposed new rider mechanisms are related to solar for all investments for low-income and disadvantaged communities, low-income senior citizen bill assistance, and energy efficiency and demand-side management programs.

On December 1, 2022, Duke Energy Kentucky filed a rate case with the KPSC requesting an annualized increase in electric base rates of approximately $75 million. The request for rate increase was driven by capital investments to strengthen the electricity generation and delivery systems along with adjusted depreciation rates for the East Bend and Woodsdale Combustion Turbine (CT) generation stations. Duke Energy Kentucky also requested approval for new programs and tariff updates, including a voluntary community-based renewable subscription program and two electric vehicle charging programs. The KPSC issued an order on October 12, 2023, including a $48 million increase in base revenues, an ROE of 9.75% for electric base rates and 9.65% for electric riders and an equity ratio of 52.145%. New rates went into effect October 13, 2023. The Company's request to align the depreciation rates of East Bend with a 2035 retirement date was denied and the KPSC ordered depreciation rates with a 2041 retirement date for the unit. The KPSC did approve the request to align the depreciation rates of Woodsdale CT with a 2040 retirement date and denied the voluntary community-based renewable subscription program and the two electric vehicle charging programs.

On November 1, 2023, Duke Energy Kentucky filed for rehearing requesting certain matters be reconsidered by the KPSC. On November 21, 2023, KPSC granted in part and denied in part the Company's request for rehearing. On February 15, 2024, the KPSC issued a briefing schedule for the rehearing process. The briefing concluded on April 1, 2024, and the matter was submitted for decision on April 2, 2024.

On December 14, 2023, Duke Energy Kentucky filed an appeal with the Franklin County Circuit Court on certain matters for which the KPSC denied rehearing, specifically as it relates to including decommissioning costs in depreciation rates for East Bend and Woodsdale. On January 8, 2024, answers to the appeal were filed by the KPSC, Kentucky Attorney General, and the Kentucky Broadband & Cable Association. On April 11, 2024, the Franklin County Circuit Court approved a briefing schedule with Duke Energy Kentucky's initial brief due June 26, 2024, appellee briefs due September 24, 2024, and Duke Energy Kentucky's reply brief due November 8, 2024.

In Duke Energy Indiana’s 2019 rate case, the IURC opened a subdocket for post-2018 coal ash related expenditures. Duke Energy Indiana filed testimony on April 15, 2020, in the coal ash subdocket requesting recovery for the post-2018 coal ash basin closure costs for plans that have been approved by the Indiana Department of Environmental Management (IDEM) as well as continuing deferral, with carrying costs, on the balance. On November 3, 2021, the IURC issued an order allowing recovery for post-2018 coal ash basin closure costs for the plans that have been approved by IDEM, as well as continuing deferral, with carrying costs, on the balance. The OUCC and the Duke Industrial Group appealed. The Indiana Court of Appeals issued its opinion on February 21, 2023, reversing the IURC's order to the extent that it allowed Duke Energy Indiana to recover federally mandated costs incurred prior to the IURC's November 3, 2021 order. In addition, the court found that any costs incurred pre-petition to determine federally mandated compliance options were not specifically authorized by the statute and should also be disallowed.

In the second quarter of 2023, Duke Energy Indiana filed its proposal to remove from rates certain costs incurred prior to the IURC's November 3, 2021 order date. On September 20, 2023, the commission approved the Company's proposal to remove the costs from its rates and assessed simple interest of the refunds of 4.71%, beginning from when the costs were initially recovered from customers. Duke Energy Indiana seeks to recover the pre-order costs denied by the Indiana Court of Appeals and certain future coal ash closure costs as part of depreciation costs in the 2024 Indiana Rate Case.

On November 23, 2021, Duke Energy Indiana filed for approval of the Transmission, Distribution, Storage Improvement Charge 2.0 investment plan for 2023-2028 (TDSIC 2.0). On June 15, 2022, the IURC approved, without modification, TDSIC 2.0, which includes approximately $2 billion in transmission and distribution investments selected to improve customer reliability, harden and improve resiliency of the grid, enable expansion of renewable and distributed energy projects and encourage economic development. In addition, the IURC set up a subdocket to consider a targeted economic development project, which the IURC approved on March 2, 2022. On July 15, 2022, the OUCC filed a notice of appeal to the Indiana Court of Appeals in Duke Energy Indiana’s TDSIC 2.0 proceeding. An appellant brief was filed on October 28, 2022, and Duke Energy Indiana filed its responsive brief on December 28, 2022. The Indiana Court of Appeals issued its opinion on March 9, 2023, affirming the IURC’s order in its entirety. The Duke Industrial Group filed a petition to transfer to the Indiana Supreme Court. The Indiana Supreme Court granted transfer and held an oral argument on September 28, 2023.

On April 4, 2024, Duke Energy Indiana filed an application with the IURC for a rate increase of $492 million, representing an overall average bill increase of approximately 16.2%, which, if approved, would be added to retail customer bills in two steps, approximately 11.7% in 2025 and approximately 4.5% in 2026. Duke Energy Indiana requested an ROE of 10.5% with an equity ratio of 53%. The rate increase is driven by $1.6 billion in investments made since the last general rate case filed in 2019 in order to reliably serve customers, improve resiliency of the system, and advance environmental sustainability. An evidentiary hearing is scheduled to begin August 29, 2024.

On April 1, 2024, Piedmont filed an application with the NCUC for a rate increase for retail customers of approximately $159 million, which represents a 12.5% increase in retail revenues. Piedmont requested an ROE of 10.5% with an equity ratio of 53%. The rate increase is driven by significant infrastructure upgrade investments since the last general rate case, offset by lower fixed natural gas costs and remaining federal and state tax reform savings to be received by customers. Approximately 40% of the plant additions being rolled into rate base are categories of plant investment that are covered under the IMR mechanism, which was originally approved as part of the 2013 North Carolina Rate Case. Piedmont plans to implement revised interim rates by November 1, 2024.