SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                ----------------
                                 SCHEDULE 13G/A
                                ----------------

                                 Amendment No. 1


             INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                                   Tronox Inc.
                                (NAME OF ISSUER)

                      Class A Common Stock, $0.01 par value
                         (TITLE OF CLASS OF SECURITIES)

                                    897051108
                                 (CUSIP NUMBER)

                                December 31, 2006
             (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)



                             (Page 1 of 17 Pages)
------------------

*    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 the disclosures provided in a prior cover page.

     The information required in 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).





CUSIP No. 897051108                 13G/A                     PAGE 2 of 17 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Partners Fund II, L.P.
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Delaware
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         _________________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    916,200
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    916,200
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          916,200
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          2.22%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
               PN
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 897051108                 13G/A                     PAGE 3 of 17 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Partners Institutional Fund, L.P.
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Delaware
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         _________________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    549,000
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    549,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          549,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          1.33%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
               PN
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 897051108                 13G/A                     PAGE 4 of 17 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Partners Renewable Energy Fund, L.P.
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Delaware
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         _________________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    100,000
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    100,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          100,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          0.24%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
               PN
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 897051108                 13G/A                     PAGE 5 of 17 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Offshore Fund Ltd.
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          British Virgin Islands
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         _________________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    684,100
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    684,100
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          684,100
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          1.66%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
               CO
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 897051108                 13G/A                     PAGE 6 of 17 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Advisory Partners
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Connecticut
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         _________________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,275,000
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,275,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,275,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.52%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
               PN; IA
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 897051108                 13G/A                     PAGE 7 of 17 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Ardsley Partners I
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          Connecticut
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         _________________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    1,465,200
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    1,465,200
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          1,465,200
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          3.55%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
               PN
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 897051108                 13G/A                     PAGE 8 of 17 PAGES

--------------------------------------------------------------------------------
     (1)  NAME OF REPORTING PERSON
          S.S. OR I.R.S. IDENTIFICATION NO.
          OF ABOVE PERSON
          Philip J. Hempleman
--------------------------------------------------------------------------------
     (2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                    (a)  [x]
                                                                    (b)  [ ]
--------------------------------------------------------------------------------
     (3)  SEC USE ONLY

--------------------------------------------------------------------------------
     (4)  CITIZENSHIP OR PLACE OF ORGANIZATION
          United States
--------------------------------------------------------------------------------

NUMBER OF      (5)  SOLE VOTING POWER
                    0
SHARES         _________________________________________________________________

BENEFICIALLY   (6)  SHARED VOTING POWER
                    2,275,000
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,275,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,275,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.52%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
               IN
--------------------------------------------------------------------------------
             ** SEE INSTRUCTIONS BEFORE FILLING OUT!





CUSIP No. 897051108                 13G/A                     PAGE 9 of 17 PAGES



ITEM 1(a).  NAME OF ISSUER:

                  The name of the issuer is Tronox Inc. (the "Company").

ITEM 1(b).  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

                  123 Robert S. Kerr Avenue, Oklahoma City, Oklahoma 73102

ITEM 2(a).  NAME OF PERSON FILING:

         This statement is filed by:

         (i)      Ardsley Partners Fund II, L.P., a Delaware limited partnership
                  ("AP II"), with respect to the shares of Class A Common Stock,
                  par value $0.01 per share ("Common Stock") directly owned by
                  it;
         (ii)     Ardsley Partners Institutional Fund, L.P., a Delaware limited
                  partnership ("Ardsley Institutional"), with respect to the
                  shares of Common Stock directly owned by it;
         (iii)    Ardsley Partners Renewable Energy Fund, L.P., a Delaware
                  limited partnership ("Ardsley Energy"), with respect to the
                  shares of Common Stock directly owned by it;
         (iv)     Ardsley Offshore Fund Ltd., a British Virgin Islands
                  Corporation ("Ardsley Offshore"), with respect to the shares
                  of Common Stock directly owned by it;
         (v)      Ardsley Advisory Partners, a New York general partnership
                  ("Ardsley") which serves as Investment Manager of Ardsley
                  Offshore and the Investment Adviser of AP II, Ardsley
                  Institutional, Ardsley Energy and certain managed accounts,
                  with respect to the shares of Common Stock directly owned by
                  Ardsley Offshore, AP II, Ardsley Institutional, Ardsley Energy
                  and the managed accounts;
         (vi)     Ardsley Partners I, a New York general partnership ("Ardsley
                  Partners") which serves as General Partner of AP II, Ardsley
                  Institutional and Ardsley Energy; and
         (vii)    Philip J. Hempleman ("Mr. Hempleman"), the Managing Partner of
                  Ardsley and Ardsley Partners, with respect to the shares of
                  Common Stock owned by AP II, Ardsley Institutional, Ardsley
                  Energy, Ardsley Offshore and the managed accounts and with
                  respect to the shares of Common Stock he owns individually.

                  The foregoing persons are hereinafter sometimes collectively
referred to as the "Reporting Persons." Any disclosures herein with respect to
persons other than the Reporting Persons are made on information and belief
after making inquiry to the appropriate party.

ITEM 2(b).  ADDRESS OF PRINCIPAL OFFICE OR, IF NONE, RESIDENCE:

         The address of the business office of each of the Reporting Persons,
with the exception of Ardsley Offshore, is 262 Harbor Drive, Stamford,
Connecticut 06902.

         The address of the registered office of Ardsley Offshore is Romasco
Place, Wickhams Cay 1, Roadtown Tortola, British Virgin Islands.

ITEM 2(c).  CITIZENSHIP:

         AP II,  Ardsley  Institutional  and Ardsley Energy are Delaware
limited partnerships. Ardsley Offshore is a British Virgin Islands Corporation.
Ardsley and Ardsley Partners are New York general partnerships. Mr. Hempleman is
a United States Citizen.





CUSIP No. 897051108                 13G/A                    PAGE 10 of 17 PAGES

ITEM 2(d).  TITLE OF CLASS OF SECURITIES: Class A Common Stock, par value $0.01
per share

ITEM 2(e).  CUSIP NUMBER:  897051108

ITEM 3.     IF THIS STATEMENT IS FILED PURSUANT TO RULES 13d-1(b), OR 13d-2(b),
CHECK WHETHER THE PERSON FILING IS A:

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

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

          (c) [ ] Insurance Company as defined in Section 3(a)(19) of the Act


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

          (e) [ ] Investment Adviser registered under Section 203 of the
                  Investment Advisers Act of 1940

          (f) [ ] Employee Benefit Plan, Pension Fund which is subject to the
                  provisions of the Employee Retirement Income Security Act of
                  1974 or Endowment Fund; see Rule 13d-1(b)(1)(ii)(F)

          (g) [ ] Parent Holding Company, in accordance with Rule
                  13d-1(b)(ii)(G); see item 7

          (h) ( ) Group, in accordance with Rule 13d-1(b)(1)(ii)(H)

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





CUSIP No. 897051108                 13G/A                    PAGE 11 of 17 PAGES

ITEM 4.   OWNERSHIP.

    A.   Ardsley Partners Fund II, L.P.
         (a)  Amount beneficially owned: 916,200
         (b)  Percent of class: 2.22%. (The percentages used herein and in the
              rest of Item 4 are calculated based upon the 18,356,778 shares
              of Common Stock, and 22,889,431 shares of Class B Common Stock,
              par value $0.01 per share, issued and outstanding as per the
              Company's Form 10-Q for the period ended October 31, 2006, as
              filed on November 11, 2006.)
         (c)  (i)   Sole Power to vote or direct the vote: -0-
              (ii)  Shared power to vote or direct the vote: 916,200
              (iii) Sole power to dispose or direct the disposition: -0-
              (iv)  Shared power to dispose or direct the disposition: 916,200


    B.   Ardsley Partners Institutional Fund, L.P.
         (a)  Amount beneficially owned: 549,000
         (b)  Percent of class: 1.33%
         (c)  (i)   Sole Power to vote or direct the vote: -0-
              (ii)  Shared power to vote or direct the vote: 549,000
              (iii) Sole power to dispose or direct the disposition: -0-
              (iv)  Shared power to dispose or direct the disposition: 549,000

    C.   Ardsley Partners Renewable Energy Fund, L.P.
         (a)  Amount beneficially owned: 100,000
         (b)  Percent of class: 0.24%
         (c)  (i)   Sole Power to vote or direct the vote: -0-
              (ii)  Shared power to vote or direct the vote: 100,000
              (iii) Sole power to dispose or direct the disposition: -0-
              (iv)  Shared power to dispose or direct the disposition: 100,000

    D.   Ardsley Offshore Fund Ltd.
         (a)  Amount beneficially owned: 684,100
         (b)  Percent of class: 1.66%
         (c)  (i)   Sole Power to vote or direct the vote: -0-
              (ii)  Shared power to vote or direct the vote: 684,100
              (iii) Sole power to dispose or direct the disposition: -0-
              (iv)  Shared power to dispose or direct the disposition: 684,100

    E.   Ardsley Advisory Partners
         (a)  Amount beneficially owned: 2,275,000
         (b)  Percent of class: 5.52%
         (c)  (i)   Sole Power to vote or direct the vote: -0-
              (ii)  Shared power to vote or direct the vote: 2,275,000
              (iii) Sole power to dispose or direct the disposition: -0-
              (iv)  Shared power to dispose or direct the disposition: 2,275,000

    F. Ardsley Partners I
         (a)  Amount beneficially owned: 1,465,200
         (b)  Percent of class: 3.55%
         (c)  (i)   Sole Power to vote or direct the vote: -0-
              (ii)  Shared power to vote or direct the vote: 1,465,200
              (iii) Sole power to dispose or direct the disposition: -0-
              (iv)  Shared power to dispose or direct the disposition: 1,465,200

    G. Philip J. Hempleman
         (a)  Amount beneficially owned: 2,275,000
         (b)  Percent of class: 5.52%
         (c)  (i)   Sole Power to vote or direct the vote: -0-
              (ii)  Shared power to vote or direct the vote: 2,275,000
              (iii) Sole power to dispose or direct the disposition: -0-
              (iv)  Shared power to dispose or direct the disposition: 2,275,000





CUSIP No. 897051108                 13G/A                    PAGE 12 of 17 PAGES

ITEM 5.   OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.

          Not applicable.

ITEM 6.   OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

         Ardsley, the Investment Manager of Ardsley Offshore and the Investment
Adviser of certain managed accounts, has the power to vote and direct the
disposition of the proceeds from the sale of the shares of Common Stock owned by
Ardsley Offshore and the managed accounts, and accordingly may be deemed the
direct "beneficial owner" of such shares of Common Stock.

         Ardsley, the Investment Adviser of AP II, Ardsley Institutional and
Ardsley Energy, shares the power to vote and direct the disposition of the
proceeds from the sale of the shares of Common Stock owned by AP II, Ardsley
Institutional and Ardsley Energy, and, accordingly, may be deemed the direct
"beneficial owner" of such shares of Common Stock.

         Ardsley Partners, the General Partner of AP II, Ardsley Institutional
and Ardsley Energy, shares the power to vote and direct the disposition of the
shares of Common Stock owned by AP II, Ardsley Institutional and Ardsley Energy,
and, accordingly, may be deemed the direct "beneficial owner" of such shares of
Common Stock.

         Mr. Hempleman is the Managing Partner of Ardsley and Ardsley Partners
and in that capacity directs their operations and therefore may be deemed to be
the indirect "beneficial owner" of the shares of Common Stock owned by Ardsley
Offshore, AP II, Ardsley Institutional, Ardsley Energy and the managed accounts.

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.

          Not applicable.

ITEM 9.   NOTICE OF DISSOLUTION OF GROUP.

          Not applicable.





CUSIP No. 897051108                 13G/A                    PAGE 13 of 17 PAGES

ITEM 10.  CERTIFICATION.

     Each of the Reporting Persons hereby makes the following certification:

          By signing below I certify, to the best of my knowledge and belief,
the securities referred to above were acquired in the ordinary course of
business, were not acquired for the purpose of and do not have the effect of
changing or influencing the control of the issuer of such securities and were
not acquired in connection with or as a participant in any transaction having
such purposes or effect.





CUSIP No. 897051108                 13G/A                    PAGE 14 of 17 PAGES

                                    SIGNATURE

          After reasonable inquiry and to the best of their knowledge and
belief, the undersigned certify that the information set forth in this statement
is true, complete and correct.


DATED:   as of February 14, 2007


                                  ARDSLEY PARTNERS FUND II, L.P.
                                  BY:  ARDSLEY PARTNERS I,
                                       GENERAL PARTNER


                                  BY:/s/ Steve Napoli
                                     ----------------
                                      Steve Napoli
                                      General Partner



                                  ARDSLEY PARTNERS INSTITUTIONAL FUND, L.P.
                                  BY:  ARDSLEY PARTNERS I,
                                       GENERAL PARTNER


                                  BY:/s/ Steve Napoli
                                     ----------------
                                      Steve Napoli
                                      General Partner


                                  ARDSLEY PARTNERS RENEWABLE ENERGY FUND, L.P.
                                  BY:  ARDSLEY PARTNERS I,
                                       GENERAL PARTNER


                                  BY:/s/ Steve Napoli
                                      ----------------
                                      Steve Napoli
                                      General Partner

                                  ARDSLEY OFFSHORE FUND LTD.


                                  BY:/s/ Neil Glass
                                     --------------
                                      Neil Glass
                                      Vice-President and Administrative Manager



                                  ARDSLEY ADVISORY PARTNERS
                                  By:  ARDSLEY PARTNERS I
                                        GENERAL PARTNER


                                  BY:/s/ Steve Napoli
                                     ----------------
                                      Steve Napoli
                                      General Partner





CUSIP No. 897051108                 13G/A                    PAGE 15 of 17 PAGES

                                  ARDSLEY PARTNERS I

                                  BY:/s/ Steve Napoli
                                     ----------------
                                      Steve Napoli
                                      General Partner



                                  PHILIP J. HEMPLEMAN, INDIVIDUALLY


                                  BY:/s/ Steve Napoli*
                                     -----------------
                                      Steve Napoli
                                  As attorney in fact for
                                  Philip J. Hempleman


*    Evidence of Power of Attorney was filed with the Schedule 13G/A filed on
     February 15, 2006 (Acc-no: 0000902664-06-000895) and is incorporated by
     reference into this filing.





CUSIP No. 897051108                 13G/A                    PAGE 16 of 17 PAGES

                                    EXHIBIT 1
               JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k)(1)

             The undersigned acknowledge and agree that the foregoing statement
on Schedule 13G is filed on behalf of each of the undersigned and that all
subsequent amendments to this statement shall be filed on behalf of each of the
undersigned without the necessity of filing additional joint filing statements.
The undersigned acknowledge that each shall be responsible for the timely filing
of such amendments, and for the completeness and accuracy of the information
concerning him, her or it contained herein, but shall not be responsible for the
completeness and accuracy of the information concerning the other entities or
persons, except to the extent that he, she or it knows or has reason to believe
that such information is inaccurate.

Dated as of February 14, 2007



                                  ARDSLEY PARTNERS FUND II, L.P.
                                  BY:  ARDSLEY PARTNERS I,
                                       GENERAL PARTNER


                                  BY:/s/ Steve Napoli
                                     ----------------
                                      Steve Napoli
                                      General Partner



                                  ARDSLEY PARTNERS INSTITUTIONAL FUND, L.P.
                                  BY:  ARDSLEY PARTNERS I,
                                       GENERAL PARTNER


                                  BY:/s/ Steve Napoli
                                     ----------------
                                      Steve Napoli
                                      General Partner


                                  ARDSLEY PARTNERS RENEWABLE ENERGY FUND, L.P.
                                  BY:  ARDSLEY PARTNERS I,
                                       GENERAL PARTNER


                                  BY:/s/ Steve Napoli
                                      ----------------
                                      Steve Napoli
                                      General Partner

                                  ARDSLEY OFFSHORE FUND LTD.


                                  BY:/s/ Neil Glass
                                     --------------
                                      Neil Glass
                                      Vice-President and Administrative Manager





CUSIP No. 897051108                 13G/A                    PAGE 17 of 17 PAGES


                                  ARDSLEY ADVISORY PARTNERS
                                  By:  ARDSLEY PARTNERS I
                                        GENERAL PARTNER


                                  BY:/s/ Steve Napoli
                                     ----------------
                                      Steve Napoli
                                      General Partner


                                  ARDSLEY PARTNERS I

                                  BY:/s/ Steve Napoli
                                     ----------------
                                      Steve Napoli
                                      General Partner



                                  PHILIP J. HEMPLEMAN, INDIVIDUALLY


                                  BY:/s/ Steve Napoli*
                                     -----------------
                                      Steve Napoli
                                      Attorney-in-fact
                                      for Philip J. Hempleman


*    Evidence of Power of Attorney was filed with the Schedule 13G/A filed on
     February 15, 2006 (Acc-no: 0000902664-06-000895) and is incorporated by
     reference into this filing.