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REGULATORY MATTERS | 12 Months Ended
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Dec. 31, 2021
Regulated Operations [Abstract] |
REGULATORY MATTERS | REGULATORY MATTERS Regulatory Assets and Liabilities Details of regulatory assets and (liabilities) reflected in the balance sheets at December 31, 2021 and 2020 are provided in the following tables:
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Company Gas
| (in millions)
At December 31, 2021 |  |  |  |  |
AROs(a)(u) | $ | 5,685 |  | $ | 1,576 |  | $ | 3,866 |  | $ | 236 |  | $ | — |
Retiree benefit plans(b)(u) | 2,998 |  | 747 |  | 962 |  | 145 |  | 95 |
Remaining net book value of retired assets(c) | 1,050 |  | 574 |  | 455 |  | 21 |  | — |
Deferred income tax charges(d) | 829 |  | 240 |  | 555 |  | 31 |  | — |
Under recovered regulatory clause revenues(e) | 806 |  | 225 |  | — |  | 49 |  | 532 |
Environmental remediation(f)(u) | 302 |  | — |  | 35 |  | — |  | 267 |
Loss on reacquired debt(g) | 281 |  | 42 |  | 231 |  | 6 |  | 2 |
Vacation pay(h)(u) | 207 |  | 81 |  | 102 |  | 10 |  | 14 |
Regulatory clauses(i) | 142 |  | 142 |  | — |  | — |  | — |
Storm damage(j) | 97 |  | — |  | 48 |  | 49 |  | — |
Long-term debt fair value adjustment(k) | 79 |  | — |  | — |  | — |  | 79 |
Nuclear outage(l) | 75 |  | 41 |  | 34 |  | — |  | — |
Software and cloud computing costs(m) | 73 |  | 35 |  | 33 |  | — |  | 5 |
Kemper County energy facility assets, net(n) | 35 |  | — |  | — |  | 35 |  | — |
Plant Daniel Units 3 and 4(o) | 28 |  | — |  | — |  | 28 |  | — |
Other regulatory assets(p) | 168 |  | 38 |  | 29 |  | 7 |  | 94 |
Deferred income tax credits(d) | (5,636) |  | (1,968) |  | (2,537) |  | (288) |  | (816) |
Other cost of removal obligations(a) | (1,826) |  | (192) |  | 278 |  | (195) |  | (1,683) |
Customer refunds(q) | (189) |  | (181) |  | (8) |  | — |  | — |
Fuel-hedging (realized and unrealized) gains(r) | (176) |  | (50) |  | (72) |  | (54) |  | — |
Storm/property damage reserves(s) | (133) |  | (103) |  | — |  | (30) |  | — |
Over recovered regulatory clause revenues(e) | (63) |  | (1) |  | (59) |  | — |  | (3) |
Other regulatory liabilities(t) | (121) |  | (29) |  | (24) |  | (4) |  | (57) |
Total regulatory assets (liabilities), net | $ | 4,711 |  | $ | 1,217 |  | $ | 3,928 |  | $ | 46 |  | $ | (1,471) |
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Company Gas
| (in millions)
At December 31, 2020 |  |  |  |  |
AROs(a)(u) | $ | 5,147 |  | $ | 1,470 |  | $ | 3,457 |  | $ | 212 |  | $ | — |
Retiree benefit plans(b)(u) | 4,958 |  | 1,265 |  | 1,647 |  | 238 |  | 187 |
Remaining net book value of retired assets(c) | 1,183 |  | 632 |  | 527 |  | 24 |  | — |
Deferred income tax charges(d) | 801 |  | 235 |  | 531 |  | 32 |  | — |
Environmental remediation(f)(u) | 310 |  | — |  | 41 |  | — |  | 269 |
Loss on reacquired debt(g) | 304 |  | 47 |  | 248 |  | 6 |  | 3 |
Storm damage(j) | 262 |  | — |  | 262 |  | — |  | — |
Vacation pay(h)(u) | 207 |  | 80 |  | 104 |  | 10 |  | 13 |
Under recovered regulatory clause revenues(e) | 185 |  | 58 |  | — |  | 52 |  | 75 |
Regulatory clauses(i) | 142 |  | 142 |  | — |  | — |  | — |
Nuclear outage(l) | 101 |  | 61 |  | 40 |  | — |  | — |
Long-term debt fair value adjustment(k) | 92 |  | — |  | — |  | — |  | 92 |
Kemper County energy facility assets, net(n) | 50 |  | — |  | — |  | 50 |  | — |
Plant Daniel Units 3 and 4(o) | 32 |  | — |  | — |  | 32 |  | — |
Software and cloud computing costs(m) | 31 |  | 17 |  | 12 |  | — |  | 2 |
Other regulatory assets(p) | 174 |  | 35 |  | 56 |  | 4 |  | 79 |
Deferred income tax credits(d) | (6,016) |  | (2,016) |  | (2,805) |  | (320) |  | (847) |
Other cost of removal obligations(a) | (1,999) |  | (335) |  | 212 |  | (194) |  | (1,649) |
Over recovered regulatory clause revenues(e) | (185) |  | (46) |  | (44) |  | — |  | (95) |
Storm/property damage reserves(s) | (81) |  | (77) |  | — |  | (4) |  | — |
Customer refunds(q) | (56) |  | (50) |  | (6) |  | — |  | — |
Other regulatory liabilities(t) | (149) |  | (37) |  | (30) |  | (6) |  | (54) |
Total regulatory assets (liabilities), net | $ | 5,493 |  | $ | 1,481 |  | $ | 4,252 |  | $ | 136 |  | $ | (1,925) |
Unless otherwise noted, the following recovery and amortization periods for these regulatory assets and (liabilities) have been approved by the respective state PSC or regulatory agency: (a)AROs and other cost of removal obligations generally are recorded over the related property lives, which may range up to 53 years for Alabama Power, 60 years for Georgia Power, 55 years for Mississippi Power, and 80 years for Southern Company Gas. AROs and cost of removal obligations will be settled and trued up following completion of the related activities. Effective January 1, 2020, Georgia Power is recovering CCR AROs, including past under recovered costs and estimated annual compliance costs, over three-year periods ending December 31, 2022, 2023, and 2024 through its ECCR tariff, as discussed further under "Georgia Power – Rate Plans" herein. See Note 6 for additional information on AROs. (b)Recovered and amortized over the average remaining service period, which may range up to 13 years for Alabama Power, Georgia Power, and Mississippi Power and up to 14 years for Southern Company Gas. Southern Company's balances also include amounts at SCS and Southern Nuclear that are allocated to the applicable regulated utilities. See Note 11 for additional information. (c)Alabama Power: Primarily represents the net book value of Plant Gorgas Units 8, 9, and 10 ($533 million at December 31, 2021) being amortized over remaining periods not exceeding 16 years (through 2037). Georgia Power: Net book values of Plant Hammond Units 1 through 4 and Plant Branch Units 3 and 4 (totaling $445 million at December 31, 2021) are being amortized over remaining periods of between two and 14 years (between 2023 and 2035) and the net book values of Plant Branch Unit 2, Plant McIntosh Unit 1, and Plant Mitchell Unit 3 (totaling $10 million at December 31, 2021) are being amortized through 2022. Mississippi Power: Represents net book value of certain environmental compliance projects associated with Plant Watson and Plant Greene County being amortized over a 10-year period through 2030. See "Mississippi Power – Environmental Compliance Overview Plan" herein for additional information. (d)Deferred income tax charges are recovered and deferred income tax credits are amortized over the related property lives, which may range up to 53 years for Alabama Power, 60 years for Georgia Power, 55 years for Mississippi Power, and 80 years for Southern Company Gas. See Note 10 for additional information. Included in the deferred income tax charges are amounts ($7 million and $4 million for Alabama Power and Georgia Power, respectively, at December 31, 2021) for the retiree Medicare drug subsidy, which are being recovered and amortized through 2027 and 2022 for Alabama Power and Georgia Power, respectively. As a result of the Tax Reform Legislation, these accounts include certain deferred income tax assets and liabilities not subject to normalization, as described further below: Alabama Power: Related amounts are being recovered and amortized ratably over the related property lives. Georgia Power: Related amounts at December 31, 2021 include $145 million of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 and approximately $220 million of deferred income tax liabilities. The recovery of deferred income tax assets related to CWIP for Plant Vogtle Units 3 and 4 is expected to be determined in a future regulatory proceeding. Effective January 1, 2020, the deferred income tax liabilities are being amortized through 2022. Mississippi Power: Related amounts at December 31, 2021 include $46 million of retail deferred income tax liabilities generally being amortized over three years (through 2023). See "Mississippi Power – 2019 Base Rate Case" herein for additional information. Southern Company Gas: Related amounts at December 31, 2021 include $3 million of deferred income tax liabilities being amortized through 2024. See "Southern Company Gas – Rate Proceedings" herein for additional information. (e)Alabama Power: Balances are recorded monthly and expected to be recovered or returned within eight years. Recovery periods could change based on several factors including changes in cost estimates, load forecasts, and timing of rate adjustments. See "Alabama Power – Rate CNP PPA," " – Rate CNP Compliance," and " – Rate ECR" herein for additional information. Georgia Power: Balances are recorded monthly and expected to be recovered or returned within two years. See "Georgia Power – Rate Plans" herein for additional information. Mississippi Power: At December 31, 2021, $24 million is being amortized over a three-year period through 2023 and the remaining $25 million is expected to be recovered through various rate recovery mechanisms over a period to be determined in future rate filings. See "Mississippi Power – Ad Valorem Tax Adjustment" herein for additional information. Southern Company Gas: Balances are recorded and recovered or amortized over periods generally not exceeding four years. In addition to natural gas cost recovery mechanisms, the natural gas distribution utilities have various other cost recovery mechanisms for the recovery of costs, including those related to infrastructure replacement programs. The significant change during 2021 was primarily driven by an increase in the cost of gas purchased in February 2021 resulting from Winter Storm Uri. (f)Georgia Power is recovering $12 million annually for environmental remediation under the 2019 ARP. Southern Company Gas' costs are recovered through environmental cost recovery mechanisms when the remediation work is performed. See Note 3 under "Environmental Remediation" for additional information. (g)Recovered over either the remaining life of the original issue or, if refinanced, over the remaining life of the new issue. At December 31, 2021, the remaining amortization periods do not exceed 26 years for Alabama Power, 31 years for Georgia Power, 20 years for Mississippi Power, and six years for Southern Company Gas. (h)Recorded as earned by employees and recovered as paid, generally within one year. Includes both vacation and banked holiday pay, if applicable. (i)Will be amortized concurrently with the effective date of Alabama Power's next depreciation study, which is expected to occur no later than 2023. (j)Georgia Power is recovering approximately $213 million annually for storm damage under the 2019 ARP. See "Georgia Power – Storm Damage Recovery" herein for additional information. Mississippi Power's balance represents deferred storm costs associated with Hurricanes Ida and Zeta to be recovered through PEP over a period to be determined in Mississippi Power's 2022 PEP proceeding. See "Mississippi Power – System Restoration Rider" herein for additional information. Also see Note 1 under "Storm Damage Reserves" for additional information. (k)Recovered over the remaining lives of the original debt issuances at acquisition, which range up to 17 years at December 31, 2021. (l)Nuclear outage costs are deferred to a regulatory asset when incurred and amortized over a subsequent period of 18 months for Alabama Power and up to 24 months for Georgia Power. See Note 5 for additional information. (m)Represents certain deferred operations and maintenance costs associated with software and cloud computing projects. For Alabama Power, costs are amortized ratably over the life of the related software, which ranges up to 10 years. See "Alabama Power – Software Accounting Order" herein for additional information. For Georgia Power, the recovery period will be determined in its next base rate case. For Southern Company Gas, costs will be amortized ratably beginning in July 2022 over the life of the related software, which ranges up to 10 years. (n)Includes $44 million of regulatory assets and $9 million of regulatory liabilities at December 31, 2021. The retail portion includes $33 million of regulatory assets and $9 million of regulatory liabilities that are expected to be fully amortized by 2023 and 2024, respectively. The wholesale portion includes $11 million of regulatory assets that are expected to be fully amortized by 2029. (o)Represents the difference between Mississippi Power's revenue requirement for Plant Daniel Units 3 and 4 under purchase accounting and operating lease accounting. At December 31, 2021, consists of the $19 million retail portion, which is being amortized over the remaining life of the units through 2041, and the $9 million wholesale portion, which is expected to be amortized over a period to be determined in a future wholesale rate filing. (p)Except as otherwise noted, comprised of numerous immaterial components with remaining amortization periods generally not exceeding 23 years for Alabama Power, 10 years for Georgia Power, six years for Mississippi Power, and 20 years for Southern Company Gas at December 31, 2021. Balances at December 31, 2021 and 2020 include deferred COVID-19 costs (except for Alabama Power), as discussed further under "Deferral of Incremental COVID-19 Costs" for each applicable Registrant herein. (q)Primarily includes approximately $181 million and $50 million at December 31, 2021 and 2020, respectively, for Alabama Power and $5 million at December 31, 2021 for Georgia Power as a result of each company exceeding its allowed retail return range. Georgia Power's balances also include immaterial amounts related to refunds for transmission service customers. See "Alabama Power – Rate RSE" and "Georgia Power – Rate Plans" herein for additional information. (r)Fuel-hedging assets and liabilities are recorded over the life of the underlying hedged purchase contracts. Upon final settlement, actual costs incurred are recovered through the applicable traditional electric operating company's fuel cost recovery mechanism. Purchase contracts generally do not exceed three and a half years for Alabama Power, three years for Georgia Power, and three years for Mississippi Power. Immaterial amounts at December 31, 2020 are included in other regulatory assets and liabilities. (s)Amortized as related expenses are incurred. See "Alabama Power – Rate NDR" and "Mississippi Power – System Restoration Rider" herein for additional information. (t)Comprised of numerous immaterial components with remaining amortization periods generally not exceeding 16 years for Alabama Power, 11 years for Georgia Power, three years for Mississippi Power, and 20 years for Southern Company Gas at December 31, 2021. (u)Generally not earning a return as they are excluded from rate base or are offset in rate base by a corresponding asset or liability. Alabama Power Alabama Power's revenues from regulated retail operations are collected through various rate mechanisms subject to the oversight of the Alabama PSC. Alabama Power currently recovers its costs from the regulated retail business primarily through Rate RSE, Rate CNP, Rate ECR, and Rate NDR. In addition, the Alabama PSC issues accounting orders to address current events impacting Alabama Power. Certificates of Convenience and Necessity In August 2020, the Alabama PSC issued its order regarding Alabama Power's 2019 petition for a CCN, which authorized Alabama Power to (i) construct an approximately 720-MW combined cycle facility at Alabama Power's Plant Barry (Plant Barry Unit 8) that is expected to be placed in service by the end of 2023, (ii) complete the acquisition of the Central Alabama Generating Station, which occurred in August 2020, (iii) purchase approximately 240 MWs of combined cycle generation under a long-term PPA, which began in September 2020, and (iv) pursue up to approximately 200 MWs of cost-effective demand-side management and distributed energy resource programs. Alabama Power's petition for a CCN was predicated on the results of Alabama Power's 2019 IRP provided to the Alabama PSC, which identified an approximately 2,400-MW resource need for Alabama Power, driven by the need for additional winter reserve capacity. See Note 15 under "Alabama Power" for additional information on the acquisition of the Central Alabama Generating Station. The Alabama PSC authorized the recovery of actual costs for the construction of Plant Barry Unit 8 up to 5% above the estimated in-service cost of $652 million. In so doing, it recognized the potential for developments that could cause the project costs to exceed the capped amount, in which case Alabama Power would provide documentation to the Alabama PSC to explain and justify potential recovery of the additional costs. At December 31, 2021, project expenditures associated with Plant Barry Unit 8 included in CWIP totaled approximately $304 million. The Alabama PSC further directed that additional solar generation of approximately 400 MWs proposed in the 2019 CCN petition, coupled with battery energy storage systems (solar/battery systems), be evaluated under an existing Renewable Generation Certificate (RGC). The contracts originally proposed expired in July 2020. See "Renewable Generation Certificate" herein for additional information. Alabama Power expects to recover costs associated with Plant Barry Unit 8 pursuant to its Rate CNP New Plant. Alabama Power is recovering all costs associated with the Central Alabama Generating Station through the inclusion in Rate RSE of revenues from the existing power sales agreement and, on expiration of that agreement, expects to recover costs pursuant to Rate CNP New Plant. The recovery of costs associated with laws, regulations, and other such mandates directed at the utility industry are expected to be recovered through Rate CNP Compliance. Alabama Power expects to recover the capacity-related costs associated with the PPAs through its Rate CNP PPA. In addition, fuel and energy-related costs are expected to be recovered through Rate ECR. Any remaining costs associated with Plant Barry Unit 8 and the acquisition of the Central Alabama Generating Station are expected to be recovered through Rate RSE. On September 23, 2021, Alabama Power entered into an agreement to acquire all of the equity interests in Calhoun Power Company, LLC, which owns and operates a 743-MW winter peak, simple-cycle, combustion turbine generation facility in Calhoun County, Alabama (Calhoun Generating Station). The total purchase price associated with the acquisition is approximately $180 million, subject to working capital adjustments. The completion of the acquisition is subject to the satisfaction and waiver of certain conditions, including, among other customary conditions, approval by the Alabama PSC and the FERC. On October 28, 2021, Alabama Power filed a petition for a CCN with the Alabama PSC to procure additional generating capacity through this acquisition. Completion of the acquisition and certain operating conditions would enable Alabama Power to retire Plant Barry Unit 5 as early as 2023. A decision from the Alabama PSC is expected by the third quarter 2022. Pending certification, Alabama Power expects to recover costs associated with the Calhoun Generating Station through its existing rate structure, primarily Rate CNP New Plant, Rate CNP Compliance, Rate ECR, and Rate RSE. Alabama Power expects to complete the transaction by September 30, 2022; however, the ultimate outcome of these matters cannot be determined at this time. Renewable Generation Certificate Through the issuance of a RGC, the Alabama PSC has authorized Alabama Power to procure up to 500 MWs of renewable capacity and energy by September 16, 2027 and to market the related energy and environmental attributes to customers and other third parties. Through December 31, 2021, Alabama Power has procured approximately 250 MWs through five projects approved under the RGC. Alabama Power owns two of the projects, totaling 18 MWs, with the remaining MWs expected to be served through three PPAs, two of which will commence in the first quarter 2024. Rate RSE The Alabama PSC has adopted Rate RSE that provides for periodic annual adjustments based upon Alabama Power's projected weighted common equity return (WCER) compared to an allowable range. Rate RSE adjustments are based on forward-looking information for the applicable upcoming calendar year. Rate RSE adjustments for any two-year period, when averaged together, cannot exceed 4.0% and any annual adjustment is limited to 5.0%. When the projected WCER is under the allowed range, there is an adjusting point of 5.98% and eligibility for a performance-based adder of seven basis points, or 0.07%, to the WCER adjusting point if Alabama Power (i) has an "A" credit rating equivalent with at least one of the recognized rating agencies or (ii) is in the top one-third of a designated customer value benchmark survey. Alabama Power continues to reduce growth in total debt by increasing equity, with corresponding reductions in debt issuances, thereby de-leveraging its capital structure. Alabama Power's goal is to achieve an equity ratio of approximately 55% by the end of 2025. At both December 31, 2021 and 2020, Alabama Power's equity ratio was approximately 51.6%. Effective for January 2019, the Alabama PSC approved modifications to Rate RSE. These modifications reduced the top of the allowed WCER range from 6.21% to 6.15% and modified the refund mechanism applicable to prior year actual results to allow Alabama Power to retain a portion of the revenue that causes the actual WCER for a given year to exceed the allowed range. These modifications were designed to position Alabama Power to address the growing pressure on its credit quality resulting from the Tax Reform Legislation, without increasing retail rates under Rate RSE in the near term. Generally, during a year without a Rate RSE upward adjustment, if Alabama Power's actual WCER is between 6.15% and 7.65%, customers will receive 25% of the amount between 6.15% and 6.65%, 40% of the amount between 6.65% and 7.15%, and 75% of the amount between 7.15% and 7.65%. Customers will receive all amounts in excess of an actual WCER of 7.65%. During a year with a Rate RSE upward adjustment, if Alabama Power's actual WCER exceeds 6.15%, customers receive 50% of the amount between 6.15% and 6.90% and all amounts in excess of an actual WCER of 6.90%. There is no provision for additional customer billings should the actual retail return fall below the WCER range. In conjunction with these modifications to Rate RSE, Alabama Power consented to a moratorium on any upward adjustments under Rate RSE for 2019 and 2020 and to return $50 million to customers through bill credits in 2019. Retail rates under Rate RSE remained unchanged for 2019 and 2020 and increased by 4.09%, or approximately $228 million annually, effective with the billing month of January 2021. At December 31, 2019, 2020, and 2021, Alabama Power's WCER exceeded 6.15%, resulting in Alabama Power establishing a current regulatory liability of $53 million, $50 million, and $181 million, respectively, for Rate RSE refunds. The 2019 and 2020 refunds were issued to customers through bill credits in April of the following year. In accordance with an Alabama PSC order issued on February 1, 2022, Alabama Power will apply $126 million of the 2021 refund to reduce the Rate ECR under recovered balance and the remaining $55 million will be refunded to customers through bill credits in July 2022. See "Rate ECR" herein for additional information. On December 1, 2021, Alabama Power made its required annual Rate RSE submission to the Alabama PSC of projected data for calendar year 2022. Projected earnings were within the specified range; therefore, retail rates under Rate RSE remain unchanged for 2022. Rate CNP New Plant Rate CNP New Plant allows for recovery of Alabama Power's retail costs associated with newly developed or acquired certificated generating facilities placed into retail service. No adjustments to Rate CNP New Plant occurred during the period 2019 through 2021. See "Certificates of Convenience and Necessity" herein for additional information. Rate CNP PPA Rate CNP PPA allows for the recovery of Alabama Power's retail costs associated with certificated PPAs. Revenues for Rate CNP PPA, as recorded on the financial statements, are adjusted for differences in actual recoverable costs and amounts billed in current regulated rates. Accordingly, changes in the billing factor will have no significant effect on Southern Company's or Alabama Power's revenues or net income but will affect annual cash flow. No adjustments to Rate CNP PPA occurred during the period 2019 through 2021 and no adjustment is expected for 2022. At December 31, 2021 and 2020, Alabama Power had an under recovered Rate CNP PPA balance of $84 million and $58 million, respectively, which is included in other regulatory assets, deferred on the balance sheet. Rate CNP Compliance Rate CNP Compliance allows for the recovery of Alabama Power's retail costs associated with laws, regulations, and other such mandates directed at the utility industry involving the environment, security, reliability, safety, sustainability, or similar considerations impacting Alabama Power's facilities or operations. Rate CNP Compliance is based on forward-looking information and provides for the recovery of these costs pursuant to factors that are calculated and submitted to the Alabama PSC by December 1 with rates effective for the following calendar year. Compliance costs to be recovered include operations and maintenance expenses, depreciation, and a return on certain invested capital. Revenues for Rate CNP Compliance, as recorded on the financial statements, are adjusted for differences in actual recoverable costs and amounts billed in current regulated rates. Accordingly, changes in the billing factor will have no significant effect on Southern Company's or Alabama Power's revenues or net income, but will affect annual cash flow. Changes in Rate CNP Compliance-related operations and maintenance expenses and depreciation generally will have no effect on net income. In November 2019, 2020, and 2021, Alabama Power submitted calculations associated with its cost of complying with governmental mandates for the following calendar year, as provided under Rate CNP Compliance. The 2019 filing reflected a projected over recovered retail revenue requirement, which resulted in a rate decrease of approximately $68 million that became effective for the billing month of January 2020. Both the 2020 and 2021 filings reflected a projected under recovered retail revenue requirement of approximately $59 million. In December 2020 and on December 7, 2021, the Alabama PSC issued consent orders that Alabama Power leave the 2020 Rate CNP Compliance factors in effect for 2021 and 2022, respectively, with any prior year under collected amount deemed recovered before any current year amounts are recovered. Any remaining under recovered amount will be reflected in the 2022 filing. At December 31, 2021, Alabama Power had an under recovered Rate CNP Compliance balance of $16 million included in other regulatory assets, deferred on the balance sheet. At December 31, 2020, Alabama Power had an over recovered Rate CNP Compliance balance of $28 million included in other regulatory liabilities, current on the balance sheet. Rate ECR Rate ECR recovers Alabama Power's retail energy costs based on an estimate of future energy costs and the current over or under recovered balance. Revenues recognized under Rate ECR and recorded on the financial statements are adjusted for the difference in actual recoverable fuel costs and amounts billed in current regulated rates. The difference in the recoverable fuel costs and amounts billed gives rise to the over or under recovered amounts recorded as regulatory assets or liabilities. Alabama Power, along with the Alabama PSC, continually monitors the over or under recovered cost balance to determine whether an adjustment to billing rates is required. Changes in the Rate ECR factor have no significant effect on Southern Company's or Alabama Power's net income but will impact operating cash flows. The Alabama PSC may approve billing rates under Rate ECR of up to 5.910 cents per KWH. In 2019, the Alabama PSC approved a decrease to Rate ECR from 2.353 cents per KWH to 2.160 cents per KWH, equal to 1.82%, or approximately $102 million annually, that became effective for the billing month of January 2020. In October 2020, Alabama Power reduced its over-collected fuel balance by $94 million in accordance with an August 2020 Alabama PSC order and returned that amount to customers in the form of bill credits. In December 2020, the Alabama PSC approved a decrease to Rate ECR from 2.160 cents per KWH to 1.960 cents per KWH, equal to 1.84%, or approximately $103 million annually, that became effective for the billing month of January 2021. On December 7, 2021, the Alabama PSC issued a consent order that Alabama Power leave the 2021 Rate ECR factors in effect for 2022. The rate will adjust to 5.910 cents per KWH in January 2023 absent a further order from the Alabama PSC. At December 31, 2021, Alabama Power's under recovered fuel costs totaled $126 million and is included in other regulatory assets, deferred on the balance sheet. In accordance with an Alabama PSC order issued on February 1, 2022, Alabama Power will apply $126 million of its 2021 Rate RSE refund to reduce the Rate ECR under recovered balance. See "Rate RSE" herein for additional information. At December 31, 2020, Alabama Power's over recovered fuel costs totaled $18 million and is included in other regulatory liabilities, current on the balance sheet. These classifications are based on estimates, which include such factors as weather, generation availability, energy demand, and the price of energy. A change in any of these factors could have a significant impact on the timing of any recovery or return of fuel costs. Software Accounting Order In 2019, the Alabama PSC approved an accounting order that authorizes Alabama Power to establish a regulatory asset for operations and maintenance costs associated with software implementation projects. The regulatory asset will be amortized ratably over the life of the related software. At December 31, 2021 and 2020, the regulatory asset balance totaled $35 million and $17 million, respectively, and is included in other regulatory assets, deferred on the balance sheet. Plant Greene County Alabama Power jointly owns Plant Greene County with an affiliate, Mississippi Power. See Note 5 under "Joint Ownership Agreements" for additional information. On September 9, 2021, the Mississippi PSC issued an order confirming the conclusion of its review of Mississippi Power's 2021 IRP with no deficiencies identified. Mississippi Power's 2021 IRP included a schedule to retire Mississippi Power's 40% ownership interest in Plant Greene County Units 1 and 2 in December 2025 and 2026, respectively, consistent with each unit's remaining useful life. The Plant Greene County unit retirements identified by Mississippi Power require the completion of transmission and system reliability improvements, as well as agreement by Alabama Power. Alabama Power will continue to monitor the status of the transmission and system reliability improvements. Currently, Alabama Power plans to retire Plant Greene County Units 1 and 2 at the dates indicated. The ultimate outcome of this matter cannot be determined at this time. Rate NDR Based on an order from the Alabama PSC, Alabama Power maintains a reserve for operations and maintenance expenses to cover the cost of damages from major storms to its transmission and distribution facilities. The order approves a separate monthly Rate NDR charge to customers consisting of two components. The first component is intended to establish and maintain a reserve balance for future storms and is an on-going part of customer billing. When the reserve balance falls below $50 million, a reserve establishment charge will be activated (and the on-going reserve maintenance charge concurrently suspended) until the reserve balance reaches $75 million. The second component of the Rate NDR charge is intended to allow recovery of any existing deferred storm-related operations and maintenance costs and any future reserve deficits over a 24-month period. The Alabama PSC order gives Alabama Power authority to record a deficit balance in the NDR when costs of storm damage exceed any established reserve balance. Absent further Alabama PSC approval, the maximum total Rate NDR charge consisting of both components is $10 per month per non-residential customer account and $5 per month per residential customer account. Alabama Power has the authority, based on an order from the Alabama PSC, to accrue certain additional amounts as circumstances warrant. The order allows for reliability-related expenditures to be charged against the additional accruals when the NDR balance exceeds $75 million. Alabama Power may designate a portion of the NDR to reliability-related expenditures as a part of an annual budget process for the following year or during the current year for identified unbudgeted reliability-related expenditures that are incurred. Accruals that have not been designated can be used to offset storm charges. Additional accruals to the NDR enhance Alabama Power's ability to mitigate the financial effects of future natural disasters, promote system reliability, and offset costs retail customers would otherwise bear. Alabama Power made additional accruals of $65 million, $100 million, and $84 million in 2021, 2020, and 2019, respectively. Alabama Power collected approximately $6 million, $5 million, and $16 million in 2021, 2020, and 2019, respectively, under Rate NDR. At December 31, 2021 and 2020, the NDR balance was $103 million and $77 million, respectively, and is included in other regulatory liabilities, deferred on the balance sheets. Beginning with June 2022 billings, the reserve establishment charge will be suspended and the reserve maintenance charge will be activated as a result of the NDR balance exceeding $75 million. Alabama Power expects to collect $8 million in 2022 and approximately $3 million annually beginning in 2023 under Rate NDR unless the NDR balance falls below $50 million. As revenue from the Rate NDR charge is recognized, an equal amount of operations and maintenance expenses related to the NDR will also be recognized. As a result, the Rate NDR charge will not have an effect on net income but will impact operating cash flows. Environmental Accounting Order Based on an order from the Alabama PSC (Environmental Accounting Order), Alabama Power is authorized to establish a regulatory asset to record the unrecovered investment costs, including the unrecovered plant asset balance and the unrecovered costs associated with site removal and closure associated with future unit retirements caused by environmental regulations. The regulatory asset is amortized and recovered over the affected unit's remaining useful life, as established prior to the decision regarding early retirement, through Rate CNP Compliance. Georgia Power Georgia Power's revenues from regulated retail operations are collected through various rate mechanisms subject to the oversight of the Georgia PSC. Georgia Power currently recovers its costs from the regulated retail business through the 2019 ARP, which includes traditional base tariffs, Demand-Side Management (DSM) tariffs, the ECCR tariff, and Municipal Franchise Fee (MFF) tariffs. In addition, financing costs on certified construction costs of Plant Vogtle Units 3 and 4 are being collected through the NCCR tariff and fuel costs are collected through a fuel cost recovery tariff, both under separate regulatory proceedings. See "Plant Vogtle Unit 3 and Common Facilities Rate Proceeding" herein for information regarding the approved recovery through retail base rates of certain costs related to Plant Vogtle Unit 3 and the common facilities shared between Plant Vogtle Units 3 and 4 (Common Facilities) that will become effective the month after Unit 3 is placed in service. As costs are included in retail base rates, the related financing costs will no longer be recovered through the NCCR tariff. See "Nuclear Construction" herein for additional information on Plant Vogtle Units 3 and 4. Rate Plans 2019 ARP In 2019, the Georgia PSC voted to approve the 2019 ARP, under which Georgia Power increased its rates on January 1, 2020. In December 2020 and on November 18, 2021, the Georgia PSC approved tariff adjustments effective January 1, 2021 and 2022, respectively. Details of tariff adjustments are provided in the table below:
Tariff | 2020 |  | 2021 |  | 2022
| (in millions)
Traditional base | $ | — |  |  | $ | 120 |  |  | $ | 192 |
ECCR(*) | 318 |  |  | 2 |  |  | (12) |
DSM | 12 |  |  | (15) |  |  | (25) |
MFF | 12 |  |  | 4 |  |  | 2 |
Total | $ | 342 |  |  | $ | 111 |  |  | $ | 157 |
(*) Effective January 1, 2020, CCR AROs are being recovered through the ECCR tariff. In 2019, the Georgia PSC voted to approve Georgia Power's modified triennial IRP (Georgia Power 2019 IRP), including Georgia Power's proposed environmental compliance strategy associated with ash pond and certain landfill closures and post-closure care in compliance with the CCR Rule and the related state rule. In the 2019 ARP, the Georgia PSC approved recovery of the estimated under recovered balance of these compliance costs at December 31, 2019 over a three-year period ending December 31, 2022 and recovery of estimated compliance costs for 2020, 2021, and 2022 over three-year periods ending December 31, 2022, 2023, and 2024, respectively, with recovery of construction contingency beginning in the year following actual expenditure. The ECCR tariff is revised for actual expenditures and updated estimates through annual compliance filings. Effective January 1, 2021 and 2022, Georgia Power adjusted its amortization of costs associated with CCR AROs by an approximate decrease of $90 million and increase of $10 million, respectively, as approved by the Georgia PSC in conjunction with Georgia Power's annual compliance filings. See "Integrated Resource Plan" herein for additional information. In February 2020, the Georgia PSC denied a motion for reconsideration filed by the Sierra Club regarding the Georgia PSC's decision in the 2019 ARP allowing Georgia Power to recover compliance costs for CCR AROs. The Superior Court of Fulton County subsequently affirmed the Georgia PSC's decision and, on October 25, 2021, the Georgia Court of Appeals affirmed the Superior Court of Fulton County's order. On December 6, 2021, the Sierra Club filed a petition for writ of certiorari to the Georgia Supreme Court. The ultimate outcome of this matter cannot be determined at this time. See Note 6 for additional information regarding Georgia Power's AROs. Under the 2019 ARP, Georgia Power's retail ROE is set at 10.50%, and earnings will be evaluated against a retail ROE range of 9.50% to 12.00%. Any retail earnings above 12.00% will be shared, with 40% being applied to reduce regulatory assets, 40% directly refunded to customers, and the remaining 20% retained by Georgia Power. There will be no recovery of any earnings shortfall below 9.50% on an actual basis. However, if at any time during the term of the 2019 ARP, Georgia Power projects that its retail earnings will be below 9.50% for any calendar year, it could petition the Georgia PSC for implementation of the Interim Cost Recovery (ICR) tariff to adjust Georgia Power's retail rates to achieve a 9.50% ROE. The Georgia PSC would have 90 days to rule on Georgia Power's request. The ICR tariff would expire at the earlier of January 1, 2023 or the end of the calendar year in which the ICR tariff becomes effective. In lieu of requesting implementation of an ICR tariff, or if the Georgia PSC chooses not to implement the ICR tariff, Georgia Power may file a full rate case. In 2020, Georgia Power's retail ROE was within the allowed retail ROE range. In 2021, Georgia Power's retail ROE exceeded 12.00%, and Georgia Power reduced regulatory assets by approximately $5 million and accrued approximately $5 million to refund to customers in 2022, subject to review and approval by the Georgia PSC. Additionally, under the 2019 ARP and pursuant to the sharing mechanism approved in the 2013 ARP whereby two-thirds of any earnings above the top of the allowed ROE range are shared with Georgia Power's customers, (i) Georgia Power used 50% (approximately $50 million) of the customer share of earnings above the band in 2018 to reduce regulatory assets and refunded 50% (approximately $50 million) to customers in 2020 and (ii) Georgia Power agreed to forego its share of 2019 earnings in excess of the earnings band so 50% (approximately $60 million) of all earnings over the 2019 band were refunded to customers in 2020 and 50% (approximately $60 million) were used to reduce regulatory assets. Georgia Power is required to file a general base rate case by July 1, 2022, in response to which the Georgia PSC would be expected to determine whether the 2019 ARP should be continued, modified, or discontinued. 2013 ARP Georgia Power's retail ROE under the 2013 ARP was set at 10.95% and earnings were evaluated against a retail ROE range of 10.00% to 12.00%. Two-thirds of any earnings above 12.00% were to be directly refunded to customers, with the remaining one-third retained by Georgia Power. In 2019 and 2018, Georgia Power's retail ROE exceeded 12.00% and, under the modified sharing mechanism pursuant to the 2019 ARP, Georgia Power reduced regulatory assets by a total of approximately $110 million and accrued approximately $110 million for retail customer refunds through bill credits that were completed in 2020. See "2019 ARP" herein for additional information. Plant Vogtle Unit 3 and Common Facilities Rate Proceeding On June 15, 2021, Georgia Power filed an application with the Georgia PSC to adjust retail base rates to include the portion of costs related to its investment in Plant Vogtle Unit 3 and Common Facilities previously deemed prudent by the Georgia PSC, as well as the related costs of operation. On November 2, 2021, the Georgia PSC voted to approve Georgia Power's application as filed, with the following modifications pursuant to a stipulated agreement between Georgia Power and the staff of the Georgia PSC. Georgia Power will include in rate base an allocation of $2.1 billion to Unit 3 and Common Facilities from the $3.6 billion of Plant Vogtle Units 3 and 4 previously deemed prudent by the Georgia PSC and will recover the related depreciation expense through retail base rates effective the month after Unit 3 is placed in service. Financing costs on the remaining portion of the total Unit 3 and the Common Facilities construction costs will continue to be recovered through the NCCR tariff or deferred. Georgia Power will defer as a regulatory asset the remaining depreciation expense (approximately $38 million annually) until Unit 4 costs are placed in retail base rates. In addition, the stipulated agreement clarified that following the prudency review, the remaining amount to be placed in retail base rates will be net of the proceeds from the Guarantee Settlement Agreement and will not be used to offset imprudent costs, if any. The related increase in annual retail base rates of approximately $302 million also includes recovery of all projected operations and maintenance expenses for Unit 3 and the Common Facilities and other related costs of operation, partially offset by the related production tax credits, and will become effective the month after Unit 3 is placed in service. This increase is partially offset by a decrease in the NCCR tariff of approximately $78 million effective January 1, 2022. As approved by the Georgia PSC, the increase in annual retail base rates will be adjusted based on the actual in-service date of Plant Vogtle Unit 3. See "Nuclear Construction" herein for additional information on Plant Vogtle Units 3 and 4. Integrated Resource Plan In 2021, as authorized in its 2019 IRP, Georgia Power requested and received certification from the Georgia PSC for 970 MWs of utility-scale PPAs for solar generation resources, which are expected to be in operation by the end of 2023. On January 31, 2022, Georgia Power filed its triennial IRP (2022 IRP). The filing included a request to decertify and retire Plant Wansley Units 1 and 2 (926 MWs based on 53.5% ownership) by August 31, 2022; Plant Bowen Units 1 and 2 (1,400 MWs) by December 31, 2027; and Plant Scherer Unit 3 (614 MWs based on 75% ownership) and Plant Gaston Units 1 through 4 (500 MWs based on 50% ownership through SEGCO) by December 31, 2028. See Note 7 under "SEGCO" for additional information. In the 2022 IRP, Georgia Power requested approval to reclassify the remaining net book value of Plant Wansley Units 1 and 2 (approximately $610 million at December 31, 2021), Plant Bowen Units 1 and 2 (approximately $937 million at December 31, 2021), and Plant Scherer Unit 3 (approximately $622 million at December 31, 2021) and any remaining unusable materials and supplies inventories upon each unit's respective retirement dates to a regulatory asset, with recovery periods to be determined in future base rate cases. In addition, the 2022 IRP includes requests for approval of the following: •Capital, operations and maintenance, and CCR ARO costs associated with ash pond and landfill closures and post-closure care. The recovery of these costs is expected to be determined in future base rate cases; •Installation of environmental controls at Plant Bowen Units 3 and 4 (1,760 MWs) and Plant Scherer Units 1 and 2 (137 MWs based on 8.4% ownership) for compliance with ELG rules; •Investments related to the hydro operations of Plants Sinclair (45 MWs), North Highlands (30 MWs), and Burton (6 MWs); •Establishment of a request for proposals (RFP) process for 2,300 MWs of renewable resources by 2029. Georgia Power expects to request an additional 3,700 MWs by 2035 through future IRP proceedings; •Procurement of 1,000 MWs of Georgia Power-owned storage resources by 2030, including the development of a 265-MW battery energy storage facility beginning in 2026; •Related transmission costs necessary to support the proposed retirements and renewable resources previously described; •Certification of six PPAs (including five affiliate PPAs with Southern Power that are also subject to approval by the FERC) with capacities of 1,567 MWs beginning in 2024, 380 MWs beginning in 2025, and 228 MWs beginning in 2028, procured through RFPs approved through the 2019 IRP; and •Certification of approximately 88 MWs of wholesale capacity to be placed in retail rate base between January 1, 2024 and January 1, 2025. A decision from the Georgia PSC on the 2022 IRP is expected in July 2022. The ultimate outcome of these matters cannot be determined at this time. Deferral of Incremental COVID-19 Costs In April 2020 and June 2020, in response to the COVID-19 pandemic, the Georgia PSC approved orders directing Georgia Power to continue its previous, voluntary suspension of customer disconnections through July 14, 2020 and to defer the resulting incremental bad debt as a regulatory asset. In June 2020 and July 2020, the Georgia PSC approved orders establishing a methodology for identifying incremental bad debt and allowing the deferral of other incremental costs associated with the COVID-19 pandemic. At December 31, 2020, the incremental costs deferred totaled approximately $38 million (including approximately $23 million of incremental bad debt costs and $15 million of other incremental costs). Since June 2021, Georgia Power has continued a review of bad debt amounts deferred under the Georgia PSC-approved methodology, including consideration of actual amounts repaid by customers from arrears and installment plans after the disconnection moratorium period ended. As a result, Georgia Power's incremental costs deferred at December 31, 2021 totaled approximately $21 million, including an immaterial amount of incremental bad debt costs. The period over which these costs will be recovered is expected to be determined in Georgia Power's next base rate case. The ultimate outcome of this matter cannot be determined at this time. Fuel Cost Recovery Georgia Power has established fuel cost recovery rates approved by the Georgia PSC. In May 2020, the Georgia PSC approved a stipulation agreement among Georgia Power, the staff of the Georgia PSC, and certain intervenors to lower total fuel billings by approximately $740 million over a two-year period effective June 1, 2020. In addition, Georgia Power further lowered fuel billings by approximately $44 million under an interim fuel rider effective June 1, 2020 through September 30, 2020. During the second half of 2021, the price of natural gas rose significantly and resulted in an under recovered fuel balance exceeding $200 million. Therefore, on November 18, 2021, the Georgia PSC voted to approve Georgia Power's interim fuel rider, which increased fuel rates by 15%, or approximately $252 million annually, effective January 1, 2022. Georgia Power continues to be allowed to adjust its fuel cost recovery rates under an interim fuel rider prior to the next fuel case if the over recovered fuel balance exceeds $200 million. Georgia Power is scheduled to file its next fuel case no later than February 28, 2023. Georgia Power's under recovered fuel balance totaled $410 million at December 31, 2021 and is included in other deferred charges and assets on Southern Company's balance sheet and deferred under recovered fuel clause revenues on Georgia Power's balance sheet. At December 31, 2020, Georgia Power's over recovered fuel balance totaled $113 million and is included in other current liabilities on Southern Company's balance sheet and over recovered fuel clause revenues on Georgia Power's balance sheet. Georgia Power's fuel cost recovery mechanism includes costs associated with a natural gas hedging program, as revised and approved by the Georgia PSC, allowing the use of an array of derivative instruments within a 36-month time horizon. Fuel cost recovery revenues as recorded on the financial statements are adjusted for differences in actual recoverable fuel costs and amounts billed in current regulated rates. Accordingly, changes in the billing factor will not have a significant effect on Southern Company's or Georgia Power's revenues or net income but will affect operating cash flows. Storm Damage Recovery Georgia Power defers and recovers certain costs related to damages from major storms as mandated by the Georgia PSC. Beginning January 1, 2020, Georgia Power is recovering $213 million annually under the 2019 ARP. At December 31, 2021 and 2020, the balance in the regulatory asset related to storm damage was $48 million and $262 million, respectively, with $48 million and $213 million, respectively, included in other regulatory assets, current on Southern Company's balance sheets and regulatory assets – storm damage on Georgia Power's balance sheets and $49 million at December 31, 2020 included in other regulatory assets, deferred on Southern Company's and Georgia Power's balance sheets. The rate of storm damage cost recovery is expected to be adjusted in future regulatory proceedings as necessary. As a result of this regulatory treatment, costs related to storms are not expected to have a material impact on Southern Company's or Georgia Power's financial statements. Nuclear Construction In 2009, the Georgia PSC certified construction of Plant Vogtle Units 3 and 4, in which Georgia Power holds a 45.7% ownership interest. In 2012, the NRC issued the related combined construction and operating licenses, which allowed full construction of the two AP1000 nuclear units (with electric generating capacity of approximately 1,100 MWs each) and related facilities to begin. Until March 2017, construction on Plant Vogtle Units 3 and 4 continued under the Vogtle 3 and 4 Agreement, which was a substantially fixed price agreement. In connection with the EPC Contractor's bankruptcy filing in March 2017, Georgia Power, acting for itself and as agent for the other Vogtle Owners, entered into several transitional arrangements to allow construction to continue. In July 2017, Georgia Power, acting for itself and as agent for the other Vogtle Owners, entered into the Vogtle Services Agreement, whereby Westinghouse provides facility design and engineering services, procurement and technical support, and staff augmentation on a time and materials cost basis. The Vogtle Services Agreement provides that it will continue until the start-up and testing of Plant Vogtle Units 3 and 4 are complete and electricity is generated and sold from both units. The Vogtle Services Agreement is terminable by the Vogtle Owners upon 30 days' written notice. In October 2017, Georgia Power, acting for itself and as agent for the other Vogtle Owners, executed the Bechtel Agreement, a cost reimbursable plus fee arrangement, whereby Bechtel is reimbursed for actual costs plus a base fee and an at-risk fee, which is subject to adjustment based on Bechtel's performance against cost and schedule targets. Each Vogtle Owner is severally (not jointly) liable for its proportionate share, based on its ownership interest, of all amounts owed to Bechtel under the Bechtel Agreement. The Vogtle Owners may terminate the Bechtel Agreement at any time for their convenience, provided that the Vogtle Owners will be required to pay amounts related to work performed prior to the termination (including the applicable portion of the base fee), certain termination-related costs, and, at certain stages of the work, the applicable portion of the at-risk fee. Bechtel may terminate the Bechtel Agreement under certain circumstances, including certain Vogtle Owner suspensions of work, certain breaches of the Bechtel Agreement by the Vogtle Owners, Vogtle Owner insolvency, and certain other events. See Note 8 under "Long-term Debt – DOE Loan Guarantee Borrowings" for information on the Amended and Restated Loan Guarantee Agreement, including applicable covenants, events of default, and mandatory prepayment events. Cost and Schedule Georgia Power's approximate proportionate share of the remaining estimated capital cost to complete Plant Vogtle Units 3 and 4, including contingency, through the end of the first quarter 2023 and the fourth quarter 2023, respectively, is as follows:
| (in millions)
Base project capital cost forecast(a)(b) | $ | 10,251 |
Construction contingency estimate | 150 |
Total project capital cost forecast(a)(b) | 10,401 |
Net investment at December 31, 2021(b) | (8,442) |
Remaining estimate to complete | $ | 1,959 |
(a)Includes approximately $590 million of costs that are not shared with the other Vogtle Owners and approximately $440 million of incremental costs under the cost-sharing and tender provisions of the joint ownership agreements described below. Excludes financing costs expected to be capitalized through AFUDC of approximately $375 million, of which $195 million had been accrued through December 31, 2021. (b)Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds. Georgia Power estimates that its financing costs for construction of Plant Vogtle Units 3 and 4 will total approximately $3.4 billion, of which $2.9 billion had been incurred through December 31, 2021. As part of its ongoing processes, Southern Nuclear continues to evaluate cost and schedule forecasts on a regular basis to incorporate current information available, particularly in the areas of engineering support, commodity installation, system turnovers and related test results, and workforce statistics. Southern Nuclear establishes aggressive target values for monthly construction production and system turnover activities, which are reflected in the site work plans. In mid-March 2020, Southern Nuclear began implementing policies and procedures designed to mitigate the risk of transmission of COVID-19 at the construction site, including worker distancing measures; isolating individuals who tested positive for COVID-19, showed symptoms consistent with COVID-19, were being tested for COVID-19, or were in close contact with such persons; requiring self-quarantine; and adopting additional precautionary measures. Since March 2020, the number of active cases at the site has fluctuated consistent with the surrounding area and impacted productivity levels and pace of activity completion, with the site experiencing peaks in the number of active cases in January 2021, August 2021, and January 2022. Georgia Power estimates the productivity impacts of the COVID-19 pandemic have consumed approximately three to four months of schedule margin previously embedded in the site work plan for Unit 3 and Unit 4. Georgia Power's proportionate share of the estimated incremental cost associated with COVID-19 mitigation actions and impacts on construction productivity is currently estimated to be between $160 million and $200 million and is included in the total project capital cost forecast. The continuing effects of the COVID-19 pandemic could further disrupt or delay construction and testing activities at Plant Vogtle Units 3 and 4. During 2021, Southern Nuclear performed additional construction remediation work necessary to ensure quality and design standards are met and support system turnovers necessary for Unit 3 hot functional testing, which was completed in July 2021, and fuel load. As a result of Unit 3 challenges including, but not limited to, construction productivity, construction remediation work, the pace of system turnovers, spent fuel pool repairs, and the timeframe and duration for hot functional and other testing, at the end of each of the second and third quarters 2021, Southern Nuclear further extended certain milestone dates, including fuel load for Unit 3, from those established in January 2021. Through the fourth quarter 2021, the project continued to face these and other challenges related to the completion of documentation, including inspection records, necessary to submit the remaining ITAACs and begin fuel load. As a result, at the end of the fourth quarter 2021, Southern Nuclear further extended certain milestone dates, including fuel load for Unit 3, from those established at the end of the third quarter 2021. The site work plan currently targets fuel load for Unit 3 in the second quarter 2022 and an in-service date during the third quarter 2022 and primarily depends on significant improvements in overall construction productivity and production levels, the volume of construction remediation work, the pace of system and area turnovers, and the progression of startup and other testing. As the site work plan includes minimal margin to these milestone dates, an in-service date during the fourth quarter 2022 or the first quarter 2023 for Unit 3 is projected, although any further delays could result in a later in-service date. As the result of productivity challenges and temporarily diverting some Unit 4 craft and support resources to Unit 3 construction efforts, at the end of each of the second and third quarters 2021, Southern Nuclear also further extended milestone dates for Unit 4 from those established in January 2021. The temporary diversion of Unit 4 resources to support Unit 3 has continued into the first quarter 2022; therefore, at the end of the fourth quarter 2021, Southern Nuclear further extended milestone dates for Unit 4 from those established at the end of the third quarter 2021. The site work plan targets an in-service date during the first quarter 2023 for Unit 4 and primarily depends on overall construction productivity and production levels significantly improving as well as appropriate levels of craft laborers, particularly electricians and pipefitters, being added and maintained. As the site work plan includes minimal margin to the milestone dates, an in-service date during the third or fourth quarter 2023 for Unit 4 is projected, although any further delays could result in a later in-service date. During 2021, established construction contingency and additional costs totaling $1.3 billion were assigned to the base capital cost forecast for costs primarily associated with schedule extensions, construction productivity, the pace of system turnovers, and support resources for Units 3 and 4. Georgia Power also increased its total capital cost forecast as of December 31, 2021 by $99 million to replenish construction contingency. After considering the significant level of uncertainty that exists regarding the future recoverability of these costs since the ultimate outcome of these matters is subject to the outcome of future assessments by management, as well as Georgia PSC decisions in future regulatory proceedings, Georgia Power recorded pre-tax charges to income in the first quarter 2021, the second quarter 2021, the third quarter 2021, and the fourth quarter 2021 of $48 million ($36 million after tax), $460 million ($343 million after tax), $264 million ($197 million after tax), and $480 million ($358 million after tax), respectively, for the increases in the total project capital cost forecast. Georgia Power may request the Georgia PSC to evaluate those expenditures for rate recovery during the prudence review following the Unit 4 fuel load pursuant to the twenty-fourth VCM stipulation described below. In addition, Georgia Power recorded a pre-tax charge to income in the fourth quarter 2021 of approximately $440 million ($328 million after tax) for incremental costs, which will not be recovered from retail customers, associated with the cost-sharing and tender provisions of the joint ownership agreements described below. As Unit 3 completes system turnover from construction and moves to testing and transition to operations, ongoing and potential future challenges include completion of construction remediation work, completion of work packages, including inspection records, and other documentation necessary to submit the remaining ITAACs and begin fuel load, and final component and pre-operational tests. As Unit 4 progresses through construction and continues to transition into testing, ongoing and potential future challenges include the pace and quality of electrical installation, availability of craft and supervisory resources, including the temporary diversion of such resources to support Unit 3 construction efforts, and the pace of work package closures and system turnovers. As construction, including subcontract work, continues on both Units 3 and 4, ongoing or future challenges include management of contractors and vendors; subcontractor performance; supervision of craft labor and related productivity, particularly in the installation of electrical, mechanical, and instrumentation and controls commodities, ability to attract and retain craft labor, and/or related cost escalation; and procurement and related installation. New challenges may arise, particularly as Units 3 and 4 move into initial testing and start-up, which may result in required engineering changes or remediation related to plant systems, structures, or components (some of which are based on new technology that only within the last few years began initial operation in the global nuclear industry at this scale). The ongoing and potential future challenges described above may change the projected schedule and estimated cost. There have been technical and procedural challenges to the construction and licensing of Plant Vogtle Units 3 and 4 at the federal and state level and additional challenges may arise. Processes are in place that are designed to ensure compliance with the requirements specified in the Westinghouse Design Control Document and the combined construction and operating licenses, including inspections by Southern Nuclear and the NRC that occur throughout construction. In connection with the additional construction remediation work described above, Southern Nuclear reviewed the project's construction quality programs and, where needed, is implementing improvement plans consistent with these processes. On November 17, 2021, the NRC issued the final significance report on its special inspection to review the root cause of this additional construction remediation work and the corresponding corrective action plans with two findings of low to moderate safety significance. Southern Nuclear had already identified and self-reported many of the issues in this report to the NRC and implemented corrective-action plans to resolve these issues. The NRC will conduct a follow-up inspection on these findings at a future date. Findings resulting from this or other inspections could require additional remediation and/or further NRC oversight. In addition, certain license amendment requests have been filed and approved or are pending before the NRC. The site work plan currently targets fuel load for Units 3 and 4 in the second quarter 2022 and the fourth quarter 2022, respectively. Various design and other licensing-based compliance matters, including the timely submittal by Southern Nuclear of the ITAAC documentation for each unit and the related reviews and approvals by the NRC necessary to support NRC authorization to load fuel, have arisen or may arise, which may result in additional license amendments or require other resolution. If any license amendment requests or other licensing-based compliance issues, including inspections and ITAACs, are not resolved in a timely manner, there may be delays in the project schedule that could result in increased costs. The ultimate outcome of these matters cannot be determined at this time. However, any extension of the in-service date beyond the first quarter 2023 for Unit 3 or the fourth quarter 2023 for Unit 4, including the current level of cost sharing described below, is estimated to result in additional base capital costs for Georgia Power of up to $60 million per month for Unit 3 and $40 million per month for Unit 4, as well as the related AFUDC and any additional related construction, support resources, or testing costs. While Georgia Power is not precluded from seeking retail recovery of any future capital cost forecast increase other than the amounts related to the cost-sharing and tender provisions of the joint ownership agreements described below, management will ultimately determine whether or not to seek recovery. Any further changes to the capital cost forecast that are not expected to be recoverable through regulated rates will be required to be charged to income and such charges could be material. Joint Owner Contracts In November 2017, the Vogtle Owners entered into an amendment to their joint ownership agreements for Plant Vogtle Units 3 and 4 to provide for, among other conditions, additional Vogtle Owner approval requirements. Effective in August 2018, the Vogtle Owners further amended the joint ownership agreements to clarify and provide procedures for certain provisions of the joint ownership agreements related to adverse events that require the vote of the holders of at least 90% of the ownership interests in Plant Vogtle Units 3 and 4 to continue construction (as amended, and together with the November 2017 amendment, the Vogtle Joint Ownership Agreements). The Vogtle Joint Ownership Agreements also confirm that the Vogtle Owners' sole recourse against Georgia Power or Southern Nuclear for any action or inaction in connection with their performance as agent for the Vogtle Owners is limited to removal of Georgia Power and/or Southern Nuclear as agent, except in cases of willful misconduct. Amendments to the Vogtle Joint Ownership Agreements In connection with a September 2018 vote by the Vogtle Owners to continue construction, Georgia Power entered into (i) a binding term sheet (Vogtle Owner Term Sheet) with the other Vogtle Owners and MEAG Power's wholly-owned subsidiaries MEAG Power SPVJ, LLC (MEAG SPVJ), MEAG Power SPVM, LLC (MEAG SPVM), and MEAG Power SPVP, LLC (MEAG SPVP) to take certain actions which partially mitigate potential financial exposure for the other Vogtle Owners, including additional amendments to the Vogtle Joint Ownership Agreements and the purchase of PTCs from the other Vogtle Owners at pre-established prices, and (ii) a term sheet (MEAG Term Sheet) with MEAG Power and MEAG SPVJ to provide up to $300 million of funding with respect to MEAG SPVJ's ownership interest in Plant Vogtle Units 3 and 4 under certain circumstances. In January 2019, Georgia Power, MEAG Power, and MEAG SPVJ entered into an agreement to implement the provisions of the MEAG Term Sheet. In February 2019, Georgia Power, the other Vogtle Owners, and MEAG Power's wholly-owned subsidiaries MEAG SPVJ, MEAG SPVM, and MEAG SPVP entered into certain amendments to the Vogtle Joint Ownership Agreements to implement the provisions of the Vogtle Owner Term Sheet (Global Amendments). Pursuant to the Global Amendments: (i) each Vogtle Owner must pay its proportionate share of qualifying construction costs for Plant Vogtle Units 3 and 4 based on its ownership percentage up to the estimated cost at completion (EAC) for Plant Vogtle Units 3 and 4 which formed the basis of Georgia Power's forecast of $8.4 billion in the nineteenth VCM plus $800 million; (ii) Georgia Power will be responsible for 55.7% of actual qualifying construction costs between $800 million and $1.6 billion over the EAC in the nineteenth VCM (resulting in $80 million of potential additional costs to Georgia Power), with the remaining Vogtle Owners responsible for 44.3% of such costs pro rata in accordance with their respective ownership interests; and (iii) Georgia Power will be responsible for 65.7% of qualifying construction costs between $1.6 billion and $2.1 billion over the EAC in the nineteenth VCM (resulting in a further $100 million of potential additional costs to Georgia Power), with the remaining Vogtle Owners responsible for 34.3% of such costs pro rata in accordance with their respective ownership interests. If the EAC is revised and exceeds the EAC in the nineteenth VCM by more than $2.1 billion, each of the other Vogtle Owners will have a one-time option at the time the project budget forecast is so revised to tender a portion of its ownership interest to Georgia Power in exchange for Georgia Power's agreement to pay 100% of such Vogtle Owner's remaining share of total construction costs in excess of the EAC in the nineteenth VCM plus $2.1 billion. In addition, pursuant to the Global Amendments, the holders of at least 90% of the ownership interests in Plant Vogtle Units 3 and 4 must vote to continue construction if certain adverse events occur, including, among other events: (i) the bankruptcy of Toshiba; (ii) the termination or rejection in bankruptcy of certain agreements, including the Vogtle Services Agreement, the Bechtel Agreement, or the agency agreement with Southern Nuclear; (iii) Georgia Power's public announcement of its intention not to submit for rate recovery any portion of its investment in Plant Vogtle Units 3 and 4 or the Georgia PSC determines that any of Georgia Power's costs relating to the construction of Plant Vogtle Units 3 and 4 will not be recovered in retail rates, excluding any additional amounts paid by Georgia Power on behalf of the other Vogtle Owners pursuant to the Global Amendments described above and the first 6% of costs during any six-month VCM reporting period that are disallowed by the Georgia PSC for recovery, or for which Georgia Power elects not to seek cost recovery, through retail rates; and (iv) an incremental extension of one year or more from the seventeenth VCM report estimated in-service dates of November 2021 and November 2022 for Units 3 and 4, respectively. The latest schedule extension triggers the requirement that the holders of at least 90% of the ownership interests in Plant Vogtle Units 3 and 4 must vote to continue construction by March 8, 2022. Georgia Power has voted to continue construction. In addition, if the holders of at least 90% of the ownership interests of Plant Vogtle Units 3 and 4 do not vote to continue construction, the DOE may require Georgia Power to prepay all outstanding borrowings under the FFB Credit Facilities over a period of five years. See Note 8 under "Long-term Debt – DOE Loan Guarantee Borrowings" for additional information. Georgia Power and the other Vogtle Owners do not agree on either the starting dollar amount for the determination of cost increases subject to the cost-sharing and tender provisions of the Global Amendments or the extent to which COVID-19-related costs impact the calculation. Based on the definition in the Global Amendments, Georgia Power believes the starting dollar amount is $18.38 billion and the current project capital cost forecast has triggered the cost-sharing provisions. The other Vogtle Owners have asserted that the project cost increases have reached the cost-sharing thresholds and have triggered the tender provisions under the Global Amendments. Georgia Power recorded an additional pre-tax charge to income in the fourth quarter 2021 of approximately $440 million ($328 million after tax) associated with these cost-sharing and tender provisions, which is included in the total project capital cost forecast. Georgia Power may be required to record further pre-tax charges to income of up to approximately $460 million associated with these provisions based on the current project capital cost forecast. The incremental charges associated with these provisions will not be recovered from retail customers. On October 29, 2021, Georgia Power and the other Vogtle Owners entered into an agreement to clarify the process for the tender provisions of the Global Amendments to provide for a decision between 120 and 180 days after the tender option is triggered, which the other Vogtle Owners assert occurred on February 14, 2022. Georgia Power's ownership interest in Plant Vogtle Units 3 and 4 continues to be 45.7%; however, it could increase if one or more of the other Vogtle Owners exercise the option to tender a portion of their ownership interest to Georgia Power and require Georgia Power to pay 100% of the remaining share of the costs necessary to complete Plant Vogtle Units 3 and 4. Georgia Power's incremental ownership interest would be calculated and conveyed to Georgia Power after Plant Vogtle Units 3 and 4 are placed in service. The ultimate outcome of these matters cannot be determined at this time. Regulatory Matters In 2009, the Georgia PSC voted to certify construction of Plant Vogtle Units 3 and 4 with a certified capital cost of $4.418 billion. In addition, in 2009 the Georgia PSC approved inclusion of the Plant Vogtle Units 3 and 4 related CWIP accounts in rate base, and the State of Georgia enacted the Georgia Nuclear Energy Financing Act, which allows Georgia Power to recover financing costs for Plant Vogtle Units 3 and 4. Financing costs are recovered on all applicable certified costs through annual adjustments to the NCCR tariff up to the certified capital cost of $4.418 billion. At December 31, 2021, Georgia Power had recovered approximately $2.7 billion of financing costs. Financing costs related to capital costs above $4.418 billion are being recognized through AFUDC and are expected to be recovered through retail rates over the life of Plant Vogtle Units 3 and 4; however, Georgia Power is not recording AFUDC related to any capital costs in excess of the total deemed reasonable by the Georgia PSC (currently $7.3 billion) and not requested for rate recovery. On November 18, 2021, the Georgia PSC approved Georgia Power's request to decrease the NCCR tariff by $78 million annually, effective January 1, 2022. Georgia Power is required to file semi-annual VCM reports with the Georgia PSC by February 28 and August 31 of each year. In 2013, in connection with the eighth VCM report, the Georgia PSC approved a stipulation between Georgia Power and the staff of the Georgia PSC to waive the requirement to amend the Plant Vogtle Units 3 and 4 certificate in accordance with the 2009 certification order until the completion of Plant Vogtle Unit 3, or earlier if deemed appropriate by the Georgia PSC and Georgia Power. In 2016, the Georgia PSC voted to approve a settlement agreement (Vogtle Cost Settlement Agreement) resolving certain prudency matters in connection with the fifteenth VCM report. In December 2017, the Georgia PSC voted to approve (and issued its related order on January 11, 2018) Georgia Power's seventeenth VCM report and modified the Vogtle Cost Settlement Agreement. The Vogtle Cost Settlement Agreement, as modified by the January 11, 2018 order, resolved the following regulatory matters related to Plant Vogtle Units 3 and 4: (i) none of the $3.3 billion of costs incurred through December 31, 2015 and reflected in the fourteenth VCM report should be disallowed from rate base on the basis of imprudence; (ii) the Contractor Settlement Agreement was reasonable and prudent and none of the $0.3 billion paid pursuant to the Contractor Settlement Agreement should be disallowed from rate base on the basis of imprudence; (iii) (a) capital costs incurred up to $5.68 billion would be presumed to be reasonable and prudent with the burden of proof on any party challenging such costs, (b) Georgia Power would have the burden to show that any capital costs above $5.68 billion were prudent, and (c) a revised capital cost forecast of $7.3 billion (after reflecting the impact of payments received under the Guarantee Settlement Agreement and related customer refunds) was found reasonable; (iv) construction of Plant Vogtle Units 3 and 4 should be completed, with Southern Nuclear serving as project manager and Bechtel as primary contractor; (v) approved and deemed reasonable Georgia Power's revised schedule placing Plant Vogtle Units 3 and 4 in service in November 2021 and November 2022, respectively; (vi) confirmed that the revised cost forecast does not represent a cost cap and that a prudence proceeding on cost recovery will occur following Unit 4 fuel load, consistent with applicable Georgia law; (vii) reduced the ROE used to calculate the NCCR tariff (a) from 10.95% (the ROE rate setting point authorized by the Georgia PSC in the 2013 ARP) to 10.00% effective January 1, 2016, (b) from 10.00% to 8.30%, effective January 1, 2020, and (c) from 8.30% to 5.30%, effective January 1, 2021 (provided that the ROE in no case will be less than Georgia Power's average cost of long-term debt); (viii) reduced the ROE used for AFUDC equity for Plant Vogtle Units 3 and 4 from 10.00% to Georgia Power's average cost of long-term debt, effective January 1, 2018; and (ix) agreed that effective the first month after Unit 3 reaches commercial operation, retail base rates would be adjusted to include the costs related to Unit 3 and common facilities deemed prudent in the Vogtle Cost Settlement Agreement (see "Plant Vogtle Unit 3 and Common Facilities Rate Proceeding" herein for additional information). The January 11, 2018 order also stated that if Plant Vogtle Units 3 and 4 are not commercially operational by June 1, 2021 and June 1, 2022, respectively, the ROE used to calculate the NCCR tariff will be further reduced by 10 basis points each month (but not lower than Georgia Power's average cost of long-term debt) until the respective Unit is commercially operational. The ROE reductions negatively impacted earnings by approximately $270 million, $150 million, and $75 million in 2021, 2020, and 2019, respectively, and are estimated to have negative earnings impacts of approximately $300 million and $265 million in 2022 and 2023, respectively. In its January 11, 2018 order, the Georgia PSC also stated if other conditions change and assumptions upon which Georgia Power's seventeenth VCM report are based do not materialize, the Georgia PSC reserved the right to reconsider the decision to continue construction. The Georgia PSC has approved 24 VCM reports covering periods through December 31, 2020, including total construction capital costs incurred through December 31, 2020 of $7.3 billion (net of $1.7 billion of payments received under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds). In the August 24, 2021 order approving the twenty-fourth VCM report, the Georgia PSC also approved a stipulation addressing the following matters: (i) beginning with its twenty-fifth VCM report, Georgia Power will continue to report to the Georgia PSC all costs incurred during the period for review and will request for approval costs up to the $7.3 billion determined to be reasonable in the Georgia PSC's seventeenth VCM order and (ii) Georgia Power will not seek rate recovery of the $0.7 billion increase to the base capital cost forecast included in the nineteenth VCM report and charged to income by Georgia Power in the second quarter 2018. In addition, the stipulation confirms Georgia Power may request verification and approval of costs above $7.3 billion for inclusion in rate base at a later time, but no earlier than the prudence review contemplated by the seventeenth VCM order described previously. The Georgia PSC is scheduled to vote on the twenty-fifth VCM report on February 17, 2022. Georgia Power also expects to file its twenty-sixth VCM report with the Georgia PSC on February 17, 2022, which will reflect the revised capital cost forecast described above. The ultimate outcome of these matters cannot be determined at this time. Mississippi Power Mississippi Power's rates and charges for service to retail customers are subject to the regulatory oversight of the Mississippi PSC. Mississippi Power's rates are a combination of base rates and several separate cost recovery clauses for specific categories of costs. These separate cost recovery clauses address such items as fuel and purchased power, ad valorem taxes, property damage, and the costs of compliance with environmental laws and regulations. Costs not addressed through one of the specific cost recovery clauses are expected to be recovered through Mississippi Power's base rates. 2019 Base Rate Case In March 2020, the Mississippi PSC approved a settlement agreement between Mississippi Power and the Mississippi Public Utilities Staff related to Mississippi Power's base rate case filed in 2019 (Mississippi Power Rate Case Settlement Agreement). Under the terms of the Mississippi Power Rate Case Settlement Agreement, annual retail rates decreased approximately $16.7 million, or 1.85%, effective for the first billing cycle of April 2020, based on a test year period of January 1, 2020 through December 31, 2020, a 53% average equity ratio, an allowed maximum actual equity ratio of 55% by the end of 2020, and a 7.57% return on investment. Additionally, the Mississippi Power Rate Case Settlement Agreement: (i) established common amortization periods of four years for regulatory assets and three years for regulatory liabilities included in the approved revenue requirement, including those related to unprotected deferred income taxes; (ii) established new depreciation rates reflecting an annual increase in depreciation of approximately $10 million; and (iii) excluded certain compensation costs totaling approximately $3.9 million. It also eliminated separate rates for costs associated with Plant Ratcliffe and energy efficiency initiatives and includes such costs in the PEP, ECO Plan, and ad valorem tax adjustment factor, as applicable. Performance Evaluation Plan Mississippi Power's retail base rates generally are set under the PEP, a rate plan approved by the Mississippi PSC. In recognition that Mississippi Power's long-term financial success is dependent upon how well it satisfies its customers' needs, PEP includes performance indicators that directly tie customer service indicators to Mississippi Power's allowed ROE. PEP measures Mississippi Power's performance on a 10-point scale as a weighted average of results in three areas: average customer price, as compared to prices of other regional utilities (weighted at 40%); service reliability, measured in percentage of time customers had electric service (40%); and customer satisfaction, measured in a survey of residential customers (20%). Typically, two PEP filings are made for each calendar year: the PEP projected filing and the PEP lookback filing. In July 2020, the Mississippi PSC approved Mississippi Power's revisions to the PEP compliance rate clause as agreed to in the Mississippi Power Rate Case Settlement Agreement. These revisions include, among other things, changing the filing date for the annual PEP rate projected filing from November of the immediately preceding year to March of the current year, utilizing a historic test year adjusted for "known and measurable" changes, using discounted cash flow and regression formulas to determine base ROE, and moving all embedded ad valorem property taxes currently collected in PEP to the ad valorem tax adjustment clause. The PEP lookback filing will continue to be filed after the end of the year and allows for review of the actual revenue requirement. Pursuant to a Mississippi PSC-approved settlement agreement between Mississippi Power and the MPUS, Mississippi Power was not required to make any PEP filings for regulatory years 2019 and 2020. On June 8, 2021, the Mississippi PSC approved Mississippi Power's annual retail PEP filing for 2021, resulting in an annual increase in revenues of approximately $16 million, or 1.8%, which became effective with the first billing cycle of April 2021. Integrated Resource Plan In 2019, Mississippi Power updated its proposed Reserve Margin Plan (RMP), originally filed in 2018, as required by the Mississippi PSC. In 2018, Mississippi Power had proposed alternatives to reduce its reserve margin and lower or avoid operating costs. In December 2020, the Mississippi PSC issued an order concluding the RMP docket and requiring Mississippi Power to incorporate into its 2021 IRP a schedule of early or anticipated retirement of 950 MWs of fossil-steam generation by year-end 2027 to reduce Mississippi Power's excess reserve margin. The order stated that Mississippi Power will be allowed to defer any retirement-related costs as regulatory assets for future recovery. On September 9, 2021, the Mississippi PSC issued an order confirming the conclusion of its review of Mississippi Power's 2021 IRP with no deficiencies identified. The 2021 IRP included a schedule to retire Plant Watson Unit 4 (268 MWs) and Mississippi Power's 40% ownership interest in Plant Greene County Units 1 and 2 (103 MWs each) in December 2023, 2025, and 2026, respectively, consistent with each unit's remaining useful life in the most recent approved depreciation studies. In addition, the schedule reflects the early retirement of Mississippi Power's 50% undivided ownership interest in Plant Daniel Units 1 and 2 (502 MWs) by the end of 2027. The Plant Greene County unit retirements require the completion by Alabama Power of transmission and system reliability improvements, as well as agreement by Alabama Power. The remaining net book value of Plant Daniel Units 1 and 2 was approximately $515 million at December 31, 2021 and Mississippi Power is continuing to depreciate these units using the current approved rates through the end of 2027. Mississippi Power expects to reclassify the net book value remaining at retirement, which is expected to total approximately $386 million, to a regulatory asset to be amortized over a period to be determined by the Mississippi PSC in future proceedings, consistent with the December 2020 order. The Plant Watson and Greene County units are expected to be fully depreciated upon retirement. The ultimate outcome of these matters cannot be determined at this time. See Note 3 under "Other Matters – Mississippi Power" for additional information on Plant Daniel Units 1 and 2. Environmental Compliance Overview Plan In accordance with a 2011 accounting order from the Mississippi PSC, Mississippi Power has the authority to defer in a regulatory asset for future recovery all plant retirement- or partial retirement-related costs resulting from environmental regulations. In accordance with a Mississippi PSC-approved settlement agreement between Mississippi Power and the MPUS, Mississippi Power was not required to make any ECO Plan filings for 2019 and 2020, and any necessary adjustments were reflected in Mississippi Power's 2019 base rate case. In 2019, the Mississippi PSC approved Mississippi Power's request for a CPCN to complete certain environmental compliance projects, primarily associated with the Plant Daniel coal units co-owned 50% with Gulf Power. The total estimated cost is approximately $125 million, with Mississippi Power's share of approximately $67 million being proposed for recovery through its ECO Plan. As of December 31, 2021, approximately $20 million of Mississippi Power's share is included in plant in service, approximately $14 million is included in CWIP, and approximately $13 million associated with ash pond closure is reflected in Mississippi Power's ARO liabilities. See Note 6 for additional information on AROs and Note 3 under "Other Matters – Mississippi Power" for additional information on Gulf Power's ownership in Plant Daniel. On June 8, 2021, the Mississippi PSC approved Mississippi Power's ECO Plan filing for 2021, resulting in a decrease in revenues of approximately $9 million annually, primarily due to a change in the amortization periods of certain regulatory assets and liabilities. The rate decrease became effective with the first billing cycle of July 2021. Fuel Cost Recovery Mississippi Power annually establishes and is required to file for an adjustment to the retail fuel cost recovery factor that is approved by the Mississippi PSC. The Mississippi PSC approved decreases of $35 million and $24 million effective in February 2019 and 2020, respectively, and increases of $2 million and $43 million effective in February 2021 and 2022, respectively. At December 31, 2021, under recovered retail fuel costs totaled approximately $4 million and were included in other customer accounts receivable on Southern Company's and Mississippi Power's balance sheets. At December 31, 2020, over recovered retail fuel costs totaled $24 million and were included in other current liabilities on Southern Company's balance sheet and over recovered regulatory clause liabilities on Mississippi Power's balance sheet. Mississippi Power has wholesale MRA and Market Based (MB) fuel cost recovery factors. Effective with the first billing cycles for January 2020, 2021, and 2022, annual revenues under the wholesale MRA fuel rate increased $1 million, decreased $5 million, and increased $11 million, respectively. The wholesale MB fuel rate did not change materially in any period presented. At December 31, 2021, under recovered wholesale fuel costs were immaterial. At December 31, 2020, over recovered wholesale fuel costs totaled approximately $10 million and were included in other current liabilities on Southern Company's balance sheet and over recovered regulatory clause liabilities on Mississippi Power's balance sheet. Mississippi Power's operating revenues are adjusted for differences in actual recoverable fuel cost and amounts billed in accordance with the currently approved cost recovery rate. Accordingly, changes in the billing factor should have no significant effect on Mississippi Power's revenues or net income but will affect operating cash flows. Ad Valorem Tax Adjustment Mississippi Power establishes annually an ad valorem tax adjustment factor that is approved by the Mississippi PSC to collect the ad valorem taxes paid by Mississippi Power. In 2020 and 2019, the annual revenues collected through the ad valorem tax adjustment factor increased by $10 million and decreased by $2 million, respectively. On April 6, 2021, the Mississippi PSC approved Mississippi Power's annual ad valorem tax adjustment filing for 2021, which requested an annual increase in revenues of approximately $28 million, including approximately $19 million of ad valorem taxes previously recovered through PEP in accordance with the Mississippi Power Rate Case Settlement Agreement. The rate increase became effective with the first billing cycle of May 2021. System Restoration Rider Mississippi Power carries insurance for the cost of certain types of damage to generation plants and general property. However, Mississippi Power is self-insured for the cost of storm, fire, and other uninsured casualty damage to its property, including transmission and distribution facilities. As permitted by the Mississippi PSC and the FERC, Mississippi Power accrues for the cost of such damage through an annual expense accrual which is credited to regulatory liability accounts for the retail and wholesale jurisdictions. The cost of repairing actual damage resulting from such events that individually exceed $50,000 is charged to the reserve. Every year, the Mississippi PSC, the MPUS, and Mississippi Power agree on SRR revenue level(s). Mississippi Power's net retail SRR accrual, which includes carrying costs and amortization of related excess deferred income tax benefits, was $(1.8) million in 2021, $0.8 million 2020, and $1.4 million in 2019. At December 31, 2020, the retail property damage reserve balance was $4 million. On October 14, 2021, the Mississippi PSC issued an accounting order giving Mississippi Power the authority to reclassify the retail costs associated with Hurricanes Zeta and Ida (approximately $49 million) to a regulatory asset to be recovered through PEP over a period to be determined in Mississippi Power's 2022 PEP proceeding. At December 31, 2021, the retail property damage reserve balance was $31 million, which reflects the impact of the reclassification. On December 7, 2021, the Mississippi PSC approved Mississippi Power's annual SRR filing, which requested an increase in retail revenues of approximately $9 million annually effective with the first billing cycle of March 2022. The Mississippi PSC also established $8 million as the minimum annual accrual amount until a target property damage reserve balance of $75 million is met. In the event the expected annual charges exceed the annual accrual or the target balance has been met, Mississippi Power and the Mississippi PSC will determine the appropriate change to the annual accrual. Additionally, if PEP earnings are above a certain threshold, Mississippi Power has the ability to apply any required PEP refund as an additional accrual to the property damage reserve in lieu of customer refunds. Municipal and Rural Associations Tariff Mississippi Power provides wholesale electric service to Cooperative Energy, East Mississippi Electric Power Association, and the City of Collins, all located in southeastern Mississippi, under a long-term, cost-based, FERC-regulated MRA tariff. In 2017, Mississippi Power and Cooperative Energy executed, and the FERC accepted, a Shared Service Agreement (SSA), as part of the MRA tariff, under which Mississippi Power and Cooperative Energy share in providing electricity to the Cooperative Energy delivery points under the tariff. The SSA may be cancelled by Cooperative Energy with 10 years notice. Cooperative Energy has the option to decrease its use of Mississippi Power's generation services under the MRA tariff up to 2.5% annually, with required notice, with a remaining total reduction of 8%, or approximately $8 million in cumulative annual base revenues. In June 2020, the FERC accepted Mississippi Power's requested $2 million annual increase in MRA base rates effective June 1, 2020, as agreed upon in a settlement agreement reached with its wholesale customers. Southern Company Gas Utility Regulation and Rate Design The natural gas distribution utilities are subject to regulation and oversight by their respective state regulatory agencies. Rates charged to customers vary according to customer class (residential, commercial, or industrial) and rate jurisdiction. These agencies approve rates designed to provide 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 ROE. As a result of operating in a deregulated environment, Atlanta Gas Light earns revenue by charging rates to its customers based primarily on monthly fixed charges that are set by the Georgia PSC and adjusted periodically. The Marketers add these fixed charges when billing customers. This mechanism, called a straight-fixed-variable rate design, minimizes the seasonality of Atlanta Gas Light's revenues since the monthly fixed charge is not volumetric or directly weather dependent. With the exception of Atlanta Gas Light, 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. Specifically, customer demand substantially increases during the Heating Season when natural gas is used for heating purposes. Southern Company Gas has various mechanisms, such as weather and revenue normalization mechanisms and weather derivative instruments, that limit exposure to weather changes within typical ranges in these utilities' respective service territories. In addition to natural gas cost recovery mechanisms, other cost recovery mechanisms and regulatory riders, which vary by utility, allow recovery of certain costs, such as those related to infrastructure replacement programs as well as environmental remediation, energy efficiency plans, and bad debts. In traditional rate designs, utilities recover a significant portion of the fixed customer service and pipeline infrastructure costs based on assumed natural gas volumes used by customers. With the exception of Chattanooga Gas, the natural gas distribution utilities have decoupled regulatory mechanisms that Southern Company Gas believes encourage conservation by separating the recoverable amount of these fixed costs from the amounts of natural gas used by customers. See "Rate Proceedings" herein for additional information. Also see "Infrastructure Replacement Programs and Capital Projects" herein for additional information regarding infrastructure replacement programs at certain of the natural gas distribution utilities. The following table provides regulatory information for Southern Company Gas' natural gas distribution utilities:
| Nicor Gas |  | Atlanta Gas Light |  | Virginia Natural Gas |  | Chattanooga Gas
Authorized ROE(a) | 9.75% |  | 10.25% |  | 9.50% |  | 9.80%
Weather normalization mechanisms(b) |  |  |  |  | ü |  | ü
Decoupled, including straight-fixed-variable rates(c) | ü |  | ü |  | ü |  |
Regulatory infrastructure program rates(d) | ü |  | ü |  | ü |  | ü
Bad debt rider(e) | ü |  |  |  | ü |  | ü
Energy efficiency plan(f) | ü |  |  |  | ü |  |
Annual base rate adjustment mechanism(g) |  |  | ü |  |  |  | ü
Year of last base rate case decision(h) | 2021 |  | 2019 |  | 2021 |  | 2018
(a)Represents the authorized ROE at December 31, 2021. (b)Designed to help stabilize operating results by allowing recovery of costs in the event of unseasonal weather, but are not direct offsets to the potential impacts on earnings of weather and customer consumption. (c)Allows for recovery of fixed customer service costs separately from assumed natural gas volumes used by customers and provides a benchmark level of revenue for recovery. (d)Programs that update or expand distribution systems and LNG facilities. Atlanta Gas Light's infrastructure program, System Reinforcement Rider, is effective for 2022 through 2024. See "Rate Proceedings – Atlanta Gas Light" herein for additional information. Chattanooga Gas' pipeline replacement program costs are recovered through its annual base rate review mechanism. (e)The recovery (refund) of bad debt expense over (under) an established benchmark expense. The gas portion of bad debt expense is recovered through purchased gas adjustment mechanisms. Nicor Gas also has a rider to recover the non-gas portion of bad debt expense. (f)Recovery of costs associated with plans to achieve specified energy savings goals. (g)Regulatory mechanism allowing annual adjustments to base rates up or down based on authorized ROE and/or ROE range. (h)Annual GRAM filing required at Atlanta Gas Light. Infrastructure Replacement Programs and Capital Projects In addition to capital expenditures recovered through base rates by each of the natural gas distribution utilities, Nicor Gas and Virginia Natural Gas have separate rate riders that provide timely recovery of capital expenditures for specific infrastructure replacement programs. Total capital expenditures incurred during 2021 for gas distribution operations were $1.5 billion. The following table and discussions provide updates on the infrastructure replacement programs and capital projects at the natural gas distribution utilities at December 31, 2021. These programs are risk-based and designed to update and replace cast iron, bare steel, and mid-vintage plastic materials or expand Southern Company Gas' distribution systems to improve reliability and meet operational flexibility and growth.
Utility |  | Program |  |  |  | Recovery |  | Expenditures in 2021 |  | Expenditures Since Project Inception |  | Pipe Installed Since Project Inception |  | Scope of Program |  | Program Duration |  | Last Year of Program
|  |  |  |  |  |  |  | (in millions) |  | (miles) |  | (miles) |  | (years) |  |
Nicor Gas |  | Investing in Illinois(*) |  |  |  | Rider |  | $ | 408 |  |  | $ | 2,508 |  |  | 1,153 |  |  | 1,394 |  |  | 9 |  | 2023
Virginia Natural Gas |  | Steps to Advance Virginia's Energy (SAVE) |  |  |  | Rider |  | 51 |  |  | 342 |  |  | 470 |  |  | 640 |  |  | 13 |  | 2024
Atlanta Gas Light |  | System Reinforcement Rider |  |  |  | Rider |  | — |  |  | — |  |  | N/A |  | N/A |  | 3 |  | 2024
Chattanooga Gas |  | Pipeline Replacement Program |  |  |  | Rate Base |  | 2 |  |  | 2 |  |  | 5 |  |  | 73 |  |  | 7 |  | 2027
Total |  |  |  |  |  |  |  | $ | 461 |  |  | $ | 2,852 |  |  | 1,628 |  |  | 2,107 |  |  |  |  |
(*)Includes replacement of pipes, compressors, and transmission mains along with other improvements such as new meters. Scope of program miles is an estimate and subject to change. Recovery of program costs is described under "Nicor Gas" herein. Nicor Gas Illinois legislation allows Nicor Gas to provide more widespread safety and reliability enhancements to its distribution system and stipulates that rate increases to customers as a result of any infrastructure investments shall not exceed a cumulative annual average of 4.0% or, in any given year, 5.5% of base rate revenues. In 2014, the Illinois Commission approved the nine-year regulatory infrastructure program, Investing in Illinois, subject to annual review. In accordance with orders from the Illinois Commission, Nicor Gas recovers program costs incurred through a separate rider and base rates. The Illinois Commission's approval of Nicor Gas' rate case on November 18, 2021 included recovery of program costs through December 31, 2021. See "Rate Proceedings – Nicor Gas" herein for additional information. Nicor Gas' capital expenditures related to qualifying projects under the Investing in Illinois program totaled $389 million and $396 million in 2020 and 2019, respectively. Virginia Natural Gas In 2019, the Virginia Commission approved amendments to and extension of the Steps to Advance Virginia's Energy (SAVE) program, an accelerated infrastructure replacement program. The extension allows Virginia Natural Gas to continue replacing aging pipeline infrastructure through 2024 and increases its authorized investment under the previously-approved plan from $35 million to $40 million in 2019 with additional annual investments of $50 million in 2020, $60 million in 2021, $70 million in each year from 2022 through 2024, and a total potential variance of up to $5 million allowed for the program, for a maximum total investment over the six-year term (2019 through 2024) of $365 million. Virginia Natural Gas' capital expenditures under the SAVE program totaled $49 million and $45 million in 2020 and 2019, respectively. The SAVE program is subject to annual review by the Virginia Commission. In accordance with the base rate case approved by the Virginia Commission in 2021, Virginia Natural Gas is recovering program costs incurred prior to November 1, 2020 through base rates. Program costs incurred subsequent to November 1, 2020 are currently being recovered through a separate rider and are subject to future base rate case proceedings. Atlanta Gas Light In 2019, the Georgia PSC approved the continuation of GRAM as part of Atlanta Gas Light's 2019 rate case order. Various infrastructure programs previously authorized by the Georgia PSC, including the Integrated Vintage Plastic Replacement Program to replace aging plastic pipe and the Integrated System Reinforcement Program to upgrade Atlanta Gas Light's distribution system and LNG facilities in Georgia, continue under GRAM and the recovery of and return on the infrastructure program investments are included in annual base rate adjustments. The amounts to be recovered through rates related to allowed, but not incurred, costs have been recognized in an unrecognized ratemaking amount that is not reflected on the balance sheets. These allowed costs are primarily the equity return on the capital investment under the infrastructure programs in place prior to GRAM and are being recovered through GRAM and base rates until the earlier of the full recovery of the related under recovered amount or December 31, 2025. The under recovered balance at December 31, 2021 was $91 million, including $47 million of unrecognized equity return. The Georgia PSC reviews Atlanta Gas Light's performance annually under GRAM. See "Unrecognized Ratemaking Amounts" herein for additional information. Atlanta Gas Light and the staff of the Georgia PSC previously agreed to a variation of the Integrated Customer Growth Program to extend pipeline facilities to serve customers in areas without pipeline access and create new economic development opportunities in Georgia. A separate tariff provides recovery of up to $15 million annually for strategic economic development projects approved by the Georgia PSC. See "Rate Proceedings – Atlanta Gas Light" herein for additional information regarding the Georgia PSC's November 18, 2021 approval of Atlanta Gas Light's GRAM filing and Integrated Capacity and Delivery Plan. The Georgia PSC also approved a new System Reinforcement Rider for authorized large pressure improvement and system reliability projects, which is expected to recover related capital investments totaling $286 million for the years 2022 through 2024. Chattanooga Gas In June 2021, the Tennessee Public Utilities Commission approved Chattanooga Gas' pipeline replacement program to replace approximately 73 miles of distribution main over a seven-year period. The estimated total cost of the program is $118 million, which will be recovered through Chattanooga Gas' annual base rate review mechanism. Natural Gas Cost Recovery With the exception of Atlanta Gas Light, the natural gas distribution utilities are authorized by the relevant regulatory agencies in the states in which they serve 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. The natural gas distribution utilities defer or accrue the difference between the actual cost of natural gas and the amount of commodity revenue earned in a given period. The deferred or accrued amount is either billed or refunded to customers prospectively through adjustments to the commodity rate. Deferred natural gas costs are reflected as regulatory assets and accrued natural gas costs are reflected as regulatory liabilities. Changes in the billing factor will not have a significant effect on Southern Company's or Southern Company Gas' net income, but will affect cash flows. Since Atlanta Gas Light does not sell natural gas directly to its end-use customers, it does not utilize a traditional natural gas cost recovery mechanism. However, Atlanta Gas Light does maintain natural gas inventory for the Marketers in Georgia and recovers the cost through recovery mechanisms approved by the Georgia PSC. At December 31, 2021, the under recovered balance was $473 million, $266 million of which was included in natural gas cost under recovery and $207 million of which was included in other regulatory assets, deferred on Southern Company's and Southern Company Gas' balance sheets. At December 31, 2020, the over recovered balance was $88 million, which was included in other regulatory liabilities on Southern Company's and Southern Company Gas' balance sheets. Rate Proceedings Nicor Gas In 2019, the Illinois Commission approved a $168 million annual base rate increase effective October 8, 2019. The base rate increase included $65 million related to the recovery of program costs under the Investing in Illinois program and was based on a ROE of 9.73% and an equity ratio of 54.2%. Additionally, the Illinois Commission approved a volume balancing adjustment, a revenue decoupling mechanism for residential customers that provides a benchmark level of revenue per rate class for recovery. On November 18, 2021, the Illinois Commission approved a $240 million annual base rate increase effective November 24, 2021. The base rate increase included $94 million related to the recovery of program costs under the Investing in Illinois program and was based on a ROE of 9.75% and an equity ratio of 54.5%. Atlanta Gas Light In 2019, the Georgia PSC approved a $65 million annual base rate increase, effective January 1, 2020, based on a ROE of 10.25% and an equity ratio of 56%. Earnings will be evaluated against a ROE range of 10.05% to 10.45%, with disposition of any earnings above 10.45% to be determined by the Georgia PSC. Additionally, the Georgia PSC approved continuation of the previously authorized inclusion in base rates of the recovery of and return on the infrastructure program investments, including, but not limited to, GRAM adjustments, and a reauthorization and continuation of GRAM until terminated by the Georgia PSC. GRAM filing rate adjustments will be based on the authorized ROE of 10.25%. GRAM adjustments for 2021 could not exceed 5% of 2020 base rates. The 5% limitation does not set a precedent in any future rate proceedings by Atlanta Gas Light. In July 2020, Atlanta Gas Light filed its annual GRAM filing with the Georgia PSC requesting an annual base rate increase of $37.6 million based on the projected 12-month period beginning January 1, 2021, which did not exceed the 5% limitation established by the Georgia PSC. Rates went into effect on January 1, 2021 in accordance with Atlanta Gas Light's 2019 rate case order. On February 16, 2021, the Georgia PSC approved a stipulation between Atlanta Gas Light and the Georgia PSC staff establishing a long-range comprehensive planning process. Under the terms of the stipulation, Atlanta Gas Light was required to develop and file at least triennially an Integrated Capacity and Delivery Plan (i-CDP). Each i-CDP will include a 10-year forecast of interstate and intrastate capacity asset requirements, including a detailed plan for the first three years consistent with Atlanta Gas Light's current capacity supply plan, and a 10-year projection of capital budgets and related operations and maintenance spending. Recovery of the related revenue requirements will be included in either subsequent annual GRAM filings or a new System Reinforcement Rider for authorized large pressure improvement and system reliability projects. On April 28, 2021, Atlanta Gas Light filed its first i-CDP with the Georgia PSC, which includes a series of ongoing and proposed pipeline safety, reliability, and growth programs for the next 10 years (2022 through 2031), as well as the required capital investments and related costs to implement the programs. The i-CDP reflected capital investments totaling approximately $0.5 billion to $0.6 billion annually. On November 18, 2021, the Georgia PSC approved an October 14, 2021 joint stipulation agreement between Atlanta Gas Light and the staff of the Georgia PSC, under which, for the years 2022 through 2024, Atlanta Gas Light will incrementally reduce its combined GRAM and System Reinforcement Rider request by 10% through Atlanta Gas Light's GRAM mechanism, or $5 million for 2022. The stipulation agreement also provides for $1.7 billion of total capital investment for the years 2022 through 2024. Also on November 18, 2021, the Georgia PSC approved Atlanta Gas Light's amended annual GRAM filing, which resulted in an annual rate increase of $43 million effective January 1, 2022. Virginia Natural Gas On September 14, 2021, the Virginia Commission approved a stipulation agreement related to Virginia Natural Gas' June 2020 general rate case filing, which allows for a $43 million increase in annual base rate revenues, including $14 million related to the recovery of investments under the SAVE program, based on a ROE of 9.5% and an equity ratio of 51.9%. Interim rate adjustments became effective as of November 1, 2020, subject to refund, based on Virginia Natural Gas' original request for an increase of approximately $50 million. Refunds to customers related to the difference between the approved rates and the interim ra tes were completed during the fourth quarter 2021. Deferral of Incremental COVID-19 Costs As discussed under "Utility Regulation and Rate Design," the natural gas distribution utilities have various regulatory mechanisms to recover bad debt expense, which helped mitigate potential increases in bad debt expense as a result of the COVID-19 pandemic. Deferred incremental costs related to the COVID-19 pandemic were immaterial for Virginia Natural Gas. Atlanta Gas Light In April 2020, in response to the COVID-19 pandemic, the Georgia PSC approved orders directing Atlanta Gas Light to continue its previous, voluntary suspension of customer disconnections. In June 2020, the Georgia PSC ordered Atlanta Gas Light to resume customer disconnections beginning July 2020, with exceptions for customers still covered by a shelter-in-place order. All suspensions for customer disconnections were lifted in October 2020. The orders provide the Marketers, including SouthStar, with a mechanism to receive credits from Atlanta Gas Light for the base rates it charged to the Marketers of non-paying customers during the suspension. Atlanta Gas Light will begin recovering these credits through GRAM rates effective January 1, 2023. Nicor Gas In March 2020, in response to the COVID-19 pandemic, the Illinois Commission issued an order directing utilities to cease disconnections for non-payment and to suspend the imposition of late payment fees or penalties. In June 2020, the Illinois Commission approved a stipulation pursuant to which Nicor Gas and other utilities in Illinois would provide more flexible credit and collection procedures to assist customers with financial hardship and which authorizes a special purpose rider for recovery of the following COVID-19 pandemic-related impacts: incremental costs directly associated with the COVID-19 pandemic, net of the offset for COVID-19 pandemic-related credits received, foregone late fees, foregone reconnection charges, and the costs associated with a bill payment assistance program. Nicor Gas resumed late payment fees in July 2020 and, on October 1, 2020, began recovery of the COVID-19 pandemic-related impacts through the special purpose rider, which will continue over a 24-month period. On March 18, 2021, the Illinois Commission approved a phased-in schedule for disconnections related to non-payment. Nicor Gas began certain disconnections in late April 2021 and resumed normal disconnections in June 2021. At December 31, 2021 and 2020, Nicor Gas' related regulatory asset was $5 million and $9 million, respectively. Unrecognized Ratemaking Amounts The following table illustrates Southern Company Gas' authorized ratemaking amounts that are not recognized on its balance sheets. These amounts are primarily composed of an allowed equity rate of return on assets associated with certain regulatory infrastructure programs. These amounts will be recognized as revenues in Southern Company Gas' financial statements in the periods they are billable to customers, the majority of which will be recovered by 2025.
| December 31, 2021 |  | December 31, 2020
| (in millions)
Atlanta Gas Light | $ | 47 |  |  | $ | 59 |
Virginia Natural Gas | 10 |  |  | 10 |
Chattanooga Gas | 4 |  |  | 2 |
Nicor Gas | — |  |  | 3 |
Total | $ | 61 |  |  | $ | 74 |

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