Exhibit 5.1

July 30, 2021

Aemetis, Inc.

20400 Stevens Creek Blvd., Suite 700

Cupertino, California 95014

Re: Registration Statement/Form S-3

Ladies and Gentlemen:

We have acted as special Nevada counsel to Aemetis, Inc., a Nevada corporation (the “Company”), in connection with the filing by the Company of a Registration Statement on Form S-3 (the “Registration Statement”), including the preliminary prospectus contained therein and any subsequent prospectus supplements and any free writing prospectuses relating thereto, relating to the registration under the Securities Act of 1933 (“Act”), as amended, of the issuance and sale from time to time by the Company, on a delayed or continuous basis pursuant to Rule 415 promulgated under the Act, of an indeterminate number of the following securities (collectively “Securities”), the aggregate initial offering price of which will not exceed $300,000,000: (i) shares common stock, par value $0.001 (“Common Stock”); (ii) shares of preferred stock, par value $0.001 (“Preferred Stock”); (iii) debt securities, in one or more series that may be convertible into or exchangeable for shares of Common Stock or Preferred Stock (“Debt Securities”); (iv) warrants to purchase Common Stock, Preferred Stock or Debt Securities (“Warrants”); (v) rights to purchase Common Stock, Preferred Stock, Debt Securities, or Warrants (“Rights”); (vi) units composed of any combination of the Debt Securities, Common Stock, Preferred Stock, and Warrants (“Units”); and (vii) such indeterminate amount of shares of Common Stock and Preferred Stock as may be issued upon conversion, exchange or exercise of the Securities registered pursuant to the Registration Statement.

In connection with this opinion, we have examined originals or copies, certified or otherwise identified to our satisfaction, of: (i) the Articles of Incorporation of the Company, as amended through the date hereof (“Articles of Incorporation”); (ii) the Bylaws of the Company, as amended through the date hereof (“Bylaws”); (iii) certain resolutions of the Board of Directors of the Company relating to the issuance, sale and registration of the Securities; and (iv) the Registration Statement. In addition, we have examined originals or copies, certified or otherwise identified to our satisfaction, of certain other corporate records, documents, instruments and certificates of public officials and of the Company, and we have made such inquiries of officers of the Company and public officials and considered such questions of law as we have deemed necessary for purposes of rendering the opinions set forth herein. In rendering our opinion, we have made the assumptions that are customary in opinion letters of this kind. We have not verified these assumptions.

In connection with this opinion, we have assumed the genuineness of all signatures and the authenticity of all items submitted to us as originals and the conformity with originals of all items submitted to us as copies. In making our examination of documents executed by parties other than the Company, we have assumed that each other party has the power and authority to execute and deliver, and to perform and observe the provisions of, such documents and has duly authorized, executed and delivered such documents, and that such documents constitute the legal, valid and binding obligations of each such party. With respect to certain factual matters, we have relied upon certificates of officers of the Company.

We have assumed that the Indenture, any warrant agreements (each a “Warrant Agreement”) relating to the Warrants, any rights agreements (each a “Rights Agreement”) relating to the Rights, any unit agreements (each a “Unit Agreement”) relating to the Units, any agreements relating to the Common Stock and Preferred Stock, and the issuance and sale of the Securities by the Company will not, in each case, violate or constitute a default or breach under: (i) any agreement or instrument to which the Company or its properties is subject; (ii) any law, rule or regulation to which the Company is subject; (iii) any judicial or regulatory order or decree of any governmental authority; or (iv) any consent, approval, license, authorization or validation of, or filing, recording or registration with any governmental authority.

We have further assumed that: (i) the Registration Statement and any amendments thereto will have become effective under the Act and comply with all applicable laws at the time the Securities are offered or issued as contemplated by the Registration Statement; (ii) an appropriate prospectus supplement, free writing prospectus or term sheet relating to the Securities offered thereby will be prepared and filed with the Commission in compliance with the Act and will comply with all applicable laws at the time the Securities are offered or issued as contemplated by the Registration Statement; (iii) all Securities will be issued and sold in compliance with the applicable provisions of the Act, the Trust Indenture Act of 1939, as applicable, and the securities or blue sky laws of various states and in the manner stated in the Registration Statement and the applicable prospectus supplement; and (iv) that the trustee under any indenture shall have been qualified pursuant to the Trust Indenture Act of 1939 at the time the Securities are offered or issued (or such later time as may be permitted pursuant to the rules, regulations, interpretations or positions of the Commission) as contemplated by the Registration Statement.

Our opinion set forth below is limited to the laws of the State of Nevada, including reported judicial decisions interpreting those laws.

Based upon, subject to and limited by the foregoing, we are of the opinion that:

1.           With respect to shares of the Common Stock, when (A) the Board of Directors of the Company or a duly constituted and acting committee thereof (such Board of Directors or committee thereof being hereinafter collectively referred to as the “Board”) has taken all necessary corporate action in conformity with the Articles of Incorporation and Bylaws to approve the issuance of the Common Stock, the terms of the offering thereof and related matters, and (B) if certificated, certificates representing shares of the Common Stock have been duly executed, registered and delivered either (i) in accordance with the applicable definitive purchase, underwriting or similar agreement approved by the Board against payment of the consideration therefor (not less than the par value of the Common Stock) as provided therein; or (ii) upon conversion, exchange or exercise of any other Security in accordance with the terms of the Security or the instrument governing the Security providing for the conversion, exchange or exercise as approved by the Board, for the consideration approved by the Board (not less than the par value of the Common Stock), such shares of Common Stock will be validly issued, fully paid and nonassessable.

2.           With respect to shares of the Preferred Stock, when (A) the Board has taken all necessary corporate action in conformity with the Certificate of Incorporation and Bylaws to approve the issuance and terms of a particular series of shares of Preferred Stock, the terms of the offering thereof and related matters, including the adoption of a Certificate of Designation for such Preferred Stock in accordance with applicable law relating to such shares of Preferred Stock and the filing of such Certificate of Designation with the Secretary of State of the State of Nevada, and (B) if certificated, certificates representing shares of the Preferred Stock have been duly executed, registered and delivered either (i) in accordance with the applicable definitive purchase, underwriting or similar agreement approved by the Board against payment of the consideration therefor (not less than the par value of the Preferred Stock) as provided therein; or (ii) upon conversion, exchange or exercise of any other Security in accordance with the terms of the Security or the instrument governing the Security providing for the conversion, exchange or exercise as approved by the Board, for the consideration approved by the Board (not less than the par value of the Preferred Stock), such shares of Preferred Stock will be validly issued, fully paid and nonassessable.

3.           With respect to the Debt Securities, when (A) the indenture relating to the Debt Securities has been duly authorized, executed and delivered by the Company, (B) the Board has taken all necessary corporate action in conformity with the Certificate of Incorporation and Bylaws to approve the issuance and terms of a particular series of such Debt Securities, the terms of the offering thereof and related matters, and (C) such Debt Securities have been duly executed, authenticated, issued and delivered either (i) in accordance with the indenture, applicable definitive purchase, underwriting or similar agreement approved by the Board against payment of the consideration therefor as provided therein; or (ii) upon conversion, exchange or exercise of any other Security in accordance with the terms of the Security or the instrument governing the Security providing for the conversion, exchange or exercise as approved by the Board, for the consideration approved by the Board, such Debt Securities will constitute binding obligations of the Company.

4.           With respect to the Warrants, when (A) the Board has taken all necessary corporate action in conformity with the Certificate of Incorporation and Bylaws to approve the form, terms, execution and delivery of a warrant agreement (including a form of certificate evidencing the Warrants), the issuance of the Warrants, the terms of the offering thereof and related matters, and (B) the certificates evidencing the Warrants with such terms are duly executed, attested, issued and delivered by duly authorized officers of the Company in accordance with the provisions of the applicable Warrant Agreement and the applicable definitive purchase, underwriting or similar agreement approved by the Board against payment of the consideration therefor as provided therein, such Warrants will be binding obligations of the Company.

5.           With respect to the Rights, when (A) the Board has taken all necessary corporate action in conformity with the Certificate of Incorporation and Bylaws to approve the form, terms, execution and delivery of a rights agreement (including a form of certificate evidencing the Rights), the issuance of the Rights, the terms of the offering thereof and related matters, and (B) the certificates evidencing Rights with such terms are duly executed, attested, issued and delivered by duly authorized officers of the Company in accordance with the provisions of the applicable rights agreement and the applicable definitive purchase, underwriting or similar agreement approved by the Board against payment of the consideration therefor as provided therein, such rights will constitute binding obligations of the Company.

6.           With respect to the Units, when (A) the Board has taken all necessary corporate action in conformity with the Certificate of Incorporation and Bylaws to approve the form, terms, execution and delivery of a unit agreement (including a form of certificate evidencing the Units), the issuance of the Units, the terms of the offering thereof and related matters, and (B) the certificates evidencing Units with such terms are duly executed, attested, issued and delivered by duly authorized officers of the Company in accordance with the provisions of the applicable unit agreement and the applicable definitive purchase, underwriting or similar agreement approved by the Board against payment of the consideration therefor as provided therein, such Units will constitute binding obligations of the Company.

We consent to the use of this opinion as an exhibit to the Registration Statement and further consent to all references to us in the Registration Statement and any amendments thereto.

Sincerely,

/s/ McDonald Carano LLP

McDonald Carano LLP