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30 Ivan Allen Jr. Boulevard, N.W.

Atlanta, Georgia 30308

(404) 506-5000

1-3164

Alabama Power Company

63-0004250

(An Alabama Corporation)

600 North 18th Street

Birmingham, Alabama 35203

(205) 257-1000

1-6468

Georgia Power Company

58-0257110

(A Georgia Corporation)

241 Ralph McGill Boulevard, N.E.

Atlanta, Georgia 30308

(404) 506-6526

001-11229

Mississippi Power Company

64-0205820

(A Mississippi Corporation)

2992 West Beach Boulevard

Gulfport, Mississippi 39501

(228) 864-1211

001-37803

Southern Power Company

58-2598670

(A Delaware Corporation)

30 Ivan Allen Jr. Boulevard, N.W.

Atlanta, Georgia 30308

(404) 506-5000

1-14174

Southern Company Gas

58-2210952

(A Georgia Corporation)

Ten Peachtree Place, N.E.

Atlanta, Georgia 30309

(404) 584-4000

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days. Yes þ No ¨

Indicate by check mark whether the registrants have submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrants were required to submit such files). Yes þ No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No þ (Response applicable to all registrants.)

This combined Form 10-Q is separately filed by The Southern Company, Alabama Power Company, Georgia Power Company, Mississippi Power Company, Southern Power Company, and Southern Company Gas. Information contained herein relating to any individual registrant is filed by such registrant on its own behalf. Each registrant makes no representation as to information relating to the other registrants.

TABLE OF CONTENTS

						Page
			Definitions			4
			Cautionary Statement Regarding Forward-Looking Information			8
			PART I—FINANCIAL INFORMATION
Item 1.			Financial Statements (Unaudited)			10
Item 2.			Management's Discussion and Analysis of Financial Condition and Results of Operations			102
Item 3.			Quantitative and Qualitative Disclosures about Market Risk			162
Item 4.			Controls and Procedures			162
			PART II—OTHER INFORMATION
Item 1.			Legal Proceedings			163
Item 1A.			Risk Factors			163
Item 2.			Unregistered Sales of Equity Securities and Use of Proceeds			Inapplicable
Item 3.			Defaults Upon Senior Securities			Inapplicable
Item 4.			Mine Safety Disclosures			Inapplicable
Item 5.			Other Information			Inapplicable
Item 6.			Exhibits			163
			Signatures			166

DEFINITIONS

Term			Meaning
2019 ARP			Alternate Rate Plan approved by the Georgia PSC in 2019 for Georgia Power for the years 2020 through 2022
AFUDC			Allowance for funds used during construction
Alabama Power			Alabama Power Company
Amended and Restated Loan Guarantee Agreement			Loan guarantee agreement entered into by Georgia Power with the DOE in 2014, as amended and restated in March 2019, under which the proceeds of borrowings may be used to reimburse Georgia Power for Eligible Project Costs incurred in connection with its construction of Plant Vogtle Units 3 and 4
ARO			Asset retirement obligation
Atlanta Gas Light			Atlanta Gas Light Company, a wholly-owned subsidiary of Southern Company Gas
Atlantic Coast Pipeline			Atlantic Coast Pipeline, LLC, a joint venture to construct and operate a natural gas pipeline in which Southern Company Gas held a 5% interest through March 24, 2020
Bechtel			Bechtel Power Corporation, the primary contractor for the remaining construction activities for Plant Vogtle Units 3 and 4
Bechtel Agreement			The 2017 construction completion agreement between the Vogtle Owners and Bechtel
CCR			Coal combustion residuals
CCR Rule			Disposal of Coal Combustion Residuals from Electric Utilities final rule published by the EPA in 2015
Chattanooga Gas			Chattanooga Gas Company, a wholly-owned subsidiary of Southern Company Gas
COD			Commercial operation date
Contractor Settlement Agreement			The December 31, 2015 agreement between Westinghouse and the Vogtle Owners resolving disputes between the Vogtle Owners and the EPC Contractor under the Vogtle 3 and 4 Agreement
COVID-19			The novel coronavirus disease declared a pandemic by the World Health Organization and the Centers for Disease Control and Prevention in March 2020
CWIP			Construction work in progress
Dalton			City of Dalton, Georgia, an incorporated municipality in the State of Georgia, acting by and through its Board of Water, Light, and Sinking Fund Commissioners
Dalton Pipeline			A pipeline facility in Georgia in which Southern Company Gas has a 50% undivided ownership interest
DOE			U.S. Department of Energy
ECCR			Georgia Power's Environmental Compliance Cost Recovery tariff
ECO Plan			Mississippi Power's environmental compliance overview plan
ELG Rules			The EPA's steam electric effluent limitations guidelines (ELG) rule (finalized in 2015) and the ELG reconsideration rule (finalized in October 2020)
Eligible Project Costs			Certain costs of construction relating to Plant Vogtle Units 3 and 4 that are eligible for financing under the loan guarantee program established under Title XVII of the Energy Policy Act of 2005
EPA			U.S. Environmental Protection Agency
EPC Contractor			Westinghouse and its affiliate, WECTEC Global Project Services Inc.; the former engineering, procurement, and construction contractor for Plant Vogtle Units 3 and 4
FERC			Federal Energy Regulatory Commission
FFB			Federal Financing Bank
FFB Credit Facilities			Note purchase agreements among the DOE, Georgia Power, and the FFB and related promissory notes which provide for two multi-advance term loan facilities
Fitch			Fitch Ratings, Inc.
Form 10-K			Annual Report on Form 10-K of Southern Company, Alabama Power, Georgia Power, Mississippi Power, Southern Power, and Southern Company Gas for the year ended December 31, 2020, as applicable
GAAP			U.S. generally accepted accounting principles
Georgia Power			Georgia Power Company

DEFINITIONS

(continued)

Term			Meaning
GRAM			Atlanta Gas Light's Georgia Rate Adjustment Mechanism
Guarantee Settlement Agreement			The June 9, 2017 settlement agreement between the Vogtle Owners and Toshiba related to certain payment obligations of the EPC Contractor guaranteed by Toshiba
Gulf Power			Gulf Power Company, until January 1, 2019 a wholly-owned subsidiary of Southern Company; effective January 1, 2021, Gulf Power Company merged with and into Florida Power and Light Company, with Florida Power and Light Company remaining as the surviving company
Heating Degree Days			A measure of weather, calculated when the average daily temperatures are less than 65 degrees Fahrenheit
Heating Season			The period from November through March when Southern Company Gas' natural gas usage and operating revenues are generally higher
HLBV			Hypothetical liquidation at book value
IGCC			Integrated coal gasification combined cycle, the technology originally approved for Mississippi Power's Kemper County energy facility
IIC			Intercompany Interchange Contract
IRP			Integrated resource plan
ITAAC			Inspections, Tests, Analyses, and Acceptance Criteria, standards established by the NRC
ITC			Investment tax credit
JEA			Jacksonville Electric Authority
Jefferson Island			Jefferson Island Storage and Hub, L.L.C, which owns a natural gas storage facility in Louisiana consisting of two salt dome caverns; a subsidiary of Southern Company Gas through December 1, 2020
KWH			Kilowatt-hour
LIBOR			London Interbank Offered Rate
LIFO			Last-in, first-out
LOCOM			Lower of weighted average cost or current market price
LTSA			Long-term service agreement
Marketers			Marketers selling retail natural gas in Georgia and certificated by the Georgia PSC
MEAG Power			Municipal Electric Authority of Georgia
Mississippi Power			Mississippi Power Company
Mississippi Power Rate Case Settlement Agreement			Settlement agreement between Mississippi Power and the Mississippi Public Utilities Staff approved by the Mississippi PSC in March 2020 related to Mississippi Power's base rate case filed in 2019
mmBtu			Million British thermal units
Moody's			Moody's Investors Service, Inc.
MRA			Municipal and Rural Associations
MW			Megawatt
natural gas distribution utilities			Southern Company Gas' natural gas distribution utilities (Nicor Gas, Atlanta Gas Light, Virginia Natural Gas, and Chattanooga Gas)
NCCR			Georgia Power's Nuclear Construction Cost Recovery
NDR			Alabama Power's Natural Disaster Reserve
Nicor Gas			Northern Illinois Gas Company, a wholly-owned subsidiary of Southern Company Gas
NRC			U.S. Nuclear Regulatory Commission
NYMEX			New York Mercantile Exchange, Inc.
OCI			Other comprehensive income
PennEast Pipeline			PennEast Pipeline Company, LLC, a joint venture in which Southern Company Gas has a 20% ownership interest
PEP			Mississippi Power's Performance Evaluation Plan
Pivotal LNG			Pivotal LNG, Inc., through March 24, 2020, a wholly-owned subsidiary of Southern Company Gas

DEFINITIONS

(continued)

Term			Meaning
PowerSecure			PowerSecure, Inc., a wholly-owned subsidiary of Southern Company
PowerSouth			PowerSouth Energy Cooperative
PPA			Power purchase agreements, as well as, for Southern Power, contracts for differences that provide the owner of a renewable facility a certain fixed price for the electricity sold to the grid
PSC			Public Service Commission
PTC			Production tax credit
Rate CNP			Alabama Power's Rate Certificated New Plant, consisting of Rate CNP New Plant, Rate CNP Compliance, and Rate CNP PPA
Rate ECR			Alabama Power's Rate Energy Cost Recovery
Rate RSE			Alabama Power's Rate Stabilization and Equalization
Registrants			Southern Company, Alabama Power, Georgia Power, Mississippi Power, Southern Power Company, and Southern Company Gas
ROE			Return on equity
S&P			S&P Global Ratings, a division of S&P Global Inc.
SAVE			Steps to Advance Virginia's Energy, an infrastructure replacement program at Virginia Natural Gas
SCS			Southern Company Services, Inc., the Southern Company system service company and a wholly-owned subsidiary of Southern Company
SEC			U.S. Securities and Exchange Commission
SEGCO			Southern Electric Generating Company, 50% owned by each of Alabama Power and Georgia Power
Sequent			Sequent Energy Management, L.P. and Sequent Energy Canada Corp., wholly-owned subsidiaries of Southern Company Gas through June 30, 2021
SNG			Southern Natural Gas Company, L.L.C., a pipeline system in which Southern Company Gas has a 50% ownership interest
Southern Company			The Southern Company
Southern Company Gas			Southern Company Gas and its subsidiaries
Southern Company Gas Capital			Southern Company Gas Capital Corporation, a 100%-owned subsidiary of Southern Company Gas
Southern Company power pool			The operating arrangement whereby the integrated generating resources of the traditional electric operating companies and Southern Power (excluding subsidiaries) are subject to joint commitment and dispatch in order to serve their combined load obligations
Southern Company system			Southern Company, the traditional electric operating companies, Southern Power, Southern Company Gas, SEGCO, Southern Nuclear, SCS, Southern Communications Services, Inc., PowerSecure, and other subsidiaries
Southern Holdings			Southern Company Holdings, Inc., a wholly-owned subsidiary of Southern Company
Southern Nuclear			Southern Nuclear Operating Company, Inc., a wholly-owned subsidiary of Southern Company
Southern Power			Southern Power Company and its subsidiaries
SouthStar			SouthStar Energy Services, LLC (a Marketer), a wholly-owned subsidiary of Southern Company Gas
SP Solar			SP Solar Holdings I, LP, a limited partnership indirectly owning substantially all of Southern Power's solar and battery energy storage facilities, in which Southern Power has a 67% ownership interest
SP Wind			SP Wind Holdings II, LLC, a holding company owning a portfolio of eight operating wind facilities, in which Southern Power is the controlling partner in a tax equity arrangement
Subsidiary Registrants			Alabama Power, Georgia Power, Mississippi Power, Southern Power, and Southern Company Gas
Tax Reform			The impact of the Tax Cuts and Jobs Act, which became effective on January 1, 2018
Toshiba			Toshiba Corporation, the parent company of Westinghouse
traditional electric operating companies			Alabama Power, Georgia Power, and Mississippi Power

DEFINITIONS

(continued)

Term			Meaning
VCM			Vogtle Construction Monitoring
VIE			Variable interest entity
Virginia Commission			Virginia State Corporation Commission
Virginia Natural Gas			Virginia Natural Gas, Inc., a wholly-owned subsidiary of Southern Company Gas
Vogtle 3 and 4 Agreement			Agreement entered into with the EPC Contractor in 2008 by Georgia Power, acting for itself and as agent for the Vogtle Owners, and rejected in bankruptcy in July 2017, pursuant to which the EPC Contractor agreed to design, engineer, procure, construct, and test Plant Vogtle Units 3 and 4
Vogtle Owners			Georgia Power, Oglethorpe Power Corporation, MEAG Power, and Dalton
Vogtle Services Agreement			The June 2017 services agreement between the Vogtle Owners and the EPC Contractor, as amended and restated in July 2017, for the EPC Contractor to transition construction management of Plant Vogtle Units 3 and 4 to Southern Nuclear and to provide ongoing design, engineering, and procurement services to Southern Nuclear
WACOG			Weighted average cost of gas
Westinghouse			Westinghouse Electric Company LLC
Williams Field Services Group			Williams Field Services Group, LLC

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION

This Quarterly Report on Form 10-Q contains forward-looking statements. Forward-looking statements include, among other things, statements concerning the potential and expected effects of the COVID-19 pandemic, regulated rates, the strategic goals for the business, customer and sales growth, economic conditions, cost recovery and other rate actions, projected equity ratios, current and proposed environmental regulations and related compliance plans and estimated expenditures, pending or potential litigation matters, access to sources of capital, financing activities, completion dates and costs of construction projects, matters related to the abandonment of the Kemper IGCC, completion of announced acquisitions, filings with state and federal regulatory authorities, and estimated construction plans and expenditures. In some cases, forward-looking statements can be identified by terminology such as "may," "will," "could," "would," "should," "expects," "plans," "anticipates," "believes," "estimates," "projects," "predicts," "potential," or "continue" or the negative of these terms or other similar terminology. There are various factors that could cause actual results to differ materially from those suggested by the forward-looking statements; accordingly, there can be no assurance that such indicated results will be realized. These factors include:

•the impact of recent and future federal and state regulatory changes, including tax, environmental, and other laws and regulations to which Southern Company and its subsidiaries are subject, as well as changes in application of existing laws and regulations;

•the potential effects of the continued COVID-19 pandemic, including, but not limited to, those described in Item 1A "Risk Factors" of the Form 10-K;

•the extent and timing of costs and legal requirements related to CCR;

•current and future litigation or regulatory investigations, proceedings, or inquiries, including litigation and other disputes related to the Kemper County energy facility;

•the effects, extent, and timing of the entry of additional competition in the markets in which Southern Company's subsidiaries operate, including from the development and deployment of alternative energy sources;

•variations in demand for electricity and natural gas;

•available sources and costs of natural gas and other fuels;

•the ability to complete necessary or desirable pipeline expansion or infrastructure projects, limits on pipeline capacity, and operational interruptions to natural gas distribution and transmission activities;

•transmission constraints;

•effects of inflation;

•the ability to control costs and avoid cost and schedule overruns during the development, construction, and operation of facilities or other projects, including Plant Vogtle Units 3 and 4 (which includes components based on new technology that only within the last few years began initial operation in the global nuclear industry at this scale) and Plant Barry Unit 8, due to current and future challenges which include, but are not limited to, changes in labor costs, availability, and productivity; challenges with management of contractors or vendors; subcontractor performance; adverse weather conditions; shortages, delays, increased costs, or inconsistent quality of equipment, materials, and labor; contractor or supplier delay; delays due to judicial or regulatory action; nonperformance under construction, operating, or other agreements; operational readiness, including specialized operator training and required site safety programs; engineering or design problems or any remediation related thereto; design and other licensing-based compliance matters, including, for nuclear units, inspections and the timely submittal by Southern Nuclear of the ITAAC documentation for each unit and the related investigations, reviews, and approvals by the NRC necessary to support NRC authorization to load fuel; challenges with start-up activities, including major equipment failure, or system integration; and/or operational performance; and challenges related to the COVID-19 pandemic;

•the ability to overcome or mitigate the current challenges at Plant Vogtle Units 3 and 4, as described in Note (B) to the Condensed Financial Statements under "Georgia Power – Nuclear Construction" in Item 1 herein, that could further impact the cost and schedule for the project;

•legal proceedings and regulatory approvals and actions related to construction projects, such as Plant Vogtle Units 3 and 4 and Plant Barry Unit 8, including PSC approvals and FERC and NRC actions;

•under certain specified circumstances, a decision by holders of more than 10% of the ownership interests of Plant Vogtle Units 3 and 4 not to proceed with construction and the ability of other Vogtle Owners to tender a portion of their ownership interests to Georgia Power following certain construction cost increases;

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION

(continued)

•in the event Georgia Power becomes obligated to provide funding to MEAG Power with respect to the portion of MEAG Power's ownership interest in Plant Vogtle Units 3 and 4 involving JEA, any inability of Georgia Power to receive repayment of such funding;

•the ability to construct facilities in accordance with the requirements of permits and licenses (including satisfaction of NRC requirements), to satisfy any environmental performance standards and the requirements of tax credits and other incentives, and to integrate facilities into the Southern Company system upon completion of construction;

•investment performance of the employee and retiree benefit plans and nuclear decommissioning trust funds;

•advances in technology, including the pace and extent of development of low- to no-carbon energy technologies and negative carbon concepts;

•performance of counterparties under ongoing renewable energy partnerships and development agreements;

•state and federal rate regulations and the impact of pending and future rate cases and negotiations, including rate actions relating to ROE, equity ratios, additional generating capacity, and fuel and other cost recovery mechanisms;

•the ability to successfully operate the electric utilities' generating, transmission, and distribution facilities and Southern Company Gas' natural gas distribution and storage facilities and the successful performance of necessary corporate functions;

•the inherent risks involved in operating and constructing nuclear generating facilities;

•the inherent risks involved in transporting and storing natural gas;

•the performance of projects undertaken by the non-utility businesses and the success of efforts to invest in and develop new opportunities;

•internal restructuring or other restructuring options that may be pursued;

•potential business strategies, including acquisitions or dispositions of assets or businesses, which cannot be assured to be completed or beneficial to Southern Company or its subsidiaries;

•the ability of counterparties of Southern Company and its subsidiaries to make payments as and when due and to perform as required;

•the ability to obtain new short- and long-term contracts with wholesale customers;

•the direct or indirect effect on the Southern Company system's business resulting from cyber intrusion or physical attack and the threat of physical attacks;

•interest rate fluctuations and financial market conditions and the results of financing efforts;

•access to capital markets and other financing sources;

•changes in Southern Company's and any of its subsidiaries' credit ratings;

•changes in the method of determining LIBOR or the replacement of LIBOR with an alternative reference rate;

•the ability of Southern Company's electric utilities to obtain additional generating capacity (or sell excess generating capacity) at competitive prices;

•catastrophic events such as fires, earthquakes, explosions, floods, tornadoes, hurricanes and other storms, droughts, pandemic health events, political unrest, or other similar occurrences;

•the direct or indirect effects on the Southern Company system's business resulting from incidents affecting the U.S. electric grid, natural gas pipeline infrastructure, or operation of generating or storage resources;

•impairments of goodwill or long-lived assets;

•the effect of accounting pronouncements issued periodically by standard-setting bodies; and

•other factors discussed elsewhere herein and in other reports (including the Form 10-K) filed by the Registrants from time to time with the SEC.

The Registrants expressly disclaim any obligation to update any forward-looking statements.