Sec Form 4 Filing - TortoiseEcofin Sponsor III LLC @ TortoiseEcofin Acquisition Corp. III - 2023-09-08

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person TortoiseEcofin Sponsor III LLC 2. Issuer Name and Ticker or Trading Symbol TortoiseEcofin Acquisition Corp. III [ TRTL] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O TORTOISEECOFIN ACQUISITION CORP. III, 195 US HWY 50, SUITE 208 3. Date of Earliest Transaction (MM/DD/YY) 09/08/2023 (Street) ZEPHYR COVE, NV89448 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Class B Ordinary Shares ( 1 ) 09/08/2023 J( 2 ) 60,000 ( 1 ) ( 1 ) Class A Ordinary Shares 60,000 $ 0 6,915,000 D ( 3 )

Reporting Owners Reporting Owner Name / Address Relatio nships Director 10% Owner Officer Other TortoiseEcofin Sponsor III LLC C/O TORTOISEECOFIN ACQUISITION CORP. III 195 US HWY 50, SUITE 208 ZEPHYR COVE, NV89448 X Hennessy Capital Growth Partners Fund I SPV V, LLC C/O TORTOISEECOFIN ACQUISITION CORP. III 195 US HWY 50, SUITE 208 ZEPHYR COVE, NV89448 X Hennessy Capital Growth Partners Fund I, LP C/O TORTOISEECOFIN ACQUISITION CORP. III 195 US HWY 50, SUITE 208 ZEPHYR COVE, NV89448 X Hennessy Thomas D C/O TORTOISEECOFIN ACQUISITION CORP. III 195 US HWY 50, SUITE 208 ZEPHYR COVE, NV89448 X X Signatures /s/ Thomas D. Hennessy, as the general partner of Hennessy Capital Growth Partners Fund I, LP, as the managing member of Hennessy Capital Growth Partners Fund I SPV V, LLC, as the managing member of TortoiseEcofin Sponsor III LLC 09/11/2023 Signature of Reporting Person Date /s/ Thomas D. Hennessy, as the general partner of Hennessy Capital Growth Partners Fund I, LP, as the managing member of Hennessy Capital Growth Partners Fund I SPV V, LLC 09/11/2023 Signature of Reporting Person Date /s/ Thomas D. Hennessy, as the general partner of Hennessy Capital Growth Partners Fund I, LP 09/11/2023 Signature of Reporting Person Date /s/ Thomas D. Hennessy 09/11/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The Class B Ordinary Shares are automatically convertible into the Issuer's Class A Ordinary Shares at the time of the Issuer's initial business combination on a one-for-one basis, subject to adjustment pursuant to certain anti-dilution rights, and have no expiration date. ( 2 )Pursuant to certain share transfer agreements, the shares were assigned by former directors of the Issuer to the reporting persons for no consideration. ( 3 )The reporting persons are the record holder of the Class B ordinary shares reported herein. Hennessy Capital Growth Partners Fund I SPV V, LLC is the managing member of TortoiseEcofin Sponsor III LLC. Hennessy Capital Growth Partners Fund I, LP is the managing member of Hennessy Capital Growth Partners Fund I SPV V, LLC, and Thomas D. Hennessy is the general partner of Hennessy Capital Growth Partners Fund I, LP. Accordingly, Hennessy Capital Growth Partners Fund I SPV V, LLC, Hennessy Capital Growth Partners Fund I, LP and Thomas D. Hennessy may be deemed to have or share beneficial ownership of the Class B ordinary shares held directly by the reporting persons. The reporting persons disclaim beneficial ownership over any securities other than to the extent of any pecuniary interest they may have therein, directly or indirectly.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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