UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16
UNDER THE SECURITIES EXCHANGE ACT OF 1934
For the month of March, 2023
Commission File Number 001-36487

Atlantica Sustainable Infrastructure plc
(Exact name of Registrant as specified in its charter)

Not applicable
(Translation of Registrant’s name into English)

Great West House, GW1, 17th floor
Great West Road
Brentford, TW8 9DF
United Kingdom
Tel: +44 203 499 0465

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

☒ Form 20-F |  | ☐ Form 40-F

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐
Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

FY 2022 Earnings Presentation March 1, 2023

DISCLAIMER Forward Looking Statements This presentation contains forward-looking statements. These forward-looking statements include, but are not limited to, all statements other than statements of historical facts contained in this presentation, including, without limitation, those regarding our future financial position and results of operations, our strategy, plans, objectives, goals and targets, future developments in the markets in which we operate or are seeking to operate. In some cases, you can identify forward-looking statements by terminology such as "anticipate," "believe," "could," "estimate," "expect,“, "guidance," "intend," "may," "plan," "potential," "predict," "should" or "will" or the negative of such terms or other similar expressions or terminology. By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. Forward-looking statements speak only as of the date of this presentation and are not guarantees of future performance and are based on numerous assumptions. Our actual results of operations, financial condition and the development of events may differ materially from (and be more negative than) those made in, or suggested by, the forward-looking statements. Except as required by law, we do not undertake any obligation to update any forward-looking statements to reflect events or circumstances after the date hereof or to reflect anticipated or unanticipated events or circumstances. Investors should read the section entitled "Item 3.D.—Risk Factors" and the description of our segments and business sectors in the section entitled "Item 4.B. Information on the Company—Business Overview", each in our Annual Report on Form 20-F for the fiscal year ended December 31, 2022, filed with the Securities and Exchange Commission (“SEC”), for a more complete discussion of the risks and factors that could affect us. Forward-looking statements include, but are not limited to, statements relating to: expected value; new investments and projects, including the ones committed or earmarked for investment in 2023, projects currently under construction or expected to start construction, as well as statements with respect to our pipeline and expected combined output capacity; our focus on North America supported by the Inflation Reduction Act in the U.S. ; our anticipated exposure to current market risks, including the potential impact from foreign exchange rates and interest rates on cash available for distribution (“CAFD”); the impact from potential caps on market prices on the net value of our assets; taxes on electricity companies in Spain; equity investments; CAFD estimates, including per currency, geography, sector and escalation factors; net corporate leverage based on CAFD estimates; debt refinancing; the quality of our off-takers and the performance of our long-term contracts; self-amortizing project debt structure and debt reduction; the use of non-GAAP measures as a useful tool for investors; the possibility to extend asset life; dividends; achievement of environmental, social and governance goals; and various other factors, including those factors discussed under “Item 3.D.—Risk Factors” and “Item 5.A.—Operating Results” in our Annual Report on Form 20-F for the fiscal year ended December 31, 2022 filed with the SEC. The CAFD, Adjusted EBITDA and other guidance referred to in this presentation are estimates as of March 1, 2023. These estimates are based on assumptions believed to be reasonable as of the date Atlantica Sustainable Infrastructure plc (“Atlantica”, the “Company”, “we” or “us”) published its 2022 Financial Results. We disclaim any current intention to update such guidance, except as required by law. Non-GAAP Financial Measures This presentation also includes certain non-GAAP financial measures, including Adjusted EBITDA, CAFD and CAFD per share. Non-GAAP financial measures are not measurements of our performance or liquidity under IFRS as issued by IASB and should not be considered alternatives to operating profit or profit for the period or net cash provided by operating activities or any other performance measures derived in accordance with IFRS as issued by the IASB or any other generally accepted accounting principles or as alternatives to cash flow from operating, investing or financing activities. Please refer to the appendix of this presentation for a reconciliation of the non-GAAP financial measures included in this presentation to the most directly comparable financial measures prepared in accordance with IFRS as well as the reasons why management believes the use of non-GAAP financial measures (including CAFD, CAFD per share and Adjusted EBITDA) in this presentation provides useful information to investors. In our discussion of operating results, we have included foreign exchange impacts in our revenue and Adjusted EBITDA growth. The constant currency presentation is not a measure recognized under IFRS and excludes the impact of fluctuations in foreign currency exchange rates. We believe that constant currency information provides valuable supplemental information regarding our results of operations. We calculate constant currency amounts by converting our current period local currency revenue and Adjusted EBITDA using the prior period foreign currency average exchange rates and comparing these adjusted amounts to our prior period reported results. This calculation may differ from similarly titled measures used by others and, accordingly, the constant currency presentation is not meant to be a substitute for recorded amounts presented in conformity with IFRS as issued by the IASB nor should such amounts be considered in isolation.

Key Messages Revenue and Adjusted EBITDA year-over-year growth of 2.9%1 and 1.5%1 on a comparable basis Compared to the year 2021, on a constant currency basis and adjusted for the consolidation of a non-recurrent Rioglass solar project in the year 2021. +5.5% year-over-year CAFD growth in 2022 up to $237.9 million 2023 CAFD guidance established at $235M-$260M +16.0% Operating Cash Flow year-over-year growth up to $586.3 million Attractive growth opportunities including ~$165-185 million in investments already committed or earmarked for 2023

1. Financial Results FY 2022 Results Presentation

∆ Excluding FX impact & non-recurrent project US$ in million (except CAFD per share) 2022 2021 ∆ Reported Revenue 1,102.0 1,211.7 (9.1)% Adjusted EBITDA 797.1 824.4 (3.3)% CAFD 237.9 225.6 5.5% CAFD per share2 2.07 2.03 2.1% HIGHLIGHTS 5.5% CAFD Growth in 2022 Compared to 2021, on a constant currency basis and adjusted for the consolidation of a non-recurrent Rioglass solar project in 2021. CAFD per share is calculated by dividing CAFD for the year by the weighted average number of shares for the year (see reconciliation on page 32). 2.9%1 1.5%1

HIGHLIGHTS Performance by Region and Sector WATER 2022 2021 ∆ 53.8 53.9 0% 36.5 38.2 (4)% RENEWABLES US$ in million 2022 2021 ∆ ∆ Excl. FX impact & non- recurrent project1 Revenue 821.4 928.5 (12)% +4% Adjusted EBITDA 588.0 602.6 (2)% +4% EFFICIENT NAT. GAS & HEAT 2022 2021 ∆ 113.6 123.7 (8)% 84.6 100.0 (15)% TRANSMISSION LINES 2022 2021 ∆ 113.2 105.6 +7% 88.0 83.6 +5% By Sector EMEA NORTH AMERICA US$ in million 2022 2021 ∆ Revenue 405.1 395.8 +2% Adjusted EBITDA 310.0 311.8 (1%) SOUTH AMERICA 2022 2021 ∆ ∆ Excl. FX impact & non- recurrent project1 530.5 660.9 (20)% +2% 360.6 393.0 (8)% +2% By Region 2022 2021 ∆ 166.4 155.0 +7% 126.5 119.6 +6% Compared to 2021, on a constant currency basis and adjusted for the consolidation of a non-recurrent Rioglass solar project in 2021.

Includes 49% of Vento II production since its acquisition. Includes curtailment in wind assets for which we receive compensation. Represents total installed capacity in assets owned or consolidated at the end of the year, regardless of our percentage of ownership in each of the assets, except for Vento II, for which we have included our 49% interest. GWh produced includes 30% share of the production from Monterrey. Availability refers to the time during which the asset was available to our client totally or partially divided by contracted or budgeted availability, as applicable. Includes 43 MW corresponding to our 30% share in Monterrey and 55 MWt corresponding to thermal capacity from Calgary District Heating. WATER RENEWABLES TRANSMISSION LINES EFFICIENT NATURAL GAS & HEAT 2022 2021 Availability4 102.3% 97.9% Mft3 in operation2 17.5 17.5 2022 2021 GWh produced1 5,319 4,655 MW in operation2 2,121 2,044 2022 2021 GWh produced3 2,501 2,292 Availability4 98.9% 100.6% MW in operation5 398 398 2022 2021 Availability4 100.0% 100.0% Miles in operation 1,229 1,166 KEY OPERATIONAL METRICS Steady Operational Performance

Consolidated cash as of December 31, 2022, decreased by $21.7 million vs December 31, 2021, including FX translation differences of $(15.6) million. CASH FLOW Operating Cash Flow US$ in million 2022 2021 Adjusted EBITDA 797.1 XX 824.4 Share in Adjusted EBITDA of unconsolidated affiliates (45.8) (31.1) Net interest and income tax paid (277.3) (342.3) Changes in working capital 78.8 ) (3.1) Non-monetary adjustments and other 33.5 57.7 OPERATING CASH FLOW 586.3 505.6 Acquisitions of subsidiaries and entities under the equity method and investments in assets under development and construction (87.3) (369.5) Distributions from entities under the equity method & other 29.9 18.3 INVESTING CASH FLOW (57.4) (351.2) FINANCING CASH FLOW (535.0) (380.1) Net change in consolidated cash1 (6.1) (225.7) +16.0%

Net debt corresponds to gross debt including accrued interest less cash and cash equivalents. Net corporate debt is calculated as long-term corporate debt plus short-term corporate debt minus cash and cash equivalents at Atlantica’s corporate level. Net project debt is calculated as long-term project debt plus short-term project debt minus cash and cash equivalents at the consolidated project level. Net corporate leverage is calculated as net corporate debt divided by 2022 CAFD before corporate debt service. CAFD pre-corporate debt service is calculated as CAFD plus corporate debt interest paid by Atlantica. US$ in million As of Dec. 31, 2022 As of Dec. 31, 2021 Net Corporate Debt2 956.4 934.8 Net Project Debt3 4,012.9 4,501.8 Net Corporate debt / CAFD pre corporate debt service4 3.4x NET DEBT Net Corporate Debt to CAFD pre corporate interest at 3.4x Net Debt Position1

Climate Change “A List” Leadership S&P Global Sustainability Yearbook 2023 GHG Emissions Reduction Approved Science-Based GHG Emissions Reduction Target Recipient of the Terra Carta Seal c 3rd consecutive year 2nd consecutive year 2nd consecutive year Utility Industry Top Rated ESG Risk Rating ESG Our Efforts on ESG Continue to be Recognized Climate Change “A List” Leadership Climate Change “A List” Leadership New 3rd consecutive year 3rd consecutive year Ranked among World's 100 Most Sustainable Corporations Bloomberg Gender-Equality Index Equal and inclusive workplaces GRESB Infrastructure Public Disclosure A Rating Ranked 1st. Best performer

2. 2023 Outlook and Growth FY 2022 Results Presentation

GROWTH UPDATE $165-185 Million Already Committed or Earmarked for 2023 Already Committed or Earmarked for 2023 $165-185M1 Coso Batteries 1 Batteries US $40-50M PV $80-85M Expansion of our existing lines Transmission $18-20M Storage, our first hydrogen project2 & others Others $25-30M North America, South America & Europe Estimation of equity already invested, committed or earmarked for investment in 2023 in projects currently under construction or expected to start construction in 2023, including expansions and repowerings. 10 MW PV and hydrogen electrolyzer and equipment. Recently won a $6.5 million grant. Most of the investment is expected in 2024-2025.

790 235 850 260 2023E Guidance1 Range in $ Millions Adjusted EBITDA2 CAFD - - See “Disclaimer – Forward Looking Statements”. See reconciliation of 2023E Guidance on page 33. Adjusted EBITDA guidance includes a negative non-cash adjustment for approximately $60.2 million corresponding to the difference between billings and revenue in assets accounted for as concessional financial assets, primarily related to ACT, a negative non-cash provision of up to $65.5 million related to electricity market prices in Spain and a positive non-cash adjustment of $58.4 million corresponding to U.S. cash grants. 2023 TARGETS 2023E Target Guidance

Appendix FY 2022 Results Presentation

CURRENCY SECTOR GEOGRAPHY Based on CAFD estimates for the 2023-2026 period as of March 1, 2023, for the assets as of December 31, 2022, including assets that have reached COD before March 1, 2023. See “Disclaimer – Forward Looking Statements”. Euro denominated cash flows from Spanish assets, net of euro-denominated corporate interest payments and general and administrative expenses, are hedged through currency options on a rolling basis 100% for the next 12 months and 75% for the following 12 months. Based on weighted outstanding debt as of December 31, 2022. of interest rates in project debt are fixed or hedged3 90 Denominated in USD or hedged2 % > 70% Renewable 15% Eff. Natural Gas & Heat 12% Transmission Lines 3% Water 40% North America 34% Europe 18% South America 8% RoW SIZEABLE AND DIVERSIFIED ASSET PORTFOLIO Portfolio Breakdown Based on Estimated CAFD1 INTEREST RATES ~92 %

Calculated as the average net euro exposure expected for the years 2023-2026 multiplied by the difference between our average euro/dollar hedged rate for 2023 and the euro/dollar rate as of February 24, 2023, reduced by 5% and dividing the result by the midpoint CAFD 2023 Guidance. Calculated as percentage of Adjusted EBITDA for the year 2022. Expected annual impact calculated on outstanding debt as of December 31, 2022, with interest rates as of December 31, 2022, divided by the midpoint CAFD 2023 Guidance. RISK MITIGATION STRATEGY Limited Exposure to Market Risks Limited Impact from Euro FX on CAFD Natural hedge: distributions of assets in Europe are partially offset with corporate interest and corporate G&A paid in euros The resulting net euro exposure is hedged through currency options on a rolling basis: 100% for the next 12 months and 75% for the following 12 months After month 24: ~2% potential impact on CAFD calculated as the difference of net euro exposure converted at current rate reduced by 5% and at average hedged rate for 20231 ~50% of the Portfolio with Indexed Revenue 32% Indexed to inflation or formula based on inflation 15% Indexed to a fixed number 53% Not indexed Interest Rate Risk Highly Covered An increase of 100bp in reference interest rates would have an impact on CAFD of ~1.5%3 Regulated Assets in Europe No expected impact from potential caps on market prices on the net value of our assets No material impact expected from taxes announced on energy companies ü

HISTORICAL FINANCIAL REVIEW Key Financials by Quarter (1/2) “Deposits into/ withdrawals from restricted accounts” and “Change in non-restricted cash at project level” are calculated on a constant currency basis to reflect actual cash movements isolated from the impact of variations generated by foreign exchange changes during the period. Prior periods have been recalculated to conform to this presentation. Dividends are paid to shareholders in the quarter after they are declared. (3) Number of shares outstanding on the record date corresponding to each dividend, except the shares issued under the ATM program between the dividend declaration date and the dividend record date. 2020 1Q21 2Q21 3Q21 4Q21 2021 1Q22 2Q22 3Q22 4Q22 2022 Revenue 1,013,260 268,178 342,997 329,244 271,331 1,211,749 247,452 307,832 303,121 243,624 1,102,029 Adjusted EBITDA 796,123 171,249 232,985 229,846 190,307 824,388 173,626 228,678 228,336 166,459 797,100 Atlantica’s pro-rata share of EBITDA from unconsolidated affiliates (14,468) (3,298) (4,295) (8,451) (15,013) (31,057) (14,202) (15,988) (7,387) (8,192) (45,769) Non-monetary items (43,943) (6,834) 8,625 33,675 20,346 55,809 10,413 10,940 10,839 (4,196) 27,996 Accounting provision for electricity market prices in Spain (22,311) (659) 11,643 41,582 24,489 77,055 7,141 10,585 10,507 (2,980) 25,253 Difference between billings and revenue in assets accounted for as concessional financial assets 43,344 8,501 11,659 6,771 11,959 38,890 18,169 15,050 14,978 13,434 61,630 Income from cash grants in the US (58,868) (14,678) (14,678) (14,678) (14,678) (58,711) (14,897) (14,695) (14,645) (14,650) (58,888) Other non-monetary items (6,108) - - - (1,424) (1,424) - - - - - Maintenance Capex (4,618) (3,278) (1,098) (246) (13,100) (17,722) (2,844) (3,614) (7,283) (4,847) (18,588) Dividends from unconsolidated affiliates 22,246 8,799 4,431 11,385 10,268 34,883 31,870 11,921 12,411 11,493 67,695 Net interest and income tax paid (287,239) (30,872) (132,857) (45,301) (133,234) (342,263) (16,546) (112,705) (32,885) (115,148) (277,284) Changes in other assets and liabilities 4,140 35,459 (1,699) (11,873) 21,806 43,696 (5,588) 6,415 52,186 49,885 102,896 Deposits into/withdrawals from debt service accounts1 90,433 (29,639) 17,229 (8,456) 23,595 2,729 11,805 8,020 (20,503) 33,696 33,018 Change in non-restricted cash at project companies1 (78,618) (71,162) 47,730 (89,947) 115,588 2,209 (103,116) 51,501 (135,718) 125,662 (61,672) Dividends paid to non-controlling interests (22,944) (4,215) (7,395) (11,717) (4,807) (28,134) (6,221) (9,800) (10,421) (12,767) (39,209) Principal amortization of indebtedness net of new indebtedness at projects (260,422) (14,972) (104,999) (40,336) (158,684) (318,991) (24,789) (112,427) (27,912) (183,183) (348,311) Cash Available For Distribution (CAFD) 200,691 51,237 58,657 58,580 57,073 225,547 54,407 62,941 61,662 58,862 237,872 Dividends declared2 173,494 47,643 47,807 48,493 49,479 193,422 50,202 51,332 51,645 51,645 204,824 # of shares3 110,797,738 111,178,846 111,477,263 112,451,438 114,095,845 115,352,085 116,055,126 116,055,126 DPS (in $ per share) 1.67 0.43 0.43 0.435 0.44 1.735 0.44 0.445 0.445 0.445 1.775 Key Financials US$ in thousands

Debt Details 2020 1Q21 2Q21 3Q21 4Q21 2021 1Q22 2Q22 3Q22 4Q22 2022 Project Debt 5,237.6 5,200.2 5,374.2 5,278.9 5,036.2 5,036.2 5,037.0 4,735.5 4,621.9 4,553.1 4,553.1 Project Cash (533.3) (624.6) (603.1) (685.0) (534.4) (534.4) (625.9) (545.1) (675.8) (540.2) (540.2) Net Project Debt 4,704.3 4,575.6 4,771.1 4,593,9 4,501.8 4,501.8 4,411.1 4,190.4 3,946.1 4,012.9 4,012.9 Corporate Debt 993.7 965.3 1,025.1 1,030.1 1,023.1 1,023.1 1,056.1 1,000.1 955.5 1,017.2 1,017.2 Corporate Cash (335.2) (434.2) (83.2) (78.6) (88.3) (88.3) (113.1) (123.1) (105.8) (60.8) (60.8) Net Corporate Debt 658.5 531.1 941.8 951.5 934.8 934.8 943.0 877.0 849.7 956.4 956.4 Total Net Debt 5,362.8 5,106.7 5,713.0 5,545.1 5,436.6 5,436.6 5,354.1 5,067.4 4,795.8 4,969.3 4,969.3 Net Corporate Debt / CAFD pre corporate interests1 3.0x 2.6x2 3.4x 3.5x 3.5x 3.5x 3.3x 3.1x 3.0x 3.4x 3.4x HISTORICAL FINANCIAL REVIEW Key Financials by Quarter (2/2) US$ in million (1) Ratios presented are the ratios shown on each earnings presentation relating to such period. (2) Net corporate debt as of March 31, 2021, was calculated pro-forma including the payment of $170 million for the Coso investment ($130 million equity investment paid in April 2021 and additional $40 million paid in July 2021 to reduce debt).

HISTORICAL FINANCIAL REVIEW Segment Financials by Quarter 2020 1Q21 2Q21 3Q21 4Q21 2021 1Q22 2Q22 3Q22 4Q22 2022 by Geography NORTH AMERICA 330,921 60,585 118,216 129,860 87,114 395,775 74,304 124,968 124,423 81,352 405,047 SOUTH AMERICA 151,460 38,308 40,043 38,778 37,856 154,985 38,528 39,804 44,217 43,892 166,441 EMEA 530,879 169,285 217,726 160,606 146,361 660,989 134,620 143,060 134,481 118,380 530,541 by Business Sector RENEWABLES 753,089 199,679 271,945 254,132 202,768 928,525 182,101 238,234 232,423 168,619 821,377 EFFICIENT NAT. GAS & HEAT 111,030 28,408 30,097 35,019 30,168 123,692 25,327 28,091 28,526 31,647 113,591 TRANSMISSION LINES 106,042 26,614 26,975 26,840 25,251 105,680 26,620 28,234 28,425 29,994 113,273 WATER 43,099 13,477 13,979 13,253 13,143 53,852 13,404 13,273 13,747 13,364 53,788 Total Revenue 1,013,260 268,178 342,996 329,244 271,331 1,211,749 247,452 307,832 303,121 243,624 1,102,029 2020 1Q21 2Q21 3Q21 4Q21 2021 1Q22 2Q22 3Q22 4Q22 2022 by Geography NORTH AMERICA 279,365 40,287 94,574 108,500 68,442 311,803 58,266 102,913 96,981 51,828 309,988 SOUTH AMERICA 120,023 29,943 30,279 30,404 28,921 119,547 29,129 29,715 36,236 31,471 126,551 EMEA 396,735 101,019 108,133 90,942 92,944 393,038 86,231 96,051 95,118 83,161 360,561 by Business Sector RENEWABLES 576,285 117,036 177,995 169,830 137,722 602,583 122,223 174,606 173,022 118,165 588,016 EFFICIENT NAT. GAS & HEAT 101,006 23,182 24,039 29,166 23,548 99,935 21,699 22,315 22,794 17,752 84,560 TRANSMISSION LINES 87,272 21,203 21,319 21,721 19,392 83,635 20,523 22,656 23,047 21,784 88,010 WATER 31,560 9,828 9,633 9,129 9,645 38,235 9,181 9,102 9,473 8,758 36,514 Total Adjusted EBITDA 796,123 171,249 232,985 229,846 190,307 824,388 173,626 228,678 228,336 166,459 797,100 Adjusted EBITDA Revenue US $ in thousands

2020 1Q21 2Q21 3Q21 4Q21 2021 1Q22 2Q22 3Q22 4Q22 2022 RENEWABLES3 (GWh) 3,244 606 1,377 1,477 1,195 4,655 1,094 1,554 1,507 1,164 5,319 (GWh)4 2,574 542 501 622 627 2,292 625 626 647 603 2,501 (availability %)5 102.1% 98.3% 100.1% 101.1% 103.0% 100.6% 100.3% 99.9% 101.1% 95.1% 98.9% TRANSMISSION LINES (availability %)5 100.0% 100.0% 99.9% 100.0% 100.0% 100.0% 99.9% 99.9% 100.0% 100.0% 100.0% WATER (availability %)5 100.1% 97.5% 101.9% 99.8% 91.9% 97.9% 104.5% 99.9% 103.3% 101.4% 102.3% 2020 1Q21 2Q21 3Q21 4Q21 2021 1Q22 2Q22 3Q22 4Q22 2022 RENEWABLES1 (MW) 1,551 1,591 2,018 2,022 2,044 2,044 2,044 2,048 2,121 2,121 2,121 EFFICIENT NAT. GAS & HEAT2 (MW) 343 343 398 398 398 398 398 398 398 398 398 TRANSMISSION LINES (Miles) 1,166 1,166 1,166 1,166 1,166 1,166 1,229 1,229 1,229 1,229 1,229 WATER1 (Mft3/day) 17.5 17.5 17.5 17.5 17.5 17.5 17.5 17.5 17.5 17.5 17.5 Capacity in operation (at the end of the period) Production / Availability Represents total installed capacity in assets owned or consolidated at the end of the period, regardless of our percentage of ownership in each of the assets, except for Vento II, for which we have included our 49% interest. Includes 43 MW corresponding to our 30% share in Monterrey and 55 MWt corresponding to thermal capacity from Calgary District Heating since May 14, 2021. Includes 49% of Vento II production since its acquisition. Includes curtailment in wind assets for which we receive compensation. GWh produced includes 30% share of the production from Monterrey. Availability refers to the time during which the asset was available to our client totally or partially divided by contracted or budgeted availability, as applicable. EFFICIENT NAT. GAS & HEAT HISTORICAL FINANCIAL REVIEW Key Performance Indicators

Historical Capacity Factors1 2020 1Q21 2Q21 3Q21 4Q21 2021 1Q22 2Q22 3Q22 4Q22 2022 SOLAR US 27.1% 18.0% 38.6% 31,0% 17.0% 26.1% 17.2% 39.1% 32.4% 16.6% 26.3% Chile2 32.0% 28.4% 20.9% 20.6% 25.8% 23.9% 25.3% 20.4% 24.6% 28.8% 24.8% Spain 16.8% 9.1% 24.8% 29.6% 10.7% 18.6% 7.3% 23.6% 27.9% 5.8% 16.2% Italy - - - 18.6% 8.3% 16.5% 12.7% 19.7% 20.0% 9.2% 15.4% Kaxu 27.3% 38.9% 26.9% 20.2% 48.4% 33.6% 36.9% 27.2% 28.8% 44.6% 34.4% US - - - 21.6% 35.4% 28.3% 38.1% 35.6% 20.3% 34.8% 32.2% Uruguay3 39.7% 32.6% 38.3% 38.2% 38.3% 36.9% 34.5% 27.7% 38.2% 41.8% 35.6% Capacity factor ratio represents actual electrical energy output over a given period of time divided by the maximum possible electrical energy output assuming continuous operation at full nameplate capacity over that period. Historical Capacity Factors are calculated from the date of entry into operation or the acquisition of each asset. Some capacity factors are not indicative of a full period of operations. Includes Chile PV 1 since Q2 2020, Chile PV 2 since Q1 2021 and Chile PV 3 since Q3 2022. Includes curtailment production in wind assets for which we receive compensation. HISTORICAL FINANCIAL REVIEW Capacity Factors WIND

Exchange rates as of December 31, 2022 (EUR/USD = 1.0705) and December 31, 2021 (EUR/USD = 1.1370). Restricted cash is cash which is restricted generally due to requirements of certain project finance agreements. US $ in million1 As of Dec. 31 2022 As of Dec. 31 2021 Corporate cash at Atlantica 60.8 88.3 Existing available revolver capacity 385.1 440.0 Total Corporate Liquidity 445.9 528.3 Cash at project companies 540.2 534.4 - Restricted2 207.6 254.3 - Other 332.6 280.1 LIQUIDITY Liquidity Position

LIQUIDITY AND DEBT MATURITIES SUMMARY Healthy Balance Sheet and Strong Liquidity Strong Liquidity and No Significant Corporate Debt Maturities in the Short-term ~$446 million @ 31/12/22 Corporate Liquidity ~4.2 years average maturity2 of current corporate debt Revolving Credit Facility’s total limit is $450 million, of which $385.1 million was available as of December 31, 2022 $445.9 million available liquidity, out of which $60.8 million was corporate cash as of Dec. 31, 2022 Corporate Debt Maturities1 Corporate Debt is the indebtedness where Atlantica Sustainable Infrastructure plc. is the primary obligor. Corporate Debt Maturities as of December 31, 2022. Corporate Liquidity means cash and cash equivalents held a Atlantica Sustainable Infrastructure plc. level plus available capacity under the Revolving Credit Facility as of December 31, 2022. Corporate Cash corresponds to cash and cash equivalents held at Atlantica Sustainable Infrastructure plc. 110 3 4

Key principle: non-recourse project financing in ring-fenced subsidiaries 100% project debt self-amortizing progressively before the end of the contracted life Low interest rate risk, with +93% of interest rates fixed or hedged ~$2bn planned debt reduction in the next 5 years1 FINANCING Self-Amortizing Project Debt Structure Project debt amortization schedule as of December 31, 2022. Does not include new project debt.

Weighted Average Life Project debt term PPAs with predefined prices for ~14 years on average1 Refinancing opportunities could increase CAFD in earlier years Possibility to extend life in many assets (excluding ATN and ATS) Tails in most assets after debt amortization Contract term2 Calculated as weighted average years remaining as of December 31, 2022 based on CAFD estimates for the 2023-2026 period, including assets that have reached COD before March 1, 2023. See “Disclaimer – Forward Looking Statements”. Regulation term in the case of Spain and Chile TL3. (3) From the total amount of $211 million project debt, $74 million are progressively repaid following a theoretical 2036 maturity, with a legal maturity in 2027. The remaining $137 million are expected to be refinanced in or before 2027. LONG-TERM STABLE CASH FLOW Portfolio of Assets 3

CORPORATE DEBT DETAILS Corporate Debt as of December 31, 2022 No significant maturities in the near term Exchange rates as of December 31, 2022 (EUR/USD = 1.0705). Amounts include principal amounts outstanding, unless stated otherwise. As of December 31, 2022, letters of credit with face value in an amount equal to $34.9 million were outstanding and $385.1 million were available under the Revolving Credit Facility. The latter has a total limit of $450 million. US $ in million1 Maturity Amounts2 Credit Facilities (Revolving Credit Facility)3 2024 29.4 (Other facilities)4 2023 – 2026 30.1 Green Exchangeable Notes5 2025 107.0 2020 Green Private Placement6 (€ denominated) 2026 308.4 Note Issuance Facility 20207 (€ denominated) 2027 147.2 Green Senior Notes8 2028 395.1 Total 1,017.2 Other facilities include the Commercial Paper Program, accrued interest payable and other debt. Senior unsecured notes dated July 17, 2020, exchangeable into ordinary shares of Atlantica, cash, or a combination of both, at Atlantica’s election. Senior secured notes dated April 1, 2020, of €290 million. Senior unsecured note facility dated July 8, 2020, of €140 million. Green Senior Unsecured Notes dated May 18, 2021, of $400 million.

fixed or hedged1 Project Debt Calculated as the weighted average of the % of fixed or hedged corporate debt and the % of fixed or hedged project debt based on outstanding balance as of December 31, 2022. (2) See our Annual Report on Form 20-F for the fiscal year ended December 31, 2022 for additional information on the specific interest rates and hedges. INTEREST RATE RISK COVERAGE 93%1 of Debt Fixed or Hedged2 ASSET INTEREST TYPE FIXED1,3 Solana Fixed 100% Mojave Fixed 100% Coso Hedged 100% Chile PV 1 & 2 Hedged 80% Palmatir Fixed 94% Cadonal Hedged 88% Melowind Hedged 75% Solaben 2 Hedged 100% Solaben 3 Hedged 100% Solacor 1 Hedged 90% Solacor 2 Hedged 90% Helioenergy 1 Hedged 99% Helioenergy 2 Hedged 99% Helios 1/2 Fixed 100% Solnova 1 Hedged 90% Solnova 3 Hedged 90% Solnova 4 Hedged 90% Solaben 1/6 Fixed 100% Kaxu Hedged 58% ACT Hedged 75% ATN Fixed 100% ATS Fixed 100% ATN 2 Fixed 100% Quadra 1 & 2 Hedged 75% Skikda Fixed 100% Tenes Fixed 100% Other Hedged 64% Hedged4 43.3% Fixed4 49.0% Total Fixed or Hedged 92.3% (3) Percentage fixed or hedged. (4) Weighted average based on outstanding balance as of December 31, 2022. (5) Other facilities include the Commercial Paper Program, accrued interest payable and other debt. INSTRUMENT INTEREST TYPE DEC. 31, 2022 Revolving Credit Facility (RCF) Variable 29.4 Green Exchangeable Notes Fixed 107.0 2020 Green Private Placement Fixed 308.4 Note Issuance Facility 2020 Hedged (100%) 147.2 Green Senior Notes Fixed 395.1 Other facilities5 Fixed 30.1 Total Outstanding Debt 1,017.2 Hedged4 14.5% Fixed4 82.0% Total Fixed or Hedged 96.5% Corporate Debt of Corporate Debt ~96% of Project Debt & ~92%

Our management believes Adjusted EBITDA, CAFD and CAFD per share are useful to investors and other users of our financial statements in evaluating our operating performance because such measures provide investors with additional tools to compare business performance across companies and across periods. Adjusted EBITDA is widely used by investors to measure a company’s operating performance without regard to items such as interest expense, taxes, depreciation and amortization, which can vary substantially from company to company depending upon accounting methods and book value of assets, capital structure and the method by which assets were acquired. Our management believes CAFD and CAFD per share are relevant supplemental measure of the Company’s ability to earn and distribute cash returns to investors and is useful to investors in evaluating our operating performance because securities analysts and other interested parties use such calculations as a measure of our ability to make quarterly distributions. In addition, CAFD and CAFD per share are used by our management team for determining future acquisitions and managing our growth. Our management uses Adjusted EBITDA, CAFD and CAFD per share as measures of operating performance to assist in comparing performance from period to period and aims to use them on a consistent basis moving forward. They also readily view operating trends as a measure for planning and forecasting overall expectations, for evaluating actual results against such expectations, and for communicating with our board of directors, shareholders, creditors, analysts and investors concerning our financial performance. Adjusted EBITDA, CAFD and CAFD per share are widely used by other companies in the same industry. We present non-GAAP financial measures because we believe that they and other similar measures are widely used by certain investors, securities analysts and other interested parties as supplemental measures of performance and liquidity. The non-GAAP financial measures may not be comparable to other similarly titled measures employed by other companies and they may have limitations as analytical tools. These measures may not be fit for isolated consideration or as a substitute for analysis of our operating results as reported under IFRS as issued by the IASB. Non-GAAP financial measures and ratios are not measurements of our performance or liquidity under IFRS as issued by the IASB. Thus, they should not be considered as alternatives to operating profit, profit for the period, any other performance measures derived in accordance with IFRS as issued by the IASB, any other generally accepted accounting principles or as alternatives to cash flow from operating, investing or financing activities. Some of the limitations of these non-GAAP measures are: they do not reflect our cash expenditures, future requirements for capital expenditures or contractual commitments; they do not reflect changes in, or cash requirements for, our working capital needs; they may not reflect the significant interest expense, or the cash requirements necessary, to service interest or principal payments, on our debts; although depreciation and amortization are non-cash charges, the assets being depreciated and amortized will often need to be replaced in the future and Adjusted EBITDA, CAFD and CAFD per share do not reflect any cash requirements that would be required for such replacements; some of the exceptional items that we eliminate in calculating Adjusted EBITDA reflect cash payments that were made, or will be made in the future; and the fact that other companies in our industry may calculate Adjusted EBITDA, CAFD and CAFD per share differently than we do, which limits their usefulness as comparative measures. We define Adjusted EBITDA as profit/(loss) for the period attributable to the parent company, after previously adding back loss/(profit) attributable to non-controlling interest, income tax expense, financial expense (net), depreciation, amortization and impairment charges of entities included in our consolidated financial statements and depreciation and amortization, financial expense and income tax expense of unconsolidated affiliates (pro-rata of our equity ownership). Until September 30, 2021, Adjusted EBITDA excluded equity of profit/(loss) of entities carried under the equity method and did not include depreciation and amortization, financial expense and income tax expense of unconsolidated affiliates (pro-rata of our equity ownership). Prior periods have been presented accordingly. CAFD is calculated as cash distributions received by the Company from its subsidiaries minus cash expenses of the Company, including debt service and general and administrative expenses. CAFD per share is calculated by dividing CAFD for the year by weighted average number of shares for the year. NON-GAAP FINANCIAL INFORMATION Reconciliation of Non-GAAP Measures

Information presented as the pro-rata share of our unconsolidated affiliates reflects our proportionate ownership of each asset in our property portfolio that we do not consolidate and has been calculated by multiplying our unconsolidated affiliates’ financial statement line items by our percentage ownership thereto. Note 7 to our consolidated financial statements as of and for the year ended December 31, 2022 includes a description of our unconsolidated affiliates and our pro rata share thereof. We do not control the unconsolidated affiliates. Multiplying our unconsolidated affiliates’ financial statement line items by our percentage ownership may not accurately represent the legal and economic implications of holding a noncontrolling interest in an unconsolidated affiliate. We include pro-rata share of depreciation and amortization, financial expense and income tax expense of unconsolidated affiliates because we believe it assists investors in estimating the effect of such items in the profit/(loss) of entities carried under the equity method (which is included in the calculation of our Adjusted EBITDA) based on our economic interest in such unconsolidated affiliates. Each unconsolidated affiliate may report a specific line item in its financial statements in a different manner. In addition, other companies in our industry may calculate their proportionate interest in unconsolidated affiliates differently than we do, limiting the usefulness of such information as a comparative measure. Because of these limitations, the information presented as the pro-rata share of our unconsolidated affiliates should not be considered in isolation or as a substitute for our or such unconsolidated affiliates’ financial statements as reported under applicable accounting principles. NON-GAAP FINANCIAL INFORMATION Reconciliation of Non-GAAP Measures

“Deposits into/ withdrawals from restricted accounts” and “Change in non-restricted cash at project level” are calculated on a constant currency basis to reflect actual cash movements isolated from the impact of variations generated by foreign exchange changes during the period. (in thousands of U.S. dollars) For the three-month period ended December 31 For the year ended December 31 2022 2021 2022 2021 Profit/(loss) for the period attributable to the Company 4,030 (11,914) (5,443) (30,080) Profit/(loss) attributable to non-controlling interest (7,922) 7,442 3,356 19,162 Income tax (22,664) (6,170) (9,689) 36,220 Depreciation and amortization, financial expense and income tax expense of unconsolidated affiliates (pro rata of our equity ownership) 7,395 6,954 24,304 18,753 Financial expense, net 86,041 89,470 310,934 340,892 Depreciation, amortization, and impairment charges 99,579 104,525 473,638 439,441 Adjusted EBITDA 166,459 190,307 797,100 824,388 Atlantica’s pro-rata share of EBITDA from unconsolidated affiliates (8,192) (15,013) (45,769) (31,057) Non-monetary items (4,196) 20,346 27,996 55,809 Accounting provision for electricity market prices in Spain (2,980) 24,489 25,253 77,055 Difference between billings and revenue in assets accounted for as concessional financial assets 13,434 11,959 61,631 38,890 Income from cash grants in the US (14,650) (14,678) (58,888) (58,711) Other non monetary items - (1,424) - (1,424) Maintenance Capex (4,847) (13,100) (18,588) (17,722) Dividends from equity method investments 11,493 10,268 67,695 34,883 Net interest and income tax paid (115,148) (133,234) (277,284) (342,263) Changes in other assets and liabilities 49,885 21,806 102,896 43,696 Deposits into/ withdrawals from restricted accounts1 33,696 23,595 33,018 2,729 Change in non-restricted cash at project level1 125,662 115,588 (61,672) 2,209 Dividends paid to non-controlling interests (12,767) (4,807) (39,209) (28,134) Debt principal repayments (183,183) (158,684) (348,311) (318,991) Cash Available For Distribution 58,862 57,073 237,872 225,547 RECONCILIATION Reconciliation of CAFD and Adjusted EBITDA to Profit for the period attributable to the Company

RECONCILIATION Reconciliation of Adjusted EBITDA to Net Cash Provided by Operating Activities (in thousands of U.S. dollars) For the three-month period ended December 31 For the three-month period ended June 30 For the year ended December 31 2022 2021 2022 2021 Net cash provided by operating activities 70,595 63,683 586,322 505,623 Net interest and income tax paid 115,149 133,234 277,284 342,263 Changes in working capital (31,027) (1,451) (78,805) 3,127 Non-monetary items & other 3,550 (20,172) (33,470) (57,682) Atlantica’s pro-rata share of EBITDA from unconsolidated affiliates 8,192 15,013 45,769 31,057 Adjusted EBITDA 166,459 190,307 797,100 824,388 Reconciliation of CAFD to CAFD per share For the three-month period ended December 31 For the year ended December 31 2022 2021 2022 2021 CAFD (in thousands of U.S. dollars) 58,862 57,073 237,872 225,547 Weighted average number of shares (basic) for the period (in thousands) 116,055 111,777 114,695 111,008 CAFD per share (in U.S. dollars) 0.5072 0.5106 2.0740 2.0318

RECONCILIATION Reconciliation of 2023 Target Guidance for Adjusted EBITDA to CAFD (in millions of U.S. dollars) Guidance1 2023E Adjusted EBITDA 790 – 850 Atlantica’s pro-rata share of EBITDA from unconsolidated affiliates (40) – (50) Dividends from equity method investments 50 – 60 Non-monetary items2 40 – 90 Net interest and income tax paid (330) – (350) Maintenance Capex (30) – (50) Dividends paid to non controlling interests (10) – (20) Principal amortization of indebtedness (290) – (310) Changes in other assets and liabilities and change in available cash at project level 0 – 80 Cash Available For Distribution 235 – 260 The forward-looking measures of 2023 Adjusted EBITDA and CAFD are non-GAAP measures that cannot be reconciled to the most directly comparable GAAP financial measure without unreasonable effort primarily because of the uncertainties involved in estimating forward looking income tax expense, mark-to-market changes in derivatives, profit attributable to non-controlling interest and Share of loss/(profit) of entities carried under the equity method to arrive at net income and which are subtracted therefrom to arrive to CAFD. Non-monetary items include (1) a positive non-cash adjustment for approximately $60.2 million corresponding to the difference between billings and revenue in assets accounted for as concessional financial assets, primarily related to ACT, (2) a positive non-cash adjustment of up to $65.5 million related to electricity market prices in Spain and (3) a negative non-cash adjustment of approximately $58.4 million related to income from cash grants in the U.S.

As of March 1, 2023 ASSET TYPE STAKE LOCATION GROSSCAPACITY OFFTAKER RATING1 YEARS INCONTRACT LEFT6 CURRENCY RENEWABLE ENERGY Solana 100% USA (Arizona) 280 MW APS BBB+/A3/BBB+ 21 USD Mojave 100% USA (California) 280 MW PG&E BB-/-/BB 17 USD Coso 100% USA (California) 135 MW SCPPA & two CCAs4 Investment grade4 16 USD Elkhorn Valley7 49% USA (Oregon) 101 MW Idaho Power Company BBB/Baa1/-- 5 USD Prairie Star7 49% USA (Minnesota) 101 MW Great River Energy --/A3/A- 5 USD Twin Groves II7 49% USA (Illinois) 198 MW Exelon Generation Co. BBB/Baa2/-- 3 USD Lone Star II7 49% USA (Texas) 196 MW n/a n/a n/a USD Chile PV 1 35% Chile 55 MW n/a n/a n/a USD3 Chile PV 2 35% Chile 40 MW n/a Not rated 8 USD3 Chile PV 3 35% Chile 73 MW n/a n/a n/a USD3 La Sierpe 100% Colombia 20 MW Coenersa5 Not rated 13 COP La Tolua 100% Colombia 20 MW Coenersa5 Not rated 10 COP Tierra Linda 100% Colombia 10 MW Coenersa5 Not rated 10 COP Albisu 100% Uruguay 10 MW Montevideo Refrescos Not rated 15 UYU Palmatir 100% Uruguay 50 MW UTE BBB/Baa2/BBB-2 11 USD Cadonal 100% Uruguay 50 MW UTE BBB/Baa2/BBB-2 12 USD Melowind 100% Uruguay 50 MW UTE BBB/Baa2/BBB-2 13 USD Mini-Hydro 100% Peru 4 MW Peru BBB/Baa1/BBB 10 USD3 Reflects the counterparties’ issuer credit ratings issued by S&P, Moody’s and Fitch, respectively, as of February 17, 2023. It refers to the credit rating of Uruguay, as UTE is unrated. USD denominated but payable in local currency. Refers to the credit rating of two Community Choice Aggregators: Silicon Valley Clean Energy and Monterrey Bar Community Power, both with A rating from S&P; Southern California Public Power Authority, the third off-taker, is not rated. AT A GLANCE Sizeable and Diversified Asset Portfolio (5) Largest electricity wholesaler in Colombia. (6) As of December 31, 2022. (7) Part of Vento II portfolio.

As of March 1, 2023 ASSET TYPE STAKE LOCATION GROSSCAPACITY OFFTAKER RATING1 YEARS INCONTRACT LEFT6 CURRENCY RENEWABLE ENERGY Solaben 2/3 70% Spain 2x50 MW Kingdom of Spain A/Baa1/A- 15/15 EUR4 Solacor 1/2 87% Spain 2x50 MW Kingdom of Spain A/Baa1/A- 14/14 EUR4 PS 10/20 100% Spain 31 MW Kingdom of Spain A/Baa1/A- 9/11 EUR4 Helioenergy 1/2 100% Spain 2x50 MW Kingdom of Spain A/Baa1/A- 14/14 EUR4 Helios 1/2 100% Spain 2x50 MW Kingdom of Spain A/Baa1/A- 14/15 EUR4 Solnova 1/3/4 100% Spain 3x50 MW Kingdom of Spain A/Baa1/A- 12/12/13 EUR4 Solaben 1/6 100% Spain 2x50 MW Kingdom of Spain A/Baa1/A- 16/16 EUR4 Seville PV 80% Spain 1 MW Kingdom of Spain A/Baa1/A- 13 EUR4 Italy PV 1 100% Italy 1.6 MW Italy BBB/Baa3/BBB 8 EUR4 Italy PV 2 100% Italy 2.1 MW Italy BBB/Baa3/BBB 8 EUR4 Italy PV 3 100% Italy 2.5 MW Italy BBB/Baa3/BBB 9 EUR4 Italy PV 4 100% Italy 3.6 MW Italy BBB/Baa3/BBB 9 EUR4 Kaxu 51% South Africa 100 MW Eskom BB-/Ba2/BB-2 12 ZAR EFFICIENT NAT. GAS & HEAT Calgary 100% Canada 55 MWt 22 High quality clients3 ~41% A+ or higher3 18 CAD ACT 100% Mexico 300 MW Pemex BBB/B1/BB- 10 USD5 Monterrey 30% Mexico 142 MW Industrial Customers Not rated 23 USD5 TRANSMISSION LINES ATN 100% Peru 379 miles Peru BBB/Baa1/BBB 18 USD5 ATS 100% Peru 569 miles Peru BBB/Baa1/BBB 21 USD5 ATN 2 100% Peru 81 miles Minera Las Bambas Not rated 10 USD5 Quadra 1/2 100% Chile 49 miles / 32 miles Sierra Gorda Not rated 12/12 USD5 Palmucho 100% Chile 6 miles Enel Generacion Chile BBB/-/BBB+ 15 USD5 Chile TL 3 100% Chile 50 miles CNE A/A2/A- n/a USD5 Chile TL 4 100% Chile 63 miles Several Mini-hydro plants Not rated 49 USD WATER Skikda 34% Algeria 3.5 Mft3/day Sonatrach & ADE Not rated 11 USD5 Honaine 26% Algeria 7 Mft3/day Sonatrach & ADE Not rated 15 USD5 Tenes 51% Algeria 7 Mft3/day Sonatrach & ADE Not rated 17 USD5 Reflects the counterparties’ issuer credit ratings issued by S&P, Moody’s and Fitch, respectively, as of February 17, 2023. It refers to the credit rating of the Republic of South Africa. Diversified mix of 22 high credit quality clients (~41% A+ rating or higher, the rest unrated). AT A GLANCE Sizeable and Diversified Asset Portfolio (4) Gross cash in euros dollarized through currency hedges. (5) USD denominated but payable in local currency. (6) As of December 31, 2022.

Great West House, GW1, 17th floor, Great West Road Brentford TW8 9DF London (United Kingdom)

SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

| Atlantica Sustainable Infrastructure plc
Date: March 1, 2023 | By: | /s/ Santiago Seage
|  | Name: | Santiago Seage
|  | Title: | Chief Executive Officer