ACQUISITIONS AND DISPOSITIONS (Tables)

9 Months Ended

Sep. 30, 2020

Business Combinations [Abstract]

Schedule of Asset Acquisitions

During the nine months ended September 30, 2020, Southern Power acquired a controlling 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
Beech Ridge II	Wind	Invenergy Renewables LLC	56	Greenbrier County, West Virginia	100% of Class A	(*)	May 2020	12 years

(*)In May 2020, Southern Power purchased 100% of the Class A membership interests and now owns the controlling interest in the project, with the Class B member, Invenergy Renewables LLC, owning the noncontrolling interest.

Schedule of Construction Projects

Project Facility	Resource	Approximate Nameplate Capacity (MW)	Location	Actual/Expected COD	PPA Contract Period
Projects Completed During the Nine Months Ended September 30, 2020
Reading(a)	Wind	200	Osage and Lyon Counties, KS	May 2020	12 years
Projects Under Construction as of September 30, 2020
Skookumchuck(b)	Wind	136	Lewis and Thurston Counties, WA	November 2020	20 years
Garland Solar Storage(c)	Battery energy storage system	88	Kern County, CA	Second quarter 2021	20 years
Tranquillity Solar Storage(c)	Battery energy storage system	72	Fresno County, CA	Second quarter 2021	20 years

(a)In 2018, Southern Power purchased 100% of the membership interests of the Reading facility pursuant to a joint development arrangement. At the time the facility was placed in service, Southern Power recorded an operating lease right-of-use asset and an operating lease liability, each in the amount of $24 million. In June 2020, Southern Power completed a tax equity transaction whereby it received $156 million and now owns 100% of the Class B membership interests.

(b)In October 2019, Southern Power purchased 100% of the membership interests of the Skookumchuck facility pursuant to a joint development arrangement. Southern Power expects to complete a tax equity transaction upon commercial operation and retain the Class B membership interests. Shortly after the completed tax equity transaction, Southern Power may sell a noncontrolling interest in these Class B membership interests to another partner. Southern Power would retain the controlling ownership interest in the facility. The ultimate outcome of these matters cannot be determined at this time.

(c)Prior to commercial operation, Southern Power may enter into one or more partnerships, in which case it would ultimately own less than 100% of the Class B membership interests, but would retain ownership of the controlling interest. The ultimate outcome of this matter cannot be determined at this time.

Disposal Groups, Including Discontinued Operations

Plants Nacogdoches (sold in June 2019) and Mankato represented individually significant components of Southern Power; therefore, pre-tax income for these components for the three months ended September 30, 2019 and the nine months ended September 30, 2020 and 2019 is presented below:

	Three Months Ended September 30, 2019		Nine Months Ended September 30,
			2020		2019
	(in millions)
Southern Power's earnings before income taxes:(*)
Plant Nacogdoches	$	—	N/A		$	16
Plant Mankato	$	12	$	2	$	20

(*)Earnings before income taxes for components reflect the cessation of depreciation and amortization on the long-lived assets being sold upon classification as held for sale in November 2018 and April 2019 for Plant Mankato and Plant Nacogdoches, respectively.