SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G
                                (RULE 13d - 102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO 13d-1(b), (c) AND (d)
                  AND AMENDMENTS THERETO FILED PURSUANT TO 13d

                                (Amendment No.)*

Tremisis Energy Acquisition Corporation
---------------------------------------
(Name of Issuer)

Common Stock
---------------------------------------
(Title of Class of Securities)

894727106
---------------------------------------
(CUSIP Number)

December 6, 2005
---------------------------------------
(Date of Event which Requires Filing of this Statement)

Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

[ ]      Rule 13d-1(b)
[x]      Rule 13d-1(c)
[ ]      Rule 13d-1(d)

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

                       (Continued on the Following Pages)



1.       NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Amaranth LLC

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

         (a)      [ ]
         (b)      [x]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Cayman Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

5.       SOLE VOTING POWER

                  0

6.       SHARED VOTING POWER

                  701,675                            

7.       SOLE DISPOSITIVE POWER

                  0

8.       SHARED DISPOSITIVE POWER

                  701,675                            

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  See 6 and 8 above.

10.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9)
         EXCLUDES CERTAIN SHARES*   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  9.1%                               

12.      TYPE OF REPORTING PERSON*

                  CO


1.       NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Amaranth Advisors L.L.C.

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

         (a)      [ ]
         (b)      [x]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

5.       SOLE VOTING POWER

                  0

6.       SHARED VOTING POWER

                  701,675                            

7.       SOLE DISPOSITIVE POWER

                  0

8.       SHARED DISPOSITIVE POWER

                  701,675                   

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  See 6 and 8 above.

10.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9)
         EXCLUDES CERTAIN SHARES*   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  9.1%                               

12.      TYPE OF REPORTING PERSON*

                  IA



1.       NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Nicholas M. Maounis

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

         (a)      [ ]
         (b)      [x]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  United States

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.       SOLE VOTING POWER

                  0

6.       SHARED VOTING POWER

                  701,675                            

7.       SOLE DISPOSITIVE POWER

                  0

8.       SHARED DISPOSITIVE POWER

                  701,675                            

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                  See 6 and 8 above.

10.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9)
         EXCLUDES CERTAIN SHARES*   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  9.1%                               

12.      TYPE OF REPORTING PERSON*

                  IN, HC



ITEM 1(a).        Name of Issuer:

     Tremisis Energy Acquisition Corporation

Item 1(b).        Address of Issuer's Principal Executive Offices:

     1775 Broadway
     Suite 604
     New York, NY 10019
             

Item 2(a).        Name of Persons Filing:
Item 2(b).        Address of Principal Business Office or, if None, Residence:
Item 2(c).        Citizenship:

     Amaranth LLC
     c/o Amaranth Advisors L.L.C.
     One American Lane
     Greenwich, Connecticut 06831
     Cayman Islands company

     Amaranth Advisors L.L.C.
     One American Lane
     Greenwich, Connecticut 06831
     Delaware limited liability company

     Nicholas M. Maounis
     c/o Amaranth Advisors L.L.C.
     One American Lane
     Greenwich, Connecticut 06831
     U.S. Citizen

Amaranth  Advisors L.L.C.  is the trading advisor for Amaranth LLC  ("Amaranth")
and has been granted investment discretion over portfolio investments, including
the Common Stock (as defined below),  held by it. Maounis is the managing member
of  Amaranth  Advisors  L.L.C.  and may,  by virtue of his  position as managing
member,  be deemed to have the power to direct the vote and  disposition  of the
Common Stock held for Amaranth.


Item 2(d).        Title of Class of Securities

     Common Stock, $0.0001 Par Value ("Common Stock")

Item 2(e).        CUSIP Number:

     894727106                 



Item 3.           If This Statement is Filed Pursuant to Rule 13d-1(b),
                  or 13d-2(b) or (c), Check Whether the Person Filing is a:

     (a) [ ] Broker or dealer registered under Section 15 of the Exchange Act.

     (b) [ ] Bank as defined in Section 3(a)(6) of the Exchange Act.

     (c) [ ] Insurance company defined in Section 3(a)(19) of the Exchange Act.

     (d) [ ] Investment  company  registered  under Section 8 of the  Investment
             Company Act.

     (e) [ ] An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E).

     (f) [ ] An employee  benefit plan or endowment fund in accordance with Rule
             13d-1(b)(1)(ii)(F).

     (g) [ ] A parent holding  company or control person in accordance with Rule
             13d-1(b)(1)(ii)(G).

     (h) [ ] A savings  association  as defined in Section  3(b) of the  Federal
             Deposit Insurance Act.

     (i) [ ] A church plan that is excluded from the definition of an investment
             company under Section 3(c)(14) of the Investment Company Act;

     (j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

     If this statement is filed pursuant to Rule 13d-1(c), check this box [x]

Item 4.           Ownership.

     Provide  the  following  information  regarding  the  aggregate  number and
percentage of the class of securities of the issuer identified in Item 1.

     (a)  Amount beneficially owned:

          701,675

     (b)  Percent of class:

          9.1%



     (c)  Number of shares as to which such person has:

          (i)   Sole power to vote or direct the vote

                0

          (ii)  Shared power to vote or to direct the vote

                See Item 4(a).

          (iii) Sole power to dispose or to direct the disposition of

                0

          (iv)  Shared power to dispose or to direct the disposition of

                See Item 4(a).

Item 5.   Ownership of Five Percent or Less of a Class.

     If this  statement  is being  filed to report  the fact that as of the date
hereof the Reporting Persons have ceased to be the beneficial owner of more than
five  percent  of  the  class  of  securities,  check  the  following  [ ].  Not
applicable.

Item 6.   Ownership of More than Five Percent on Behalf of Another Person.

     Shareholders of Amaranth indirectly participate in the receipt of dividends
from,  and  proceeds  from the sale of, the Common Stock held for the account of
Amaranth.

Item 7.   Identification  and  Classification  of the  Subsidiary  Which
          Acquired the Security Being Reported on by the Parent Holding
          Company.

     Not applicable.

Item 8.   Identification and Classification of Members of the Group.

     See Item 2 in lieu of an Exhibit.

Item 9.   Notice of Dissolution of Group.

     Not applicable.



Item 10.  Certification.

     By  signing  below  the  undersigned  certifies  that,  to the  best of its
knowledge and belief, the securities referred to above were not acquired and are
not held for the purpose of or with the effect of changing  or  influencing  the
control of the issuer of the  securities  and were not acquired and are not held
in connection with or as a participant in any transaction having that purpose or
effect.

                                   SIGNATURES

     After reasonable inquiry and to the best of its knowledge and belief,  each
of the undersigned  certifies that the information  with respect to it set forth
in this statement is true, complete, and correct.


Dated:   December 16, 2005                 

         AMARANTH LLC
             by Amaranth Advisors L.L.C., as Trading Advisor

             By: /s/ Nicholas M. Maounis
                 ----------------------------------------
                     Nicholas M. Maounis, Managing Member


          AMARANTH ADVISORS L.L.C.

             By: /s/ Nicholas M. Maounis
                 ----------------------------------------
                     Nicholas M. Maounis, Managing Member


          NICHOLAS M. MAOUNIS

          /s/ Nicholas M. Maounis
          -----------------------------------------------
              Nicholas M. Maounis



                                    EXHIBIT A
                             JOINT FILING AGREEMENT

     The  undersigned  hereby agree that the statement on Schedule 13G signed by
each of the  undersigned  shall be,  filed on behalf of each of the  undersigned
pursuant to and in accordance  with the  provisions  of Rule 13d-1(k)  under the
Securities Exchange Act of 1934, as amended.

Dated:   December 16, 2005                 

         AMARANTH LLC
             by Amaranth Advisors L.L.C., as Trading Advisor

             By: /s/ Nicholas M. Maounis
                 ----------------------------------------
                     Nicholas M. Maounis, Managing Member


          AMARANTH ADVISORS L.L.C.

             By: /s/ Nicholas M. Maounis
                 ----------------------------------------
                     Nicholas M. Maounis, Managing Member


          NICHOLAS M. MAOUNIS

          /s/ Nicholas M. Maounis
          -----------------------------------------------
              Nicholas M. Maounis