NOTICE OF FILING Act No. 41 of 2025 and S.C. Code Ann. Section 58-42-30 and the Establishment of Competitive Procurement Programs for Duke Energy Carolinas, LLC and Duke Energy Progress, LLC for Energy Storage Facilities to Be Located in South Carolina Docket No. 2025 -21 7-E Why is this Notice Important? • Pursuant to Commission Order No. 2025 -636l on November 21 l 2025 l Duke Energy Carolinas, LLC (“DEC”) and Duke Energy Progress, LLC (“DEP”) (jointly the “Companies”) filed an Application for Approval of Proposal for Competitive Procurement of South Carolina-Sited Energy Storage Resources under Act 41 of 2025 (“Stage 1 Application”) with the Public Service Commission of South Carolina (the “Commission”). • The Stage 1 Application requests approval of the Companies‚ initial proposal for biennial competitive procurement of South Carolina-Sited energy storage resources and it includes proposed conceptual design of the procurement process and key concepts. • If the Stage 1 Application is approved by the Commission, the Companies will file a Stage 2 Application which will include the planned Request for Proposals document. • Must the Companies Conduct a Competitive Procurement for Stand-Alone Energy Storage Facilities? • The Companies must conduct competitive procurements of South Carolina-sited transmission-connected energy storage resources of more than 20 megawatts. • What are the Companies’ Target Procurement Volume for Stand-Alone Energy Storage Acquisition? • The Companies‚ “target procurement volume for stand-alone ’ energy] storage acquisition may not exceed the portion of stand-alone storage in the most recent commission approved integrated resource plan or integrated resource plan annual update that is equal to the portion of the respective electrical utility‚ s peak load attributable to South Carolina customers. “ (S.C. Code Ann. § 58-42-30(A)(2)) ■ In the Companies‚ service territories, South Carolina retail customers account for approximately twenty percent (20%) of system load in the years considered for this case. ■ The Companies seek to competitively procure 1 50MW of South Carolina-sited stand-alone energy storage resource. ENERGY STORAGE OPERATIONAL REQUIREMENTS (see Attachment 3 of Application for entire document) Facility Design Minimum POI (point of interconnection) size of 20 MWac; 4-hour battery duration; Lithium-ion based batteries; grid charging equals same rate as battery maximum export rating Planned Outages During the months of April, May or October, unless otherwise agreed to by the Buyer Storage Availability Guarantee The contract will include an annual storage availability calculation The case was filed according to Commission Order No. 2025-636, South Carolina Energy Security Act of 2025 (“Act 41“) at S.C. Code Ann. § § 58-42-10, 58-42-30, 58 -27-820, and 58-3-140(A), and S.C. Code Ann. Regs. 103-823 . For the entire Case visit¤ https://dms.psc.sc.gov/Web/Dockets/Detail/119440 Who Can I Talk to About This Notice? Duke Energy Carolinas, LLC and Duke Energy 803 -988 -71 32 Progress, LLC 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 Friday, January 9, 2026; or • Mail a Petition to Intervene to 101 Executive Center Drive, Suite 100, Columbia, SC 29210 no later than Friday, January 9, 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. Pursuant to Commission Order No. 2025 -636, the Office of Regulatory Staff’ s and All Other Parties’ Comments regarding the Companies’ Application are due Thursday, January 15, 2026 and the Companies’ Reply Comments are due Thursday, January 29, 2026. A Commission Staff Procedural Status Conference is scheduled to begin at 11:00 a.m. on Monday, February 2, 2026. 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. December 5 , 2025 PJM