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Regulatory Matters | 6 Months Ended
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Jun. 30, 2025
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 regulates and approves rates for wholesale electric sales and interstate transmission rates. The FERC also regulates certification and siting of new interstate natural gas pipeline projects. For open regulatory matters, unless otherwise noted, the Subsidiary Registrants cannot predict the outcome or ultimate resolution of their respective matters. Duke Energy Carolinas and Duke Energy Progress Hurricanes Debby and Helene In 2024, hurricanes Debby and Helene significantly impacted the Duke Energy Carolinas and Duke Energy Progress territories in North Carolina and South Carolina. As of June 30, 2025, the total cumulative operations and maintenance expense incurred for restoration and rebuilding of infrastructure associated with the hurricanes was approximately $812 million ($530 million and $282 million for Duke Energy Carolinas and Duke Energy Progress, respectively). The reduction in cumulative operations and maintenance expense compared to December 31, 2024, of $82 million for Duke Energy Carolinas and an increase of $34 million for Duke Energy Progress, was recorded in Regulatory assets within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets. In addition, through June 30, 2025, there have been cumulative capital investments of $468 million ($378 million and $90 million for Duke Energy Carolinas and Duke Energy Progress, respectively) associated with the hurricanes. Amounts are net of expected insurance recoveries and could change going forward as storm restoration and rebuild work is finalized. Additional estimated capital costs of approximat ely $70 million are expected to be incurred through the first half of 2026 t o rebuild the systems from hurricane damage. North Carolina Storm Cost Securitization In December 2024, Duke Energy Carolinas and Duke Energy Progress filed their joint petition for review and approval of storm recovery costs (Phase 1) with the NCUC to securitize the North Carolina-retail allocable share of storm costs associated with hurricanes Helene, Debby and Ian, as well as Hurricane Zeta and Winter Storm Izzy, and the establishment of storm reserves for $200 million at Duke Energy Carolinas and $100 million at Duke Energy Progress. On February 3, 2025, Duke Energy Carolinas and Duke Energy Progress filed their joint petition for financing orders (Phase 2). In February 2025, Duke Energy Carolinas and Duke Energy Progress reached a settlement agreement with the North Carolina Public Staff and other intervening parties that resolved all issues between the parties in the Phase 1 proceeding and removed the establishment of storm reserves from the securitization proceeding. Further, the settlement outlined agreement on certain issues in the Phase 2 proce eding. On April 16, 2025, the NCUC issued its Phase 1 order approving the settlement and determining that approximately $584 million for Duke Energy Carolinas and $461 million for Duke Energy Progress in storm recovery costs are reasonable and prudent and eligible for securitization. The order authorized the companies to proceed to Phase 2 of the securitization process. On April 15, 2025, Duke Energy Carolinas and Duke Energy Progress filed a settlement with the North Carolina Public Staff resolving all remaining issues in Phase 2. On June 18, 2025, the NCUC issued its Phase 2 order approving the settlement and issuing the financing orders. Duke Energy Carolinas and Duke Energy Progress expect to securitize the North Carolina-retail allocable share of storm costs by the end of 2025. South Carolina Storm Cost Securitization On March 21, 2025, Duke Energy Carolinas filed a petition for storm securitization with the PSCSC for authorization to finance the estimated South Carolina-retail allocable share of storm costs primarily related to Hurricane Helene storm recovery activities and inclusive of funding $25 million related to storm reserves. On June 25, 2025, an evidentiary hearing was held. Duke Energy Carolinas reached a comprehensive settlement among all parties in the proceeding which was filed with the PSCSC supporting securitization of approximately $556 million, including the storm reserve funding. On July 10, 2025, the PSCSC approved the settlement and the financing order was issued on August 1, 2025. Duk e Energy Carolinas expects to securitize the South Carolina-retail allocable share of storm costs by the end of 2025. Due to the relatively low level of storm costs incurred by Duke Energy Progress in South Carolina, Duke Energy Progress will not seek to pursue securitization of those costs and has offset them against established storm reserve balances. Application to Combine Utilities On July 30, 2025, Duke Energy Carolinas and Duke Energy Progress (together, the Companies) filed a notice of intent with the NCUC and PSCSC that notifies the respective state regulatory commissions of the Companies' intent to file applications for approval to combine utilities, by which Duke Energy Progress will merge into Duke Energy Carolinas, resulting in a single electric utility serving the Companies' North Carolina and S outh Carolina service territories. The Companies plan to file applications no earlier than August 14, 2025, with the NCUC, PSCSC and FERC. The Companies have been engaging with stakeholders and will continue to do so in advance of filing and intend to propose a procedural schedule for consideration at the time of filing. Subject to regulatory approvals, the Company is currently targeting an effective date of January 1, 2027. There is no assurance that Duke Energy Carolinas and Duke Energy Progress will obtain the required regulatory approvals from the NCUC, PSCSC, and the FERC, and the transaction cannot proceed without all three. Duke Energy Carolinas Oconee Subsequent License Renewal On June 7, 2021, Duke Energy Carolinas filed a subsequent license renewal (SLR) application for Oconee with the NRC to renew the operating licenses. On March 31, 2025, the NRC issued the subsequent renewed licenses for Oconee, allowing an additional 20 years of operation to 2053 (units 1 and 2) and 2054 (unit 3). 2023 North Carolina Rate Case In January 2023, Duke Energy Carolinas filed a performance-based regulation (PBR) application with the NCUC to request an increase in base rate retail revenues. The PBR application 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 Performance Incentive Mechanisms (PIMS) as required by HB951. In August 2023, Duke Energy Carolinas filed with the NCUC a partial settlement with the North Carolina Public Staff in connection with its PBR application. The partial settlement included, among other things, a greement 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 t he PBR application. On August 28, 2023, Duke Energy Carolinas filed with the NCUC a second partial settlement with the North Carolina Public Staff resolving additional issues, including the future treatment of nuclear PTCs related to the IRA, through a stand-alone rider that would provide the benefits to customers. This stand-alone rider was effective in rates beginning January 1, 2025. On December 1 5, 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. T he 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 COV ID-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 on September 1, 2023. New revised Year 1 rates and the residential decoupling were implemented on January 15, 2024. In February 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 electric membership cooperatives (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. In July 2024, the Supreme Court of North Carolina consolidated these appeals with the parallel appeals of the NCUC's order regarding the Duke Energy Progress PBR application. Briefing is complete and oral arguments occurred on February 13, 2025. Duke Energy Carolinas anticipates a decision to be issued no later than the fourth quarter of 2025. 2025 South Carolina Rate Case On July 1, 2025, Duke Energy Carolinas filed a base rate case with the PSCSC requesting an annualized increase in electric base rates of approximately $151 million and an ROE of 10.85% with an equity ratio of 53%. This is an overall average customer rate increase of approximately 7.7%. The request for the rate increase is driven by significant capital investments, including generation plant additions, as well as transmission, distribution and grid improvements. Duke Energy Carolinas has requested new rates to go into effect no later than March 1, 2026. An evidentiary hearing is scheduled to commence on November 13, 2025. An order is expected by the end of 2025. Duke Energy Progress 2022 North Carolina Rate Case In October 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 HB951. In April 2023, Duke Energy Progress filed with the NCUC a partial settlement with North Carolina 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 North Carolina Public Staff and CIGFUR II filed a separate settlement reaching agreement on PIMs, Tracking Metrics and the Residential Decoupling Mechanism under t he 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 COV ID-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 on June 1, 2023, and implemented revised Year 1 rates and the residential decoupling on October 1, 2023. In October 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. In November 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. In November 2023, Du ke Energy Progress, the North Carolina 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. In July 2024, the Supreme Court of North Carolina consolidated these appeals with the parallel appeals of the NCUC's order regarding the Duke Energy Carolinas PBR application. Briefing is complete and oral arguments occurred in February 2025. Duke Energy Progress anticipates a decision to be issued no later than the fourth quarter of 2025. Person County Combined Cycle CPCN On February 7, 2025, Duke Energy Progress filed with the NCUC its application to construct and operate a second 1,360-MW hydrogen-capable, advanced-class CC unit in Person County at the Roxboro Plant. NCEMC has also notified Duke Energy Progress of NCEMC's intent to co-own approximately 225 MW of the second CC and Duke Energy Progress and NCEMC began negotiations on the contractual arrangement in the second quarter of 2025. NCEMC has the right to co-own the facility under its existing supply agreement with Duke Energy Progress. Pending regulatory approvals, construction of the second CC is planned to start in 2026 with the unit targeted to be placed in service by the end of 2029. 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 2030 North Carolina retail revenue requirement for the proposed facility is estimated to be $113 million, representing an approximate average retail rate increase of 2.6% across all classes. The air permit issued by the NCDEQ in December 2024, also pertains to the second CC. An evidentiary hearing on the second CC CPCN concluded on July 22, 2025. An order is expected by the end of 2025. Robinson Subsequent License Renewal In April 2025, Duke Energy Progress filed an SLR application for Robinson with the NRC to renew Robinson’s operating license for an additional 20 years. The current license expires in 2030 and the renewal would extend the operating license of the facility to 2050. The NRC is performing the safety and environmental reviews for the application and is scheduled to reach a decision by April 2026. 2025 South Carolina Rate Case On June 12, 2025, Duke Energy Progress filed a base rate case with the PSCSC requesting an annualized increase in electric base rates of approximately $75 million and an ROE of 10.85% with an equity ratio of 53%. This is an overall average customer rate increase of approximately 12.1%. The request for the rate increase is driven by significant capital investments, primarily including transmission, distribution and grid improvements. Duke Energy Progress has requested new rates to go into effect no later than February 1, 2026. An evidentiary hearing is scheduled to commence on October 27, 2025. Duke Energy Florida Clean Energy Connection In July 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 749 MW. The FPSC approved the program in January 2021, allowing 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 10 new solar generation facilities were completed and all of the remaining sites were in service by the end of 2024 at a cost of approximately $1.1 billion. These investments are included in base rates offset by the revenue from the subscription fees, with credits included in the fuel cost recovery clause. In February 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 in February 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. In September 2022, the FPSC issued a revised order and submitted it 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 in February 2023. On July 17, 2025, the Supreme Court of Florida issued an order affirming the revised FPSC order. The ruling did not change the solar program or have other financial implications. This matter is now fully resolved. Storm Protection Plan At least every three years, Duke Energy Florida must file an SPP with the FPSC. Each plan covers a 10-year period and includes investments in transmission and distribution meant to strengthen infrastructure, reduce outage times associated with extreme weather events, reduce restoration costs and improve ove rall service reliability. In April 2022, Duke Energy Florida filed an SPP for approval with the FPSC for the 2023-2032 time frame. The plan reflected approximately $7 billion of capital investment in transmission and distribution. The evidentiary hearing began in August 2022. In October 2022, the FPSC approved 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. In December 2022, the Office of Public Counsel (OPC) filed a notice of appeal of this order to the Supreme Court of Florida and briefs were filed by the OPC and Duke Energy Florida during 2023. On November 14, 2024, the Supreme Court of Florida issued an order upholding the FPSC's approval of Duke Energy Florida's plan. In January 2025, Duke Energy Florida filed an SPP for approval with the FPSC for the 2026-2035 time frame reflecting approximately $7 billion of capital investment in transmission and distribution. On March 12, 2025, the OPC filed testimony recommending that the pace of the proposed spend be reduced, as well as challenging three subprograms in Duke Energy Florida's SPP. Duke Energy Florida filed rebuttal testimony on April 2, 2025, requesting that the FPSC approve its SPP as filed. On May 16, 2025, Duke Energy Florida and the OPC filed Joint Stipulations to resolve all matters, and the FPSC issued an order on June 19, 2025, approving those stipulations. The stipulations require Duke Energy Florida to defer certain work in two programs from 2026 to 2027 and later. The remainder of Duke Energy Florida's filed SPP was approved without modification. This matter is now fully resolved. Hurricanes Debby, Helene and Milton In 2024, Hurricane Debby (Category 1 storm), Hurricane Helene (Category 4 storm) and Hurricane Milton (Category 3 storm) made landfall in Florida and caused significant damage. Duke Energy Florida has certain existing storm reserve regulatory liability amounts, which are applied to the recovery of storm costs. The storm reserve amount was approximately $63 million as of July 31, 2024, prior to the damage resulting from hurricanes Debby, Helene and Milton. Duke Energy Florida is permitted to petition the FPSC for recovery of incremental operation and maintenance costs resulting from the storms and to replenish the retail customer storm reserve to approximately $132 million. In December 2024, Duke Energy Florida filed its petition to recover the estimated costs incurred to respond to all three storms, including replenishment of the storm reserve, see king recovery of approximately $1.1 billion over 12 months beginning with the first billing cycle in March 2025. Approxim ately $454 million and $936 million of the operation and maintenance expens es, net of storm reserves, are deferred in Regulatory assets within Current assets as of June 30, 2025, and December 31, 2024, respectively. Approximately $81 million of capital related to these storms will be sought for recovery in future base rate case filings. On February 4, 2025, the FPSC voted to approve Duke Energy Florida's request for recovery of these estimated storm costs as filed, subject to true-up after the actual costs are filed. New rates were effective March 1, 2025. Duke Energy Ohio Duke Energy Ohio Natural Gas Base Rate Case In June 2022, Duke Energy Ohio filed a natural gas base rate case application with the PU CO. The drivers for this case were 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 Capital Expenditure Program (CEP) rider. In April 2023, Duke Energy Ohio filed a stipulation with all parties to the case except the Ohio Consumers' Counsel (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 in May 2023. On November 1, 2023, PUCO issued an order approving the stipulation as filed and new rates went into effect November 1, 2023. In December 2023, the OCC filed an application for rehearing and the PUCO granted OCC's application for rehearing for further consideration of issues raised. As a result of a Supreme Court of Ohio decision regarding procedural issues related to applications for rehearing, PUCO denied OCC’s rehearing request. In October 2024, the OCC filed its Notice of Appeal with the Supreme Court of Ohio. The case is full y briefed, and oral argument is scheduled for October 7, 2025. Duke Energy Ohio Electric Security Plan In April 2024, Duke Energy Ohio filed with the PUCO a request for an Electric Security Plan (ESP). The ESP application proposed a three-year term from June 1, 2025, through May 31, 2028, and included continuation of market-based rates for generation supply through competitive procurement processes and continuation and expansion of existing rider mechanisms. Duke Energy Ohio proposed 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, as well as future battery storage projects and two electric vehicle programs. Additional proposals included new rider mechanisms related to solar for all investments for low-income and disadvantaged communities, low-income senior citizen bill assistance, and energy efficiency (EE) and demand-side management programs. In November 2024, Duke Energy Ohio filed a stipulation that the majority of the intervenors signed as either signatory or non-opposing parties. The stipulation includes the continuation of market-based customer rates for generation supply through competitive procurement auctions and the continuation of all existing riders. It further establishes new caps for certain riders. Duke Energy Ohio also agreed to withdraw its proposals for an infrastructure modernization rider, battery storage projects and electric vehicle programs. The stipulation includes a residential EE program with provisions for low-income customers. On May 14, 2025, PUCO issued its order, approving the stipulation without modification. On May 15, 2025, the governor of Ohio signed Ohio Substitute House Bill 15 (HB15) into law to be effective on August 14, 2025. HB15 requires electric distribution utilities to file a base rate case every three years, commencing no later than December 31, 2029, and establishes an opportunity to apply for approval of a three-year rate plan with forward-looking test periods to mitigate regulatory lag. HB15 eliminates ESPs and certain distribution-related riders, but allows ESPs approved as of its effective date to remain in place through the end of their authorized term. HB15 also eliminates Duke Energy Ohio's Legacy Generation Rider upon the effective date of HB15 and prevents the PUCO from future reauthorization of similar arrangements. As a result of HB15, future losses related to Duke Energy Ohio's Inter-Company Power Agreement with OVEC will not be recoverable from retail customers. Additionally, regulatory assets related to OVEC as of HB15's effective date may not be recoverable. Regulatory assets related to OVEC were $6 million and $30 million as of June 30, 2025, and December 31, 2024, respectively. Duke Energy Ohio RTO Adder On February 24, 2022, the OCC filed a complaint asserting that FERC should reduce the ROE utilized in transmission formulas for Duke Energy Ohio and certain transmission providers by eliminating the 50 basis point adder associated with RTO membership. The OCC contends this is required because Ohio law mandates that transmission owning utilities join an RTO and that the 50 basis point adder is only applicable where RTO membership is voluntary. On December 15, 2022, FERC denied the complaint as it related to Duke Energy Ohio, but granted it for certain other transmission providers. As a result of appeal by certain other transmission providers, the U.S. Court of Appeals for the Sixth Circuit (Sixth Circuit) on January 17, 2025, reversed the prior decision from FERC. In the decision, the Sixth Circuit ruled the 50 basis point adder is available only where RTO membership is voluntary. The decision noted that Ohio law requires Ohio's transmission utilities to be a member of an RTO and therefore it is unlawful for FERC to remove the adder from certain transmission providers but not also remove the adder from Duke Energy Ohio. As a result, the issue was remanded back to FERC to revise their prior decision. As a result of the ruling, Duke Energy Ohio recognized a pre-tax charge during 2025, the results of which were not material. On March 26, 2025, the Sixth Circuit denied requests for rehearing. On April 16, 2025, the Sixth Circuit agreed to stay the mandate pending further appeal to the U.S. Supreme Court. On July 17, 2025, Duke Energy Ohio filed a brief at the U.S. Supreme Court requesting review of the Sixth Circuit's decision. Duke Energy Kentucky 2022 Electric Base Rate Case In December 2022, Duke Energy Kentucky filed a rate case with the KPSC 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. Duke Energy Kentucky'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 approved the request to align depreciation rates of Woodsdale CT with a 2040 retirement date and denied the voluntary community-based renewable subscription program and electric vehicle charging programs. Revised rates were implemented in August 2024 after a rehearing request. On December 14, 2023, Duke Energy Kentucky filed an appe al with the Franklin County Circuit Court on certain matters for which the KPSC denied rehearing, specifically as it relates to the inclusion of decommissioning costs in depreciation rates for East Bend and Woodsdale. The case is fully briefed. Duke Energy Kentucky is awaiting the scheduling of oral arguments and outcome of the appeal. Duke Energy Kentucky 2024 Electric Base Rate Case In December 2024, Duke Energy Kentucky filed a base rate case with the KPSC requesting an annualized increase in electric base rates of approximately $70 million and an ROE of 10.85% with an equity ratio of 52.728%. This is an overall average customer rate increase of approximately 14.7%. The request for the rate increase is driven by capital investments to strengthen the electricity generation and delivery systems. The evidentiary hearing occurred in May 2025. New rates went into effect on July 3, 2025, subject to refund. An order is expected by October 3, 2025. Duke Energy Kentucky 2025 Natu ral Gas Base Rate Case On June 2, 2025, Duke Energy Kentucky filed a base rate case with the KPSC requesting an annualized increase in natural gas base rates of approximately $26 million and an ROE of 10.75% with an equity ratio of 52.649%. This is an overall average customer rate increase of approximately 17%. The request for the rate increase is driven by capital investments to strengthen the natural gas delivery system. An evidentiary hearing is scheduled for October 28, 2025. New rates are anticipated to go into effect around January 2, 2026. 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. In April 2020, Duke Energy Indiana filed testimony in the coal ash subdocket requesting recovery for post-2018 coal ash basin closure costs associated with closure plans that were approved by the Indiana Department of Environmental Management (IDEM) at that time as well as continued deferral approval and carrying costs on the balance of such coal ash basin closure costs. On November 3, 2021, the IURC issued an order allowing recovery of the post-2018 coal ash basin closure costs, 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 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 IURC approved Duke Energy Indiana's proposal to remove the costs from its rates and assessed simple interest on the refunds at a rate of 4.71%, beginning from when the costs were initially recovered from customers. In the 2024 Indiana Rate Case, Duke Energy Indiana included a request 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. The IURC's January 29, 2025 order in the 2024 Indiana Rate Case denied recovery of the pre-order costs previously denied by the Indiana Court of Appeals but approved the recovery of certain future coal ash closure costs as part of depreciation costs. In 2023, Duke Energy Indiana filed a 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. On May 8, 2024, the IURC issued a CPCN and approved these coal ash related compliance projects as federally mandated compliance projects. In June 2024, the Citizens Action Coalition of Indiana (CAC) filed a notice of appeal of the IURC's order. Briefing was completed in January 2025, and Duke Energy Indiana is awaiting an opinion from the appellate court. TDSIC 2.0 In November 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 July 2022, the OUCC filed a notice of appeal to the Indiana Court of Appeals in Duke Energy Indiana’s TDSIC 2.0 proceeding. 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. On December 19, 2024, the Indiana Supreme Court affirmed the Indiana Court of Appeals decision, concluding there was substantial evidence that the IURC's conclusion was reasonable and the TDSIC 2.0 plan met the statutory requirements. On January 21, 2025, the Duke Industrial Group filed a motion for rehearing. On March 4, 2025, the Indiana Supreme Court denied the Duke Industrial Group's petition for rehearing. There can be no further appeals on TDSIC 2.0 and this matter is now fully resolved. 2024 Indiana Rate Case In April 2024, Duke Energy Indiana filed an application with the IURC for a rate increase for retail customers. T he request for rate increase was 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 order for the rate case was issued by the IURC on January 29, 2025, and revised February 3, 2025, which authorized an ROE of 9.75%, an equity ratio of 53% and an annual revenue increase of $296 million. Based on review of these orders, Duke Energy Indiana identified an inconsistency in the calculation of operating revenues before the effect of trackers. On February 7, 2025, Duke Energy Indiana made a compliance filing in accordance with the IURC's findings in its order and addressed the identified inconsistencies. The compliance filing also clarified the annual revenue increase was approximately $385 million. On February 18, 2025, one industrial customer submitted a filing requesting the IURC to clarify its revenue allocation in these proceedings, which was denied by the Commission on April 16, 2025. On February 25, 2025, the IURC approved Duke Energy Indiana’s compliance filing and new rates were implemented February 27, 2025. The industrial customer filed a notice of appeal on February 28, 2025, regarding cost of service allocation. On April 9, 2025, the IURC issued an order clarifying the intent of its January 29, 2025 order regarding the rate migration adjustment, resulting in revised rates that were effective on May 19, 2025. On May 14, 2025, the industrial customer filed a motion to dismiss its appeal, and on May 20, 2025, the Indiana Court of Appeals granted the industrial customer's motion to dismiss. This matter is now fully resolved. Cayuga Combined Cycle CPCN On February 13, 2025, Duke Energy Indiana filed for a CPCN seeking approval to construct two 1x1 CC natural gas-fired units with a combined winter rating of 1,476 MW. The Cayuga CC Project is proposed to be constructed on the same site as the retiring Cayuga coal-fired steam units with a winter rating of 1,005 MW. The Cayuga CC Project will result in an incremental 471 MW for the Duke Energy Indiana system and will allow Duke Energy Indiana to avoid expected maintenance and environmental compliance costs needed for the coal units to continue operating. The estimated cost of the Cayuga CC project is approximatel y $3.3 billion, plus actual AFUDC. Duke Energy Indiana has proposed recovery of certain facility costs during construction, including AFUDC, through construction work in progress ratemaking via a proposed generation cost adjustment tracker mechanism. The estimated average retail rate impact during construction and initial in-service periods from April 2026 through May 2031 is approximately 5.4%. Duke Energy Indiana expects CC 1 to be placed in service in 2029 and CC 2 to be placed in service in 2030. A final air permit was issued by IDEM on March 5, 2025. On June 17, 2025, Duke Energy Indiana entered into a settlement agreement with one of the parties in this proceeding to conduct a study evaluating the feasibility of third-party operation of the Cayuga coal units. On July 11, 2025, Duke Energy Indiana entered into a settlement agreement with an additional party in this proceeding agreeing to the need of the units and addressing accounting and ratemaking components. Neither agreement alters the underlying plans in the pending CPCN application. An evidentiary hearing is scheduled for August 21, 2025. An order is expected in the fourth quarter of 2025.

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