Company: TSLTF
Filing Date: 2025-12-12
Form Type: SUPPL
Source: 0001193125-25-317786
Chunk: 170

Company: TRANSALTA CORP
Filing Date: 2025-12-12
Form: SUPPL
Chunk 170
---
— Spinning Reserve Self-Report On Nov. 30, 2022, TransAlta self-reported to the Market Surveillance Administrator (MSA) a potential violation of the Independent System Operator rules relating to offers of active spinning reserves at Brazeau when it was not properly configured to do so between Aug. 13, 2021, and Nov. 1, 2022. In 2022 a provision of $20 million was initially recognized in revenue reflecting a potential disgorgement of revenue and $2 million for potential penalties and fines. On Nov. 29, 2024, the MSA issued penalties to TransAlta for this self-report and TransAlta made a payment of $33 million in January 2025.

| F101 |     | TransAlta Corporation |     | 2024 Integrated Report |

Notes to the Consolidated Financial Statements 38. Segment Disclosures A. Description of Reportable Segments The Company has six reportable segments as described in Note 1. The Gas reportable segment includes Heartland, which was acquired on Dec. 4, 2024. The Company has aggregated Heartland within the Gas operating segment as they are similar in the nature of the product and process and are subject to similar environmental regulations. Refer to Note 4 for more details. The following tables provides each segment’s results in the format that the TransAlta’s President and Chief Executive Officer (the chief operating decision maker) (CODM) reviews the Company’s segments to make operating decisions and assess performance. The CODM assesses the performance of the operating segments based on a measure of adjusted EBITDA. This measurement basis represents earnings before income taxes, adjusted for the effects of: depreciation of property, plant and equipment and amortization of intangibles, depreciation of right-of-useassets, finance lease income, unrealized mark-to-marketgains or losses, gains and losses related to closed positions effectively settled by offsetting positions with exchanges recorded in the year the positions are settled, unrealized foreign exchange gains or losses on commodity transactions, interest income recorded on the prepaid funds, Brazeau penalties, acquisition-related transaction and restructuring costs, ERP integration costs, revenues and fuel and purchased power related to the Planned Divestitures, items within the Energy Transition segment that may not be reflective of ongoing operations including certain costs related to decisions made to accelerate our transition off-coalin Alberta and our planned transition off-coalfor Centralia, Sundance A decommissioning costs reimbursement, impairment charges,