Joint Plant (Tables)

3 Months Ended

Mar. 31, 2023

Public Utilities, Property, Plant and Equipment [Abstract]

Schedule of Jointly Owned Utility Plants

MGE has purchased, completed, or ongoing jointly-owned generation construction projects, as shown in the following table. Incurred costs are reflected in "Property, plant, and equipment, net" or "Construction work in progress" on the consolidated balance sheets.

Project	Ownership Interest	Source	Share of Generation	Share of Estimated Costs(a)	Costs incurred as of March 31, 2023(a)	Date of Commercial Operation
Red Barn(b)(c)	10%	Wind	9.16 MW	$18 million	$0.4 million	April 2023
Badger Hollow II(d)	33%	Solar	50 MW	$76 million	$52.1 million(g)	Second half of 2023(h)
Paris(e)	10%	Solar/Battery	20 MW/11 MW	$51 million	$24.0 million	2023(h)(i)
Darien(f)	10%	Solar/Battery	25 MW/ 7.5 MW	$45 million	$1.1 million	2024(h)(i)
West Riverside	3.4%	Natural Gas	25 MW	$25 million	$24.8 million	(j)

(a)Excluding AFUDC.

(b)The Red Barn Wind Farm is located in the Towns of Wingville and Clifton in Grant County, Wisconsin.

(c)In April 2023, the Red Barn Wind Farm was placed in-service. MGE acquired its share of the project upon in-service date. MGE's share of the total costs incurred for Red Barn was $16.4 million after the April closing.

(d)The Badger Hollow II solar farm is located in southwestern Wisconsin in Iowa County, near the villages of Montfort and Cobb.

(e)Paris Solar-Battery Park is located in the Town of Paris in Kenosha County, Wisconsin.

(f)Darien Solar Energy Center is located in Walworth and Rock Counties in southern Wisconsin.

(g)Includes an allocation of common facilities at Badger Hollow placed in service in November 2021.

(h)Estimated date of commercial operation.

(i)Battery storage timing to be determined.

(j)In March 2023, MGE purchased an ownership interest in West Riverside, a natural gas-fired facility located in Beloit, WI, from WPL, operator and co-owner of the plant. West Riverside was placed in-service in 2020.