Property, Plant, and Equipment (Tables)

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant, and Equipment

Property, plant, and equipment consisted of the following as of December 31:

	MGE Energy				MGE
(In thousands)	2022		2021		2022		2021
Utility:
Electric	$	1,585,847	$	1,516,533	$	1,585,864	$	1,516,550
Plant anticipated to be retired early(a)		147,659		158,983		147,659		158,983
Gas		566,551		546,390		566,562		546,401
Utility property, plant, and equipment, gross		2,300,057		2,221,906		2,300,085		2,221,934
Less: Accumulated depreciation and amortization		673,669		636,804		673,669		636,804
Utility property, plant, and equipment, net		1,626,388		1,585,102		1,626,416		1,585,130
Nonregulated:
Nonregulated		318,443		317,881		318,443		317,881
Less: Accumulated depreciation and amortization		79,479		74,812		79,479		74,812
Nonregulated property, plant, and equipment, net		238,964		243,069		238,964		243,069
Construction work in progress:
Utility construction work in progress(b)		101,529		49,211		101,529		49,211
Nonregulated construction work in progress		4,219		1,392		4,219		1,392
Total property, plant, and equipment	$	1,971,100	$	1,878,774	$	1,971,128	$	1,878,802

(a)An asset that will be retired in the near future and substantially in advance of its previously expected retirement date is subject to abandonment accounting. In the second quarter of 2021, the operator of Columbia received approval from MISO to retire Columbia Units 1 and 2. The co-owners intend to retire Unit 1 and Unit 2 by June 2026. Final timing and retirement dates are subject to change depending on operational, regulatory, and other factors. As of December 31, 2022, early retirement of Columbia was probable. "Plant anticipated to be retired early" in table above is the net book value of these generating units. Assets for Columbia Unit 1 and Unit 2 are currently included in rate base, and MGE continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the PSCW that included retirement dates of 2029 for Unit 1. The PSCW approved in its 2023 electric rate case limited reopener to revise the depreciation schedule for Columbia Unit 2 to 2029 to align with Unit 1. See Footnote 9 for further details on MGE's rate proceedings. If it becomes probable that regulators will disallow full recovery or a return on the remaining net book value of a generating unit that is either abandoned or probable of being abandoned, an impairment loss would be required. An impairment loss would be recorded to the extent that the remaining net book value of the generating unit exceeds the present value of the amount expected to be recovered from ratepayers. No impairment was recorded as of December 31, 2022.

(b)Includes Badger Hollow II and Paris solar projects. See Footnote 6 for further information on renewable projects.