SC 13D/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 6)*

Green Plains Renewable Energy, Inc.

(Name of Issuer)

Common Stock, $.001 Par Value

(Title of Class of Securities)

393222104

(CUSIP Number)

Robert L. Verigan

Sidley Austin LLP

One South Dearborn Street

Chicago, Illinois 60603

(312) 853-7000

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

February 16, 2012

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

* 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).

CUSIP No. 393222104

(1)	Names of reporting persons NTR plc
(2)	Check the appropriate box if a member of a group (a) If any of the shares beneficially owned by a reporting person are held as a member of a group and the membership is expressly affirmed, please check.  ¨ (b) If the reporting person disclaims membership in a group or describes a relationship with other person but does not affirm the existence of a group, please check.  x
(3)	SEC use only
(4)	Source of funds (see instructions) Not Applicable
(5)	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)     ¨
(6)	Citizenship or place of organization Ireland
Number of shares beneficially owned by each reporting person with		(7)	Sole voting power
		(8)	Shared voting power 577,653
		(9)	Sole dispositive power
		(10)	Shared dispositive power 577,653
(11)	Aggregate amount beneficially owned by each reporting person 577,653
(12)	Check if the aggregate amount in Row (11) excludes certain shares     ¨
(13)	Percent of class represented by amount in Row (11) 2.0% (Calculation is based upon 29,213,611 shares outstanding as of March 9, 2012 after completion of the Repurchase described herein, as disclosed in the Issuer’s prospectus supplement filed with the Commission on March 1, 2012.)
(14)	Type of reporting person (see instructions) CO, HC

CUSIP No. 393222104

(1)	Names of reporting persons Greenstar North America Holdings, Inc.
(2)	Check the appropriate box if a member of a group (a) If any of the shares beneficially owned by a reporting person are held as a member of a group and the membership is expressly affirmed, please check.  ¨ (b) If the reporting person disclaims membership in a group or describes a relationship with other person but does not affirm the existence of a group, please check.  x
(3)	SEC use only
(4)	Source of funds (see instructions) Not Applicable
(5)	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)    ¨
(6)	Citizenship or place of organization Delaware
Number of shares beneficially owned by each reporting person with		(7)	Sole voting power
		(8)	Shared voting power 577,653
		(9)	Sole dispositive power
		(10)	Shared dispositive power 577,653
(11)	Aggregate amount beneficially owned by each reporting person 577,653
(12)	Check if the aggregate amount in Row (11) excludes certain shares     ¨
(13)	Percent of class represented by amount in Row (11) 2.0% (Calculation is based upon 29,213,611 shares outstanding as of March 9, 2012 after completion of the Repurchase described herein, as disclosed in the Issuer’s prospectus supplement filed with the Commission on March 1, 2012.)
(14)	Type of reporting person (see instructions) CO, HC

CUSIP No. 393222104

(1)	Names of reporting persons Greenstar Investments LLC
(2)	Check the appropriate box if a member of a group (a) If any of the shares beneficially owned by a reporting person are held as a member of a group and the membership is expressly affirmed, please check.  ¨ (b) If the reporting person disclaims membership in a group or describes a relationship with other person but does not affirm the existence of a group, please check.  x
(3)	SEC use only
(4)	Source of funds (see instructions) OO
(5)	Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)    ¨
(6)	Citizenship or place of organization Delaware
Number of shares beneficially owned by each reporting person with		(7)	Sole voting power
		(8)	Shared voting power 577,653
		(9)	Sole dispositive power
		(10)	Shared dispositive power 577,653
(11)	Aggregate amount beneficially owned by each reporting person 577,653
(12)	Check if the aggregate amount in Row (11) excludes certain shares     ¨
(13)	Percent of class represented by amount in Row (11) 2.0% (Calculation is based upon 29,213,611 shares outstanding as of March 9, 2012 after completion of the Repurchase described herein, as disclosed in the Issuer’s prospectus supplement filed with the Commission on March 1, 2012.)
(14)	Type of reporting person (see instructions) OO, HC

This Amendment No. 6 to Schedule 13D/A (this “Amendment No. 6”) is being filed pursuant to Rule 13d-2(a) to amend and supplement (i) the Schedule 13D filed by certain of the Reporting Persons with the Securities and Exchange Commission (“SEC”) on October 27, 2008 (the “initial Schedule 13D”), (ii) Amendment No. 1 to Schedule 13D filed by certain of the Reporting Persons with the SEC on November 4, 2008 (“Amendment No. 1”), (iii) Amendment No. 2 to Schedule 13D filed by certain of the Reporting Persons with the SEC on February 17, 2010 (“Amendment No. 2”), (iv) Amendment No. 3 to Schedule 13D filed by certain of the Reporting Persons with the SEC on March 23, 2010 (“Amendment No. 3”), (v) Amendment No. 4 to Schedule 13D filed by certain of the Reporting Persons with the SEC on June 4, 2010 (“Amendment No. 4”), and (vi) Amendment No. 5 to Schedule 13D filed by certain of the Reporting Persons with the SEC on September 21, 2011 (collectively with the foregoing, this “Schedule 13D/A”). Excluded Items are either inapplicable or remain unchanged. Capitalized terms used and not otherwise defined in this Amendment No. 6 have the meanings given them in the initial Schedule 13D, Amendment No. 1, Amendment No. 2, Amendment No. 3, Amendment No. 4 and Amendment No. 5, as applicable.

Item 1. Security and Issuer

Common stock, par value $0.001 per share, of the Issuer (“Common Stock”). The Issuer’s principal executive offices are located at 450 Regency Parkway, Ste. 400, Omaha, Nebraska 68114.

Item 2. Identity and Background

This Amendment No. 6 is being filed on behalf of each of the following reporting persons (collectively, the “Reporting Persons”):

NTR plc, a public limited company registered in Ireland (“NTR”), which has its principal office address at Burton Court, Burton Hall Drive, Sandyford, Dublin 18, Ireland. NTR is a leading international developer and operator of renewable energy and sustainable waste management projects.

Greenstar North America Holdings, Inc., a Delaware corporation (“GSNA”), which has its principal office address at 3411 Richmond Avenue, Suite 700 Houston TX 77046. GSNA is a holding company and a wholly owned subsidiary of NTR.

Greenstar Investments LLC, a Delaware limited liability company (“Greenstar Investments”), which has its principal office address as c/o NTR plc, Burton Court, Burton Hall Drive, Sandyford, Dublin 18, Ireland. Greenstar Investments is a holding company and a wholly owned subsidiary of GSNA.

During the last five years, none of the Reporting Persons has been (a) convicted in a criminal proceeding nor (b) a party to a civil proceeding of a judicial or administrative body of competent jurisdiction as a result of which it was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws finding any violation with respect to such laws.

Item 3. Source and Amount of Funds or Other Consideration

Pursuant to an Assignment and Assumption Agreement, dated as of February 16, 2012, GSNA transferred a total of 7,727,653 shares of Common Stock (the “Shares”) to Greenstar Investments (the “Transfer”). No cash was exchanged between the parties in connection with the transfer. GSNA and Greenstar Investments are each wholly owned direct or indirect subsidiaries of NTR, which remains the indirect beneficial owner of all such Shares.

Item 4. Purpose of Transaction.

Greenstar Investments acquired the Shares on February 16, 2012 in connection with an internal reorganization undertaken by GSNA.

Following the Transfer, Greenstar Investments (i) sold 3,450,000 of the Shares on March 6, 2012 at a price to Greenstar Investments of $10.06 per share (the “Secondary Offering”) pursuant to the Underwriting Agreement, dated as of March 1, 2012 (the “Underwriting Agreement”), among the Issuer, Jefferies & Company, Inc. and Greenstar Investments, and (ii) sold 3,700,000 shares of Common Stock to the Issuer on March 9, 2012 at a price of

$10.06 per share (the “Repurchase” and, together with the Transfer and Secondary Offering, the “Transactions”) pursuant to the Stock Repurchase Agreement, dated as of February 29, 2012 (the “Repurchase Agreement”), among the Issuer, GSNA and Greenstar Investments.

Item 5. Interest in Securities of the Issuer

The Reporting Persons beneficially own 577,653 shares of Common Stock, or approximately 2.0% of the Issuer’s outstanding Common Stock. Greenstar Investments, GSNA, by virtue of its ownership of Greenstar Investments, and NTR, by virtue of its ownership of GSNA, each have shared power to vote and dispose of the Shares.

The description of the Transactions contained in Item 4 is incorporated herein by reference. Following the completion of the Repurchase on March 9, 2012, the Reporting Persons ceased to be the beneficial owners of more than five percent of the Issuer’s outstanding Common Stock.

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer

Pursuant to the Underwriting Agreement, NTR executed a lock-up agreement pursuant to which it agreed, subject to specified exceptions, not to directly or indirectly (i) sell, offer, contract or grant any option to sell (including any short sale), pledge, transfer, establish an open “put equivalent position” within the meaning of Rule 16a-l(h) under the Securities Exchange Act of 1934, as amended, or otherwise dispose of any Common Stock, options or warrants to acquire Common Stock, or securities exchangeable or exercisable for or convertible into Common Stock owned either of record or beneficially, or (ii) publicly announce an intention to do any of the foregoing for a period of 45 days after March 1, 2012 without the prior written consent of Jefferies & Company, Inc. Subject to certain exceptions, this restriction terminates after the close of trading of Common Stock on the 45th day after March 1, 2012.

Pursuant to the Repurchase Agreement, Greenstar Investments sold 3.7 million shares of Common Stock to the Issuer at a price of $10.06 per share on March 9, 2012 (the “Repurchase Closing Date”). On the Repurchase Closing Date, the Issuer paid $10,060,000 of the aggregate purchase price in cash, in respect of 1 million shares of Common Stock, and delivered to Greenstar Investments a promissory note with an aggregate principal amount of $27,162,000 (the “Note”) in respect of 2.7 million shares of Common Stock. The Note bears interest at 5.0% per annum. Pursuant to an Assignment and Pledge of Stock and LLC Interest, dated as of March 9, 2012, between Greenstar Investments and the Issuer, the Issuer’s obligations under the Note are secured by 2.7 million shares of Common Stock (the “Collateral Shares”) and by the Issuer’s interest in Green Plains Shenandoah LLC. The Reporting Persons are not deemed to be the beneficial owners of the Collateral Shares.

Item 7. Material to Be Filed as Exhibits

Exhibits (a) – (m) and (o) – (s) listed below have been previously filed as exhibits (as indicated below) and are incorporated by reference in this Schedule 13D/A by reference thereto. Exhibits (n) and (t)—(x) are filed herewith or incorporated herein by reference.

(a)*	Agreement and Plan of Merger dated May 7, 2008, by and among Green Plains Renewable Energy, Inc., Green Plains Merger Sub, Inc., and VBV LLC
(b)*	Stock Purchase Agreement dated May 7, 2008 by and among Green Plains Renewable Energy, Inc., Bioverda International Holdings Limited and Bioverda US Holdings LLC
(c)*	Shareholders’ Agreement dated October 15, 2008 by and among Green Plains Renewable Energy, Inc., Bioverda International Holdings Limited, Bioverda US Holdings LLC and Wayne Hoovestol
(d)*	Lock-Up and Voting Agreement dated May 7, 2008 by and among Green Plains Renewable Energy, Inc., Bioverda International Holdings Limited and Bioverda US Holdings LLC
(e)*	Put and Call Agreement (VBV) dated April 1, 2008 by and among Bioverda International, Bioverda US Holdings LLC and Wilon Holdings S.A.
(f)*	Notice of exercise of Put Option (VBV) dated October 1, 2008, as amended effective October 15, 2008
(g)*	Put and Call Agreement (GPRE) dated April 1, 2008 by and among Bioverda International, Bioverda US Holdings LLC and Wilon Holdings S.A.

(h)*	Notice of exercise of Put Option (GPRE) dated October 1, 2008, as amended effective October 15, 2008
(i)*	Lock-Up and Voting Agreement dated May 7, 2008 by and among Green Plains Renewable Energy, Inc. and Wilon Holdings S.A.
(j)*	Lock-Up and Voting Agreement dated May 7, 2008 by and between Wayne Hoovestol and VBV LLC
(k)*	Joint Filing Agreement, dated October 27, 2008, among NTR plc, Bioverda International Holdings Limited and Bioverda US Holdings LLC
(l)*	Amendment No. 1 to Joint Filing Agreement, dated February 16, 2010, among NTR plc, NTR US Biosystems Holdings Limited and Greenstar North America Holdings, Inc.
(m)*	Form of Amendment No. 2 to Joint Filing Agreement among NTR plc, NTR US Biosystems Holdings Limited and Greenstar North America Holdings, Inc.
(n)	Amendment No. 3 to Joint Filing Agreement, dated March 13, 2012, among NTR plc, Greenstar North America Holdings, Inc. and Greenstar Investments LLC
(o)*	Assignment and Assumption Agreement dated February 12, 2010 between NTR US Biosystems Holdings Limited and Greenstar North American Holdings, Inc.
(p)*	Assignment and Assumption Agreement dated May 25, 2010 between NTR US Biosystems Holdings Limited and Greenstar North American Holdings Inc.
(q)*	Stock Repurchase Agreement, dated September 9, 2011 between Green Plains Renewable Energy, Inc. and Greenstar North American Holdings, Inc.
(r)*	Promissory Note, dated September 16, 2011
(s)*	Assignment and Pledge of Stock, dated September 16, 2011, between Green Plains Renewable Energy, Inc. and Greenstar North American Holdings, Inc.
(t)	Assignment and Assumption Agreement, dated as of February 16, 2012, between Greenstar North America Holdings, Inc. and Greenstar Investments LLC
(u)	Underwriting Agreement, dated as of March 1, 2012, among Green Plains Renewable Energy, Inc., Jefferies & Company, Inc. and Greenstar Investments LLC (incorporated by reference to Exhibit 1.1 to the Issuer’s Current Report on Form 8-K, filed on March 2, 2012)
(v)	Stock Repurchase Agreement, dated as of February 29, 2012, among Green Plains Renewable Energy, Inc., Greenstar North America Holdings, Inc. and Greenstar Investments LLC (incorporated by reference to Exhibit 10.1 to the Issuer’s Current Report on Form 8-K, filed on March 2, 2012)
(w)	Promissory Note, dated March 9, 2012
(x)	Assignment and Pledge of Stock and LLC Interest, dated as of March 9, 2012, between Greenstar Investments and Green Plains Renewable Energy, Inc.

* Previously filed

Signature

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

March 13, 2012

Date

NTR plc

Greenstar North America Holdings, Inc.

Greenstar Investments LLC

/s/ Caroline Bergin

Signature

Authorized Signatory

Name/Title

The original statement shall be signed by each person on whose behalf the statement is filed or his authorized representative. If the statement is signed on behalf of a person by his authorized representative (other than an executive officer or general partner of the filing person), evidence of the representative’s authority to sign on behalf of such person shall be filed with the statement: provided, however, that a power of attorney for this purpose which is already on file with the Commission may be incorporated by reference. The name and any title of each person who signs the statement shall be typed or printed beneath his signature.

Attention: Intentional misstatements or omissions of fact constitute Federal criminal violations (See 18 U.S.C. 1001)

EX-99.N

Exhibit 99.n

AMENDMENT NO. 3 TO JOINT FILING AGREEMENT

This Amendment No. 3 to Joint Filing Agreement is entered into as of this 13th day of March, 2012 (this “Amendment”), among NTR plc (“NTR”), Greenstar North America Holdings, Inc. (“GSNA”), Greenstar Investments LLC (“Greenstar Investments” and, together with NTR and GSNA, the “Reporting Persons”). This Amendment amends the Joint Filing Agreement, dated as of October 27, 2008, between NTR and GSNA, as amended to date (the “Joint Filing Agreement”).

WHEREAS, Greenstar Investments has become the owner of shares of common stock, par value $0.001 per share (“Common Stock”), of Green Plains Renewable Energy, Inc., an Iowa corporation (“GPRE”); and

WHEREAS, the Reporting Persons desire to amend the Joint Filing Agreement to add Greenstar Investments as a party thereto.

NOW, THEREFORE, in consideration of the foregoing, the Reporting Persons hereto agree as follows:

1. Inclusion in Joint Filing Agreement. The Joint Filing Agreement is hereby amended to provide that Greenstar Investments is a party to the Joint Filing Agreement, and is subject to all of the terms and conditions contained therein.

2. Joint Filing Agreement. Except as amended hereby, the Joint Filing Agreement shall remain in full force and effect and is hereby ratified, confirmed and approved in all respects.

The Joint Filing Agreement may be executed in any number of counterparts all of which together shall constitute one and the same instrument.

[remainder of page intentionally left blank]

IN WITNESS WHEREOF, the undersigned hereby execute this Amendment as of the date first written above.

NTR plc
By:	/s/ Neil Parkinson
Name: Neil Parkinson Title: Chief Financial Officer

GREENSTAR NORTH AMERICA HOLDINGS, INC.
By:	/s/ Neil Parkinson
Name: Neil Parkinson Title: Director

GREENSTAR INVESTMENTS LLC
By:	/s/ Neil Parkinson
	Name: Neil Parkinson Title: Chief Financial Officer

EX-99.T

Exhibit 99.t

ASSIGNMENT AND ASSUMPTION AGREEMENT

This ASSIGNMENT AND ASSUMPTION AGREEMENT (this “Agreement”), dated as of February 16, 2012 is entered into by and among GREENSTAR NORTH AMERICA HOLDINGS, INC., a company organized under the laws of Ireland (“Assignor”), and GREENSTAR INVESTMENTS LLC, a Delaware limited liability company (the “Company”, each of Company and Assignor being referred to as a “Party”, and collectively as the “Parties”).

RECITALS

WHEREAS, Assignor is the holder of record of 7,727,653 shares of common stock (the “Shares”) of Green Plains Renewable Energy, Inc., an Iowa corporation (“GPRE”);

WHEREAS, Assignor is party to that certain Shareholders’ Agreement dated as of May 7, 2008 (the “Shareholders’ Agreement”) among GPRE, Assignor, and the investors listed on Schedule A to the Shareholders’ Agreement, pursuant to which Assignor has acquired certain rights and assumed certain obligations in connection with its ownership of the Shares;

WHEREAS, Assignor desires to assign and transfer to Company all of its respective right, title and interest in and to the Shares, and Company is desirous of acquiring the same; and

WHEREAS, in connection with the foregoing, Assignor intends to assign (and the Company intends to accept such assignment) all of such Assignor’s rights and obligations under the Shareholders’ Agreement.

NOW, THEREFORE, in consideration of the foregoing, and of other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Assignor and Company hereby agree as follows:

ARTICLE I

CONTRIBUTION OF SHARES

1.1 In exchange for consideration received, the adequacy of which is hereby acknowledged, Assignor hereby conveys, assigns, transfers, and delivers, any and all of Assignor’s (or it’s affiliates’) right, title, and interest in, to, and under the Shares.

ARTICLE II

ASSIGNMENT AND ASSUMPTION OF SHAREHOLDERS’ AGREEMENT

2.1 Assignor hereby irrevocably conveys, assigns, transfers and delivers to the Company, all of Assignor’s (or it’s affiliates’) rights and obligations under or with respect to the Shareholders’ Agreement.

2.2 The Company hereby expressly assumes all the rights, obligations and liabilities under or with respect to the Shareholders’ Agreement, and undertakes and agrees to perform and otherwise discharge in accordance with the terms thereof each obligation and liability under or with respect to the Shareholders’ Agreement.

ARTICLE III

MISCELLANEOUS

3.1 Further Assurances. Each Party shall take such other actions and execute such other documents and instruments of conveyance and transfer as may be reasonably requested by the other Party from time to time to effectuate the consummation of the transactions contemplated by this Agreement, including any documents or communications reasonably necessary for transferring of the Shares to Company as required by GPRE or its transfer agent. Assignor shall be responsible for filing or recording any instruments or documents evidencing, or otherwise notifying persons who are not parties to this Agreement, of the consummation of the transactions contemplated by this Agreement, including the notification required by Section 7.1 of the Shareholders’ Agreement.

3.2 Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of Delaware applicable to contracts made and performed in such State.

3.3 Severability. If any term or other provision of this Agreement is invalid, illegal, or incapable of being enforced by any law or public policy, all other terms or provisions of this Agreement shall nevertheless remain in full force and effect so long as its economic or legal substance is not affected in any manner materially adverse to a Party. Upon such determination that any term or other provision is invalid, illegal, or incapable of being enforced, the Parties shall negotiate in good faith to modify this Agreement so as to effect the original intent of the parties as closely as possible in a reasonably acceptable manner.

3.4 Counterparts. This Agreement may be executed in two or more counterparts, each of which will be deemed to be an original copy of this Agreement and all of which, when taken together, will be deemed to constitute one and the same agreement.

[remainder of page intentionally left blank]

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WHEREFORE, the Parties hereby acknowledge their agreement and consent to the terms and conditions set forth above as of the date first written above:

GREENSTAR NORTH AMERICA HOLDINGS, INC.
By:	/s/ Michael McNicholas
Name: Michael McNicholas
Title: Director

GREENSTAR INVESTMENTS LLC
By:	/s/ Neil Parkinson
Name: Neil Parkinson
Title: Director

Acknowledged as of this 21 day of February, 2012

GREEN PLAINS RENEWABLE ENERGY, INC.

By:	/s/ Michelle Mapes
Name: Michelle Mapes
Title: EVP – General Counsel & Corporate Secretary

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EX-99.W

Exhibit 99.w

PROMISSORY NOTE

$27,162,000.00 Dated as of: March 9, 2012

For value received, GREEN PLAINS RENEWABLE ENERGY, INC., an Iowa corporation (the “Debtor”), agrees to pay to the order of GREENSTAR INVESTMENTS LLC, a Delaware limited liability company (“Greenstar”), the principal sum of Twenty Seven Million One Hundred Sixty Two Thousand and 00/100 U.S. Dollars ($27,162,000.00) together with interest thereon as specified herein, all of which shall be due and payable on the first anniversary of the date hereof (the “Due Date”). Interest shall accrue on the principal amount of this Note at a rate of Five Percent (5.0%) per annum for the period beginning on the date of this Note and ending on the Due Date.

This Promissory Note (the “Note) is delivered pursuant to Section 4(c) of that certain Stock Repurchase Agreement by and between Greenstar and Debtor (the “Repurchase Agreement”) and will be secured by that certain Assignment and Pledge of Stock and LLC Interest dated on or about the date herewith (“Assignment”) executed by Debtor in favor of Greenstar pledging certain shares of treasury stock of Debtor and Debtor’s interest in Green Plains Superior LLC. Greenstar is not required, but may choose at its sole discretion, to rely on any security granted to it for the payment of this Promissory Note in the case of default, but may proceed directly against the Debtor.

In addition to exercising any rights Greenstar has been granted by Debtor under the Assignment, Debtor, as evidenced by its signature below, authorizes Greenstar to seek any other legal means of collection if Debtor is in default of this Note.

If Debtor fails to pay the principal and accrued interest, if applicable, on this Note in full on or before the selected Due Date (an “Event of Default”) then this Note and all of the obligations hereunder shall become due immediately.

The whole or part of the principal due hereunder may be prepaid at any time without penalty provided there exists at the time of prepayment no default hereunder. Payments shall be applied first to the payment of any fees, expenses or past due amounts owing by the Debtor to Greenstar, second to interest accrued on the unpaid principal balance, if applicable, and third to the principal balance.

Except as expressly set forth herein, the Debtor hereby waives presentment, demand, notice, protest and all other demands and notices in connection with the delivery, acceptance, performance or enforcement of this Note. If an Event of Default occurs, Greenstar shall be entitled to recover from Debtor all reasonable costs and expenses of collection of the Greenstar, including court costs and reasonable attorney’s fees, in the event collection procedures are commenced by the Greenstar in accordance with the terms of this Note or the Assignment after any amount hereunder becomes due and payable.

If any provision of this Note is deemed by any court, having jurisdiction thereon to be invalid or unenforceable, the balance of this Note shall remain in effect; if any provision of this Note is deemed by any such court to be unenforceable because such provision is too broad in scope, such provision shall be construed to be limited in scope to the extent such court shall deem necessary to make it enforceable; and if any provision is deemed inapplicable by any such court to any person or circumstances, it shall nevertheless be construed to apply to all other persons and circumstances.

No delay or omission on the part of Greenstar in exercising any right hereunder shall operate as a waiver of such right or of any other right under this Note. No waiver of any right shall be effective unless in writing and signed by the Greenstar nor shall a waiver on one occasion be construed as a bar to or waiver of any such right on any future occasion.

This Note shall only be amended if such amendment is agreed to by both Debtor and Greenstar, in writing, and executed by both Debtor and Greenstar.

This Note shall be governed by and construed in accordance with the laws of the State of Iowa, without regard to its rules of conflict of laws.

GREEN PLAINS RENEWABLE ENERGY, INC.
By:	/s/ Michelle Mapes
Name: Michelle Mapes
Title: EVP – General Counsel & Corporate Secretary

Date as of: March 9, 2012                                        

2

EX-99.X

Exhibit 99.x

ASSIGNMENT AND PLEDGE OF STOCK AND LLC INTEREST

THIS ASSIGNMENT AND PLEDGE OF STOCK AND LLC INTEREST (“Assignment”) is made and entered into as of March 9, 2012 (the “Effective Date”), by and between GREEN PLAINS RENEWABLE ENERGY, INC., an Iowa corporation (the “Grantor”), and GREENSTAR INVESTMENTS LLC, a Delaware limited liability company (the “Secured Party”).

Recitals

A. In accordance with that certain Stock Repurchase Agreement dated as of February 28, 2012 between Grantor, Greenstar North America Holdings, Inc. and Secured Party (“Repurchase Agreement”), Secured Party sold 3,700,000 shares of Grantor’s common stock (“Shares”) on the terms set forth in the Repurchase Agreement. Grantor has executed a Promissory Note in favor of Secured Party in the original principal amount of $27,162,000 for that portion of the Purchase Price due at the Due Date (as amended, modified, or restated, the “Note”).

B. As a material inducement for Secured Party to enter into the Repurchase Agreement and to accept the Note in lieu of full payment on the date herewith, Grantor has agreed to deliver this Assignment to Secured Party.

NOW, THEREFORE, in consideration of the premises and for other valuable consideration, the receipt and sufficiency of which is hereby acknowledged, Grantor and Secured Party hereby agree as follows:

Agreement

1. Incorporation of Recitals and of Certain Provisions of the Repurchase Agreement. The above recitals are hereby incorporated in this Assignment by reference and made a part hereof. The provisions of Sections 5 (Representations and Warranties), 6 (Shenandoah Interests) and 12 (Miscellaneous) of the Repurchase Agreement are hereby incorporated by reference into this Assignment as if fully set forth herein and shall apply mutatis mutandis to this Assignment.

2. Assignment and Grant of Security Interest. Grantor hereby assigns and conveys to Secured Party, and hereby grants Secured Party a first priority security interest in, all of its right, title and interest in and to (a) 2,700,000 Shares (the “Collateral Shares”), and all certificates, if any, representing such Shares, and all dividends, distributions of whatever nature, profits, liquidation proceeds, cash, instruments and other property or proceeds from time to time received, receivable or otherwise distributed in respect of, arising out of, or in exchange for, any or all of such Shares; (b) all of the limited liability company interests (the “Interests”) of Green Plains Shenandoah LLC, a Delaware limited liability company (“Shenandoah”), and all certificates, if any, representing such Interests, and all dividends, distributions of whatever nature, profits, liquidation proceeds, cash, instruments and other property or proceeds from time to time received, receivable or otherwise distributed in respect of, arising out of, or in exchange for, any or all of such Interests; (c) all proceeds of any of the foregoing, and other amounts or

property of any kind whatsoever due or to become due to Grantor thereunder or with respect thereto; (d) all replacements of and additions to any of the foregoing; and (e) all of the foregoing whether now owned or hereafter acquired (all of the foregoing interests of all of the Grantor being hereinafter collectively referred to as the (“Collateral”).

3. Security for Indebtedness. The Collateral shall secure the payment and performance of all of Grantor’s obligations under the Repurchase Agreement, the Note and this Assignment, and any amounts expended by or on behalf of Secured Party for the protection and preservation of the security interest granted herein (collectively, the “Indebtedness”).

4. Further Assurance by Grantor; Representations and Covenants.

(a) Grantor has the requisite power and authority to enter into this Assignment and the Note (the “Grantor Documents”). The execution and delivery of the Grantor Documents and the consummation by Grantor of the transactions contemplated by thereby have been duly authorized by the board of directors of Grantor and no other action is necessary to approve the Grantor Documents and the transactions contemplated thereby. The Grantor Documents have been executed and delivered by Grantor and constitute the legal, valid and binding obligation of Grantor enforceable against Grantor in accordance with their terms.

(b) The execution and delivery of the Grantor Documents by Grantor, and the consummation of the transactions contemplated thereby will not (i) conflict with, or result in any violation of, Grantor’s organizational documents, (ii) result in any violation or breach of, or default (with or without notice or lapse of time, or both) under, or give rise to a right of termination, cancellation or acceleration of any obligation or result in the creation of any lien (other than that created under this Assignment in favor of Secured Party) upon the properties or assets of Grantor or Shenandoah under, any provision of any agreement, note, bond, mortgage, indenture, lease or other contractual obligation to which Grantor or Shenandoah is a party or by which either of Grantor’s or Shenandoah’s properties and assets are bound or (iii) contravene or violate any provision of any law, rule or regulation.

(c) Grantor agrees that from time to time, at its sole expense, Grantor will promptly execute and deliver all further instruments and documents and take all further action that may be necessary or advisable, or that Secured Party may reasonably request, in order to protect the security interest granted hereby or to enable Secured Party to exercise and enforce its rights and remedies hereunder with respect to any Collateral, including without limitation to, promptly following any Event of Default, issue the Collateral Shares to the Secured Party, which shares shall be validly issued, fully paid and non-assessable, and to deliver duly executed instruments of transfer or assignment in blank with respect to the Interests, all in form and substance satisfactory to Secured Party. Grantor agrees not to take any action that is designed to frustrate the intent and purpose of the security interest created hereby.

(d) Grantor hereby authorizes Secured Party to file one or more financing or continuation statements, and amendments thereto, with respect to all or any part of the Collateral without the signature of such Grantor where permitted by law.

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(e) Grantor will defend the right, title and interest hereunder of the Secured Party, as a security interest in the Collateral granted by such Grantor, against the claims and demands of all persons whomsoever and will not sell or otherwise dispose of the Collateral while any Indebtedness remains outstanding.

(f) Without the prior written consent of the Secured Party, the Grantor shall not create or suffer to be created pursuant to the Uniform Commercial Code any other security interest in the Collateral, including replacements and additions thereto, or any other claims, liens or encumbrances (other than that created by this Assignment in favor of Secured Party).

5. Delivery of Collateral. On the Effective Date, all certificates or instruments representing or evidencing any of the Collateral shall be delivered to and held by or on behalf of Secured Party pursuant hereto and shall be in suitable form for transfer by delivery. Upon an Event of Default (as hereinafter defined), Secured Party shall have the right, at any time in its discretion, to transfer to or to register in the name of Secured Party or any of its nominees any or all of the Collateral.

6. Events of Default. An “Event of Default” under this Assignment shall be deemed to have occurred if any of the following occur: (a) the occurrence of an “Event of Default” as such term is defined and used in the Note; or (b) any default in the payment or performance under, failure to comply in any material respect with any covenant of, or breach of any representation or warranty in, this Assignment or the Indebtedness.

7. Remedies Upon Default. If any Event of Default, as defined in Section 6 hereof, shall have occurred:

(a) Secured Party may exercise, in respect of the Collateral, in addition to any and all other rights and remedies provided for herein or otherwise available to it, all the rights and remedies of a secured party under the Uniform Commercial Code as presently in effect in the State of Iowa (the “Code”), and may also (without notice except as specified below) sell the Collateral at public or private sale, at Secured Party’s office or elsewhere, for cash, credit or future delivery and at such price or prices and upon such other terms as Secured Party may deem to be commercially reasonable as allowed under the Code. Secured Party shall not be obligated to make any sale of Collateral regardless of notice of sale having been given. Secured Party may adjourn any public or private sale from time to time by announcement at the time and place fixed therefor, and such sale may, without further notice, be made at the time and place to which it was so adjourned.

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(b) All cash proceeds received by Secured Party in respect of any sale of, collection from (whether or not pursuant to a sale), or other realization upon (whether or not pursuant to a sale) all or any part of the Collateral may, in the sole discretion of Secured Party, be held by Secured Party as collateral for, and/or then or at any time thereafter applied (after payment of any amounts payable to Secured Party pursuant to Section 8 hereof) by Secured Party, against all or any part of the Indebtedness, in such order as the Secured Party shall elect, in its sole discretion. Any surplus of such cash or cash proceeds held by Secured Party and remaining after payment in full of all the Indebtedness shall be paid over to whomsoever may be lawfully entitled to receive such surplus.

(c) The Secured Party may transfer the whole or any part of the Collateral into the name of the Secured Party or the name of its nominee and thereafter exercise all voting and other rights in connection with the Collateral.

(d) Grantor hereby waives (to the extent permitted by law) all rights of redemption, stay and/or appraisal which it now has or may at any time in the future have under any rule of law or statute now existing or hereafter enacted. Grantor hereby waives any claims against Secured Party by reason of the fact that the price at which any Collateral may have been sold at such a private sale, if commercially reasonable, was less than the price which might have been obtained at a public sale, even if Secured Party accepts the first offer received and does not offer such Collateral to more than one of offeree.

(e) Grantor agrees that, to the extent notice of sale shall be required by law, at least ten days’ notice to Grantor of the time and place of any public sale or the time after which any private sale is to be made shall constitute reasonable notification.

(f) Secured Party shall not be obligated to make any sale of Collateral regardless of notice of sale having been given. Secured Party may adjourn any public or private sale from time to time by announcement at the time and place fixed therefor, and such sale may, without further notice, be made at the time and place to which it was so adjourned. Assuming that such sales are made in compliance with federal and state securities laws, Secured Party shall incur no liability as a result of the sale of the Collateral, or any part thereof, at any public or private sale.

(g) Grantor recognizes that Secured Party may elect in its sole discretion to sell all or a part of the Collateral to one or more purchasers in privately negotiated transactions in which the purchasers will be obligated to agree, among other things, to acquire the Collateral for their own account, for investment and not with a view to the distribution or resale thereof. Grantor acknowledges that any such private sales may be at prices and on terms less favorable than those obtainable through a public sale (including, without limitation, a public offering made pursuant to a registration statement under the Securities Act of 1933, as amended (the “Securities Act”)), and Grantor and Secured Party agree that such private sales shall be made in a commercially reasonable manner and that Secured Party has no obligation to engage in public sales and no obligation to delay sale of any Collateral to permit the issuer thereof to register the Collateral for a form of public sale requiring registration under the Securities Act.

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(h) If Secured Party disposes of the Collateral, Grantor agrees to pay any deficiency remaining after application of the net proceeds to any indebtedness secured hereby.

8. Expenses. Grantor will, upon demand, pay to Secured Party the amount of any and all expenses, including the fees and expenses of its counsel and of any experts and agents, which Secured Party may incur in connection with (a) the sale of, collection from, or other realization upon, any of the Collateral, (b) the exercise or enforcement of any of the rights of Secured Party hereunder, or (c) the failure by any Grantor to perform or observe any of the provisions hereof.

9. Security Interest Absolute. All rights of Secured Party and the security interest hereunder, and all obligations of Grantor hereunder, shall be absolute and unconditional irrespective of:

(a) any lack of validity or enforceability of any other agreement or instrument relating thereto;

(b) any change in the time, manner or place of payment of, or in any other term of, all or any of the Note, or any other amendment or waiver of or any consent to any departure from any other agreement or instrument relating thereto; or

(c) any other circumstance which might otherwise constitute a defense available to, or a discharge of, the Grantor.

10. Continuing Assignment and Security Interest. This Assignment shall create a continuing assignment of and security interest in the Collateral and shall: (a) remain in full force and effect until payment and performance in full of all of the Indebtedness; (b) be binding upon Grantor and their respective successors and assigns; and (c) inure to the benefit of Secured Party, its representatives, successors, transferees and assigns. Upon the payment and performance in full of all of the Indebtedness owed by Grantor to Secured Party, the assignment and security interest granted hereby shall terminate and all rights to the Collateral shall revert to the Grantor. Upon any such termination, Secured Party will execute and deliver to Grantor such documents as Grantor shall reasonably request to evidence such termination.

IN WITNESS WHEREOF, the parties hereto have duly executed this Assignment as of the date first above written.

[Balance of this page intentionally left blank; signatures to follow.]

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COUNTERPART SIGNATURE PAGE TO

ASSIGNMENT AND PLEDGE OF STOCK AND LLC INTEREST

GRANTOR:
GREEN PLAINS RENEWABLE ENERGY, INC.
By:	/s/ Michelle Mapes
Name: Michelle Mapes
Title: EVP – General Counsel & Corporate Secretary

SECURED PARTY:
GREENSTAR INVESTMENTS LLC
By:	/s/ Neil Parkinson
Name: Neil Parkinson
Title: Chief Financial Officer

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