NOTICE OF FILING Application of Duke Energy Progress, LLC for Approval of Demand-Side Management and Energy Efficiency Rider 18, Increasing Residential Rates and Increasing Non-Residential Rates Docket No. 2026-173-E Why is this Notice Important? • This Notice is for electric customers of Duke Energy Progress, LLC (the “Company” or “DEP”) and interested persons. • The Company filed an Application for Approval of Demand-Side Management (“DSM”) and Energy Efficiency (“EE”) Rider for 2027 (“Rider 18”), that will increase residential rates and non-residential rates with the Public Service Commission of South Carolina (the “Commission”). • The Commission decides what rates a utility can charge. What is Duke Energy Progress, LLC asking the Commission to approve? • The Company has requested approval to recover its costs and revenue associated with DSM and EE programs under S.C. Code Ann. § 58-37-20 and the existing DSM/EE cost recovery mechanism approved by the Commission in Order No. 2021-33 (the “Existing Mechanism”). • The Existing Mechanism is currently under review by the Commission in Docket No. 2026- 57-E and could be updated by the Commission by the time that rates in this docket are in effect. Those updates could impact the rates in the Application. • Therefore, the Company has provided rate scenarios for the Commission that account for the possibility of an updated DSM/EE cost recovery mechanism, which are higher rates than the Company is currently recovering under its previous DSM/EE Rider 17 filing for both residential and non-residential customers. • However, the Company will only implement one set of rates. What rates are Duke Energy Progress, LLC Proposing? • First Rate Scenario: Under the Existing Mechanism Rates, the Company proposes that the Commission: o Issue an Order allowing the Company to recover the following revenue through the proposed Rider 18:  $17,920,058 for Residential Customers; and  $7,407,901 for Non-Residential Customers. o Approve the following billing factors for the period of January 1, 2027 – December 31, 2027: Residential Billing Factors (Existing Mechanism Rates) ¢/kWh Residential Rider 18 0.8488 Non-Residential Billing Factors (Existing Mechanism Rates) ¢/kWh Year 2027 EE 0.4887 Year 2027 DSM 0.0429 • Second Rate Scenario (Informational Only): The Company provides an informational rate calculation for the Commission’s reference of what rates would be if the Existing Mechanism is updated and the rate mitigation adjustment in the third scenario is not applied, the Company would be requesting: o An Order allowing the Company to recover the following revenue through the proposed Rider 18:  $26,637,114 for Residential Customers; and  $10,748,115 for Non-Residential Customers. o Approval of the same billing factors as listed above for the Existing Mechanism for the period of January 1, 2027 – December 31, 2027, except the following changes: Residential Billing Factors (Common Mechanism Rates) ¢/kWh Residential Rider 18 1.2617 Non-Residential Billing Factors (Common Mechanism Rates) ¢/kWh Legacy DEP EE Participant 0.3492 Legacy DEP DSM Participant (0.0774) Vintage 2027 EE Participant 0.3564 Vintage 2027 DSM Participant 0.1429 • Third Rate Scenario: These are the rates that the Company is requesting the Commission to approve if the Common Mechanism is approved. The Company is requesting rates that include a one-time adjustment under the Common Mechanism to mitigate the impact on customers associated with the transition to the Common Mechanism. Specifically, the Company is requesting: o Order allowing the Company to recover the following revenue through the proposed Rider 18:  $20,798,572 for Residential Customers; and  $7,836,842 for Non-Residential Customers. o Approval of the same billing factors as listed above for the Existing Mechanism for the period of January 1, 2027 – December 31, 2027, except the following changes: Residential Billing Factors (Adjusted Common Mechanism Rates) ¢/kWh Residential Rider 18 0.9851 Non-Residential Billing Factors (Adjusted Common Mechanism Rates) ¢/kWh Legacy DEP EE Participant 0.1566 Legacy DEP DSM Participant (0.0937) Vintage 2027 EE Participant 0.3564 Vintage 2027 DSM Participant 0.1429 • The case was filed according to S.C. Code Ann. Section 58-37-20 and S.C. Code Ann. Regs. 103-819 and 103-823, and the Rules of Practice and Procedure of the Commission. For the Company’s complete proposal visit: https://dms.psc.sc.gov/Attachments/Matter/06ef9387-19e9-4461-bd87-24878bd5622f For the entire Case visit: https://dms.psc.sc.gov/Web/Dockets/Detail/119754 Who Can I Talk to About This Notice? Duke Energy Progress, LLC 803-988-7132 Office of Regulatory Staff 803-737-5230 or 1-800-922-1531 Department of Consumer Affairs 803-734-4200 or 1-800-922-1594 Public Service Commission 803-896-5100 How Can I Participate in this Case? A customer may participate in the case by the ways listed below. Option A: File a L•et • ter of Protest by Emailing the completed Letter of Protest to contact@psc.sc.gov; or Mailing the completed Letter of Protest to 101 Executive Center Drive, Suite 100, Columbia, SC 29210. More information is available here: https://psc.sc.gov/consumer-info/file-letter-protest Option B: File a Petition to Intervene. An Intervenor becomes a party in the case and must follow the Commission’s Rules of Practice and Procedure. To inte•rv• ene, you must: Email a Petition to Intervene to contact@psc.sc.gov no later than Monday, September 14, 2026; or Mail a Petition to Intervene to 101 Executive Center Drive, Suite 100, Columbia, SC 29210 no later than Monday, September 14, 2026. Please include your email address. **You must give a copy of your Petition to Intervene to all Parties in this case. Petitions to Intervene must meet the requirements of Commission Regulation 103-825 and must be approved by the Commission. Intervenors must file written comments with the Commission regarding Duke Energy Progress, LLC’s Application in Docket No. 2026-173-E on or before October 12, 2026 (Order No. 2022-506). In the above referenced case, if the proposed tariffs contain any request for a change of rates, the proposed rates may be changed by the Commission. Persons seeking further information about these procedures should contact the Commission at 803-896-5100 or visit its website at www.psc.sc.gov July 8, 2026 GRR