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Jointly-Owned Electric Utility Plant | 12 Months Ended
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Dec. 31, 2016
Jointly-Owned Electric Utility Plant | JOINTLY-OWNED ELECTRIC UTILITY PLANT Under joint ownership agreements with other utilities, IPL and WPL have undivided ownership interests in jointly-owned coal-fired EGUs. Each of the respective owners is responsible for the financing of its portion of the construction costs. KWh generation and operating expenses are primarily divided between the joint owners on the same basis as ownership. IPL’s and WPL’s shares of expenses from jointly-owned coal-fired EGUs are included in the corresponding operating expenses (e.g., electric production fuel, other operation and maintenance, etc.) in their income statements. Information relative to IPL’s and WPL’s ownership interest in these jointly-owned coal-fired EGUs at December 31, 2016 was as follows (dollars in millions):
|  |  |  |  | Accumulated |  | Construction
| Ownership |  | Electric |  | Provision for |  | Work in
| Interest % |  | Plant |  | Depreciation |  | Progress
IPL |  |  |  |  |  |  |
Ottumwa Unit 1 | 48.0 | % |  |  | $489.4 |  |  |  | $137.3 |  |  |  | $11.1 |
George Neal Unit 4 | 25.7 | % |  | 185.2 |  |  | 80.8 |  |  | 1.6 |
George Neal Unit 3 | 28.0 | % |  | 150.7 |  |  | 49.1 |  |  | 0.3 |
Louisa Unit 1 | 4.0 | % |  | 36.5 |  |  | 21.8 |  |  | 0.6 |
|  |  | 861.8 |  |  | 289.0 |  |  | 13.6 |
WPL |  |  |  |  |  |  |
Columbia Units 1-2 | 46.2 | % |  | 640.2 |  |  | 185.0 |  |  | 51.0 |
Edgewater Unit 4 | 68.2 | % |  | 99.4 |  |  | 58.4 |  |  | 0.2 |
|  |  | 739.6 |  |  | 243.4 |  |  | 51.2 |
Alliant Energy |  |  |  | $1,601.4 |  |  |  | $532.4 |  |  |  | $64.8 |
In November 2016, WPL received an order from the PSCW approving amendments to the Columbia joint operating agreement, which allow the co-owners to forgo certain capital expenditures at Columbia (excluding capital expenditures related to the Columbia Unit 2 SCR currently being constructed), resulting in WPL incurring these additional capital expenditures in exchange for a proportional increase in its ownership share of Columbia. Based on the additional capital expenditures WPL currently expects to incur through June 1, 2020, WPL’s ownership interest in Columbia is expected to increase in the future. In December 2016, WPL filed a request with FERC for approval of these amendments to the Columbia joint operating agreement, effective January 1, 2017. WPL currently expects to receive FERC’s decision on these amendments in 2017. In November 2016, various electric cooperatives, which currently have wholesale power supply agreements with WPL, notified WPL of their intent to exercise purchase options for a partial ownership interest in the Riverside expansion. WPL currently expects the exercise of the purchase options to be effective in 2017.
IPL [Member] |
Jointly-Owned Electric Utility Plant | JOINTLY-OWNED ELECTRIC UTILITY PLANT Under joint ownership agreements with other utilities, IPL and WPL have undivided ownership interests in jointly-owned coal-fired EGUs. Each of the respective owners is responsible for the financing of its portion of the construction costs. KWh generation and operating expenses are primarily divided between the joint owners on the same basis as ownership. IPL’s and WPL’s shares of expenses from jointly-owned coal-fired EGUs are included in the corresponding operating expenses (e.g., electric production fuel, other operation and maintenance, etc.) in their income statements. Information relative to IPL’s and WPL’s ownership interest in these jointly-owned coal-fired EGUs at December 31, 2016 was as follows (dollars in millions):
|  |  |  |  | Accumulated |  | Construction
| Ownership |  | Electric |  | Provision for |  | Work in
| Interest % |  | Plant |  | Depreciation |  | Progress
IPL |  |  |  |  |  |  |
Ottumwa Unit 1 | 48.0 | % |  |  | $489.4 |  |  |  | $137.3 |  |  |  | $11.1 |
George Neal Unit 4 | 25.7 | % |  | 185.2 |  |  | 80.8 |  |  | 1.6 |
George Neal Unit 3 | 28.0 | % |  | 150.7 |  |  | 49.1 |  |  | 0.3 |
Louisa Unit 1 | 4.0 | % |  | 36.5 |  |  | 21.8 |  |  | 0.6 |
|  |  | 861.8 |  |  | 289.0 |  |  | 13.6 |
WPL |  |  |  |  |  |  |
Columbia Units 1-2 | 46.2 | % |  | 640.2 |  |  | 185.0 |  |  | 51.0 |
Edgewater Unit 4 | 68.2 | % |  | 99.4 |  |  | 58.4 |  |  | 0.2 |
|  |  | 739.6 |  |  | 243.4 |  |  | 51.2 |
Alliant Energy |  |  |  | $1,601.4 |  |  |  | $532.4 |  |  |  | $64.8 |
WPL [Member] |
Jointly-Owned Electric Utility Plant | JOINTLY-OWNED ELECTRIC UTILITY PLANT Under joint ownership agreements with other utilities, IPL and WPL have undivided ownership interests in jointly-owned coal-fired EGUs. Each of the respective owners is responsible for the financing of its portion of the construction costs. KWh generation and operating expenses are primarily divided between the joint owners on the same basis as ownership. IPL’s and WPL’s shares of expenses from jointly-owned coal-fired EGUs are included in the corresponding operating expenses (e.g., electric production fuel, other operation and maintenance, etc.) in their income statements. Information relative to IPL’s and WPL’s ownership interest in these jointly-owned coal-fired EGUs at December 31, 2016 was as follows (dollars in millions):
|  |  |  |  | Accumulated |  | Construction
| Ownership |  | Electric |  | Provision for |  | Work in
| Interest % |  | Plant |  | Depreciation |  | Progress
IPL |  |  |  |  |  |  |
Ottumwa Unit 1 | 48.0 | % |  |  | $489.4 |  |  |  | $137.3 |  |  |  | $11.1 |
George Neal Unit 4 | 25.7 | % |  | 185.2 |  |  | 80.8 |  |  | 1.6 |
George Neal Unit 3 | 28.0 | % |  | 150.7 |  |  | 49.1 |  |  | 0.3 |
Louisa Unit 1 | 4.0 | % |  | 36.5 |  |  | 21.8 |  |  | 0.6 |
|  |  | 861.8 |  |  | 289.0 |  |  | 13.6 |
WPL |  |  |  |  |  |  |
Columbia Units 1-2 | 46.2 | % |  | 640.2 |  |  | 185.0 |  |  | 51.0 |
Edgewater Unit 4 | 68.2 | % |  | 99.4 |  |  | 58.4 |  |  | 0.2 |
|  |  | 739.6 |  |  | 243.4 |  |  | 51.2 |
Alliant Energy |  |  |  | $1,601.4 |  |  |  | $532.4 |  |  |  | $64.8 |
In November 2016, WPL received an order from the PSCW approving amendments to the Columbia joint operating agreement, which allow the co-owners to forgo certain capital expenditures at Columbia (excluding capital expenditures related to the Columbia Unit 2 SCR currently being constructed), resulting in WPL incurring these additional capital expenditures in exchange for a proportional increase in its ownership share of Columbia. Based on the additional capital expenditures WPL currently expects to incur through June 1, 2020, WPL’s ownership interest in Columbia is expected to increase in the future. In December 2016, WPL filed a request with FERC for approval of these amendments to the Columbia joint operating agreement, effective January 1, 2017. WPL currently expects to receive FERC’s decision on these amendments in 2017. In November 2016, various electric cooperatives, which currently have wholesale power supply agreements with WPL, notified WPL of their intent to exercise purchase options for a partial ownership interest in the Riverside expansion. WPL currently expects the exercise of the purchase options to be effective in 2017.

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