GUARANTY AGREEMENT GUARANTY AGREEMENT

GUARANTY AGREEMENT


GUARANTY AGREEMENT (this "Agreement"), dated as of October 25, 2006, by
GREENSHIFT CORPORATION, a Delaware corporation, GS AGRIFUELS CORPORATION, a
Delaware corporation, GS ENERGY CORPORATION, a Delaware corporation and GS
CLEANTECH CORPORATION, a Delaware corporation (each a "Guarantor" and
collectively, the "Guarantors") in favor or THE STILLWATER ASSET-BACKED FUND LP,
a Delaware limited partnership (the "Lender"). The Lender and NextGen
Acquisition Inc., a Delaware corporation (the "Borrower") are parties to a
Credit Agreement, dated as of the date hereof, (as modified and supplemented and
in effect from time to time, the "Credit Agreement"), providing, subject to the
terms and conditions thereof, for extensions of credit (by the making of a Term
Loan) to be made by the Lender to the Borrower in the principal amount of
$6,000,000.

To induce the Lender to enter into the Credit Agreement and to extend
credit thereunder, and for other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, the Guarantor have agreed,
subject to the terms and conditions of the Intercreditor Agreement, to jointly
and severally guarantee the Guaranteed Obligations (as hereinafter defined) on
the terms and conditions set forth in this Agreement. Accordingly, the parties
hereto hereby agree as follows:

Section 1. Definitions. All capitalized terms used herein but not defined
herein shall have the meanings set forth in the Credit Agreement. As used
herein, the following terms shall have the following meanings:

"Costs" shall have the meaning ascribed thereto in Section 2.01
hereof.

"Guaranteed Obligations" shall mean the obligations described in
Section 2.01 hereof.

Section 2. The Guarantee.

2.01 The Guarantee. (a) Each Guarantor, hereby absolutely, unconditionally and
irrevocably guarantees to the Lender, the full and prompt payment when due,
whether at maturity or earlier, by reason of acceleration, mandatory
prepayment or otherwise, and at all times thereafter, the principal owing
by the Borrower to the Lender on the Loans, and all fees, costs and
expenses under the Credit Agreement or any other Financing Agreements.

(b) Each Guarantor further agrees to pay, upon demand, all costs and
expenses ("Costs"), including, without limitation, all court costs and
reasonable attorneys' fees and expenses, paid or incurred by the
Lender (a) in endeavoring to collect all or any part of the
Obligations from, or in prosecuting any action against, such Guarantor
or (b) in endeavoring to realize upon (whether by judicial,
nonjudicial or other proceedings) any collateral securing any of such
Guarantor's liabilities under this Guaranty ("Guarantor Collateral").

2.02 Obligations Unconditional. The obligations of each Guarantor under Section
2.01 hereof are absolute and unconditional, irrespective of the value,
genuineness, validity, regularity or enforceability of the Credit
Agreement, the Note or any other agreement or instrument (including,
without limitation, any other Financing Agreements) referred to herein or
therein, or any substitution, release or exchange of any other Financing
Agreements of or security for any of the Guaranteed Obligations or for the
obligations of such Guarantor hereunder, and, to the fullest extent
permitted by applicable law, irrespective of any other circumstance
whatsoever which might otherwise constitute a legal or equitable discharge
or defense of a surety or guarantor, it being the intent of this Section
2.02 that the obligations of such Guarantor hereunder shall be absolute and
unconditional, under any and all circumstances. Without limiting the
generality of the foregoing, it is agreed that the occurrence of any one or
more of the following shall not alter or impair the liability of each
Guarantor hereunder which shall remain absolute and unconditional as
described above:

(i) at any time or from time to time, without notice to such Guarantor,
the time for any performance of or compliance with any of the
Guaranteed Obligations shall be extended, or such performance or
compliance shall be waived;

(ii) any of the acts mentioned in any of the provisions of the Credit
Agreement or the Note or any other agreement or instrument referred to
herein or therein (including, without limitation, any other Financing
Agreements) shall be done or omitted;

(iii) the maturity of any of the Guaranteed Obligations shall be
accelerated, or any of the Guaranteed Obligations shall be modified,
supplemented or amended in any respect, or any right under the Credit
Agreement or the Note or any other agreement or instrument referred to
herein or therein (including, without limitation, any other Financing
Agreements) shall be waived or any other guarantee of any of the
Guaranteed Obligations or any security therefor shall be released or
exchanged in whole or in part or otherwise dealt with; or

(iv) any lien granted to, or in favor of the Lender as security for any of
the Guaranteed Obligations shall be released, exchanged, enforced or
shall fail to be perfected.

Except as expressly provided in this Agreement, each Guarantor hereby expressly
waives diligence, presentment, demand of payment, protest and all notices
whatsoever, and any requirement that the Lender exhaust any right, power or
remedy to proceed against the Borrower under the Credit Agreement or the Note or
any other agreement or instrument referred to herein or therein (including,
without limitation, any other Financing Agreements), or against any other person
under any other guarantee of, or security for, any of the Guaranteed Obligations
or any of the obligations of such Guarantor hereunder.

2.03 Reinstatement. The obligations of each Guarantor under this Section 2 shall
be automatically reinstated if and to the extent that for any reason any
payment by or on behalf of the Borrower in respect of the Guaranteed
Obligations is rescinded or must be otherwise restored by any holder of any
of the Guaranteed Obligations, whether as a result of any proceedings in
bankruptcy or reorganization or otherwise, and such Guarantor agrees that
it will indemnify the Lender on demand for all reasonable costs and
expenses (including, without limitation, reasonable fees of counsel)
incurred by the Lender in connection with any such rescission or
restoration, including any such costs and expenses incurred in defending
against any claim alleging that such payment constituted a preference,
fraudulent transfer or similar payment under any bankruptcy, insolvency or
similar law. The provisions of this Section 2.03 shall survive the
termination of this Agreement.

2.04 Subrogation. Each Guarantor hereby waives all rights of subrogation or
contribution, whether arising by contract or operation of law (including,
without limitation, any such right arising under the Federal Bankruptcy
Code) or otherwise by reason of any payment by such Guarantor pursuant to
the provisions of this Section 2 and further agrees with the Borrower for
the benefit of such Guarantor's creditors that any such payment by such
Guarantor shall constitute a contribution of capital by such Guarantor to
the Borrower.

2.05 Remedies. Each Guarantor agrees that, as between such Guarantor and the
Lender, the obligations of the Borrower under the Credit Agreement and the
Note may be declared to be forthwith due and payable as provided in the
Credit Agreement (and shall be deemed to have become automatically due and
payable in the circumstances provided therein) for purposes of Section 2.01
hereof notwithstanding any stay, injunction or other prohibition preventing
such declaration (or such obligations from becoming automatically due and
payable) as against the Borrower and that, in the event of such declaration
(or such obligations being deemed to have become automatically due and
payable), such obligations (whether or not due and payable by the Borrower)
shall forthwith become due and payable by such Guarantor for purposes of
said Section 2.01.

2.06 Continuing Guarantee. The guarantee in this Section 2 is a continuing
guarantee, and shall apply to all Guaranteed Obligations whenever arising.

2.07 Interest on Defaulted Guaranteed Obligations. If any Guarantor fails to pay
any amount when due pursuant to Section 2.01 hereof, such Guarantor agrees
to pay interest on the amount of such payment not so paid from said due
date until such payment shall be paid in full at a rate per annum equal to
the rate set forth in Section 2.3 of the Credit Agreement, payable on
demand of the Lender.

2.08 Application of Payments. Cash