XML 110 R40.htm IDEA: XBRL DOCUMENT
v3.24.3

Plant Closures (Policies) | 12 Months Ended
--- | ---
Sep. 30, 2024
Plant Closure [Abstract] |
Plant Retirement and Abandonment, Policy [Policy Text Block] | Background TVA must continuously evaluate all generating assets to ensure an optimal energy portfolio that provides safe, clean, and reliable power while maintaining flexibility and fiscal responsibility to the people of the Tennessee Valley. Based on results of assessments presented to the TVA Board in 2019, the retirement of Bull Run Fossil Plant ("Bull Run") by December 2023 was approved, and as of September 30, 2023, the facility was retired. In January 2023, TVA issued its Record of Decision to retire two coal-fired units at Cumberland Fossil Plant ("Cumberland") by the end of CY 2026 and CY 2028. In April 2024, TVA issued its Record of Decision to retire the nine coal-fired units at Kingston Fossil Plant ("Kingston") by CY 2027. In addition, TVA is evaluating the impact of retiring the balance of the coal-fired fleet by 2035, and that evaluation includes environmental reviews, public input, and TVA Board approval. Financial Impact TVA's policy is to adjust depreciation rates to reflect the most current assumptions, ensuring units will be fully depreciated by the applicable retirement dates. As a result of TVA's decision to accelerate the retirement of Bull Run, TVA has recognized a cumulative $659 million of accelerated depreciation since the second quarter of 2019 through September 30, 2023. Of this amount, $177 million and $140 million were recognized for the years ended September 30, 2023, and 2022, respectively. TVA's decision to retire the two units at Cumberland is estimated to result in approximately $16 million of additional depreciation quarterly, which does not include any potential impact from additions or retirements to net completed plant. The cumulative impact approximates $112 million of additional depreciation since January 2023, related to this decision. In addition, TVA's decision to retire the nine units at Kingston is estimated to result in approximately $9 million of additional depreciation quarterly, which does not include any potential impact from additions or retirements to net completed plant. The cumulative impact approximates $18 million of additional depreciation since April 2024, related to this decision. TVA also recognized $15 million, $14 million, and $22 million in Operating and maintenance expense related to additional inventory reserves and project write-offs for the coal-fired fleet, including Kingston, Cumberland, and Bull Run, for the years ended September 30, 2024, 2023, and 2022, respectively.

X
- Definition Plant Closure + References No definition available. + Details
Name: | tve_PlantClosureAbstract
Namespace Prefix: | tve_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of accounting policy for plant retirement and for abandonment (under construction or in use) in regulated industries when abandonment becomes probable. Any difference between the new asset and the asset cost is recognized as a loss in the income statement. May also indicate the discount rate used in the calculation of present value of recoverable abandoned assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 35 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478654/980-360-35-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 35 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478654/980-360-35-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 35 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478654/980-360-35-3 + Details
Name: | us-gaap_PlantRetirementAndAbandonmentPolicy
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration