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Summary Of Significant Accounting Policies (Policy) | 9 Months Ended
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Sep. 30, 2022
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the SEC. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the 2021 Form 10-K.In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2022 are not necessarily indicative of results that may be expected for the year ending December 31, 2022.
General, Use of Estimates | A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred.
General, Reclassification | Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes.
Cash and Cash Equivalents | At September 30, 2022, Alliant Energy’s, IPL’s and WPL’s cash and cash equivalents included $334 million, $39 million and $295 million of money market fund investments, respectively, with weighted average interest rates of 3%.
Variable Interest Entities | In 2022, WPL 2022 Solar Holdco, LLC was formed as a joint venture to own and operate project companies responsible for the construction, ownership and operation of various solar generation assets. Members of the joint venture were a WPL subsidiary (the managing member) and a tax equity partner. In the second quarter of 2022, the WPL subsidiary and the tax equity partner contributed $62 million and $29 million, respectively, to WPL 2022 Solar Holdco, LLC in exchange for membership interests, and $88 million of the contributed funds were paid to WPL in exchange for equity interests in the project companies. In the second quarter of 2022, Alliant Energy and WPL consolidated this joint venture as it was a VIE in which WPL held a variable interest, and WPL controlled decisions that were significant to the joint venture’s ongoing operations and economic results (i.e., WPL was the primary beneficiary). In August 2022, the Inflation Reduction Act of 2022 was enacted. Following its enactment, WPL evaluated the provisions of the new legislation and determined that retaining full ownership of the solar projects is expected to result in lower costs for its customers. As a result, in the third quarter of 2022, WPL and the tax equity partner terminated the tax equity partnership, and WPL returned the $29 million of initial funding to the tax equity partner. Alliant Energy and WPL no longer expect their solar generation project construction costs to be financed with capital from tax equity partners, which would result in higher rate base amounts compared to those previously approved by the PSCW for WPL’s planned approximately 1,100 MW of solar generation. Alliant Energy and WPL concluded that no disallowance of anticipated higher rate base amounts was required as of September 30, 2022 given full ownership of WPL's planned solar generation is expected to result in lower costs for WPL's customers. Refer to Note 6 for discussion of a noncontrolling interest that was initially associated with the joint venture prior to the termination of the tax equity partnership.
IPL [Member] |
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the SEC. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the 2021 Form 10-K.In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2022 are not necessarily indicative of results that may be expected for the year ending December 31, 2022.
General, Use of Estimates | A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred.
General, Reclassification | Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes.
Cash and Cash Equivalents | At September 30, 2022, Alliant Energy’s, IPL’s and WPL’s cash and cash equivalents included $334 million, $39 million and $295 million of money market fund investments, respectively, with weighted average interest rates of 3%.
WPL [Member] |
General, Basis of Accounting | The interim unaudited Financial Statements included herein have been prepared pursuant to the rules and regulations of the SEC. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted, although management believes that the disclosures are adequate to make the information presented not misleading. These Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the 2021 Form 10-K.In the opinion of management, all adjustments, which unless otherwise noted are normal and recurring in nature, necessary for a fair presentation of the results of operations, financial position and cash flows have been made. Results for the nine months ended September 30, 2022 are not necessarily indicative of results that may be expected for the year ending December 31, 2022.
General, Use of Estimates | A change in management’s estimates or assumptions could have a material impact on financial condition and results of operations during the period in which such change occurred.
General, Reclassification | Certain prior period amounts in the Financial Statements and Notes have been reclassified to conform to the current period presentation for comparative purposes.
Cash and Cash Equivalents | At September 30, 2022, Alliant Energy’s, IPL’s and WPL’s cash and cash equivalents included $334 million, $39 million and $295 million of money market fund investments, respectively, with weighted average interest rates of 3%.
Variable Interest Entities | In 2022, WPL 2022 Solar Holdco, LLC was formed as a joint venture to own and operate project companies responsible for the construction, ownership and operation of various solar generation assets. Members of the joint venture were a WPL subsidiary (the managing member) and a tax equity partner. In the second quarter of 2022, the WPL subsidiary and the tax equity partner contributed $62 million and $29 million, respectively, to WPL 2022 Solar Holdco, LLC in exchange for membership interests, and $88 million of the contributed funds were paid to WPL in exchange for equity interests in the project companies. In the second quarter of 2022, Alliant Energy and WPL consolidated this joint venture as it was a VIE in which WPL held a variable interest, and WPL controlled decisions that were significant to the joint venture’s ongoing operations and economic results (i.e., WPL was the primary beneficiary). In August 2022, the Inflation Reduction Act of 2022 was enacted. Following its enactment, WPL evaluated the provisions of the new legislation and determined that retaining full ownership of the solar projects is expected to result in lower costs for its customers. As a result, in the third quarter of 2022, WPL and the tax equity partner terminated the tax equity partnership, and WPL returned the $29 million of initial funding to the tax equity partner. Alliant Energy and WPL no longer expect their solar generation project construction costs to be financed with capital from tax equity partners, which would result in higher rate base amounts compared to those previously approved by the PSCW for WPL’s planned approximately 1,100 MW of solar generation. Alliant Energy and WPL concluded that no disallowance of anticipated higher rate base amounts was required as of September 30, 2022 given full ownership of WPL's planned solar generation is expected to result in lower costs for WPL's customers. Refer to Note 6 for discussion of a noncontrolling interest that was initially associated with the joint venture prior to the termination of the tax equity partnership.

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