Regulatory Matters (Tables)

3 Months Ended

Mar. 31, 2024

Regulated Operations [Abstract]

Schedule of Cost Recovery Clauses

The recovery balances for certain retail regulatory clauses of the traditional electric operating companies and Southern Company Gas at March 31, 2024 and December 31, 2023 were as follows:

Regulatory Clause	Balance Sheet Line Item	March 31, 2024		December 31, 2023
		(in millions)
Alabama Power
Rate CNP Compliance	Other regulatory assets, current	$	8	$	8
	Other regulatory assets, deferred	19		25
Rate CNP PPA	Other regulatory assets, current	18		18
	Other regulatory assets, deferred	82		85
Rate ECR	Regulatory assets – under recovered retail fuel clause revenues	173		246
Georgia Power
Fuel Cost Recovery	Receivables – under recovered retail fuel clause revenues	$	679	$	694
	Deferred under recovered retail fuel clause revenues	1,044		1,211
Mississippi Power
Fuel Cost Recovery(*)	Receivables – customer accounts, net	$	20	$	—
	Deferred under recovered retail fuel clause revenues	—		50
	Over recovered retail fuel clause revenues	—		27
Ad Valorem Tax	Other regulatory assets, deferred	13		12
Southern Company Gas
Natural Gas Cost Recovery	Natural gas cost over recovery	$	150	$	214

(*)Mississippi Power also has wholesale MRA and Market Based (MB) fuel cost recovery factors. At March 31, 2024 and December 31, 2023, wholesale MRA fuel costs were over recovered $10 million and $5 million, respectively, and were included in other current liabilities on Mississippi Power's balance sheets. The wholesale MB fuel cost recovery was immaterial for both periods presented.

Nuclear Construction Cost and Schedule

Georgia Power's net capital costs incurred through March 31, 2024 in connection with Plant Vogtle Units 3 and 4, and its approximate proportionate share of additional capital costs to be incurred after March 31, 2024, including completion of testing and start-up for Unit 4 through April 2024 and demobilizing the site after Unit 4's in-service date, is as follows:

	(in millions)
Total project capital cost forecast(a)(b)	$	10,753
Net investment at March 31, 2024(b)	(10,608)
Remaining estimate to complete	$	145

(a)Includes approximately $610 million of costs that are not shared with the other Vogtle Owners, including $33 million of construction monitoring costs, and approximately $567 million of incremental costs under the cost-sharing provisions of the Vogtle Joint Ownership Agreements (as defined below). Excludes financing costs expected to be capitalized through AFUDC of approximately $440 million, of which $435 million had been accrued through March 31, 2024.

(b)Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds.