EX-4.1

Exhibit 4.1

THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR (B) AN OPINION OF COUNSEL TO THE HOLDER (IF REQUESTED BY THE COMPANY), IN A FORM REASONABLY ACCEPTABLE TO THE COMPANY, THAT REGISTRATION IS NOT REQUIRED UNDER SAID ACT OR (II) UNLESS SOLD OR ELIGIBLE TO BE SOLD PURSUANT TO RULE 144 OR RULE 144A UNDER SAID ACT. NOTWITHSTANDING THE FOREGOING, THE SECURITIES MAY BE PLEDGED IN CONNECTION WITH A BONA FIDE MARGIN ACCOUNT OR OTHER LOAN OR FINANCING ARRANGEMENT SECURED BY THE SECURITIES. ANY TRANSFEREE OF THIS NOTE SHOULD CAREFULLY REVIEW THE TERMS OF THIS NOTE. THE PRINCIPAL AMOUNT REPRESENTED BY THIS NOTE MAY BE DIFFERENT FROM THE AMOUNTS SET FORTH ON THE FACE HEREOF.

THIS AMENDED AND RESTATED PROMISSORY NOTE AND THE RIGHTS AND OBLIGATIONS EVIDENCED HEREBY ARE SUBORDINATE IN THE MANNER AND TO THE EXTENT SET FORTH IN THAT CERTAIN SUBORDINATION AGREEMENT, DATED AS OF JULY 2, 2025 (THE “SUBORDINATION AGREEMENT”), AMONG AV SECURITIES, INC. AND THE OTHER SUBORDINATED CREDITORS PARTY THERETO (COLLECTIVELY, THE “SUBORDINATED CREDITORS”) AND ACQUIOM AGENCY SERVICES LLC, AS ADMINISTRATIVE AGENT FOR THE LENDERS (IN SUCH CAPACITY, TOGETHER WITH ITS SUCCESSORS AND ASSIGNS, THE “ADMINISTRATIVE AGENT”); AND EACH HOLDER OF THIS AMENDED AND RESTATED PROMISSORY NOTE, BY ITS ACCEPTANCE HEREOF, IRREVOCABLY AGREES TO BE BOUND BY THE PROVISIONS OF THE SUBORDINATION AGREEMENT. IN THE EVENT OF ANY CONFLICT BETWEEN THE TERMS OF THE SUBORDINATION AGREEMENT AND THIS AMENDED AND RESTATED PROMISSORY NOTE, THE TERMS OF THE SUBORDINATION AGREEMENT SHALL GOVERN AND CONTROL.

FTC SOLAR, INC.

AMENDED AND RESTATED PROMISSORY NOTE

Issuance Date: December 4, 2024 (amended and restated on July 2, 2025)

Original Principal Amount: $15,000,000

FOR VALUE RECEIVED, FTC Solar, Inc., a Delaware corporation (the “Company”), hereby promises to pay to the order of AV Securities, Inc. or its affiliates or registered assigns (“Holder”) the amount set forth above as the Original Principal Amount (as reduced pursuant to the terms hereof pursuant to redemption, conversion or otherwise, the “Principal”) when due, whether upon the Maturity Date, or upon acceleration, redemption or otherwise (in each case in accordance with the terms hereof and subject to the terms, conditions and restrictions of the Subordination Agreement) and, subject to the terms, conditions and restrictions of the Subordination Agreement, to pay interest (“Interest”) on any outstanding Principal at the applicable Interest Rate (as defined below) plus, after the occurrence and continuation of

any Event of Default and written request of the Holder, the Default Rate (as provided in Section 2(c) below), from December 4, 2024 (the “Issuance Date”) until the same becomes due and payable, whether upon the Maturity Date or upon acceleration, conversion, redemption or otherwise (in each case, subject to the terms, conditions and restrictions of the Subordination Agreement and in accordance with the terms hereof). This Promissory Note (including all Promissory Notes issued in exchange, transfer or replacement hereof, this “Note”) is one of an issue of Promissory Notes issued pursuant to the Securities Purchase Agreement, dated as of December 4, 2024 (the “Subscription Date”), by and among the Company and the investors (the “Buyers”) referred to therein, as amended by Amendment No.1 thereto, dated as of July 2, 2025 and as further amended from time to time (collectively, the “Notes”)). Certain capitalized terms used herein are defined in Section 21. Capitalized terms not defined herein shall have the meanings ascribed to them in the Securities Purchase Agreement.

1. PAYMENT; PREPAYMENT. On the Maturity Date, the Company shall pay to the Holder an amount in cash representing all outstanding Principal and accrued and unpaid Interest. Subject to the terms, conditions and restrictions of the Subordination Agreement, the Company is permitted to prepay the amounts due hereunder, including all outstanding Principal and accrued and unpaid Interest (such payment a “Prepayment”).

2. INTEREST; INTEREST RATE.

(a) Interest on this Note shall commence accruing on the Issuance Date and shall be computed on the basis of a 360-day year and twelve 30-day months.

(b) Interest is due semiannually and shall be payable on the final Business Day in June and on the final Business Day in December (each such date, an “Interest Date”). Subject to the terms, conditions and restrictions of the Subordination Agreement, Interest shall be payable on each Interest Date, to the record holder of this Note, (i) at the PIK Interest Rate as paid in kind, and not in cash, by adding the amount of such Interest at the PIK Interest Rate payable on such Interest Date to the outstanding Principal amount hereof (“Original PIK Interest”) and (ii) at the Cash Interest Rate in cash (“Cash Interest”); provided that if Cash Interest is not permitted under the Subordination Agreement to be paid in cash, then the Company shall instead add the amount of Cash Interest payable on such Interest Date to the outstanding Principal amount hereof (“Additional PIK Interest” and, together with Original PIK Interest, the “PIK Interest”) on the applicable Interest Date. All such PIK Interest shall be added to the Principal on the applicable Interest Date. The Company shall deliver a written notice (each, an “Interest Election Notice”) to each holder of the Notes on or prior to the fifth (5th) Trading Day immediately prior to the applicable Interest Date (each, an “Interest Notice Due Date”) (the date such notice is delivered to the Holder, the “Interest Notice Date”) which notice (i) either (A) confirms that Cash Interest to be paid on such Interest Date is to be paid in cash as provided under the Subordination Agreement and shall be paid entirely in cash or (B) states that it is required to pay Cash Interest as Additional PIK Interest pursuant to the Subordination Agreement.

(c) Upon the occurrence and continuation of any Event of Default and the written request of the Holders, the Default Rate (in addition to the Interest Rate) will apply to all outstanding amounts due under this Note; provided, however, such amount of Default Rate shall be capitalized and added to the outstanding principal amount hereof as PIK Interest on the applicable Interest Date and shall not be paid as cash.

3. RIGHTS UPON EVENT OF DEFAULT.

(a) Event of Default. Each of the following events shall constitute an “Event of Default.” Subject to the terms, conditions and restrictions of the Subordination Agreement, if an Event of Default occurs, and is not waived by the Holder, the entire unpaid principal and accrued Interest of this Note shall become and be immediately due and payable upon written demand of the Holder, without any other notice or demand of any kind or any presentment or protest:

(i) the Company’s (A) failure to cure a Delivery Failure (as defined in the Warrants) by delivery of the required number of shares of Common Stock within seven (7) Trading Days after the applicable exercise date under the Warrants or (B) written notice to any holder of the Warrants, including, without limitation, by way of public announcement or through any of its agents, at any time, of its intention not to comply, as required, with a request for exercise of any Warrants for shares of Common Stock in accordance with the provisions of the Warrants;

(ii) the Company’s or any Subsidiary’s failure to pay to the Holder any amount of Principal, Interest or other amounts when and as due under this Note or any other Transaction Document (as defined in the Securities Purchase Agreement) or any other agreement, document, certificate or other instrument delivered in connection with the transactions contemplated hereby and thereby, except (x) in the case of a failure to pay Interest, if paid as Cash Interest when and as due, in which case only if such failure remains uncured for a period of at least three (3) Trading Days and (y) a failure to pay Interest as Cash Interest due to the restrictions contained in the Subordination Agreement;

(iii) the occurrence of any default under or redemption of any Indebtedness, the effect of which default or redemption causes the acceleration prior to maturity of at least an aggregate of $500,000 of Indebtedness, other than with respect to this Note or any non-recourse performance or surety bonds;

(iv) bankruptcy, insolvency, reorganization or liquidation proceedings or other proceedings for the relief of debtors shall be instituted by or against the Company or any Subsidiary and, if instituted against the Company or any Subsidiary by a third party, shall not be dismissed within sixty (60) days of their initiation;

(v) the commencement by the Company or any Subsidiary of a voluntary case or proceeding under any applicable federal, state or foreign bankruptcy, insolvency, reorganization or other similar law or of any other case or proceeding to be adjudicated a bankrupt or insolvent, or the consent by it to the entry of a decree, order, judgment or other similar document in respect of the Company or any Subsidiary in an involuntary case or proceeding under any applicable federal, state or foreign bankruptcy, insolvency, reorganization or other similar law or to the commencement of any bankruptcy or insolvency case or proceeding against it, or the filing by it of a petition or answer or consent seeking reorganization or relief under any applicable federal, state or foreign law, or the consent by it to the filing of such petition or to the appointment of or taking possession by a custodian, receiver, liquidator, assignee, trustee, sequestrator or other similar official of the Company or any Subsidiary or of any substantial part of its property, or the making by it of an assignment for the benefit of creditors, or the execution of a composition of debts, or the occurrence of any other similar federal, state or foreign proceeding, or the admission by it in writing of its inability to pay its debts generally as they become due, the taking of corporate action by the Company or any Subsidiary in furtherance of any such action or the taking of any action by any Person to commence a Uniform Commercial Code foreclosure sale or any other similar action under federal, state or foreign law;

(vi) the entry by a court of (i) a decree, order, judgment or other similar document in respect of the Company or any Subsidiary of a voluntary or involuntary case or proceeding under any applicable federal, state or foreign bankruptcy, insolvency, reorganization or other similar law or (ii) a decree, order, judgment or other similar document adjudging the Company or any Subsidiary as bankrupt or insolvent, or approving as properly filed a petition seeking liquidation, reorganization, arrangement, adjustment or composition of or in respect of the Company or any Subsidiary under any applicable federal, state or foreign law or (iii) a decree, order, judgment or other similar document appointing a custodian, receiver, liquidator, assignee, trustee, sequestrator or other similar official of the Company or any Subsidiary or of any substantial part of its property, or ordering the winding up or liquidation of its affairs, and the continuance of any such decree, order, judgment or other similar document or any such other decree, order, judgment or other similar document unstayed and in effect for a period of thirty (30) consecutive days;

(vii) a final judgment or judgments for the payment of money aggregating in excess of $500,000 are rendered against the Company and/or any of its Subsidiaries and which judgments are not, within thirty (30) days after the entry thereof, bonded, discharged, settled or stayed pending appeal, or are not discharged within sixty (60) days after the expiration of such stay; provided, however, any judgment which is covered by insurance or an indemnity from a credit worthy party shall not be included in calculating the $500,000 amount set forth above so long as the Company provides the Holder a written statement from such insurer or indemnity provider (which written statement shall be reasonably satisfactory to the Holder) to the effect that such judgment is covered by insurance or an indemnity and the Company or such Subsidiary (as the case may be) will receive the proceeds of such insurance or indemnity within thirty (30) days of the issuance of such judgment;

(viii) the Company and/or any Subsidiary, individually or in the aggregate, either (i) fails to pay, when due, or within any applicable grace period, any payment with respect to any Indebtedness in excess of $500,000 due to any third party (other than, with respect to unsecured Indebtedness only, payments contested by the Company and/or such Subsidiary (as the case may be) in good faith by proper proceedings and with respect to which adequate reserves have been set aside for the payment thereof in accordance with GAAP) or is otherwise in breach or violation of any agreement for monies owed or owing in an amount in excess of $500,000, which non-payment breach or violation causes the acceleration of the amounts due thereunder, or (ii) suffer to exist any other circumstance or event that would, with or without the passage of time or the giving of notice, result in a default or event of default under any agreement (other than under the Credit Agreement or the Loan Documents (as defined in the Credit Agreement)) binding the Company or any Subsidiary, which default or event of default would or is likely to have a material adverse effect on the business, assets, operations (including results thereof), liabilities, properties, condition (including financial condition) or prospects of the Company or any of its Subsidiaries, individually or in the aggregate;

(ix) other than as specifically set forth in another clause of this Section 3(a), the Company or any Subsidiary breaches any representation or warranty, or any covenant or other term or condition of any Transaction Document (including this Note), except, in the case of a breach of a covenant or other term or condition that is curable, only if such breach remains uncured for a period of two (2) consecutive Trading Days;

(x) any Material Adverse Effect occurs;

(xi) any provision of any Transaction Document shall at any time for any reason (other than pursuant to the express terms thereof) cease to be valid and binding on or enforceable against the parties thereto, or the validity or enforceability thereof shall be contested by any party thereto, or a proceeding shall be commenced by the Company or any Subsidiary or any governmental authority having jurisdiction over any of them, seeking to establish the invalidity or unenforceability thereof, or the Company or any Subsidiary shall deny in writing that it has any liability or obligation purported to be created under any Transaction Document (excluding the Warrants); or

(xii) the Company’s failure to maintain the listing or authorization for quotation (as the case may be) of the Common Stock on an Eligible Market (as defined in the Warrant).

4. NONCIRCUMVENTION. Subject to the terms, conditions and restrictions of the Subordination Agreement, the Company hereby covenants and agrees that the Company will not, by amendment of its Certificate of Incorporation or Bylaws or through any reorganization, transfer of assets, consolidation, merger, scheme of arrangement, dissolution, issue or sale of securities, or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Note, and will at all times in good faith carry out all of the provisions of this Note and take all actions as may be required to protect the rights of the Holder of this Note.

5. VOTING RIGHTS. The Holder shall have no voting rights as the holder of this Note, except as required by law (including, without limitation, the Delaware General Corporation Law) and as expressly provided in this Note.

6. COVENANTS. Until all of the Notes have been converted, redeemed or otherwise satisfied in accordance with their terms:

(a) Rank. All payments due under this Note shall rank junior to the indebtedness evidenced by the Credit Agreement and the other Loan Documents (as defined in the Credit Agreement) and pari passu with any other Indebtedness of the Company. The Company shall not, and shall not be required to, make any payments with respect to the Notes in violation of the Subordination Agreement and shall otherwise comply in full with the terms of the Subordination Agreement.

(b) Incurrence of Indebtedness. The Company shall not, and the Company shall cause each of its Subsidiaries to not, directly or indirectly, incur or guarantee, assume or suffer to exist any Indebtedness for borrowed money, other than (collectively, “Permitted Indebtedness”): (i) the Indebtedness evidenced by this Note; (ii) Indebtedness and related Obligations (as defined in the Credit Agreement) arising under the Credit Agreement and the other Loan Documents (as defined in the Credit Agreement), in each case, including all amendments, restatements, supplements, modifications, extensions, renewals, replacements and increases of such Indebtedness and Obligations; (iii) all Permitted Indebtedness (as defined in the Credit Agreement as in effect from time to time), with any dollar basket included as a Permitted Indebtedness under (and as defined in) the Credit Agreement being 20% higher for purposes of this Section 6(b); and (iv) Indebtedness (as defined in the Credit Agreement) related obligations incurred in connection with any recapitalization of Alpha Steel, LLC (the “Alpha Steel JV”) or any purchase of any securities or interests of the Alpha Steel JV (either directly from the Alpha Steel JV or from any equityholder or member thereof), including, without limitation, any seller notes, earnout, any similar Indebtedness (as defined in the Credit Agreement) and any Indebtedness (as defined in the Credit Agreement) incurred to finance such recapitalization or purchases.

(c) Change in Nature of Business. The Company shall not, and the Company shall cause each of its Subsidiaries to not, directly or indirectly, engage in any material line of business substantially different from those lines of business conducted by or publicly contemplated to be conducted by the Company and each of its Subsidiaries on the Subscription Date or any business substantially related or incidental thereto.

(d) Maturity of Indebtedness. Other than with respect to any Permitted Indebtedness, the Company shall not, and the Company shall cause each of its Subsidiaries to not, directly or indirectly, permit any Indebtedness of the Company or any of its Subsidiaries to mature or accelerate prior to the Maturity Date (except to the extent any Indebtedness outstanding on the date on which the Original Note was issued or on the date of this Amended and Restated Promissory Note provided for maturity prior to the Maturity Date.

(e) Preservation of Existence, Etc. The Company shall maintain and preserve, and cause each of its Subsidiaries to maintain and preserve, its existence, rights and privileges, and become or remain, and cause each of its Subsidiaries to become or remain, duly qualified and in good standing in each jurisdiction in which the character of the properties owned or leased by it or in which the transaction of its business makes such qualification necessary.

(f) Maintenance of Properties, Etc. The Company shall maintain and preserve, and cause each of its Subsidiaries to maintain and preserve, all of its properties which are necessary or useful in the proper conduct of its business in good working order and condition, ordinary wear and tear excepted, and comply, and cause each of its Subsidiaries to comply, at all times with the provisions of all leases to which it is a party as lessee or under which it occupies property, so as to prevent any loss or forfeiture thereof or thereunder.

(g) Maintenance of Intellectual Property. The Company will, and will cause each of its Subsidiaries to, take all action necessary or advisable to maintain all of the Intellectual Property of the Company and/or any of its Subsidiaries that are necessary or material to the conduct of its business in full force and effect.

(h) Maintenance of Insurance. The Company shall maintain, and cause each of its Subsidiaries to maintain, insurance with responsible and reputable insurance companies or associations (including, without limitation, comprehensive general liability, hazard, rent and business interruption insurance) with respect to its properties (including all real properties leased or owned by it) and business, in such amounts and covering such risks as is required by any governmental authority having jurisdiction with respect thereto or as is carried generally in accordance with sound business practice by companies in similar businesses similarly situated.

(i) Stay, Extension and Usury Laws. To the extent that it may lawfully do so, the Company (A) agrees that it will not at any time insist upon, plead, or in any manner whatsoever claim or take the benefit or advantage of, any stay, extension or usury law (wherever or whenever enacted or in force) that may affect the covenants or the performance of this Note; and (B) expressly waives all benefits or advantages of any such law and agrees that it will not, by resort to any such law, hinder, delay or impede the execution of any power granted to the Holder by this Note, but will suffer and permit the execution of every such power as though no such law has been enacted.

(j) Taxes. The Company and its Subsidiaries shall pay when due all taxes, fees or other charges of any nature whatsoever (together with any related interest or penalties) now or hereafter imposed or assessed against the Company and its Subsidiaries or their respective assets or upon their ownership, possession, use, operation or disposition thereof or upon their rents, receipts or earnings arising therefrom (except where the failure to pay would not, individually or in the aggregate, have a material effect on the Company or any of its Subsidiaries). The Company and its Subsidiaries shall file on or before the due date therefor all personal property tax returns (except where the failure to file would not, individually or in the aggregate, have a material effect on the Company or any of its Subsidiaries). Notwithstanding the foregoing, the Company and its Subsidiaries may contest, in good faith and by appropriate proceedings, taxes for which they maintain adequate reserves therefor in accordance with GAAP.

7. [RESERVED].

8. AMENDING THE TERMS OF THIS NOTE. The prior written consent of the Holder shall be required for any amendment, modification or waiver to this Note. Subject to the terms, conditions and restrictions of the Subordination Agreement, any amendment, modification or waiver so approved shall be binding upon all existing and future holders of this Note; provided, however, that no such change, waiver or, as applied to any of the Notes held by any particular holder of Notes, shall, without the written consent of that particular holder, (i) reduce the amount of Principal, reduce the amount of accrued and unpaid Interest, or extend the Maturity Date, of the Notes, (ii) disproportionally and adversely affect any rights under the Notes of any holder of Notes; or (iii) modify any of the provisions of, or impair the right of any holder of Notes under, this Section 8.

9. TRANSFER. This Note may be offered, sold, assigned or transferred by the Holder without the consent of the Company, subject only to the provisions of Section 2(g) of the Securities Purchase Agreement.

10. REISSUANCE OF THIS NOTE.

(a) Transfer. If this Note is to be transferred, the Holder shall surrender this Note to the Company, whereupon the Company will forthwith issue and deliver upon the order of the Holder a new Note (in accordance with Section 10(d)), registered as the Holder may request, representing the outstanding Principal being transferred by the Holder and, if less than the entire outstanding Principal is being transferred, a new Note (in accordance with Section 10(d)) to the Holder representing the outstanding Principal not being transferred. The Holder and any assignee, by acceptance of this Note, acknowledge and agree that the outstanding Principal represented by this Note may be less than the Principal stated on the face of this Note.

(b) Lost, Stolen or Mutilated Note. Upon receipt by the Company of evidence reasonably satisfactory to the Company of the loss, theft, destruction or mutilation of this Note (as to which a written certification and the indemnification contemplated below shall suffice as such evidence), and, in the case of loss, theft or destruction, of any indemnification undertaking by the Holder to the Company in customary and reasonable form and, in the case of mutilation, upon surrender and cancellation of this Note, the Company shall execute and deliver to the Holder a new Note (in accordance with Section 10(d)) representing the outstanding Principal.

(c) Note Exchangeable for Different Denominations. This Note is exchangeable, upon the surrender hereof by the Holder at the principal office of the Company, for a new Note or Notes (in accordance with Section 10(d) and in principal amounts of at least $1,000) representing in the aggregate the outstanding Principal of this Note, and each such new Note will represent such portion of such outstanding Principal as is designated by the Holder at the time of such surrender.

(d) Issuance of New Notes. Whenever the Company is required to issue a new Note pursuant to the terms of this Note, such new Note (i) shall be of like tenor with this Note, (ii) shall represent, as indicated on the face of such new Note, the Principal remaining outstanding (or in the case of a new Note being issued pursuant to Section 10(a) or Section 10(c), the Principal designated by the Holder which, when added to the principal represented by the other new Notes issued in connection with such issuance, does not exceed the Principal remaining outstanding under this Note immediately prior to such issuance of new Notes), (iii) shall have an issuance date, as indicated on the face of such new Note, which is the same as the Issuance Date of this Note, (iv) shall have the same rights and conditions as this Note, (v) shall represent accrued and unpaid Interest on the Principal and Interest of this Note, from the Issuance Date and (vi) shall be subject to the terms, conditions and restrictions of the Subordination Agreement.

11. REMEDIES, CHARACTERIZATIONS, OTHER OBLIGATIONS, BREACHES AND INJUNCTIVE RELIEF. Subject to the terms, conditions and restrictions of the Subordination Agreement, the remedies provided in this Note shall be cumulative and in addition to all other remedies available under this Note and any of the other Transaction Documents (other than the Warrants) at law or in equity (including a decree of specific performance and/or other injunctive relief), and nothing herein shall limit the Holder’s right to pursue actual and consequential damages for any failure by the Company to comply with the terms of this Note. No failure on the part of the Holder to exercise, and no delay in exercising, any right, power or remedy hereunder shall operate as a waiver thereof; nor shall any single or partial exercise by the Holder of any right, power or remedy preclude any other or further exercise thereof or the exercise of any other right, power or remedy. In addition, the exercise of any right or remedy of the Holder at law or equity or under this Note or any of the documents shall not be deemed to be an election of Holder’s rights or remedies under such documents or at law or equity. The Company covenants to the Holder that there shall be no characterization concerning this instrument other than as expressly provided herein. Amounts set forth or provided for herein with respect to payments, conversion and the like (and the computation thereof) shall be the amounts to be received by the Holder and shall not, except as expressly provided herein, be subject to any other obligation of the Company (or the performance thereof). The Company acknowledges that a breach by it of its obligations hereunder will cause irreparable harm to the Holder and that the remedy at law for any such breach may be inadequate. The Company therefore agrees that, in the event of any such breach or threatened breach, subject to the terms, conditions and restrictions of the Subordination Agreement, the Holder shall be entitled, in addition to all other available remedies, to specific performance and/or temporary, preliminary and permanent injunctive or other equitable relief from any court of competent jurisdiction in any such case without the necessity of proving actual damages and without posting a bond or other security. The Company shall provide all information and documentation to the Holder that is requested by the Holder to enable the Holder to confirm the Company’s compliance with the terms and conditions of this Note.

12. PAYMENT OF COLLECTION, ENFORCEMENT AND OTHER COSTS. Subject to the terms, conditions and restrictions of the Subordination Agreement, if (a) this Note is placed in the hands of an attorney for collection or enforcement or is collected or enforced through any legal proceeding or the Holder otherwise takes action to collect amounts due under this Note or to enforce the provisions of this Note or (b) there occurs any bankruptcy, reorganization, receivership of the Company or other proceedings affecting Company creditors’ rights and involving a claim under this Note, then the Company shall pay the costs incurred by the Holder for such collection, enforcement or action or in connection with such bankruptcy, reorganization, receivership or other proceeding, including, without limitation, attorneys’ fees and disbursements. The Company expressly acknowledges and agrees that no amounts due under this Note shall be affected, or limited, by the fact that the purchase price paid for this Note was less than the original Principal amount hereof.

13. CONSTRUCTION; HEADINGS. This Note shall be deemed to be jointly drafted by the Company and the initial Holder and shall not be construed against any such Person as the drafter hereof. The headings of this Note are for convenience of reference and shall not form part of, or affect the interpretation of, this Note. Unless the context clearly indicates otherwise, each pronoun herein shall be deemed to include the masculine, feminine, neuter, singular and plural forms thereof. The terms “including,” “includes,” “include” and words of like import shall be construed broadly as if followed by the words “without limitation.” The terms “herein,” “hereunder,” “hereof” and words of like import refer to this entire Note instead of just the provision in which they are found. Unless expressly indicated otherwise, all section references are to sections of this Note. Terms used in this Note and not otherwise defined herein, but defined in the other Transaction Documents, shall have the meanings ascribed to such terms on the Closing Date in such other Transaction Documents unless otherwise consented to in writing by the Holder.

14. FAILURE OR INDULGENCE NOT WAIVER. No failure or delay on the part of the Holder in the exercise of any power, right or privilege hereunder shall operate as a waiver thereof, nor shall any single or partial exercise of any such power, right or privilege preclude other or further exercise thereof or of any other right, power or privilege. No waiver shall be effective unless it is in writing and signed by an authorized representative of the waiving party.

15. NOTICES; CURRENCY; PAYMENTS.

(a) Notices. Whenever notice is required to be given under this Note, unless otherwise provided herein, such notice shall be given in accordance with Section 8(f) of the Securities Purchase Agreement. The Company shall provide the Holder with prompt written notice of all actions taken pursuant to this Note, including in reasonable detail a description of such action and the reason therefore.

(b) Currency. All dollar amounts referred to in this Note are in United States Dollars (“U.S. Dollars”), and all amounts owing under this Note shall be paid in U.S. Dollars. All amounts denominated in other currencies (if any) shall be converted into the U.S. Dollar equivalent amount in accordance with the Exchange Rate on the date of calculation. “Exchange Rate” means, in relation to any amount of currency to be converted into U.S. Dollars pursuant to this Note, the U.S. Dollar exchange rate as published in the Wall Street Journal on the relevant date of calculation (it being understood and agreed that where an amount is calculated with reference to, or over, a period of time, the date of calculation shall be the final date of such period of time).

(c) Payments. Whenever any payment of cash is to be made by the Company to any Person pursuant to this Note, unless otherwise expressly set forth herein, such payment shall be made in lawful money of the United States of America by a certified check drawn on the account of the Company and sent via overnight courier service to such Person at such address as previously provided to the Company in writing (which address, in the case of each of the Buyers, shall initially be as set forth on the Schedule of Buyers attached to the Securities Purchase Agreement), provided that the Holder may elect to receive a payment of cash via wire transfer of immediately available funds by providing the Company with prior written notice setting out such request and the Holder’s wire transfer instructions. Whenever any amount expressed to be due by the terms of this Note is due on any day which is not a Business Day, the same shall instead be due on the next succeeding day which is a Business Day.

16. CANCELLATION. After all Principal, accrued Interest and other amounts at any time owed on this Note have been paid in full, this Note shall automatically be deemed canceled, shall be surrendered to the Company for cancellation and shall not be reissued.

17. GOVERNING LAW. This Note shall be construed and enforced in accordance with, and all questions concerning the construction, validity, interpretation and performance of this Note shall be governed by, the internal laws of the State of New York, without giving effect to any choice of law or conflict of law provision or rule (whether of the State of New York or any other jurisdictions) that would cause the application of the laws of any jurisdictions other than the State of New York. The Company hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in The City of New York, Borough of Manhattan, for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is brought in an inconvenient forum or that the venue of such suit, action or proceeding is improper. Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law. Nothing contained herein shall be deemed

to limit in any way any right to serve process in any manner permitted by law. Nothing contained herein shall be deemed or operate to preclude the Holder from bringing suit or taking other legal action against the Company in any other jurisdiction to collect on the Company’s obligations to the Holder, or to enforce a judgment or other court ruling in favor of the Holder. THE COMPANY HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE TO, AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION WITH OR ARISING OUT OF THIS NOTE OR ANY TRANSACTION CONTEMPLATED HEREBY.

18. JUDGMENT CURRENCY.

(a) If for the purpose of obtaining or enforcing judgment against the Company in any court in any jurisdiction it becomes necessary to convert into any other currency (such other currency being hereinafter in this Section 30 referred to as the “Judgment Currency”) an amount due in U.S. dollars under this Note, the conversion shall be made at the Exchange Rate prevailing on the Trading Day (as defined in the Warrant) immediately preceding:

(i) the date actual payment of the amount due, in the case of any proceeding in the courts of New York or in the courts of any other jurisdiction that will give effect to such conversion being made on such date: or

(ii) the date on which the foreign court determines, in the case of any proceeding in the courts of any other jurisdiction (the date as of which such conversion is made pursuant to this Section 30(a)(ii) being hereinafter referred to as the “Judgment Conversion Date”).

(b) If in the case of any proceeding in the court of any jurisdiction referred to in Section 30(a)(ii) above, there is a change in the Exchange Rate prevailing between the Judgment Conversion Date and the date of actual payment of the amount due, the applicable party shall pay such adjusted amount as may be necessary to ensure that the amount paid in the Judgment Currency, when converted at the Exchange Rate prevailing on the date of payment, will produce the amount of US dollars which could have been purchased with the amount of Judgment Currency stipulated in the judgment or judicial order at the Exchange Rate prevailing on the Judgment Conversion Date.

(c) Any amount due from the Company under this provision shall be due as a separate debt and shall not be affected by judgment being obtained for any other amounts due under or in respect of this Note.

19. SEVERABILITY. If any provision of this Note is prohibited by law or otherwise determined to be invalid or unenforceable by a court of competent jurisdiction, the provision that would otherwise be prohibited, invalid or unenforceable shall be deemed amended to apply to the broadest extent that it would be valid and enforceable, and the invalidity or unenforceability of such provision shall not affect the validity of the remaining provisions of this Note so long as this Note as so modified continues to express, without material change, the original intentions of the parties as to the subject matter hereof and the prohibited nature, invalidity or unenforceability of the provision(s) in question does not substantially impair the respective expectations or reciprocal obligations of the parties or the practical realization of the benefits that would otherwise be conferred upon the parties. The parties will endeavor in good faith negotiations to replace the prohibited, invalid or unenforceable provision(s) with a valid provision(s), the effect of which comes as close as possible to that of the prohibited, invalid or unenforceable provision(s).

20. MAXIMUM PAYMENTS. Without limiting Section 8(d) of the Securities Purchase Agreement, nothing contained herein shall be deemed to establish or require the payment of a rate of interest or other charges in excess of the maximum permitted by applicable law. In the event that the rate of interest required to be paid or other charges hereunder exceed the maximum permitted by such law, any payments in excess of such maximum shall be credited against amounts owed by the Company to the Holder and thus refunded to the Company.

21. CERTAIN DEFINITIONS. For purposes of this Note, the following terms shall have the following meanings:

(a) “1933 Act” means the Securities Act of 1933, as amended, and the rules and regulations thereunder.

(b) “1934 Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder.

(c) “Affiliate” means, with respect to any Person, any other Person that directly or indirectly controls, is controlled by, or is under common control with, such Person, it being understood for purposes of this definition that “control” of a Person means the power directly or indirectly either to vote 10% or more of the stock having ordinary voting power for the election of directors of such Person or direct or cause the direction of the management and policies of such Person whether by contract or otherwise.

(d) “Business Day” means any day other than Saturday, Sunday or other day on which commercial banks in The City of New York are authorized or required by law to remain closed; provided, however, for clarification, commercial banks shall not be deemed to be authorized or required by law to remain closed due to “stay at home”, “shelter-in-place”, “non-essential employee” or any other similar orders or restrictions or the closure of any physical branch locations at the direction of any governmental authority so long as the electronic funds transfer systems (including for wire transfers) of commercial banks in The City of New York generally are open for use by customers on such day.

(e) “Cash Interest Rate” means five percent (5%) per annum.

(f) “Closing Date” shall have the meaning set forth in the Securities Purchase Agreement, which date is the date the Company initially issued Notes pursuant to the terms of the Securities Purchase Agreement.

(g) “Common Stock” means (i) the Company’s shares of common stock, $0.0001 par value per share, and (ii) any capital stock into which such common stock shall have been changed or any share capital resulting from a reclassification of such common stock.

(h) “Credit Agreement” shall mean that certain Credit Agreement, dated as of July 2, 2025, by and among the Company, as borrower, the lenders party thereto from time to time (the “Lenders”) and Acquiom Agency Services LLC, as the administrative agent for the Lenders, as amended, restated, supplemented or otherwise modified from time to time.

(i) “Default Rate” means five percent (5%).

(j) “GAAP” means United States generally accepted accounting principles, consistently applied.

(k) “Indebtedness” shall have the meaning ascribed to such term in the Securities Purchase Agreement.

(l) “Interest Rate” means, subject to the terms, conditions and restrictions of the Subordination Agreement, the Cash Interest Rate and the PIK Interest Rate.

(m) “Maturity Date” shall mean January 2, 2030.

(n) “Person” means an individual, a limited liability company, a partnership, a joint venture, a corporation, a trust, an unincorporated organization, any other entity or a government or any department or agency thereof.

(o) “PIK Interest Rate” means seven percent (7%) per annum.

(p) “Principal Market” means the Nasdaq Capital Market.

(q) “SEC” means the United States Securities and Exchange Commission or the successor thereto.

(r) “Securities Purchase Agreement” means that certain securities purchase agreement, dated as of the Subscription Date, by and among the Company and the initial holders of the Notes pursuant to which the Company issued the Notes, as may be amended from time to time.

(s) “Subordination Agreement” means that certain Subordination Agreement, dated as of July 2, 2025, by and among the subordinated creditors party thereto and Acquiom Agency Services LLC, as administrative agent, and acknowledged by the Company.

(t) ”Subscription Date” means December 4, 2024.

(u) Subsidiaries” means, as of any date of determination, collectively, all Current Subsidiaries and all New Subsidiaries, and each of the foregoing, individually, a “Subsidiary.”

(v) “Trading Day” means, as applicable, (x) with respect to all price or trading volume determinations relating to the Common Stock, any day on which the Common Stock is traded on the Principal Market, or, if the Principal Market is not the principal trading market for the Common Stock, then on the principal securities exchange or securities market on which the Common Stock is then traded, provided that “Trading Day” shall not include any day on which the Common Stock is scheduled to trade on such exchange or market for less than 4.5 hours or any day that the Common Stock is suspended from trading during the final hour of trading on such exchange or market (or if such exchange or market does not designate in advance the closing time of trading on such exchange or market, then during the hour ending at 4:00:00 p.m., New York time) unless such day is otherwise designated as a Trading Day in writing by the Holder or (y) with respect to all determinations other than price determinations relating to the Common Stock, any day on which The New York Stock Exchange (or any successor thereto) is open for trading of securities.

(w) “Warrants” has the meaning ascribed to such term in the Securities Purchase Agreement, and shall include all warrants issued in exchange therefor or replacement thereof.

22. DISCLOSURE. Upon delivery by the Company to the Holder (or receipt by the Company from the Holder) of any notice in accordance with the terms of this Note, unless the Company has in good faith determined that the matters relating to such notice do not constitute material, non-public information relating to the Company or any of its Subsidiaries, the Company shall on or prior to 9:00 am, New York city time on the Business Day immediately following such notice delivery date, publicly disclose such material, non-public information on a Current Report on Form 8-K or otherwise. In the event that the Company believes that a notice contains material, non-public information relating to the Company or any of its Subsidiaries, the Company so shall indicate to the Holder explicitly in writing in such notice (or immediately upon receipt of notice from the Holder, as applicable), and in the absence of any such written indication in such notice (or notification from the Company immediately upon receipt of notice from the Holder), the Holder shall be entitled to presume that information contained in the notice does not constitute material, non-public information relating to the Company or any of its Subsidiaries. Nothing contained in this Section 22 shall limit any obligations of the Company, or any rights of the Holder, under Section 4(i) of the Securities Purchase Agreement.

23. ABSENCE OF TRADING AND DISCLOSURE RESTRICTIONS. The Company acknowledges and agrees that the Holder is not a fiduciary or agent of the Company and that the Holder shall have no obligation to (a) maintain the confidentiality of any information provided by the Company or (b) refrain from trading any securities while in possession of such information in the absence of a written non-disclosure agreement signed by an officer of the Holder that explicitly provides for such confidentiality and trading restrictions. In the absence of such an executed, written non-disclosure agreement, the Company acknowledges that the Holder may freely trade in any securities issued by the Company, may possess and use any information provided by the Company in connection with such trading activity, and may disclose any such information to any third party.

24. AMENDMEN AND RESTATEMENT. This Note amends and restates in its entirety that certain Senior Secured Promissory Note, dated as of December 4, 2025 (the “Original Note”), made by the Company in favor of the Holder, and the terms and provisions of the Original Note shall be superseded and continued hereby. In furtherance of and, without limiting, the foregoing from and after the date hereof, the terms, conditions and covenants governing the obligations outstanding under the Original Note shall be solely as set forth in this Note, which shall supersede the Original Note in its entirety.

[signature page follows]

IN WITNESS WHEREOF, the Company has caused this Amended and Restated Promissory Note to be duly executed as of the Issuance Date set out above.


FTC SOLAR, INC.

By:		/s/ Cathy Behnen
Name: Cathy Behnen
Title: President and Chief Executive Officer

ACCEPTED AND AGREED


AV SECURITIES, INC.

By:		/s/ Claudio Dolman
Name: Claudio Dolman
Title: Director

[Signature Page – Amended and Restated Promissory Note]