NOTICE OF FILING Joint Application of Duke Energy Carolinas, LLC and Duke Energy Progress, LLC for Review of the Demand- Side Management/Energy Efficiency (DSM/EE) Mechanisms Docket No. 2026-57-E Why is this Notice Important? · This Notice is for electric customers of Duke Energy Progress, LLC (“DEP” or the “Company”) and interested persons. The Company filed a Joint Application with Duke Energy Carolinas, LLC (“DEC”) on March 16, 2026, (the “Joint Application”), requesting that the Public Service Commission of South Carolina (the “Commission”) approve an updated demand-side management and energy efficiency cost recovery mechanism (the “Common Mechanism”) to be effective beginning January 1, 2027. What is the Company asking the Commission to approve? • The Company is asking the Commission to review and approve updates to its existing, Commission-approved demand-side management and energy efficiency (“DSM/EE”) cost recovery mechanism (the “Existing Mechanism”). This review is required by Commission Order No. 2021- 33. The Joint Application does not seek any cost recovery or rate change at this time in this case. • The Existing Mechanism governs approval and administration of the Company’s DSM/EE programs, which are offered to customers and approved by the Commission. The Existing Mechanism also allows the Company to recover certain costs related to the implementation of these customer programs. • The Joint Application describes the proposed updates to the Existing Mechanism and the stakeholder process that led to the Joint Application. If approved, the Common Mechanism would be used by both the Company and DEC to administer their DSM/EE programs. • The Joint Application provides that the Common Mechanism will carry forward the core principles of the Existing Mechanism, while updating certain provisions, such as (i) updated values used for cost- effectiveness tests, (ii) a broader definition of low-income customer, and (iii) a framework pursuant to which the Company can provide new measures to customers faster than previously possible. The entire Joint Application can be accessed in the link below. • The Common Mechanism also updates certain cost recovery provisions and proposes a new utility incentive structure. Has the Commission Approved a Comment Schedule in this Case? DEADLINE DATE Office of Regulatory Staff and Intervenors Initial July 22, 2026 Comments Company’s Responsive Comments August 12, 2026 The Joint Application was filed pursuant to S.C. Code Ann. Section 58-37-20, S.C. Code Ann. Regs. 103-823, Order No. 2021-33, and the Rules of Practice and Procedure of the Commission. For the entire Case visit: https://dms.psc.sc.gov/Web/Dockets/Detail/119638 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 stakeholder may participate in the case by the ways listed below. Option A: File a Letter 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. Intervenors have the right to testify, cross-examine witnesses, seek reconsideration of the Commission’s Final Decision, and must follow the Commission’s Rules of Practice and Procedure. To intervene, you must: • Email a Petition to Intervene to contact@psc.sc.gov no later than Wednesday, June 10, 2026; or • Mail a Petition to Intervene to 101 Executive Center Drive, Suite 100, Columbia, SC 29210 no later than Wednesday, June 10, 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. 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. 3/26/26 GRR