Company: TSLTF
Filing Date: 2025-12-12
Form Type: SUPPL
Source: 0001193125-25-317786
Chunk: 228

Company: TRANSALTA CORP
Filing Date: 2025-12-12
Form: SUPPL
Chunk 228
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| As this investment is part of our regular power- generating operations, we have included our proportionate share of the adjusted EBITDA of the Skookumchuck wind facility in our total adjusted                                                   
 EBITDA. In addition, in the Wind and Solar adjusted results, we have included our proportionate share of revenues and expenses to reflect the full operational results of this investment. We have not included EMG International, LLC’s adjusted 
 EBITDA in our total adjusted EBITDA as it does not represent our regular power- generating operations.                                                                                                                                            |

Average Annual EBITDA Average annual EBITDA is a forward-looking non-IFRSfinancial measure that is used to show the average annual EBITDA that the project is expected to generate. Funds From Operations (FFO) FFO is an important metric as it provides a proxy for cash generated from operating activities before changes in working capital and provides the ability to evaluate cash flow trends in comparison with results from prior periods. FFO is a non-IFRSmeasure. For a description of the adjustments made to Cash Flow from Operations (the most directly comparable IFRS measure) to calculate FFO, see the tables on pages M70 and M74. Adjustments to Cash Flow from Operations

| • |     | FFO related to the Skookumchuck wind facility, which is treated as an equity-accounted investment                                                                                                                                                     
 under IFRS and equity income, net of distributions from joint ventures, is included in cash flow from operations under IFRS. As this investment is part of our regular power- generating operations, we have included our proportionate share of FFO. |

| • |     | Payments received on finance lease receivables are reclassified to reflect cash from operations. |

| • |     | We adjust for 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-coal in Alberta and our planned transition off-coal for Centralia. These 
 are included in the “Clean energy transition provisions and adjustments” in the reconciliation.                                                                        |

| • |     | Sundance A decommissioning cost reimbursement in 2024 is not included as it relates to a settlement 
 of a contingency for a facility that is no longer in operation.                                     |

| • |     | Cash received/paid on closed positions are reflected in the period that the position is settled. |

| • |     | We adjust for costs associated with acquisition-related