Acquisitions and Dispositions (Tables)

9 Months Ended

Sep. 30, 2021

Business Combination and Asset Acquisition [Abstract]

Schedule of Asset Acquisitions

During the nine months ended September 30, 2021, Southern Power acquired a controlling membership interest in the wind facility listed below. Acquisition-related costs were expensed as incurred and were not material.

Project Facility	Resource	Seller	Approximate Nameplate Capacity (MW)	Location	Southern Power Ownership Percentage	COD	PPA Contract Period
Deuel Harvest(*)	Wind	Invenergy Renewables, LLC	300	Deuel County, SD	100% of Class B	February 2021	25 years and 15 years

(*)On March 26, 2021, Southern Power acquired a controlling interest in the project from Invenergy Renewables LLC and, on March 30, 2021, Southern Power completed a tax equity transaction whereby it sold the Class A membership interests in the project. Southern Power consolidates the project's operating results in its financial statements and the tax equity partner and Invenergy Renewables LLC each own a noncontrolling interest.

Schedule of Construction Projects

Project Facility	Resource	Approximate Nameplate Capacity (MW)	Location	Actual/Expected COD	PPA Contract Period
Projects Under Construction at September 30, 2021
Garland Solar Storage(a)	Battery energy storage system	88	Kern County, CA	September 2021 and fourth quarter 2021(b)	20 years
Tranquillity Solar Storage(a)	Battery energy storage system	72	Fresno County, CA	Fourth quarter 2021 and first quarter 2022	20 years
Glass Sands(c)	Wind	118	Murray County, OK	Fourth quarter 2021	12 years

(a)During the third quarter 2021, Southern Power further restructured its ownership in the Garland and Tranquillity battery energy storage projects and completed tax equity transactions whereby it sold the Class A membership interests in the projects. Southern Power consolidates each project's operating results in its financial statements and the tax equity partner and two other partners each own a noncontrolling interest.

(b)The facility has a total capacity of 88 MWs, of which 45 MWs were placed in service in September 2021 and 43 MWs are expected to be placed in service later in the fourth quarter 2021.

(c)In December 2020, Southern Power purchased 100% of the membership interests of the Glass Sands facility.

Schedule of Assets Held for Sale

The following table provides the major classes of assets classified as held for sale by Southern Company at September 30, 2021 and December 31, 2020:

	Southern Company
	At September 30,		At December 31,
	2021		2020
	(in millions)
Assets Held for Sale:
Total property, plant, and equipment	$	6	$	8
Leveraged leases	45		52
Total Assets Held for Sale	$	51	$	60