Source: American Electric Power Form 10-K for the year ended December 31, 2025, Item 2 Properties (net maximum capacity by plant as of December 31, 2025; approximately 25,400 MW owned). Form 10-Q for the quarter ended June 30, 2026, Acquired Generation Facilities table and environmental-matters paragraph (approximately 26,500 MW owned, of which approximately 10,200 MW coal-fired, as of June 30, 2026). https://www.sec.gov/Archives/edgar/data/4904/000000490426000013/aep-20251231.htm https://www.sec.gov/Archives/edgar/data/4904/000000490426000059/aep-20260630.htm

Source: American Electric Power Form 10-K for the year ended December 31, 2025, Item 1 Business, summary table of AEP subsidiary operating companies (Approximate Number of Retail Customers as of December 31, 2025). https://www.sec.gov/Archives/edgar/data/4904/000000490426000013/aep-20251231.htm

Source: American Electric Power Form 8-K Exhibit 99.1, Summary of Selected Sales Data (Regulated Connected Load, retail by class in millions of KWh). Q3 2024 and Q3 2025 from the quarter ended September 30, 2025 release. Q4 2024 and Q4 2025 from the year ended December 31, 2025 release. Q1 2025 and Q1 2026 from the quarter ended March 31, 2026 release. Q2 2025 and Q2 2026 from the quarter ended June 30, 2026 release. Q3 2026 from the quarter ended September 30, 2026 release (https://www.sec.gov/Archives/edgar/data/4904/000000490426000069/a3q20268kpressreleaseex991.htm), whose Q3 2025 comparatives match the stored values. Vertically Integrated and Transmission and Distribution retail classes are summed as printed. https://www.sec.gov/Archives/edgar/data/4904/000000490426000055/a2q20268kpressreleaseex991.htm

Source: American Electric Power Form 8-K Exhibit 99.1, Summary of Selected Sales Data, Total Retail line for Vertically Integrated Utilities and Transmission and Distribution Utilities (millions of KWh). Same five releases as the customer-class chart: quarters ended September 30, 2025; December 31, 2025; March 31, 2026; June 30, 2026 (https://www.sec.gov/Archives/edgar/data/4904/000000490426000055/a2q20268kpressreleaseex991.htm); September 30, 2026 (https://www.sec.gov/Archives/edgar/data/4904/000000490426000069/a3q20268kpressreleaseex991.htm).

Source: American Electric Power Form 10-K for the year ended December 31, 2025, Item 1 Business, AEP Transmission Holdco discussion of annual formula rate filings (State Transcos in aggregate filed formula rate base totals of $13.3 billion, $11.4 billion and $10.7 billion for 2025, 2024 and 2023). https://www.sec.gov/Archives/edgar/data/4904/000000490426000013/aep-20251231.htm