Company: AILIM
Filing Date: 2025-02-18
Form Type: 10-K
Source: 0001002910-25-000055
Chunk: 275

Company: Ameren Illinois Co
Filing Date: 2025-02-18
Form: 10-K
Item: Item 7
Chunk 275
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 to pursue transmission investments, as well as our ability to obtain necessary regulatory approvals, among other factors. Any changes in future generation, transmission, or distribution needs could result in significant changes in capital expenditures or losses, which could be material. Compliance with environmental regulations could also have significant impacts on the level of capital expenditures.

In 2021, the MISO issued a report outlining a preliminary long-range transmission planning roadmap of projects through 2039, which considers the rapidly changing generation mix within MISO resulting from significant additions of renewable generation, actual and expected generation plant closures, and state mandates or goals for clean energy or carbon emissions reductions. In 2022, the MISO approved the first tranche of projects under the roadmap. A portion of these projects were assigned to various utilities, of which Ameren was awarded projects that are estimated to cost approximately $1.8 billion, based on the MISO’s cost estimate. Related to these projects, Ameren began substation upgrades in May 2024 in advance of transmission line construction, which is expected to begin in 2026, with forecasted completion dates near the end of this decade. In addition, the MISO awarded three competitive bid projects to ATXI that represent a total estimated investment of approximately $220 million for ATXI. Also in December 2024, the MISO approved a first set of second tranche projects. A portion of these projects were assigned to Ameren and are estimated to cost approximately $1.3 billion, based on the MISO’s cost estimate. The first set of second tranche projects also includes competitive bid projects that are estimated to cost $6.5 billion, which includes projects located in Illinois that are estimated to cost $1.8 billion, based on the MISO’s cost estimate. The competitive bid process is expected to take place through 2026. The MISO is assessing future long-range transmission scenarios in the first quarter of 2025 and development of a second set of second tranche projects will follow this assessment.

Environmental Capital Expenditures

Ameren Missouri will continue to incur costs to comply with federal and state regulations, including those requiring the reduction of SO2, NOx, CO2, and mercury emissions from its coal-fired energy centers, compliance with the CCR Rule, and potential modifications to cooling water intake structures at existing power plants under Clean Water Act rules. See Note 14 – Commitments and Contingencies under Part II, Item 8, of this report for a discussion of existing