Biggest changeThe following table sets forth, for the periods indicated, the shipment volumes and revenues for primary aluminum shipments: SHIPMENTS - PRIMARY ALUMINUM (1) United States Iceland Total Tonnes Revenue $ Tonnes Revenue $ Tonnes Revenue $ (dollars in millions) 2022 459,991 $ 1,650.4 308,700 $ 1,040.1 768,691 $ 2,690.5 2021 468,729 1,368.0 314,918 790.8 783,647 2,158.8 2020 495,433 985.3 315,743 570.8 811,176 1,556.1 (1) Excludes scrap aluminum, purchased aluminum and alumina sales Results of Operations Year Ended December 31, 2022 Compared to Year Ended December 31, 2021 Net sales (in millions) 2022 2021 Twelve months ended December 31, $ 2,777.3 $ 2,212.5 Net sales: Net sales (excluding scrap aluminum and alumina sales) increased by $564.8 million for the twelve months ended December 31, 2022, compared to the same period in 2021, primarily driven by favorable LME and regional premium price realizations of $496.9 million and favorable product mix of $82.0 million driven by higher value-added product premiums, partially offset by $26.8 million in volume primarily related to the full curtailment of our Hawesville smelter in the third quarter of 2022. 29 Gross profit (loss) (in millions) 2022 2021 Twelve months ended December 31, $ 46.7 $ 124.2 Gross profit (loss) : Gross profit decreased by $77.5 million for the twelve months ended December 31, 2022, compared to the same period in 2021, primarily driven by unfavorable raw material price realizations of $338.4 million and unfavorable power price realizations of $285.5 million.
Biggest changeThe following table sets forth, for the periods indicated, the shipment volumes and revenues for primary aluminum shipments: 34 SHIPMENTS - PRIMARY ALUMINUM (1) United States Iceland Total Tonnes Revenue $ Tonnes Revenue $ Tonnes Revenue $ (dollars in millions) 2023 389,331 $ 1,139.0 311,349 $ 827.0 700,680 $ 1,966.0 2022 459,991 $ 1,650.4 308,700 $ 1,040.1 768,691 $ 2,690.5 2021 468,729 $ 1,368.0 314,918 $ 790.8 783,647 $ 2,158.8 (1) Excludes scrap aluminum, purchased aluminum and alumina sales Results of Operations Year Ended December 31, 2023 Compared to Year Ended December 31, 2022 Net sales (in millions) 2023 2022 Twelve months ended December 31, $ 2,185.4 $ 2,777.3 Net sales: Net sales decreased by $591.9 million for the twelve months ended December 31, 2023, compared to the same period in 2022, primarily driven by unfavorable LME and regional premium price realizations of $384.6 million and unfavorable volume of $376.7 million primarily related to the full curtailment of our Hawesville smelter in the third quarter of 2022, partially offset by favorable alumina prices and sales volume of $186.1 million primarily attributable to Jamalco sales of $150.3 million since acquisition in May 2023.
The indenture governing the 2028 Notes contains customary covenants which may limit our ability, and the ability of certain of our subsidiaries, to: (i) incur additional debt; (ii) incur additional liens; (iii) pay dividends or make distributions in respect of capital stock; (iv) purchase or redeem capital stock; (v) 32 make investments or certain other restricted payments; (vi) sell assets; (vii) issue or sell stock of certain subsidiaries; (viii) enter into transactions with shareholders or affiliates; and (ix) effect a consolidation or merger.
The indenture governing the 2028 Notes contains customary covenants which may limit our ability, and the ability of certain of our subsidiaries, to: (i) incur additional debt; (ii) incur additional liens; (iii) pay dividends or make distributions in respect of capital stock; (iv) purchase or redeem capital stock; (v) make investments or certain other restricted payments; (vi) sell assets; (vii) issue or sell stock of certain subsidiaries; (viii) enter into transactions with shareholders or affiliates; and (ix) effect a consolidation or merger.
("CAWV") filed a class action complaint for declaratory judgment against the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union ("USW"), the USW’s local and certain CAWV retirees, individually and as class representatives ("CAWV Retirees"), seeking a declaration of CAWV’s rights to modify/terminate retiree medical benefits.
("CAWV") filed a class action complaint for declaratory judgment against the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers 40 International Union ("USW"), the USW’s local and certain CAWV retirees, individually and as class representatives ("CAWV Retirees"), seeking a declaration of CAWV’s rights to modify/terminate retiree medical benefits.
Although we believe that the assumptions used to estimate the market value of our inventory are reasonable, actual market conditions at the time our inventory is sold may be more or less favorable than management’s current estimates. Pension and Other Postretirement Benefit Liabilities We sponsor several pension and OPEB plans.
Although we believe that the assumptions used to estimate the market value of our inventory are reasonable, actual market conditions at the time our inventory is sold may be more or less favorable than management’s current estimates. 41 Pension and Other Postretirement Benefit Liabilities We sponsor several pension and OPEB plans.
In June 2022, we entered into a Fourth Amendment to our existing $220.0 million U.S. revolving credit facility, increasing the maximum capacity from $220.0 million to $250.0 million, including up to $150.0 million under a letter of credit sub-facility. The U.S. 31 revolving credit facility matures in June 2027.
In June 2022, we entered into a Fourth Amendment to our existing $220.0 million U.S. revolving credit facility, increasing the maximum capacity from $220.0 million to $250.0 million, including up to $150.0 million under a letter of credit sub-facility. The U.S. revolving credit facility matures in June 2027.
Market-based energy prices are driven in large part by the price of coal, natural gas, and 28 other fuel sources, weather influenced reservoir or generation levels for wind, solar and hydro production and weather-influenced electric loads.
Market-based energy prices are driven in large part by the price of coal, natural gas, and other fuel sources, weather influenced reservoir or generation levels for wind, solar and hydro production and weather-influenced electric loads.
The timing and amount of any shares repurchased will be determined by our management based on its evaluation of market conditions, the trading price of our common stock and other factors. We made no repurchases during the years ended 2022, 2021, and 2020. As of December 31, 2022, we had $43.7 million remaining under the repurchase program authorization.
The timing and amount of any shares repurchased will be determined by our management based on its evaluation of market conditions, the trading price of our common stock and other factors. We made no repurchases during the years ended 2023, 2022, and 2021. As of December 31, 2023, we had $43.7 million remaining under the repurchase program authorization.
We are a defendant in several actions relating to various aspects of our business. While it is impossible to predict the ultimate disposition of any litigation, we do not believe that any of these lawsuits, either individually or in the aggregate, will have a material adverse effect on our financial condition, results of operations or liquidity. See Note 16.
We are a defendant in several actions relating to various aspects of our business. While it is impossible to predict the ultimate disposition of any litigation, we do not believe that any of these lawsuits, either individually or in the aggregate, will have a material adverse effect on our financial condition, results of operations or liquidity. See Note 17.
Based on the LME forward market at December 31, 2022 and our expected level of Hawesville's operations, we believe that we will not be required to make payments on the contingent obligation during the term of the agreement, which expires in 2028. There can be no assurance that circumstances will not change thus accelerating the timing of such payments.
Based on the LME forward market at December 31, 2023 and our expected level of Hawesville's operations, we believe that we will not be required to make payments on the contingent obligation during the term of the agreement, which expires in 2028. There can be no assurance that circumstances will not change thus accelerating the timing of such payments.
The Casthouse Facility also contains customary covenants, including restrictions on mergers and acquisitions, indebtedness, preservation of assets, and dispositions of assets and contains a covenant that requires Grundartangi to maintain a minimum equity ratio. As of December 31, 2022, we were in compliance with all such covenants or maintained availability above such covenant triggers.
The Casthouse Facility also contains customary covenants, including restrictions on mergers and acquisitions, indebtedness, preservation of assets, and dispositions of assets and contains a covenant that requires Grundartangi to maintain a minimum equity ratio. As of December 31, 2023, we were in compliance with all such covenants or maintained availability above such covenant triggers.
Grundartangi also has a 25 MW power purchase agreement with Landsvirkjun at LME-based variable rates. Production/Shipment Volumes Shipment volume is another key determinant of our financial results. In normal circumstances, fluctuations in production and shipment volumes, other than through acquisitions or expansions, are generally small period over period.
Grundartangi also has a 25 MW power purchase agreement with Landsvirkjun at LME-based variable rates. Production/Shipment Volumes Shipment volume is another key determinant of our financial results. Fluctuations in production and shipment volumes, other than through acquisitions or expansions, are generally small period over period.
Our foreign subsidiaries, together with Nordural US LLC, Century Aluminum Development LLC and Century Aluminum of West Virginia, Inc., are collectively referred to as the "Non-Guarantor Subsidiaries". We allocate corporate expenses or income to our subsidiaries and charge interest on certain intercompany balances.
Our foreign subsidiaries, together with Nordural US LLC, Century Aluminum Development LLC, Century Aluminum of West Virginia, Inc. and Century Aluminum Jamaica Holdings, Inc. are collectively referred to as the "Non-Guarantor Subsidiaries." We allocate corporate expenses or income to our subsidiaries and charge interest on certain intercompany balances.
Our analysis gives consideration to recent plan performance and historical returns; however, the assumptions are primarily based on long-term, prospective rates of return. The weighted average long-term rate of return on plan assets for our defined benefit pension plans is 7.25% for 2022.
Our analysis gives consideration to recent plan performance and historical returns; however, the assumptions are primarily based on long-term, prospective rates of return. The weighted average long-term rate of return on plan assets for our defined benefit pension plans is 7.25% for 2023.
We historically elected to defer certain payments under the PBGC Settlement Agreement and provided the PBGC with the appropriate security.
We historically elected to defer certain payments 39 under the PBGC Settlement Agreement and provided the PBGC with the appropriate security.
As of December 31, 2022, we were in compliance with all such covenants or maintained availability above such covenant triggers. Grundartangi Casthouse Facility On November 2, 2021, in connection with the casthouse project at Grundartangi, we entered into an eight-year Term Facility Agreement with Arion Bank hf, to provide for borrowings up to $130.0 million (the “Casthouse Facility”).
As of December 31, 2023, we were in compliance with all such covenants or maintained availability above such covenant triggers. Grundartangi Casthouse Facility 37 On November 2, 2021, in connection with the casthouse project at Grundartangi, we entered into an eight-year Term Facility Agreement with Arion Bank hf, to provide for borrowings up to $130.0 million (the “Casthouse Facility”).
Asset impairment charge (in millions) 2022 2021 Twelve months ended December 31, $ 159.4 $ — Asset impairment charge: An asset impairment charge was recognized for the twelve months ended December 31, 2022 as a result of the temporary curtailment of the Hawesville facility, announced during June 2022.
Asset impairment charge (in millions) 2023 2022 Twelve months ended December 31, $ — $ 159.4 Asset impairment charge: An asset impairment charge was recognized for the twelve months ended December 31, 2022 as a result of the temporary curtailment of the Hawesville facility, announced during June 2022.
Additionally, extreme geopolitical events, such as the Russia-Ukraine conflict in 2022, which led to the cut-off of natural gas supply to Western Europe and increased exports of U.S natural gas as result, may result in significant power costs globally. Our Mt. Holly plant has a power supply agreement with Santee Cooper that runs through December 2023.
Additionally, extreme geopolitical events, such as the on-going Russia-Ukraine conflict, which led to the cut-off of natural gas supply to Western Europe and increased exports of U.S natural gas as result, may result in significant power costs globally. Our Mt. Holly plant has a power supply agreement with Santee Cooper that runs through December 2026.
This contingent obligation consists of the aggregate payments made to Big Rivers by the third party on CAKY’s behalf in excess of the agreed upon base amount under the long-term cost-based power contract with Kenergy. As of December 31, 2022, the principal and accrued interest for the contingent obligation was $29.5 million, which was fully offset by a derivative asset.
This contingent obligation consists of the aggregate payments made to Big Rivers by the third party on CAKY’s behalf in excess of the agreed upon base amount under the long-term cost-based power contract with Kenergy. As of December 31, 2023, the principal and accrued interest for the contingent obligation was $30.9 million, which was fully offset by a derivative asset.
Upon approval of the settlement, we paid $5.0 million to the aforementioned trust in September 2017 and agreed to pay the remaining amounts under the settlement agreement in annual increments of $2.0 million for nine years. At December 31, 2022, we had $2.0 million in other current liabilities and $4.8 million in other liabilities related to this agreement.
Upon approval of the settlement, we paid $5.0 million to the aforementioned trust in September 2017 and agreed to pay the remaining amounts under the settlement agreement in annual increments of $2.0 million for nine years. At December 31, 2023, we had $2.0 million in other current liabilities and $3.3 million in other liabilities related to this agreement.
Summary of Significant Accounting Policies to the consolidated financial statements. The preparation of the financial statements requires that management make judgments, assumptions and estimates in applying these accounting policies. Those judgments are normally based on knowledge and experience about past and current events and on assumptions about future events.
The preparation of the financial statements requires that management make judgments, assumptions and estimates in applying these accounting policies. Those judgments are normally based on knowledge and experience about past and current events and on assumptions about future events.
On February 4, 2022, we amended the Iceland revolving credit facility and increased the facility amount to $80.0 million in the aggregate. On September 28, 2022, we further amended the Iceland revolving credit facility and increased the facility amount to $100.0 million in the aggregate. The Iceland revolving credit facility matures November 2024.
On February 4, 2022, we amended the Iceland revolving credit facility and increased the facility amount to $80.0 million in the aggregate. On September 28, 2022, we further amended the Iceland revolving credit facility and increased the facility amount to $100.0 million in the aggregate. The Iceland revolving credit facility matures December 2026.
Although we attempt to mitigate the effects of price fluctuations from time to time through the use of various fixed-price commitments, financial instruments and also by negotiating LME-based pricing in some of our raw materials and electrical power contracts, these efforts also limit our ability to take advantage of favorable changes in the market prices for primary aluminum or raw materials and may affect our financial position, results of operations and cash flows.
Although we attempt to mitigate the effects of price fluctuations from time to time through the use of various fixed-price commitments, financial instruments and also by negotiating LME-based pricing in some of our raw materials and electrical power contracts, these efforts also limit our ability to take advantage of favorable changes in the market prices for primary aluminum or raw materials and may affect our financial position, results of operations and cash flows. 33 Alumina and electrical power represent the two largest components of our cost of goods sold.
Borrowings under the Iceland Term Facility will bear interest at a rate equal to 3.2% plus EUR EURIBOR 1 month as published by the European Money Markets Institute. As of December 31, 2022, there were $14.5 million (€13.6 million) in outstanding borrowings under the Iceland Term Facility.
Borrowings under the Iceland Term Facility will bear interest at a rate equal to 3.2% plus EUR EURIBOR 1 month as published by the European Money Markets Institute. As of December 31, 2023, there were $1.3 million (€1.1 million ) in outstanding borrowings under the Iceland Term Facility.
Weighted Average Discount Rate Assumption for: 2022 2021 Pension plans 5.50% 2.89% OPEB plans 5.57% 2.75% 36 A change of a half percentage point in the discount rate for our defined benefit plans would have the following effects on our obligations under these plans as of December 31, 2022: Effect of changes in the discount rates on the Projected Benefit Obligations for: 50 basis point increase 50 basis point decrease (dollars in millions) Pension plans $ (14.4) $ 16.0 OPEB plans (2.9) 3.1 Long-term Rate of Return on Plan Assets Assumption Our expected long-term rate of return on plan assets is derived from our asset allocation strategies and anticipated future long-term performance of individual asset classes.
Weighted Average Discount Rate Assumption for: 2023 2022 Pension plans 5.19% 5.50% OPEB plans 5.19% 5.57% A change of a half percentage point in the discount rate for our defined benefit plans would have the following effects on our obligations under these plans as of December 31, 2023: Effect of changes in the discount rates on the Projected Benefit Obligations for: 50 basis point increase 50 basis point decrease (dollars in millions) Pension plans $ (15.0) $ 16.8 OPEB plans (3.0) 3.2 Long-term Rate of Return on Plan Assets Assumption Our expected long-term rate of return on plan assets is derived from our asset allocation strategies and anticipated future long-term performance of individual asset classes.
As of December 31, 2022, we made contributions of $2.4 million related to the Amended PBGC Settlement Agreement. Section 232 Aluminum Tariff On March 23, 2018, the U.S. implemented a 10% tariff on imported primary aluminum products into the U.S.
As of December 31, 2023, we made contributions of $6.9 million related to the Amended PBGC Settlement Agreement. Section 232 Aluminum Tariff On March 23, 2018, the U.S. implemented a 10% tariff on imported primary aluminum products into the U.S.
Sources and Uses of Cash Our cash flows from operating, investing and financing activities as reflected in the consolidated statement of cash flows for the twelve months ended December 31, 2022, 2021 and 2020 are summarized below: Twelve months ended December 31, 2022 2021 2020 (dollars in millions) Net cash provided by (used in) operating activities $ 25.9 $ (64.7) $ 42.9 Net cash used in investing activities (85.5) (82.6) (11.8) Net cash provided by financing activities 74.4 103.7 13.5 Change in cash, cash equivalents and restricted cash $ 14.8 $ (43.6) $ 44.6 Year Ended December 31, 2022 Compared to Year Ended December 31, 2021 Net cash provided by operating activities for 2022 was $25.9 million, compared to cash used in operating activities of $64.7 million in 2021.
Sources and Uses of Cash Our cash flows from operating, investing and financing activities as reflected in the consolidated statement of cash flows for the twelve months ended December 31, 2023, 2022 and 2021 are summarized below: Twelve months ended December 31, (in millions) 2023 2022 2021 Net cash provided by (used in) operating activities $ 105.6 $ 25.9 $ (64.7) Net cash used in investing activities (57.8) (85.5) (82.6) Net cash (used in) provided by financing activities (13.0) 74.4 103.7 Change in cash, cash equivalents and restricted cash $ 34.8 $ 14.8 $ (43.6) 36 Year Ended December 31, 2023 Compared to Year Ended December 31, 2022 Net cash provided by operating activities for 2023 was $105.6 million compared to $25.9 million in 2022.
The amount of a valuation allowance is based upon our best estimate of our ability to realize the net deferred tax assets. We have a valuation allowance of $487.9 million recorded against our net U.S. deferred tax assets and a portion of our Icelandic deferred tax assets as of December 31, 2022.
The amount of a valuation allowance is based upon our best estimate of our ability to realize the net deferred tax assets. We have a valuation allowance of $537.6 million recorded against our net U.S. and Jamaican deferred tax assets and a portion of our Icelandic deferred tax assets as of December 31, 2023.
The availability period for borrowings under the Vlissingen Facility Agreement ends December 2, 2024. Amounts drawn, if any, under the Vlissingen Facility Agreement are expected to be used for general corporate and working capital purposes of Century and its subsidiaries. As of December 31, 2022, there were no outstanding borrowings under the Vlissingen Facility Agreement.
The availability period for borrowings under the Vlissingen Facility Agreement ends December 2, 2024. Amounts drawn, if any, under the Vlissingen Facility Agreement are expected to be used for general corporate and working capital purposes of Century and its subsidiaries. As of December 31, 2023, there were $10.0 million in borrowings under the Vlissingen Facility Agreement.
Imports that receive a product exclusion from the Department of Commerce may also enter the US duty free. In July 2022, the International Trade Commission (ITC) initiated a review of the Section 301 and 232 duties as required by law every four years. The process will conclude no later than March 15, 2023.
Imports that receive a product exclusion from the Department of Commerce may also enter the US duty free. In July 2022, the International Trade Commission (ITC) initiated a review of the Section 301 and 232 duties as required by law every four years.
Of the outstanding letters of credit, $21.6 million related to our power commitments, $13.3 million are related to hedging collateral, and the remainder are primarily for the purpose of securing certain secured debt and workers’ compensation commitments. As of December 31, 2022, our Iceland revolving credit facility had a borrowing base of $95.1 million and $35.0 million in outstanding borrowings.
Of the outstanding letters of credit, $13.7 million related to our power commitments, $47.7 million are related to hedging collateral, and the remainder are primarily for the purpose of securing certain secured debt and workers’ compensation commitments. As of December 31, 2023, our Iceland revolving credit facility had a borrowing base of $100.0 million and no outstanding borrowings.
Under certain circumstances, in periods of lower primary aluminum prices relative to our cost of operations, we were able to defer one or more of these payments, provided that we provide the PBGC with acceptable security for such deferred payments. We did not make any contributions during the years ended December 31, 2021 and 2020.
Under certain circumstances, in periods of lower primary aluminum prices relative to our cost of operations, we were able to defer one or more of these payments, provided that we provide the PBGC with acceptable security for such deferred payments.
The Casthouse Facility bears interest at a rate equal to USD LIBOR 3 month plus an applicable margin. The Casthouse Facility is secured by a $430.0 million general bond. As of December 31, 2022, there were $50.0 million in borrowings outstanding under the Casthouse Facility.
The Casthouse Facility bears interest at a rate equal to a base rate plus the applicable margin as set forth in the agreement. The Casthouse Facility is secured by a $430.0 million general bond. As of December 31, 2023, there were $104.3 million in borrowings outstanding under the Casthouse Facility.
The Company’s or Guarantors’ amounts due from, amounts due to, and transactions with the Non-Guarantor Subsidiaries are disclosed below: December 31, 2022 December 31, 2021 Current assets $ 305.7 $ 395.3 Non-current assets 704.5 935.3 Current liabilities 309.6 375.1 Non-current liabilities 487.1 556.1 33 Twelve months ended December 31, 2022 Net sales $ 1,737.2 Gross profit (loss) (37.6) Income (loss) before income taxes (187.6) Net income (loss) (14.1) As of December 31, 2022 and December 31, 2021, an intercompany receivable due to the Company and Guarantors from the Non-Guarantor Subsidiaries totaled $18.2 million and $15.1 million, respectively, and an intercompany non-current loan due to the Company from the Non-Guarantor Subsidiaries totaled $466.3 million and $554.2 million, respectively.
The Company’s or Guarantors’ amounts due from, amounts due to, and transactions with the Non-Guarantor Subsidiaries are disclosed below: December 31, 2023 December 31, 2022 Current assets $ 361.5 $ 305.7 Non-current assets 648.6 704.5 Current liabilities 253.6 309.6 Non-current liabilities 485.7 487.1 Twelve months ended December 31, 2023 Net sales $ 1,427.7 Gross profit (loss) 112.6 Income (loss) before income taxes 74.0 Net income (loss) (43.1) As of December 31, 2023 and December 31, 2022, an intercompany receivable due to the Company and Guarantors from the Non-Guarantor Subsidiaries totaled $48.7 million and $18.2 million, respectively, and an intercompany non-current loan due to the Company from the Non-Guarantor Subsidiaries totaled $384.9 million and $466.3 million, respectively.
Future uncertainty in the U.S. and international markets and economies may adversely affect our liquidity, our ability to access the debt or capital markets and our financial condition. Capital expenditures incurred for the year ended December 31, 2022 were $17.3 million, excluding expenditures of $16.2 million associated with the restart at Mt.
Future uncertainty in the U.S. and international markets and economies may adversely affect our liquidity, our ability to access the debt or capital markets and our financial condition. Capital expenditures incurred for the year ended December 31, 2023 were $25.9 million, excluding expenditures of $69.1 million associated with the Grundartangi casthouse project.
Holly and $40.0 million associated with the Grundartangi casthouse project. We 35 estimate our total capital spending in 2023, excluding the Grundartangi casthouse project, will be approximately $24 million, related to our ongoing investment and sustainability projects at our plants. Critical Accounting Estimates Our significant accounting policies are described in Note 1.
We estimate our total capital spending in 2024, excluding the Grundartangi casthouse project, will be approximately $20 to $30 million, related to our ongoing investment and sustainability projects at our plants. Critical Accounting Estimates Our significant accounting policies are described in Note 1. Summary of Significant Accounting Policies to the consolidated financial statements.
As of December 31, 2022, our credit facilities had $100.7 million of net availability after consideration of our outstanding borrowings and letters of credit. We may borrow and make repayments under our revolving credit facilities in the ordinary course based on a number of factors, including the timing of payments from our customers and payments to our suppliers.
We may borrow and make repayments under our revolving credit facilities in the ordinary course based on a number of factors, including the timing of payments from our customers and payments to our suppliers.
Income tax (expense) benefit (in millions) 2022 2021 Twelve months ended December 31, $ (47.4) $ 30.6 Income tax benefit (expense): We have a valuation allowance against all of our U.S. and certain foreign deferred tax assets. We recognized $(47.4) million income tax expense in 2022 as compared to income tax benefit of $30.6 million in 2021.
Income tax benefit (expense) (in millions) 2023 2022 Twelve months ended December 31, $ 14.6 $ (47.4) Income tax benefit (expense): We have a valuation allowance recorded against our net U.S. and Jamaican deferred tax assets, and a portion of our Icelandic deferred tax assets as of December 31, 2023.
Other Items 34 On January 17, 2023, our wholly owned subsidiary, Mt. Holly Commerce Park LLC, entered into a binding agreement, subject to ordinary course conditions, to sell approximately 133 acres of land for approximately $28.5 million. We previously formed the commerce park, located near our Mt.
On January 17, 2023, our wholly owned subsidiary, Mt. Holly Commerce Park LLC, entered into a binding agreement, subject to ordinary course conditions, to sell approximately 133 acres of land for approximately $28.5 million. On September 12, 2023, the Mt. Holly Land Sale Agreement was completed at a revised purchase price of $25.7 million.
Determination as to whether and how much an asset is impaired involves significant management judgment involving highly uncertain matters, including estimating the future sales volumes, future selling prices and estimated raw material and conversion costs, alternative uses for the asset, and estimated proceeds from the disposal of the asset.
These estimates of future cash flows include management’s assumptions about the expected use of the assets (asset group), the remaining useful life, expenditures to maintain the service potential, market and cost assumptions. 42 Determination as to whether and how much an asset is impaired involves significant management judgment involving highly uncertain matters, including estimating the future sales volumes, future selling prices and estimated raw material and conversion costs, alternative uses for the asset, and estimated proceeds from the disposal of the asset.
Selling, general and administrative expenses (in millions) 2022 2021 Twelve months ended December 31, $ 37.5 $ 57.6 Selling, general and administrative expenses: Selling, general and administrative expenses decreased $20.1 million in 2022 compared to 2021, primarily due to decreases in share-based compensation due to fluctuations in the Company's stock price year over year.
Selling, general and administrative expenses (in millions) 2023 2022 Twelve months ended December 31, $ 44.3 $ 37.5 Selling, general and administrative expenses: Selling, general and administrative expenses increased $6.8 million in 2023 compared to 2022, primarily due to increases in share-based compensation due to the increase in the Company's stock price year over year. See Note 14.
We regularly explore various other financing alternatives. Our principal uses of cash include the funding of operating costs (including post-retirement benefits), debt service requirements, capital expenditures, investments in our growth activities and in related businesses, working capital and other general corporate requirements.
Our principal uses of cash include the funding of operating costs (including post-retirement benefits), debt service requirements, capital expenditures, investments in our growth activities and in related businesses, working capital and other general corporate requirements. We believe that cash provided from operations and financing activities will be adequate to cover our operations and business needs over the next 12 months.
As of December 31, 2022, our U.S. revolving credit facility had a borrowing base of $165.5 million, $90.0 million in outstanding borrowings, and $34.9 million in letters of credit outstanding. The borrowing base under the U.S. revolving credit facility has been adversely affected by the curtailment of our Hawesville facility.
As of December 31, 2023, our U.S. revolving credit facility had a borrowing base of $128.8 million, $23.7 million in outstanding borrowings, and $ 61.4 million in letters of credit outstanding. The borrowing base under the U.S. revolving credit facility has been adversely affected by the curtailment of our Hawesville facility and a reduction in LME and regional premium prices.
The average European Duty Paid premium was $466 per tonne in 2022 compared to $272 per tonne in 2021 and $126 per tonne in 2020. Energy, Key Supplies and Raw Materials Our operating costs are significantly impacted by changes in the prices of the materials used in the production of aluminum, including alumina, electrical power and carbon products.
December 31, ($ per tonne) 2023 2022 2021 Average LME $ 2,252 $ 2,707 $ 2,475 Average MWP $ 512 $ 657 $ 581 Average EDPP $ 277 $ 466 $ 272 Energy, Key Supplies and Raw Materials Our operating costs are significantly impacted by changes in the prices of the materials used in the production of aluminum, including alumina, electrical power and carbon products.
In 2011, our Board of Directors approved a $60.0 million common stock repurchase program and subsequently increased this program by $70.0 million in the first quarter of 2015.
The Grundartangi casthouse project began in late 2021 and is fully funded through the Casthouse Facility. The project is progressing and is expected to start production in the first quarter of 2024. In 2011, our Board of Directors approved a $60.0 million common stock repurchase program and subsequently increased this program by $70.0 million in the first quarter of 2015.
In Iceland, approximately 70 % of the power requirements for our Grundartangi plant are indexed to the price of primary aluminum, which provides a natural hedge of one of our largest production costs.
Under this power supply agreement, 100% of Mt. Holly’s current electrical power requirements are supplied from Santee Cooper’s generation at cost of service based rates. In Iceland, approximately 70% of the power requirements for our Grundartangi plant are indexed to the price of primary aluminum, which provides a natural hedge of one of our largest production costs.
The change in net cash provided by financing activities from 2022 compared to 2021 was primarily due to borrowings under the Grundartangi casthouse facility and Iceland term facility in 2022 as compared to net borrowings on our revolving credit facilities in 2021.
The change in net cash used in financing activities in 2023 compared to net cash provided by financing activities in 2022 was primarily due to net repayments on our revolving credit facilities in 2023 and repayment of the Iceland Term Facility, partially offset by the sale of carbon credits and proceeds from the Vlissingen Facility Agreement.
Alumina and electrical power represent the two largest components of our cost of goods sold. As a result, the availability of these cost components at competitive prices is critical to the profitability of our operations. The pricing under our alumina supply contracts varies from contract to contract.
As a result, the availability of these cost components at competitive prices is critical to the profitability of our operations. The pricing under our alumina supply contracts varies from contract to contract. A major portion of our alumina requirements is indexed to the price of primary aluminum, which provides a natural hedge to one of our largest production costs.
The changes were partially offset by favorable LME and regional premium price realizations of $496.9 million, and favorable volume and product mix of $28.2 million driven by the restart at our Mt. Holly facility, curtailment at our Hawesville smelter and higher value-added product premiums.
The changes were partially offset by unfavorable LME and regional premium price realizations of $384.6 million and unfavorable volume and product mix of $33.0 million driven by the curtailment at our Hawesville smelter.
From time to time, we may manage our exposure to fluctuations in our alumina costs by purchasing certain of our 38 alumina requirements under supply contracts with prices tied to the same indices as our aluminum sales contracts (the LME price of primary aluminum).
From time to time, we may manage our exposure to fluctuations in our alumina costs by purchasing certain of our alumina requirements under supply contracts with prices tied to the same indices as our aluminum sales contracts (the LME price of primary aluminum). 43 Market-Based Power Price Sensitivity Market-Based Electrical Power Agreements Hawesville and Sebree have a market-based electrical power agreement with Kenergy and Century Marketer, LLC ("Century Marketer"), Century's wholly-owned subsidiary that acts as a MISO market participant.
Net gain (loss) on forward and derivative contracts (in millions) 2022 2021 Twelve months ended December 31, $ 197.1 $ (212.4) Net gain (loss) on forward and derivative contracts: In 2022, we recognized gains of $197.1 million primarily driven by decreases in LME and MWP forward prices, and increased gains on Nord Pool derivative contracts due to Nord Pool power forward price increases.
In 2022, we recognized gains of $197.1 million primarily driven by decreases in LME and MWP forward prices, and increased gains on Nord Pool derivative contracts due to Nord Pool power forward price increases. See Note 20. Derivatives to the consolidated financial statements included herein for additional information.
Market-Based Power Price Sensitivity Market-Based Electrical Power Agreements Hawesville and Sebree have market-based electrical power agreements pursuant to which EDF and Kenergy purchase electrical power on the open market and pass it through at MISO energy pricing, plus transmission and other costs incurred by them. See
Under this agreement, Century Marketer purchases electrical power on the open market for resale to Kenergy, which then resells the power to Hawesville and Sebree at MISO energy pricing, plus transmission and other costs incurred by them. See
As of December 31, 2022, we had cash and cash equivalents of approximately $54.3 million, unused availability under our revolving credit facilities of $100.7 million, and additional liquidity of $90.0 million under the Vlissingen Facility Agreement, resulting in a total liquidity position of approximately $245.0 million.
As of December 31, 2023, we had cash and cash equivalents of approximately $88.8 million and unused availability under our revolving credit facilities of $223.7 million (including $80.0 million under the Vlissingen Facility Agreement referred to below).
"Guarantor Subsidiaries" refers to all of our material domestic subsidiaries except for Nordural US LLC, Century Aluminum Development LLC and Century Aluminum of West Virginia, Inc. The Guarantor Subsidiaries are 100% owned by Century. All guarantees will be full and unconditional; all guarantees will be joint and several.
The Guarantor Subsidiaries are 100% owned by Century. All guarantees will be full and unconditional; all guarantees will be joint and several.
Any adverse changes in the conditions that affect shipment volumes could have a material adverse effect on our results of operations and cash flows.
Any adverse changes in the conditions that affect shipment volumes could have a material adverse effect on our results of operations and cash flows. Our 2023 shipment volumes were adversely impacted by the curtailment of our Hawesville facility in August 2022. This was partially offset by a full year of Mt. Holly operating at 75% capacity in 2023.
The alumina price is influenced by a number of factors, including global supply-demand balance, natural disasters and weather events, and other factors outside of our control. The average market alumina index price as a percentage of market LME price per tonne for 2022 was 13 % compared to 13% for 2021 and 16% for 2020.
We also purchase alumina based on a published alumina index and at fixed prices. The alumina price is influenced by a number of factors, including global supply-demand balance, natural disasters and weather events, and other factors outside of our control.
As of December 31, 2022, we have not issued any debt securities pursuant to the Universal Shelf Registration Statement. However, any securities that we may issue in the future may limit our ability, and the ability of certain of our subsidiaries, to pay dividends or make distributions in respect of capital stock.
As of December 31, 2023, we have not issued any debt securities pursuant to the Universal Shelf Registration Statement.
The change in net cash provided by operating activities was primarily driven by improvement in results of operations year over year. The change was further due to changes in working capital primarily attributable to timing of payables, timing of raw material receipts, and pricing increases, and partially offset by hedge settlements.
The change in net cash provided by operating activities was due to changes in working capital primarily attributable to timing of receipts and payments. The decrease in net cash used in investing activities during 2023 was primarily attributable to $25.7 million in proceeds from the Mt.
We also have access to our existing U.S. and Iceland revolving credit facilities (collectively, the "revolving credit facilities") and have raised capital in the past through public equity and debt markets. Additionally, on December 9, 2022, Vlissingen entered into the Vlissingen Facility Agreement (defined below) pursuant to which it may borrow from time to time up to $90.0 million.
Liquidity and Capital Resources Liquidity Our principal sources of liquidity are available cash and cash flow from operations. We also have access to our existing U.S. and Iceland revolving credit facilities (collectively, the "revolving credit facilities") and have raised capital in the past through public equity and debt markets. We regularly explore various other financing alternatives.
In 2021, we recognized losses of $212.4 million primarily related to LME and MWP fixed forward financial sales contracts. The losses were primarily driven by fluctuations in forward prices. See Note 19. Derivatives to the consolidated financial statements included herein for additional information.
Share-based compensation to the consolidated financial statements included herein for additional information. 35 Net (loss) gain on forward and derivative contracts (in millions) 2023 2022 Twelve months ended December 31, $ (61.8) $ 197.1 Net (loss) gain on forward and derivative contracts: In 2023, we recognized losses of $61.8 million primarily driven by decreases in LME and Nord Pool forward prices.
The increase in net cash used in investing activities during 2022 was primarily due to higher spending on capital projects during the twelve months ended December 31, 2022, driven by capital investments in the Mt. Holly restart project and the Grundartangi casthouse project.
Holly Commerce Park Land sale and $11.5 million related to the acquisition of Jamalco, net of cash acquired, partially offset by higher spending on capital projects during the twelve months ended December 31, 2023.
Holly smelter, to develop excess land at the site and to assist the county with bringing additional business and commerce to the area. During 2021, we initiated efforts to restart the curtailed capacity at our Mt. Holly facility. The project was completed during the second quarter of 2022, resulting in total production of 75% of Mt. Holly's full capacity.
The proceeds from this sale are restricted to be used on capital expenditures. We previously formed the commerce park, located near our Mt. Holly smelter, to develop excess land at the site and to assist the county with bringing additional business and commerce to the area. During 2021, we announced plans for construction of a new billet casthouse at Grundartangi.