SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                ----------------

                                  SCHEDULE 13G

                                ----------------



             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)

                               September 21, 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                    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
                    849,400
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    849,400
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          849,400
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          2.06%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
          PN
--------------------------------------------------------------------------------
                     ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 897051108                   13G                    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
                    496,500
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    496,500
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          496,500
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          1.20%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
          PN
--------------------------------------------------------------------------------
                     ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 897051108                   13G                    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
                    95,000
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    95,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          95,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          0.23%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
          PN
--------------------------------------------------------------------------------
                     ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 897051108                   13G                    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
                    830,100
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    830,100
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          830,100
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          2.01%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
          CO
--------------------------------------------------------------------------------
                     ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 897051108                   13G                    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
                    2,295,000
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,295,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,295,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.56%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
          PN; IA
--------------------------------------------------------------------------------
                     ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 897051108                   13G                    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
                    1,440,900
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    1,440,900
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          1,440,900
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          3.49%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
          PN
--------------------------------------------------------------------------------
                     ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 897051108                   13G                    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
                    2,295,000
OWNED BY       _________________________________________________________________

EACH           (7)  SOLE DISPOSITIVE POWER
                    0
REPORTING      _________________________________________________________________

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    2,295,000
--------------------------------------------------------------------------------
     (9)  AGGREGATE AMOUNT BENEFICIALLY OWNED
          BY EACH REPORTING PERSON
          2,295,000
--------------------------------------------------------------------------------
    (10)  CHECK BOX IF THE AGGREGATE AMOUNT
          IN ROW (9) EXCLUDES CERTAIN SHARES **                          [ ]
--------------------------------------------------------------------------------
    (11)  PERCENT OF CLASS REPRESENTED
          BY AMOUNT IN ROW (9)
          5.56%
--------------------------------------------------------------------------------
    (12)  TYPE OF REPORTING PERSON **
          IN
--------------------------------------------------------------------------------
                     ** SEE INSTRUCTIONS BEFORE FILLING OUT!






CUSIP No. 897051108                   13G                    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;
       (iii)  Ardsley  Offshore Fund Ltd., a British Virgin  Islands Corporation
              ("Ardsley Offshore"), with  respect to the shares of  Common Stock
              directly owned by it;
       (iv)   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;
       (v)    Ardsley  Partners  I,  a  New  York  general partnership ("Ardsley
              Partners")  which  serves  as  General  Partner of  AP II, Ardsley
              Institutional and Ardsley Energy; and
       (vi)   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                    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                    PAGE 11 of 17 PAGES

ITEM 4.   OWNERSHIP.

      A.   Ardsley Partners Fund II, L.P.
           (a)  Amount beneficially owned: 849,400
           (b)  Percent of class: 2.06%. (The percentages used herein and
                in the rest of Item 4 are calculated based upon the
                18,358,133 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 June 30, 2006, as filed on August 14, 2006.)
           (c)  (i) Sole Power to vote or direct the vote: -0-
               (ii) Shared power to vote or direct the vote: 849,400
              (iii) Sole power to dispose or direct the disposition: -0-
               (iv) Shared power to dispose or direct the disposition: 849,400

      B.   Ardsley Partners Institutional Fund, L.P.
           (a) Amount beneficially owned: 496,500
           (b) Percent of class: 1.20%
           (c) (i) Sole Power to vote or direct the vote: -0-
              (ii) Shared power to vote or direct the vote: 496,500
             (iii) Sole power to dispose or direct the disposition: -0-
              (iv) Shared power to dispose or direct the disposition: 496,500

      C.   Ardsley Partners Renewable Energy Fund, L.P.
           (a) Amount beneficially owned: 95,000
           (b) Percent of class: 0.23%
           (c) (i) Sole Power to vote or direct the vote: -0-
              (ii) Shared power to vote or direct the vote: 95,000
             (iii) Sole power to dispose or direct the disposition: -0-
              (iv) Shared power to dispose or direct the disposition: 95,000

      D.   Ardsley Offshore Fund Ltd.
           (a) Amount beneficially owned: 830,100
           (b) Percent of class: 2.01%
           (c) (i) Sole Power to vote or direct the vote: -0-
              (ii) Shared power to vote or direct the vote: 830,100
             (iii) Sole power to dispose or direct the disposition: -0-
              (iv) Shared power to dispose or direct the disposition: 830,100

      E.   Ardsley Advisory Partners
           (a) Amount beneficially owned: 2,295,000
           (b) Percent of class: 5.56%
           (c) (i) Sole Power to vote or direct the vote: -0-
              (ii) Shared power to vote or direct the vote: 2,295,000
             (iii) Sole power to dispose or direct the disposition: -0-
              (iv) Shared power to dispose or direct the disposition: 2,295,000

      F.   Ardsley Partners I
           (a) Amount beneficially owned: 1,440,900
           (b) Percent of class: 3.49%
           (c) (i) Sole Power to vote or direct the vote: -0-
              (ii) Shared power to vote or direct the vote: 1,440,900
             (iii) Sole power to dispose or direct the disposition: -0-
              (iv) Shared power to dispose or direct the disposition: 1,440,900

      G.   Philip J. Hempleman
           (a) Amount beneficially owned: 2,295,000
           (b) Percent of class: 5.56%
           (c) (i) Sole Power to vote or direct the vote: -0-
              (ii) Shared power to vote or direct the vote: 2,295,000
             (iii) Sole power to dispose or direct the disposition: -0-
              (iv) Shared power to dispose or direct the disposition: 2,295,000






CUSIP No. 897051108                   13G                    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                    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                    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 September 29, 2006


                                   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 PARNTERS 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                    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                    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 September 29, 2006


                                   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 PARNTERS 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                    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
                                       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.