Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

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.

Aggregate market value of The Southern Company's common stock held by non-affiliates of The Southern Company at June 29, 2018: $47.030, 2021: $64.1 billion. All of the common stock of the other registrants is held by The Southern Company. A description of each registrant's common stock follows:

Documents incorporated by reference: specified portions of The Southern Company's Definitive Proxy Statement on Schedule 14A relating to the 20192022 Annual Meeting of Stockholders are incorporated by reference into PART III. In addition, specified portions of theAlabama Power Company's Definitive InformationProxy Statement on Schedule 14C of Alabama Power Company14A relating to its 20192022 Annual Meeting of Shareholders are incorporated by reference into PART III.

This combined Form 10-K 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 companyregistrant is filed by such companyregistrant on its own behalf. Each companyregistrant makes no representation as to information relating to the other companies.registrants.

Table of Contents

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION

Southern Company was incorporated under the laws of Delaware on November 9, 1945. Southern Companyis a holding company that owns all of the outstanding common stock of three traditional electric operating companies, Southern Power Company, and Southern Company Gas.

Southern Company also owns all of the outstanding common stock or membership interests of SCS, Southern Linc, Southern Holdings, Southern Nuclear, PowerSecure, and other direct and indirect subsidiaries. SCS, the system service company, has contracted with Southern Company, each traditional electric operating company, Southern Power, Southern Company Gas, Southern Nuclear, SEGCO, and other subsidiaries to furnish, at direct or allocated cost and upon request, the following services: general executive and advisory, general and design engineering, operations, purchasing, accounting, finance, treasury, legal, tax, information technology, marketing, auditing, insurance and pension administration, human resources, systems and procedures, digital wireless communications, cellular tower space, and other services with respect to business and operations, construction management, and Southern Company power pool transactions. Southern Linc provides digital wireless communications for use by Southern Company and its subsidiary companies and also markets these services to the public and provides fiber optics services withinthrough its subsidiary, Southern Telecom, Inc. Southern Linc's system covers approximately 127,000 square miles in the Southeast. Southern Holdings is an intermediate holding company subsidiary, primarily forwhich invests in various projects. During 2021, Southern Company'sHoldings sold or terminated three of its leveraged lease investments in leveraged leases and energy-related funds and companies, and for other electric and natural gas products and

Alabama Power and Georgia Power each own 50% of the outstanding common stock of SEGCO. SEGCO is an operating public utility company that owns electric generating units with an aggregate capacity of 1,020 MWs at Plant Gaston on the Coosa River near Wilsonville, Alabama. Alabama Power and Georgia Power are each entitled to one-half of SEGCO's capacity and energy. Alabama Power acts as SEGCO's agent in the operation of SEGCO's units and furnishes fuel to SEGCOSee "The Southern Company System" herein for its units. Seeadditional information. Also see Note 715 to the financial statements in Item 8 herein for additional information.

The registrants'Registrants' Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and any amendments to those reports are made available on Southern Company's website, free of charge, as soon as reasonably practicable after such material is electronically filed with or furnished to the SEC. Southern Company's internet address is www.southerncompany.com.

Traditional Electric Operating Companies

The traditional electric operating companies are vertically integrated utilities that own generation, transmission, and distribution facilities. See PROPERTIES in Item 2 herein for additional information on the traditional electric operating companies' generating facilities. Each company's transmission facilities are connected to the respective company's own generating plants and other sources of power (including certain generating plants owned by Southern Power) and are interconnected with the transmission facilities of the other traditional electric operating companies and SEGCO. For information on the State of Georgia's integrated transmission system, see "Territory Served by the Southern Company System – Traditional Electric Operating Companies and Southern Power" herein.

Agreements in effect with principal neighboring utility systems provide for capacity and energy transactions that may be entered into from time to time for reasons related to reliability or economics. Additionally, the traditional electric operating companies have entered into various reliability agreements with certain neighboring utilities, each of which provides for the establishment and periodic review of principles and procedures for planning and operation of generation and transmission facilities, maintenance schedules, load retention programs, emergency operations, and other matters affecting the reliability of bulk power supply. The traditional electric operating companies have joined with other utilities in the Southeast to form the SERC to augment further

the reliability and adequacy of bulk power supply. Through the SERC, the traditional electric operating companies are represented onat the North American Electric Reliability Council.Corporation. In February 2021, Southern Company joined a filing at the FERC proposing a Southeast Energy Exchange Market (SEEM) that included many of the other electric service providers in the Southeast. In October 2021, the proposal became effective by operation of law following a tie vote by the FERC, subject to certain rehearing requests. A petition for appeal has been filed regarding the FERC's orders. SEEM is an extension of the existing bilateral market where participants will use an automated, intra-hour energy exchange to buy and sell power close to the time the energy is consumed, utilizing available unreserved transmission. SEEM is expected to begin service in mid-2022. The ultimate outcome of this matter cannot be determined at this time.

The utility assets of the traditional electric operating companies and certain utility assets of Southern Power Company are operated as a single integrated electric system, or Southern Company power pool, pursuant to the IIC. Activities under the IIC are administered by SCS, which acts as agent for the traditional electric operating companies and Southern Power Company. The fundamental purpose of the Southern Company power pool is to provide for the coordinated operation of the electric facilities in an effort to achieve the maximum possible economies consistent with the highest practicable reliability of service. Subject to service requirements and other operating limitations, system resources are committed and controlled through the application of centralized economic dispatch. Under the IIC, each traditional electric operating company and Southern Power Company retains its lowest cost energy resources for the benefit of its own customers and delivers any excess energy to the Southern Company power pool for use in serving customers of other traditional electric operating companies or Southern Power Company or for sale by the Southern Company power pool to third parties. The IIC provides for the recovery of specified costs associated with the affiliated operations thereunder, as well as the proportionate sharing of costs and revenues resulting from Southern Company power pool transactions with third parties. In connection with the sale of former subsidiary Gulf Power in January 2019, an appendix was added to the IIC setting forth terms and conditions governing Gulf Power's continued participation in the IIC for a defined transition period that, subjectperiod. On December 21, 2021, NextEra Energy provided a 180-day notice of its intention to certain potential adjustments, is scheduled to end on January 1, 2024.leave the Southern Company power pool.

Southern Power and Southern Linc have secured from the traditional electric operating companies certain services which are furnished in compliance with FERC regulations.

Alabama Power and Georgia Power each have agreements with Southern Nuclear to operate the Southern Company system's existing nuclear plants, Plants Farley, Hatch, and Vogtle. In addition, Georgia Power has an agreement with Southern Nuclear to develop, license, construct, and operate Plant Vogtle Units 3 and 4. See "Regulation – Nuclear Regulation" herein for additional information.

Southern Power

Southern Power develops, constructs, acquires, owns, and manages power generation assets, including renewable energy facilities,projects, and sells electricity at market-based rates (under authority from the FERC) in the wholesale market. Southern Power continually seeks opportunities to execute its strategy to create value through various transactions including acquisitions, dispositions, and sales of partnership interests, development and construction of new generating facilities, and entry into PPAs, including contracts for differences that provide the owner of a renewable facility a certain fixed price for electricity sold to the grid, primarily with investor-owned utilities, IPPs, municipalities, electric cooperatives, and other load-serving entities, as well as commercial and industrial customers. The electricity from the natural gas generating facilities owned by Southern Power's business activities are not subject to traditional state regulation likePower is primarily sold under long-term, fixed-price capacity PPAs both with unaffiliated wholesale purchasers as well as with the traditional electric operating companies, but the majority of its business activities are subject to regulation by the FERC.companies. Southern Power has attempted to insulate itself from significant fuel supply, fuel transportation, and electric transmission risks by generally making such risks the responsibility of the counterparties to its PPAs. However, Southern Power's future earnings will depend on the parameters of the wholesale market and the efficient operation of its wholesale generating assets, as well as Southern Power's ability to execute its growth strategy and to develop and construct generating facilities. Southern Power's business activities are not subject to traditional state regulation like the traditional electric operating companies, but the majority of its business activities are subject to regulation by the FERC. For additional information on Southern Power's business activities, see MANAGEMENT'S DISCUSSION AND ANALYSIS – OVERVIEW – "Business Activities" of Southern Power in Item 7 herein.

Southern Power Company directly owns and manages generation assets primarily in the Southeast, which are included in the Southern Company power pool, and has various subsidiaries whichwhose generation assets are not included in the Southern Company power pool. These subsidiaries were created to own, operate, and operatepursue natural gas and renewable generation facilities, either wholly or in partnership with various third parties. At December 31, 2018,2021, Southern Power's generation fleet, which is owned in part with its various partners, totaled 11,88812,446 MWs of nameplate capacity in commercial operation (including 4,5085,066 MWs of nameplate capacity owned by its subsidiaries and including Plant Mankato, which is classified as heldsubsidiaries). See "Traditional Electric Operating Companies" herein for sale inadditional information on the financial statements). In addition, Southern Power Company has other subsidiaries that are pursuing additional natural gas generation and other renewable generation development opportunities. The generation assets of Southern Power Company's subsidiaries are not included in the power pool.

A majority of Southern Power's partnerships in renewable facilities allow for the sharing of cash distributions and tax benefits at differing percentages, with Southern Power being the controlling member and thus consolidating the assets and operations of the partnerships. At December 31, 2018,2021, Southern Power has three tax-equityhad eight tax equity partnership arrangements where the tax-equitytax equity investors receive substantially all of the tax benefits from the facilities, including ITCs and PTCs. In addition, Southern Power holds controlling interests in eightnon-tax equity partnerships in solar facilities through SP Solar. For seven of these solar partnerships, Southern Power andwith its new 33% partner, Global Atlantic, are entitledownership interests primarily ranging from 51% to 51% of all cash distributions and the respective partner that holds the Class B membership interests is entitled to 49% of all cash distributions. For the Desert Stateline partnership, Southern Power and Global Atlantic are entitled to 66% of all cash distributions and the Class B member is entitled to 34% of all cash distributions. In addition, Southern Power and Global Atlantic are entitled to substantially all of the federal tax benefits with respect to these eight partnership entities. Finally, for the Roserock partnership, Southern Power is entitled to 51% of all cash distributions and substantially all of the federal tax benefits, with the Class B member entitled to 49% of all cash distributions..

See PROPERTIES in Item 2 herein for additional detail regarding Southern Power's partnership arrangements and Note 15 to the financial statements under "Southern Power" in Item 8 herein for additional information regarding Southern Power's acquisitions, dispositions, construction, and development projects.

Southern Power calculates an investment coverage ratio for its generating assets, including those owned with various partners, based on the ratio of investment under contract to total investment using the respective generation facilities' net book value (or expected in-service value for facilities under construction or being acquired)construction) as the investment amount. With the inclusion of investments associated with the wind and natural gas facilities currently under construction, as well as other capacity and energy contracts, Southern Power has anPower's average investment coverage ratio at December 31, 2018, of 93%2021 was 95% through 20232026 and 91%92% through 2028,2031, with an average remaining contract duration of approximately 14 years (including Plant Mankato, which is classified as held for sale in13 years. For the financial statements).year ended December 31, 2021, approximately 47% of contracted MWs were with AAA to A- or equivalent rated counterparties, 42% were with BBB+ to BBB- or equivalent rated counterparties, and 8% were with unrated entities that either have ratemaking authority or have posted collateral to cover potential credit exposure.

Southern Power's electricity sales from natural gas and biomass salesgenerating facilities are primarily through long-term PPAs that consist of two types of agreements. The first type, referred to as a unit or block sale, is a customer purchase from a dedicated plant unit where all or a portion of the generation from that unit is reserved for that customer. Southern Power typically has the ability to serve the unit or block sale customer from an alternate resource. The second type, referred to as requirements service, provides that Southern Power serves

Southern Power's electricity sales from solar and wind generating facilities are predominantlyalso primarily through long-term PPAs; however, these solar and wind PPAs do not have a capacity charge and customers either purchase the energy output of a dedicated renewable facility through an energy charge or provide Southern Power a certain fixed price for the electricity sold to the grid. As a result, Southern Power's ability to recover fixed and variable operations and maintenance expenses is dependent upon the level of energy generated from these facilities, which can be impacted by weather conditions, equipment performance, transmission constraints, and other factors. Generally, under the renewable generation PPAs, the purchasing party retains the right to keep or resell the renewable energy credits.

Southern Company Gas

Southern Company Gas is an energy services holding company whose primary business is the distribution of natural gas through the natural gas distribution utilities. Southern Company Gas is also involved in several other businesses that are complementary to the distribution of natural gas, including gas pipeline investments wholesale gas services, and gas marketing services. During the fourth quarter 2018, Southern Company Gas changed its reportable segments to further align with the way its new Chief Operating Decision Maker reviews operating results andalso has reclassified prior years' data to conform to the new reportablean "all other" non-reportable segment presentation. This change resulted in a new reportable segment, gas pipeline investments, which was formerly included in gas midstream operations. Gas pipeline investments consists primarily of joint ventures in natural gas pipeline investments including a 50% interest in SNG, two significant pipeline construction projects, and a 50% joint ownership interest in the Dalton Pipeline. Gas distribution operations, wholesale gas services, and gas marketing services continue to remain as separate reportable segments and reflect the impact of the Southern Company Gas Dispositions. The all other non-reportable segmentthat includes segments below the quantitative threshold for separate disclosure, including the storage and fuels operations that were formerly included in gas midstream operations and other subsidiaries that fall below the quantitative threshold for separate disclosure. Prior to the sale of Sequent on July 1, 2021, Southern Company Gas' other businesses also included wholesale gas services. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 herein for information regarding Southern Company Gas' recent dispositions, including the sale of Sequent.

Gas distribution operations, the largest segment of Southern Company Gas' business, operates, constructs, and maintains approximately 75,20076,289 miles of natural gas pipelines and 14 storage facilities, with total capacity of 158157 Bcf, to provide natural gas to residential, commercial, and industrial customers. Gas distribution operations serves approximately 4.24.3 million customers across four states.

markets in Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, and Tennessee.

Gas marketing services is comprised of SouthStar, and provides natural gas commodity and related services to customers in competitive markets or markets that provide for customer choice. SouthStar, servingwhich serves approximately 697,000603,000 natural gas commodity customers, markets gas to residential, commercial, and industrial customers and offers energy-related products that provide natural gas price stability and utility bill management.management in competitive markets or markets that provide for customer choice.

The subsidiary companies of Southern Company are engaged in continuous construction programs, including capital expenditures to accommodate existing and estimated future loads on their respective systems. For estimated constructionsystems and environmental expenditures for the periods 2019 through 2023, see MANAGEMENT'S DISCUSSION AND ANALYSIS – FINANCIAL CONDITION AND LIQUIDITY – "Capital Requirements and Contractual Obligations" of each registrant in Item 7 herein. The Southern Company system's construction program consists of capital investment and capital expenditures to comply with environmental laws and regulations.regulations, as applicable. In 2019,2022, the Southern Company system's construction program is expected to be apportioned approximately as follows:

The construction programs are subject to periodic review and revision, and actual construction costs may vary from these estimates because of numerous factors. These factors include: changes in business conditions; changes in load projections; changes in environmental laws and regulations; the outcome of any legal challenges to environmental rules; changes in electric generating plants, including unit retirements and replacements and adding or changing fuel sources at existing electric generating units, to meet regulatory requirements; changes in FERC rules and regulations; state regulatory agency approvals; changes in the expected environmental compliance program; changes in legislation; the cost and efficiency of construction labor, equipment, and materials; project scope and design changes; storm impacts; and the cost of capital. In addition, there can

For information relating to KWH sales by customer classification for the traditional electric operating companies, see MANAGEMENT'S DISCUSSION AND ANALYSIS – RESULTS OF OPERATIONS of Southern Company and each traditional electric operating company in Item 7 herein. For information relating to the number of retail customers served by customer classification for the traditional electric operating companies, see SELECTED FINANCIAL DATA of Southern Company and each traditional electric operating company in Item 6 herein. Also, for information relating to the sources of revenues for Southern Company, each traditional electric operating company, and Southern Power, reference is made tosee Item 7 herein and Note 1 to the financial statements under "Revenues – Traditional Electric Operating Companies" and " – Southern Power" and Note 4 to the financial statements in Item 8 herein.

The RUS has authority to make loans to cooperative associations or corporations to enable them to provide electric service to customers in rural sections of the country. As of January 1, 2019,December 31, 2021, there were approximately 5862 electric cooperative distribution systems operating in the territoryterritories in which the traditional electric operating companies provide electric service at retail or wholesale.

Alabama Power also has entered into a separate agreement with PowerSouth involving interconnection between their systems. The delivery of capacity and energy from PowerSouth to certain distributing cooperatives in the service territory of Alabama Power is governed by the Southern Company/PowerSouth Network Transmission Service Agreement. The rates for this service to PowerSouth are on file with the FERC.

Mississippi Power has an interchange agreement with Cooperative Energy, a generating and transmitting cooperative, pursuant to which various services are provided. Cooperative Energy also has a 10-year network integration transmission service agreement with SCS for transmission service to certain delivery points on Mississippi Power's transmission system through March 31, 2031. See Note 2 to the financial statements under "Mississippi Power – Municipal and Rural Associations Tariff" in Item 8 herein for information on an additional agreement between Mississippi Power and Cooperative Energy.

As of January 1, 2019,December 31, 2021, there were approximately 7172 municipally-owned electric distribution systems operating in the territory in which the traditional electric operating companies provide electric service at retail or wholesale.

Georgia Power has entered into substantially similar agreements with GTC, MEAG Power, and Dalton providing for the establishment of an integrated transmission system to carry the power and energy of all parties. The agreements require an investment by each party in the integrated transmission system in proportion to its respective share of the aggregate system load. See PROPERTIES – "Jointly-Owned"Electric – Jointly-Owned Facilities" in Item 2 herein for additional information.

Southern Power assumed or entered intohas PPAs with Georgia Power, investor-owned utilities, IPPs, municipalities, electric cooperatives, and other load-serving entities, as well as commercial and industrial customers. See "The Southern Company System – Southern Power" aboveherein and MANAGEMENT'S DISCUSSION AND ANALYSIS – FUTURE EARNINGS POTENTIAL – "Power"Southern Power's Power Sales Agreements" of Southern Power in Item 7 herein for additional information concerning Southern Power's PPAs.information.

SCS, acting on behalf of the traditional electric operating companies, also has a contract with SEPA providing for the use of the traditional electric operating companies' facilities at government expense to deliver to certain cooperatives and municipalities,

Southern Company Gas

Southern Company Gas is engaged in the distribution of natural gas in four states through the natural gas distribution utilities. The natural gas distribution utilities construct, manage, and maintain intrastate natural gas pipelines and distribution facilities. Details of the natural gas distribution utilities at December 31, 20182021 are as follows:

Electric

The electric utility industry in the U.S. is continuing to evolve as a result of regulatory and competitive factors. Among the early primary agents of change was the Energy Policy Act of 1992, which allowed IPPs to access a utility's transmission network in order to sell electricity to other utilities.

The retail service rights of all electric suppliers in the State of Georgia are regulated by the Territorial Electric Service Act of 1973. Pursuant to the provisions of this Act, all areas within existing municipal limits were assigned to the primary electric supplier therein. Areas outside of such municipal limits were either to be assigned or to be declared open for customer choice of supplier by action of the Georgia PSC pursuant to standards set forth in this Act. Consistent with such standards,Act, the Georgia PSC has assigned substantially all of the land area in the state to a supplier. Notwithstanding such assignments, this Act provides that any new customer locating outside of 1973 municipal limits and having a connected load of at least 900 KWs may exercise a one-time choice for the life of the premises to receive electric service from the supplier of its choice.

Pursuant to the 1956 Utility Act, the Mississippi PSC issued "Grandfather Certificates" of public convenience and necessity to Mississippi Power and to six distribution rural cooperatives operating in southeastern Mississippi, then served in whole or in part by Mississippi Power, authorizing them to distribute electricity in certain specified geographically described areas of the state. The six cooperatives serve approximately 325,000 retail customers in a certificated area of approximately 10,300 square miles. In areas included in a "Grandfather Certificate," the utility holding such certificate may extend or maintain its electric system subject to certain regulatory approvals; extensions of facilities by such utility, or extensions of facilities into that area by other utilities, may not be made except uponunless the Mississippi PSC grants a showing of, and a grant of a certificate of, public convenience and necessity.CPCN. Areas included in a CPCN that are subsequently annexed to municipalities may continue to be served by the holder of the CPCN, irrespective of whether it has a franchise in the annexing municipality. On the other hand, the holder of the municipal franchise may not extend service into such newly annexed area without authorization by the Mississippi PSC.

Generally, the traditional electric operating companies have experienced, and expect to continue to experience, competition in their respective retail service territories in varying degrees from the development and deployment of alternative energy sources such as self-generation (as described below) and distributed generation technologies, as well as other factors. Further technological advancements or the implementation of policies in support of alternative energy sources may result in further competition.

Southern Power competes with investor-owned utilities, IPPs, and others for wholesale energy sales across various U.S. utility markets. The needs of these markets are driven by the demands of end users and the generation available. Southern Power's success in wholesale energy sales is influenced by various factors including reliability and availability of Southern Power's plants, availability of transmission to serve the demand, price, and Southern Power's ability to contain costs.

As of December 31, 2018,2021, Georgia Power had contracts in effect with 28to purchase generation from 36 small power producers whereby Georgia Power purchases their excess generation.IPPs. During 2018,2021, Georgia Power purchased 2.14.9 billion KWHs from such companies at a cost of $140$289 million. Georgia Power also has PPAs for electricity with fourfive cogeneration facilities. Payments are subject to reductions for failure to meet minimum capacity output. During 2018,2021, Georgia Power purchased 26406 million KWHs at a cost of $0.8$34 million from these facilities.

Natural Gas

Southern Company Gas' natural gas distribution utilities do not compete with other distributors of natural gas in their exclusive franchise territories but face competition from other energy products. Their principal competitors are electric utilities and fuel oil and propane providers serving the residential, commercial, and industrial markets in their service areas for customers who are considering switching to or from a natural gas appliance.

Competition for heating as well as general household and small commercial energy needs generally occurs at the initial installation phase when the customer or builder makes decisions as to which types of equipment to install. Customers generally use the chosen energy source for the life of the equipment.

Customer demand for natural gas could be affected by numerous factors, including:

TheSouthern Company Gas has natural gas-related programs that generally emphasize natural gas as the fuel of choice for customers and seek to expand the use of natural gas through a variety of promotional activities. In addition, Southern Company Gas partners with third-party entities to market the benefits of natural gas appliances.

The demand for electric power and natural gas supply is affected by seasonal differences in the weather. While the electric power sales of some of the traditional electric operating companiesutilities peak in the summer, others peak in the winter. In the aggregate, during normal weather conditions, the Southern Company system's electric power sales peak during both the summer with a smaller peak during theand winter. In most of the areas Southern Company Gas serves, natural gas demand peaks during the winter. As a result, the overall operating results of Southern Company, the traditional electric operating companies, Southern Power, and Southern Company GasRegistrants in the future may fluctuate substantially on a seasonal basis. In addition, the traditional electric operating companies, Southern Power, and Southern Company GasSubsidiary Registrants have historically sold less power and natural gas when weather conditions are milder.

States

The traditional electric operating companies and the natural gas distribution utilities are subject to the jurisdiction of their respective state PSCs or applicable state regulatory agencies. These regulatory bodies have broad powers of supervision and regulation over public utilities operating in the respective states, including their rates, service regulations, sales of securities (except for the Mississippi PSC), and, in the cases of the Georgia PSC and the Mississippi PSC, in part, retail service territories. See "Territory Served by the Southern Company System" and "Rate Matters" herein for additional information.

Federal Power Act

The traditional electric operating companies, Southern Power Company and certain of its generation subsidiaries, and SEGCO are all public utilities engaged in wholesale sales of energy in interstate commerce and, therefore, are subject to the rate, financial, and accounting jurisdiction of the FERC under the Federal Power Act. The FERC must approve certain financings and allows an "at cost standard" for services rendered by system service companies such as SCS and Southern Nuclear. The FERC is also authorized to establish regional reliability organizations which enforce reliability standards, address impediments to the construction of transmission, and prohibit manipulative energy trading practices.

Alabama Power and Georgia Power are also subject to the provisions of the Federal Power Act or the earlier Federal Water Power Act applicable to licensees with respect to their hydroelectric developments. As of December 31, 2018,2021, among the hydroelectric projects subject to licensing by the FERC are 14 existing Alabama Power generating stations having an aggregate installed capacity of 1,670,0001.7 million KWs and 17 existing Georgia Power generating stations and one generating station partially owned by Georgia Power, with a combined aggregate installed capacity of 1,101,4021.1 million KWs.

In 2013, the FERC issued a new 30-year license to Alabama Power for Alabama Power's seven hydroelectric developments on the Coosa River (Weiss, Henry, Logan Martin, Lay, Mitchell, Jordan, and Bouldin). Alabama Power filed a petition requesting rehearing of the FERC order granting the relicense seeking revisions to several conditions of the license. Alabama Rivers Alliance, American Rivers, the Georgia Environmental Protection Division, and the Atlanta Regional Commission also filed petitions for rehearing of the FERC order. In 2016, the FERC issued an order granting in part and denying in part Alabama Power's rehearing request. The order also denied all of the other rehearing requests. Also in 2016,American Rivers and Alabama Rivers Alliance and American Rivers filed a second rehearing request and also filed a petition withmultiple appeals of the FERC's 2013 order for the new 30-year license and, in 2018, the U.S. Court of Appeals for the District of Columbia Circuit for review of the license and the rehearing denial order. The FERC issued an order in 2016 denying the second rehearing request, and American Rivers and Alabama Rivers Alliance subsequently filed an appeal of that order at the U.S. Court of Appeals for the District of Columbia Circuit. The U.S. Court of Appeals for the District of Columbia Circuit consolidated the two appeals into one proceeding and, on July 6, 2018, vacated the FERC's 2013 order for the new 30-year license and remanded the proceeding to the FERC. Alabama Power continues to operate the Coosa River developments under annual licenses issued by the FERC. The ultimate outcome of this matter cannot be determined at this time.

In 2018,November 2021, Alabama Power continuedfiled an application with the process of developing an applicationFERC to relicense the Harris Dam project on the Tallapoosa River, which is expected to be filed with the FERC by November 30, 2021.River. The current Harris Dam project license will expire on November 30, 2023.

On May 31, 2018, Georgia Power filed an application to relicense the Wallace Dam project on the Oconee River. The current Wallace Dam project license will expire on June 1, 2020. On July 3, 2018, Georgia Power filed a Notice of Intent to relicense the Lloyd Shoals project on the Ocmulgee River. The application to relicense the Lloyd Shoals project is expected to be filed with the FERC by December 31, 2021. The current Lloyd Shoals project license will expire on December 31, 2023. On December 18,In 2018, Georgia Power filed applications to surrender the Langdale and Riverview hydroelectric projects on the Chattahoochee River upon their license expirations on December 31, 2023. Both projects together represent 1,520 KWs of Georgia Power's hydro fleet capacity.

Georgia Power and OPC also have a license, expiring in 2027,2026, for the Rocky Mountain project, a pure pumped storage facility of 903,000 KW installed capacity. In December 2021, OPC, as an agent for co-licensees of the project, filed a notice of intent with the FERC to relicense the project. An application to relicense the project is expected to be filed with the FERC by December 31, 2024. See PROPERTIES – "Jointly-Owned"Electric – Jointly-Owned Facilities" in Item 2 herein for additional information.

Licenses for all projects, excluding those discussed above, expire in the years 2034-2066 in the case offor Alabama Power's projects and in the years 2035-2044 in the case of2034-2060 for Georgia Power's projects.

Upon or after the expiration of each license, the U.S. Government, by act of Congress, may take over the project or the FERC may relicense the project either to the original licensee or to a new licensee. In the event of takeover or relicensing to another, the original licensee is to be compensated in accordance with the provisions of the Federal Power Act, such compensation to reflect the net investment of the licensee in the project, not in excess of the fair value of the property, plus reasonable damages to other property of the licensee resulting from the severance therefrom of the property. The FERC may grant relicenses subject to certain requirements that could result in additional costs.

The ultimate outcome of these matters cannot be determined at this time.

Nuclear Regulation

Alabama Power, Georgia Power, and Southern Nuclear are subject to regulation by the NRC. The NRC is responsible for licensing and regulating nuclear facilities and materials and for conducting research in support of the licensing and regulatory process, as mandated by the Atomic Energy Act of 1954, as amended; the Energy Reorganization Act of 1974, as amended; and the Nuclear Nonproliferation Act of 1978, as amended; and in accordance with the National Environmental Policy Act of 1969, as amended, and other applicable statutes. These responsibilities also include protecting public health and safety, protecting the

The NRC licenses for Georgia Power's Plant Hatch Units 1 and 2 expire in 2034 and 2038, respectively. The NRC licenses for Alabama Power's Plant Farley Units 1 and 2 expire in 2037 and 2041, respectively. The NRC licenses for Plant Vogtle Units 1 and 2 expire in 2047 and 2049, respectively.

Environmental Laws and resulting regulations, including, but not limited to, proposed and existing regulations related to air quality, water quality, CCR, and global climate issues, has been, and will continue to be, a significant focus for each of the registrants and SEGCO. Compliance with any new or revised environmental laws and regulations could affect many areas of the traditional electric operating companies', Southern Power's, SEGCO's, and Southern Company Gas' operations. Regulations

See "Construction Programs" herein, MANAGEMENT'S DISCUSSION AND ANALYSIS – FUTURE EARNINGS POTENTIAL – "Environmental Matters" of each of the registrants in Item 7 herein, for additional information about environmental issues.

Rate Structure and Cost Recovery Plans

The rates and service regulations of the traditional electric operating companies are uniform for each class of service throughout their respective retail service territories. Rates for residential electric service are generally of the block type based upon KWHs used and include minimum charges. Residential and other rates contain separate customer charges. Rates for commercial service are presently of the block type and, for large customers, the billing demand is generally used to determine capacity and minimum bill charges. These large customers' rates are generally based upon usage by the customer and include rates with special features to encourage off-peak usage. Additionally, Alabama Power and Mississippi Power are generally allowed by

The traditional electric operating companies recover certain costs through a variety of forward-looking, cost-based rate mechanisms. Fuel and net purchased energy costs are recovered through specific fuel cost recovery provisions. These fuel cost recovery provisions are adjusted to reflect increases or decreases in such costs as needed or on schedules as required by the respective PSCs. Approved compliance, storm damage, and certain other costs are recovered at Alabama Power and Mississippi Power through specific cost recovery mechanisms approved by their respective PSCs. Certain similar costs at Georgia Power are recovered through various base rate tariffs as approved by the Georgia PSC. Costs not recovered through specific cost recovery mechanisms are recovered at Alabama Power and Mississippi Power through annual, formulaic cost recovery proceedings and at Georgia Power through periodic base rate proceedings.

See MANAGEMENT'S DISCUSSION AND ANALYSIS – FUTURE EARNINGS POTENTIAL – "Regulatory Matters" of Southern Company and each of the traditional electric operating companies in Item 7 herein and Note 2 to the financial statements in Item 8 herein for a discussion of rate matters and certain cost recovery mechanisms. Also see Note 1 to the financial statements in Item 8 herein for a discussion of recovery of fuel costs, storm damage costs, and compliance costs through rate mechanisms.

The traditional electric operating companies and Southern Power Company and certain of its generation subsidiaries are authorized by the FERC to sell power to non-affiliates, including short-term opportunity sales, at market-based prices. Specific FERC approval must be obtained with respect to a market-based contract with an affiliate.

Mississippi Power servesprovides service under long-term contracts with rural electric cooperative associations and a municipality located in southeastern Mississippi under full requirements cost-based electric tariffs, which are subject to regulation by the FERC. The contracts with these wholesale customers represented 17.3%14.3% of Mississippi Power's total operating revenues in 20182021 and are generally subject to 10-year rolling cancellation notices. Historically, these wholesale customers have acted as a group and any changes in contractual relationships for one customer are likely to be followed by the other wholesale customers.

Southern Company Gas' natural gas distribution utilities are subject to regulation and oversight by their respective state regulatory agencies. Rates charged to these customers vary according to customer class (residential, commercial, or industrial) and rate jurisdiction. These agencies approve rates designed to provide each natural gas distribution utility the opportunity to generate revenues to recover all prudently-incurred costs, including a return on rate base sufficient to pay interest on debt and provide a reasonable return.ROE.

With the exception of Atlanta Gas Light, whichthe earnings of the natural gas distribution utilities can be affected by customer consumption patterns that are largely a function of weather conditions and price levels for natural gas. The natural gas distribution utilities have weather or revenue normalization mechanisms that mitigate revenue fluctuations from customer consumption changes. Atlanta Gas Light operates in a deregulated environment in which Marketers rather than a traditional utility sell natural gas to end-use customers and earns revenue by charging rates to its customers based primarily on monthly fixed charges that are set by the Georgia PSC, the earnings of the natural gas distribution utilities can be affected by customer consumption patterns that are largely a function of weather conditions and price levels for natural gas.PSC.

The natural gas distribution utilities, excluding Atlanta Gas Light, are authorized to use natural gas cost recovery mechanisms that adjust rates to reflect changes in the wholesale cost of natural gas and ensure recovery of all costs prudently incurred in purchasing natural gas for customers. In addition to natural gas cost recovery mechanisms, the natural gas distribution utilities have other cost recovery mechanisms such asand regulatory riders, which vary by utility, but allow recovery of certain costs, such as those related to infrastructure replacement programs as well as environmental remediation, and energy efficiency plans.plans, and bad debts.

See MANAGEMENT'S DISCUSSION AND ANALYSIS – FUTURE EARNINGS POTENTIAL – "Regulatory Matters – Utility Regulation and Rate Design" of Southern Company Gas in Item 7 herein and Note 2 to the financial statements under "Southern Company Gas" in Item 8 herein for a discussion of rate matters and certain cost recovery mechanisms.

Integrated Resource Planning

Each of the traditional electric operating companies continually evaluates its electric generating resources in order to ensure that it maintains a cost-effective and reliable mix of resources to meet the existing and future demand requirements of its customers. See MANAGEMENT'S DISCUSSION AND ANALYSIS – FUTURE EARNINGS POTENTIAL – "Environmental Laws and Regulations" aboveMatters" in Item 7 herein for a discussion of existing and potential environmental regulations that may impact the future generating resource needs of the traditional electric operating companies.companies, as well as a discussion of the Southern Company system's continued generating fleet transition.

Triennially, Alabama Power provides an IRP report to the Alabama PSC. This report overviews Alabama Power's resource planning process and contains information that serves as the foundation for certain decisions affecting Alabama Power's portfolio of supply-side and demand-side resources. The IRP report facilitates Alabama Power's ability to provide reliable and cost-effective electric service to customers, while accounting for the risks and uncertainties inherent in planning for resources sufficient to meet expected customer demand. Under State of Alabama law, a CPCNCCN must be obtained from the Alabama PSC before Alabama Power constructs any new generating facility, unless such construction is deemed an ordinary extension of an existing system in the usual course of business. On October 28, 2021, Alabama Power filed a petition for a CCN with the Alabama PSC to procure additional generating capacity through the acquisition of a 743-MW winter peak, simple-cycle, combustion turbine generation facility in Calhoun County, Alabama. The ultimate outcome of this matter cannot be determined at this time. See Note 2 to the financial statements under "Alabama Power – Certificates of Convenience and Necessity" in Item 8 herein for additional information.

On February 6, 2018,In 2019, the Mississippi PSC approvedestablished the Integrated Resource Planning and Reporting Rule, which requires long-term plans to best meet the needs of electric utility customers through a settlement agreement relatedcombination of demand-side and supply-side resources and considering transmission needs, including the triennial filing of an IRP, with supply-side updates midway through the three-year cycle, and an annual report on energy delivery improvements. The IRP filing is not intended to cost recoverysupplant or replace the Mississippi PSC's existing regulatory processes for petition and approval of CPCNs for new generating resources. On September 9, 2021, the Kemper County energy facility, pursuant to which Mississippi Power filed a Reserve Margin Plan (RMP) on August 6, 2018. The RMP includes manyPSC issued an order confirming the conclusion of the same aspectsits review of a traditional IRP, but the RMP also contains alternatives proposed by Mississippi Power to address its existing reserve capacity, which is greater than the level required to meet Mississippi Power's projected summer peak demand. Mississippi Power developed the alternatives by evaluating the economics of each unit in Mississippi Power's fleet, the opportunities currently available in the wholesale market, and the operational constraints of the Southern Company system. The ultimate outcome of this matter cannot be determined at this time. For additional information, see2021 IRP with no deficiencies identified. See Note 2 to the financial statements under "Kemper County Energy Facility""Mississippi Power – Integrated Resource Plan" in Item 8 herein.herein for additional information.

The Southern Company system supports the well-being of its employees through a comprehensive total rewards strategy with three measurable categories: physical, financial, and emotional well-being. The Southern Company system provides competitive salaries, annual incentive awards for nearly all employees, and health, welfare, and retirement benefits. The Southern Company system has a qualified defined benefit, trusteed pension plan and a qualified defined contribution, trusteed 401(k) plan which provides a competitive company matching contribution. Substantially all Southern Company system employees are eligible to participate in these plans. There are differences between the pension plan benefit formulas based on when and by which subsidiary an employee is hired. See Note 11 to the financial statements for additional information. At December 31, 2021, the average age of the Southern Company system employees was 45 and the average tenure with the Southern Company system was 15 years. Turnover rate, calculated as the percent of employees that terminated employment with the Southern Company system, including voluntary and involuntary terminations and retirements, divided by total employees, was 7.7%.

Southern Company system management believes the safety of employees and customers is paramount. The Southern Company system seeks to meet or exceed applicable laws and regulations while continually improving its safety technologies and processes. The Southern Company System Safety and Health Council, which includes leaders from each Registrant, works collectively across the Southern Company system to provide safety leadership, share learning, work collaboratively to address safety-related issues, and govern the consistency of safety programs. The safety programs are focused on the prevention and elimination of life-altering events, serious injuries, and fatalities. These programs include continuous process improvements to put critical controls in place to prevent serious injuries, promote learning, and implement appropriate corrective actions. In 2021, the Southern Company system had a serious injury rate of 0.05, which represents the number of incidents per 100 employees (calculated by taking the number of serious injuries multiplied by 200,000 workhours and divided by the total employee workhours during the year). A serious injury is one that is life-threatening or life-changing for the employee. Serious injury examples, as defined by applicable safety regulators, include fatalities, amputations, trauma to organs, certain bone fractures, severe burns, and eye injuries.

Since the onset of 29,192the COVID-19 pandemic in early 2020, the Southern Company system has continued to provide essential services to customers while protecting employees, customers, and communities by implementing applicable business continuity plans, including teleworking, canceling nonessential business travel, increasing cleaning frequency at business locations, implementing applicable safety and health guidelines issued by federal, state, and local officials, and establishing protocols for required work on its payroll at January 1, 2019.customer premises. To date, these procedures have been effective in maintaining the Southern Company system's critical operations, while also emphasizing employee, customer, and community safety.

At December 31, 2021, approximately 32% of Southern Company system employees were covered by agreements apply with certain exceptions to operating, maintenance,unions, with agreements expiring between 2023 and construction employees.