Item 2. Properties
ITEM 2. PROPERTIES
Alliant Energy - As a holding company, Alliant Energy doesn’t directly own any significant properties other than the stock of its subsidiaries. The principal properties of those subsidiaries are as follows:
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Table of C o ntents
IPL and WPL
Electric - At December 31, 2023, IPL’s and WPL’s facilities by primary fuel type were as follows:
IPL Generating
In-service Capacity
Name of Facility and Location Dates in MW (a)
Marshalltown Generating Station (Units 1-3); Marshalltown, IA 2017 656
Emery Generating Station (Units 1-3); Mason City, IA 2004 533
Marshalltown Combustion Turbines (Units 1-3); Marshalltown, IA 1978 162
Burlington Generating Station (Unit 1); Burlington, IA 1968 160
Prairie Creek Generating Station (Unit 4); Cedar Rapids, IA 1967 114
Burlington Combustion Turbines (Units 1-4); Burlington, IA 1994-1996 36
Total Gas 1,661
Upland Prairie (121 Units); Clay and Dickinson Cos., IA 2019 299
Whispering Willow - North (81 Units); Franklin Co., IA 2020 201
Whispering Willow - East (121 Units); Franklin Co., IA 2009 200
Golden Plains (82 Units); Winnebago and Kossuth Cos., IA 2020 200
English Farms (69 Units); Poweshiek Co., IA 2019 172
Richland (53 Units); Sac Co., IA 2020 131
Franklin County (60 Units); Franklin Co., IA 2012 99
Total Wind 1,302
Ottumwa Generating Station (Unit 1); Ottumwa, IA (b) 1981 348
George Neal Generating Station (Unit 4); Sioux City, IA (c) 1979 166
George Neal Generating Station (Unit 3); Sioux City, IA (d) 1975 143
Prairie Creek Generating Station (Units 1 and 3); Cedar Rapids, IA 1958-1997 36
Louisa Generating Station (Unit 1); Louisa, IA (e) 1983 30
Total Coal 723
Lime Creek Combustion Turbines (Units 1-2); Mason City, IA 1991 71
Total Oil 71
Dubuque Solar Facility; Dubuque, IA 2017 5
Marshalltown Solar Facility; Marshalltown, IA 2020 3
Total Solar 8
Battery Storage; various locations in IA 2019-2023 9
Total Battery Storage 9
Total capacity 3,774
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Table of C o ntents
WPL Generating
In-service Capacity
Name of Facility and Location Dates in MW (a)
Riverside Energy Center (Units 1-3); Beloit, WI 2004 530
West Riverside Energy Center (Units 1-3); Beloit, WI (f) 2020 508
Neenah Energy Facility (Units 1-2); Neenah, WI 2000 299
South Fond du Lac Combustion Turbines (2 Units); Fond du Lac, WI (g) 1994 164
Total Gas 1,501
Bent Tree (122 Units); Freeborn Co., MN 2010-2011 201
Kossuth (56 Units); Kossuth Co., IA 2020 152
Cedar Ridge (41 Units); Fond du Lac Co., WI 2008 68
Forward Wind Energy Center (37 Units); Dodge and Fond du Lac Cos., WI (h) 2008 59
Total Wind 480
Columbia Energy Center (Units 1-2); Portage, WI (i) 1975-1978 606
Edgewater Generating Station (Unit 5); Sheboygan, WI 1985 406
Total Coal 1,012
Wood County Solar Facility, Wood Co., WI 2022 150
Onion River Solar Facility, Sheboygan Co., WI 2023 150
Springfield Solar Facility, Dodge Co., WI 2023 100
Wautoma Solar Facility, Waushara Co., WI 2023 99
Crawfish River Solar Facility, Jefferson Co., WI 2023 75
Paddock Solar Facility, Rock Co., WI 2023 65
Bear Creek Solar Facility, Richland Co., WI 2022 50
North Rock Solar Facility, Rock Co., WI 2022 50
Albany Solar Facility, Green Co., WI 2023 50
Beaver Dam Solar Facility, Dodge Co., WI 2023 50
Cassville Solar Facility, Grant Co., WI 2023 50
West Riverside Solar Facility, Beloit, WI (f) 2021 3
Customer- and Community-hosted Solar; various locations in WI 2021-2022 4
Total Solar 896
Prairie du Sac Hydro Plant (8 Units); Prairie due Sac, WI 1914-1940 17
Kilbourn Hydro Plant (4 Units); Wisconsin Dells, WI 1926-1939 7
Total Hydro 24
Battery Storage; various locations in WI 2022-2023 9
Total Battery Storage 9
Total capacity 3,922
(a) Based on the summer installed generating capacity included in MISO’s resource adequacy process for the planning period from June 2023 through May 2024, except for wind facilities, solar facilities and battery storage, which are based on nameplate capacity.
(b) Represents IPL’s 48% ownership interest, which is operated by IPL.
(c) Represents IPL’s 25.695% ownership interest, which is operated by MidAmerican Energy Company.
(d) Represents IPL’s 28% ownership interest, which is operated by MidAmerican Energy Company.
(e) Represents IPL’s 4% ownership interest, which is operated by MidAmerican Energy Company.
(f) Represents WPL’s 73.8% ownership interest, which is operated by WPL.
(g) Represents Units 2 and 3, which WPL owns. WPL also operates, but does not own, South Fond du Lac Combustion Turbines Units 1 and 4.
(h) Represents WPL’s 42.64% ownership interest, which is operated by Invenergy Services, LLC.
(i) Represents WPL’s 53.5% ownership interest, which is operated by WPL.
IPL and WPL own overhead electric distribution line, underground electric distribution cable and substation distribution transformers, substantially all of which are located in Iowa for IPL and Wisconsin for WPL.
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Table of C o ntents
Gas - IPL’s and WPL’s gas properties consist primarily of mains and services, meters, regulating and gate stations and other related transmission and distribution equipment. IPL’s and WPL’s gas distribution facilities include gas mains located in Iowa and Wisconsin, respectively.
Other - IPL’s other property includes steam service assets. Refer to Note 10 for information regarding WPL’s lease of the Sheboygan Falls Energy Facility from AEF’s Non-utility Generation business.
Corporate Services - Corporate Services’ property included in “Property, plant and equipment, net” on Alliant Energy’s balance sheet at December 31, 2023 consisted primarily of computer software, and the corporate headquarters building located in Madison, Wisconsin.
AEF - AEF’s principal properties included in “Property, plant and equipment, net” on Alliant Energy’s balance sheet at December 31, 2023 were as follows:
Non-utility Generation - Includes the Sheboygan Falls Energy Facility, a 347 MW, simple-cycle, natural gas-fired facility near Sheboygan Falls, Wisconsin that was placed in service in 2005 and is leased to WPL. The summer installed generating capacity included in MISO’s resource adequacy process for the planning period from June 2023 through May 2024 for the Sheboygan Falls Energy Facility was 297 MW.
Travero - Includes a short-line rail freight service in Iowa; a Mississippi River barge, rail and truck freight terminal in Illinois; wind turbine blade recycling services; and a rail-served warehouse in Iowa.
Development-ready Sites - includes various rail-served and ready-to-build manufacturing and industrial sites throughout Iowa and Wisconsin, with access to various airports, interstate freeways and Alliant Energy’s electric services.