FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES 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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(Print or Type Responses)

1. Name and Address of Reporting Person *   ECP ControlCo, LLC 2. Date of Event Requiring Statement (Month/Day/Year) 04/27/2017 3. Issuer Name and Ticker or Trading Symbol DYNEGY INC. [DYN] (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY, SUITE 200 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) SHORT HILLS, NJ 07078 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 19,541,152 I See footnotes (1) (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ECP ControlCo, LLC 51 JOHN F. KENNEDY PARKWAY SUITE 200 SHORT HILLS, NJ 07078	Â	  X	Â	Â

Signatures

ECP ControlCo, LLC, By: /s/ Peter Labbat, Manging Member		06/01/2017
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Terawatt Holdings, LP is the record holder of the securities reported herein. ECP Control Co, LLC ("ECP Control Co") is the managing member of Energy Capital Partners III, LLC ("ECP GP"), which is the general partner of Energy Capital Partners GP III, LP ("ECP Fund GP"), which is the general partner of each of Energy Capital Partners III, LP, Energy Capital Partners III-A, Energy Capital Partners III-B (Terawatt IP), LP and Energy Capital Partners III-C, LP (collectively, the "ECP Funds"), which are the sole members of Terawatt Holdings GP, LLC ("Terawatt GP"), which is the general partner of Terawatt Holdings, LP.
(2)	Douglas Kimmelman, Thomas Lane, Andrew Singer, Peter Labbat, Tyler Reeder and Rahman D'Argenio are the managing members of ECP ControlCo and share the power to vote and dispose of the securities beneficially owned by ECP ControlCo. As such, each of Terawatt GP, the ECP Funds, ECP Fund GP, ECP GP, ECP ControlCo and Messrs. Kimmelman, Lane, Singer, Labbat, Reeder and D'Argenio may be deemed to have or share beneficial ownership of the Common Stock held directly by Terawatt Holdings. Each such entity or individual disclaims any such beneficial ownership except to the extent of their pecuniary interest therein.

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