Property And Plant, Net (Tables)

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Schedule Of Property And Plant, Net

The following table presents components of “Property, plant, and equipment, net” at December 31, 2021 and 2020:

	Ameren Missouri		Ameren Illinois		Other		Ameren
2021
Property, plant, and equipment at original cost:(a)
Electric generation:
Coal(b)(c)	$	3,955	$	—	$	—	$	3,955
Natural gas	1,105		—		—		1,105
Nuclear	5,615		—		—		5,615
Renewable(d)	1,889		—		—		1,889
Electric distribution	7,286		7,017		—		14,303
Electric transmission	1,628		4,105		1,800		7,533
Natural gas	607		3,586		—		4,193
Other(e)	1,584		1,183		242		3,009
	23,669		15,891		2,042		41,602
Less: Accumulated depreciation and amortization	9,784		4,100		330		14,214
	13,885		11,791		1,712		27,388
Construction work in progress:
Nuclear fuel in process	133		—		—		133
Other	674		432		30		1,136
Plant to be abandoned, net(f)	604		—		—		604
Property, plant, and equipment, net	$	15,296	$	12,223	$	1,742	$	29,261
2020
Property, plant, and equipment at original cost:(a)
Electric generation:
Coal(b)(c)	$	4,875	$	—	$	—	$	4,875
Natural gas	1,097		—		—		1,097
Nuclear	5,608		—		—		5,608
Renewable(d)	1,301		—		—		1,301
Electric distribution	6,784		6,649		—		13,433
Electric transmission	1,482		3,575		1,774		6,831
Natural gas	561		3,308		—		3,869
Other(e)	1,390		1,070		245		2,705
	23,098		14,602		2,019		39,719
Less: Accumulated depreciation and amortization	9,689		3,780		304		13,773
	13,409		10,822		1,715		25,946
Construction work in progress:
Nuclear fuel in process	75		—		—		75
Other	395		379		12		786
Property, plant, and equipment, net	$	13,879	$	11,201	$	1,727	$	26,807

(a)The estimated lives for each asset group are as follows: 5 to 72 years for electric generation, excluding Ameren Missouri’s hydroelectric generating assets, which have useful lives of up to 150 years; 20 to 80 years for electric distribution; 50 to 75 years for electric transmission; 20 to 80 years for natural gas; and 2 to 55 years for other.

(b)Includes $29 million and $36 million of oil-fired generation at December 31, 2021 and 2020, respectively.

(c)Original cost amounts include two CTs that have related financing obligations. The gross cumulative asset value of those agreements was $243 million and $240 million at December 31, 2021 and 2020, respectively. The total accumulated depreciation associated with the two CTs was $105 million and $99 million at December 31, 2021 and 2020, respectively. See Note 5 – Long-term Debt and Equity Financings for additional information on these agreements.

(d)Renewable includes hydroelectric, wind, solar, and methane gas generation facilities.

(e)Other property, plant, and equipment includes assets used to support electric and natural gas services.

(f)Represents the net book value of the Rush Island Energy Center and related construction work in progress as Ameren Missouri expects to retire the energy center significantly in advance of its previously expected useful life and in the near term. See Plant to be Abandoned, Net under Note 1 – Summary of Significant Accounting Policies and NSR and Clean Air Act Litigation under Note 14 – Commitments and Contingencies for additional information on the planned accelerated retirement of the Rush Island Energy Center.

Schedule of Capitalized Software

Capitalized software costs are classified within “Property, Plant, and Equipment, Net” on the balance sheet and are amortized on a straight-line basis over the expected period of benefit, ranging from 2 to 15 years. The following table presents the amortization, gross carrying value, and related accumulated amortization of capitalized software by year:

	Amortization Expense						Gross Carrying Value				Accumulated Amortization
	2021		2020		2019		2021		2020		2021		2020
Ameren	$	125	$	93	$	78	$	1,199	$	1,021	$	(757)	$	(640)
Ameren Missouri	66		44		30		523		398		(255)		(189)
Ameren Illinois	53		45		45		452		397		(291)		(238)

Schedule of Capitalized Software, Future Amortization Expense

Annual amortization expense for capitalized software placed in service as of December 31, 2021, is estimated to be as follows:

	2022		2023		2024		2025		2026
Ameren	$	135	$	119	$	87	$	47	$	21
Ameren Missouri	75		69		54		31		14
Ameren Illinois	56		47		31		14		6