<PAGE>

                                                                   Exhibit 10.20

CONFIDENTIAL TREATMENT REQUESTED: Certain portions of this document have been
omitted pursuant to a request for confidential treatment and, where applicable,
have been marked with an asterisk ("[****]") to denote where omissions have been
made. The confidential material has been filed separately with the Securities
and Exchange Commission.

                                SUPPLY AGREEMENT

This Supply Agreement ("Agreement") is made this 24th day of November, 2005, by
and between:

SOLAR GRADE SILICON LLC, 3322 Road, "N" N.E., Moses Lake, Washington 98837, USA
(hereinafter referred to as "SGSIL") and

EVERGREEN SOLAR, INC., a Delaware corporation with its principal executive
offices located at 138 Bartlett Street, Marlboro, Massachusetts, USA
(hereinafter referred to as "CUSTOMER" ).

SGSIL and Customer are each sometimes referred to here in as a "Party" and are
jointly referred to sometimes as the "Parties."

                                    RECITALS

Customer desires to purchase a supply of polycrystalline solar grade silicon
from SGSIL for its own use in the production of silicon wafers for solar
application, subject to the terms and conditions set forth herein.

SGSIL manufactures and sells solar grade polycrystalline silicon products and is
willing to supply such products to Customer, subject to the terms and conditions
set forth herein.

Now, therefore, in consideration of the foregoing, SGSIL and Customer agree as
follows:

1.   DEFINITIONS

"AFFILIATE" shall have the meaning set forth in the Master Joint Venture
Agreement.

"BLANKET PURCHASE ORDER" shall mean an [****] purchase order of the amount of
Products Customer will order during a [****], setting forth delivery dates and
quantities for such Products.

"CHANGE OF CONTROL" shall have the meaning set forth in the Master Joint Venture
Agreement.

"GOVERNMENTAL AUTHORITY" shall mean any US, or German or Norwegian, federal,
national, supranational, state, provincial, municipal, local, or similar
government, governmental, regulatory or administrative authority, agency or
commission or any court, tribunal, or judicial or arbitral body.

"MASTER JOINT VENTURE AGREEMENT" shall mean that certain Master Joint Venture
Agreement by and between Evergreen Solar, Inc., Q-Cells AG and Renewable Energy
Corporation, dated 24 November 2005.

"PRODUCTS" shall mean the solar grade polycrystalline silicon products to be
sold pursuant to this Agreement as listed in Attachment 1 and described in the
Specifications, as may be modified, from time to time by the Parties in a
written Amendment to this Agreement, signed by both Parties.

"SHARES" shall have the meaning set forth in the Master Joint Venture Agreement.

"SPECIFICATIONS" shall mean the Product technical specifications and the other
Product information listed, described or referred to in Attachment 1.

2.   PURCHASE OF PRODUCT.

2.1  SGSIL shall sell and deliver, and Customer shall purchase, the quantities
     of Products set forth in each Order Confirmation, based on Customer's
     [****] Blanket Purchase Order.

<PAGE>

     Customer acknowledges and agrees that if it desires to purchase additional
     Products in excess of its then-current Blanket Purchase Order and, in any
     event, if in excess of the maximum quantities set forth in Section 3, any
     such purchase shall be subject to SGSIL having the relevant free production
     capacity at the time of any such excess order by Customer, and subject to
     the provisions of Section 8, below.

2.2  Notwithstanding the fact that Products may be ordered only pursuant to the
     issuance of an [****] Blanket Purchase Order, for SGSIL's planning and
     forecasting purposes, Customer agrees to deliver in writing to SGSIL its
     forecasted requirements of Products for the periods and at the times as
     follows:

     (i)  The rolling [****] quantity forecast set forth in Attachment 2 shall
          be updated [****] during the Term.

     (ii) The rolling [****] quantity forecast set forth in Attachment 2 shall
          be updated [****] during the Term.

2.3  Contemporaneously with the execution of this Agreement, a Blanket Purchase
     Order for [****] in the form of Attachment 4 shall be deemed issued to
     SGSIL in the [****] quantity amount set forth therein (which amount shall
     be not less than the minimum quantity set forth in Attachment 2), and
     setting forth the [****] delivery dates, commencing in January, 2006, for
     the delivery of the [****] quantity of Products set forth therein in [****]
     quantities. For each subsequent [****] in the Term, Customer shall issue a
     Blanket Purchase Order in similar form, except the [****] quantity stated
     in such Blanket Purchase Order shall be delivered in [****] deliveries on
     the delivery dates set forth therein, by not later than [****] of the
     then-current [****]. In the event such an [****] Blanket Purchase Order is
     not timely issued hereunder for any [****] during the initial [****] Term,
     Customer shall be deemed to have issued a Blanket Purchase Order for the
     corresponding minimum [****] quantity of Products for such year set forth
     in Attachment 2, to be delivered in [****] shipments by SGSIL.

3.   QUANTITIES.

3.1  Subject to the minimum quantity of Products to be purchased by Customer
     during [****] as specified in Attachment 2, and the maximum quantities of
     Products to be purchased by Customer stated therein, the quantity of
     Products purchased by Customer under this Agreement shall be the quantities
     set forth in each [****] Blanket Purchase Order issued in accordance with
     Section 2.3. For subsequent years during the term of this agreement, the
     Parties will agree to a minimum and target amount of product to be
     delivered, but in no case will the minimum and target quantities be less
     than those listed in 2008, unless mutually agreed to by the Parties.

4.   PRODUCT PRICING & PAYMENT TERMS.

4.1  The price of the Products during the term of this Agreement will be the
     lesser of (i) [****] By [****] the Parties mean the [****] All prices set
     forth herein do not include freight, insurance, sales or value added tax,
     customs duties, or like charges which will be billed to Customer if SGSIL
     advances them.


                                       -2-

<PAGE>

4.2  In the event the Parties cannot agree on [****] Product pricing by [****]
     of the immediately preceding calendar year, then Parties shall submit the
     issue to binding determination of the applicable price in accordance with
     Section 4.1, and the price determined by the arbitration shall be used for
     the Products for such [****]. The determination shall be done by an expert
     on the solar energy sector, to be appointed [****] and shall follow such
     procedural rules as the Parties agree on with the determinator.

4.3  Customer shall pay SGSIL the full price, in U.S. dollars, of all Products
     purchased under this Agreement by paying SGSIL the balance, without
     deduction, shown on each [****] invoice issued by SGSIL pursuant to Section
     5.7, by wire transfer in readily available U.S. funds, within [****] after
     the date of such invoice. Interest shall accrue on overdue invoices the
     lesser of [****] or at the maximum rate permitted by applicable law. If
     Customer fails to timely pay an invoice, SGSIL may, in its sole and
     absolute discretion, demand the balance owed on such invoice including
     accrued interest, and/or may stop future deliveries of Products to Customer
     until Customer pays such delinquent invoice. In addition, in the event of a
     dispute regarding payment of amounts due hereunder, the losing Party shall
     pay the prevailing Party's reasonable costs and expenses in such collection
     or defense as the case may be, including reasonable attorneys' fees, costs
     of expert witnesses, costs of translators and any other collection cost or
     cost of suit, whether or not an action or proceeding is commenced or
     concluded.

5.   DELIVERY; INVOICING.

5.1  Products will be purchased by Customer through the issuance of [****]
     Blanket Purchase Orders and any additional Products in excess of the
     quantities stated in such Blanket Purchase Orders will be purchased by
     Customer at the then-current pricing in effect at the time of such purchase
     order, through the issuance by Customer of a separate purchase order, which
     additional purchase order shall not be effective until the quantity and
     requested delivery date(s) set forth in such additional purchase order are
     accepted and confirmed in writing by SGSIL.

5.2  All Products to be purchased hereunder, whether pursuant to a Blanket
     Purchase Order or an additional purchase order, shall be delivered FCA from
     SGSIL's Washington Distribution Facility in Kent, Washington, USA, (the
     "Washington Distribution Facility") to Customer's facility at the location
     specified by Customer in writing, together with the correct documentation
     and adequate packing and labeling as set forth in Attachment 1.

5.3  In accordance with Section 2.3, the initial delivery of Products to be
     shipped to Customer pursuant to this Agreement shall be in January, 2006
     Product quantity amount set forth in Customer's [****] Blanket Purchase
     Order.

5.4  The Products shall be deemed delivered by SGSIL to Customer under the
     then-current Blanket Purchase Order when transferred to Customer's chosen
     carrier at SGSIL's Washington Distribution Facility in Kent, Washington, or
     such other shipping point in the United States of America designated in
     writing by SGSIL. Upon any such delivery of Products to Customer, Customer
     shall have purchased that quantity of Products and shall be obligated to
     pay SGSIL for such Products unless rejected as not conforming to the
     Product Specifications and returned by Customer within [****] of Customer's
     receipt of the Products.

5.5  Title and risk of loss to the Products shall pass to Customer when SGSIL
     delivers the Products to Customer at the Washington Distribution Facility
     in accordance with the terms set forth in Section 5.4.


                                       -3-

<PAGE>

5.6  Any [****] order of Products pursuant to the then-current Blanket Purchase
     Order or any additional order of Products during a [****] in excess of the
     amounts stated therein may be confirmed or issued by Customer, as the case
     may be, on Customer's usual order acknowledgment form or purchase order;
     provided, however, the provisions of this Agreement shall govern and
     supersede all inconsistent, different, or additional terms, conditions, and
     instructions contained in Customer's order acknowledgment or purchase order
     form or in any other Customer transactional documentation provided by
     Customer to SGSIL after the effective date of this Agreement.

5.7  Upon SGSIL's shipment of any order under this Agreement, whether a [****]
     delivery under a Blanket Purchase Order or an additional delivery pursuant
     to a separate purchase order, SGSIL shall in writing, sent electronically
     or by facsimile transmission, invoice Customer for such order. All invoices
     issued by SGSIL hereunder shall list the date of each shipment, the
     quantity and type of Products shipped to Customer, the unit and extended
     prices of all Products shipped and the total price owed by Customer for
     such shipment. Upon Customer's receipt of SGSIL's invoice, Customer is
     obligated to pay the amount set forth therein in accordance with Section
     4.3.

5.8  SGSIL shall exercise its commercially reasonable efforts to manufacture and
     deliver from SGSIL's Washington Distribution Facility the Products ordered
     by Customer under this Agreement, on or before the delivery date or dates
     set forth in SGSIL's Blanket Purchase Order or additional purchase order
     confirmation. Any such additional purchase order shall be confirmed by
     SGSIL electronically or by facsimile transmission within [****] of SGSIL's
     receipt of any such additional purchase order. However, without prejudice
     to SGSIL's obligation to exercise its [****] efforts to deliver the
     Products to Customer on any date of delivery given by SGSIL to Customer,
     whether pursuant to an [****] Blanket Purchase Order or a separate
     additional purchase order, SGSIL shall immediately inform Customer in
     writing if any delay is foreseen.

6.   WARRANTY AND LIMITATION OF LIABILITY.

6.1  LIMITED WARRANTY. SGSIL warrants that, for [****] from the date of
     delivery, the Products will conform to SGSIL's published product
     description set forth in the Specifications. If Customer timely notifies
     SGSIL in writing of a nonconformity, upon verification of the
     nonconformity, SGSIL, in its sole discretion, shall provide Customer with
     one of the following remedies: (i) replacement of the Products that SGSIL
     verifies do not conform to this warranty; (ii) retreatment of the Products
     to bring them into conformity with this warranty; or (iii) issuance of a
     credit to Customer's account to reflect the decrease in value of the
     Products resulting from the non-conformance with this warranty. The
     election of remedies provided in this section shall be SGSIL's exclusive
     obligation with respect to remedying any warranty claims for Products and
     Customer's sole and exclusive remedy for all claims of defects. If the
     remedy chosen by SGSIL in its sole discretion hereunder is adjudicated to
     be insufficient, including, without limitation, any finding of failure of
     essential purpose, SGSIL shall be entitled to the alternative remedy of
     refunding the price paid by Customer for such defective Products and SGSIL
     shall have no other liability to Customer for breach of this limited
     warranty. No Products furnished by SGSIL shall be covered by this warranty
     if the claimed defect is due to Customer's failure to properly store,
     maintain, or use the Products in accordance with good industry practices or
     specific recommendations or instructions of SGSIL. ALL OTHER WARRANTIES,
     EXPRESS OR IMPLIED, INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR
     FITNESS FOR ANY PARTICULAR PURPOSE, ARE DISCLAIMED.

6.2  The warranties set forth in Section 6.1 do not extend to any Product that:
     (i) has been subjected to misuse, neglect or abuse not caused by SGSIL,
     (ii) has a defect caused by having been modified or altered by a party
     other than SGSIL, (iii) has a defect caused by a combination with another
     product


                                       -4-

<PAGE>

     not supplied or specified by SGSIL, or (iv) has been used in violation of
     the Specifications and/or other approved written instructions furnished to
     Customer by SGSIL prior to the delivery of the Product.

6.3  Customer shall ship a claimed defective Product to SGSIL's designated
     repair location FCA, Customer's location, freight collect. Within [****]
     after receipt of a defective Product, SGSIL shall ship the retreated or
     replacement Product, at SGSIL's expense to Customer's designated location
     (freight prepaid, DDU, Customer's destination). If SGSIL determines that
     the Product is not defective and conforms to the Specifications, SGSIL
     shall ship the non-defective Product to Customer at Customer's expense,
     FCA, SGSIL's designated repair location, freight collect, and Customer
     shall refund all freight, shipping, insurance, customs, duties and other
     charges previously paid by SGSIL in connection with Customer's return of
     the Product. Customer shall include the following information with the
     return of the claimed defective Product: (i) Customer's name and complete
     address, (ii) name(s) and telephone number(s) of Customer's designated
     contact if there are questions regarding the claimed defective Product,
     (iii) the "ship-to" address for the retreated or replacement Product, (iv)
     complete list of all claimed defective Product being returned, and (v)
     nature of each Product's claimed defect or failure.

6.4  LIMITATION OF LIABILITY. In no event shall SGSIL's liability for damages in
     relation to any Products sold to Customer pursuant to this Agreement exceed
     the purchase price paid by Customer for the goods directly having caused
     those damages. In no event shall SGSIL be liable for consequential,
     incidental, special, punitive or exemplary damages. Customer acknowledges
     and agrees that these limitations are reasonable and that such limitations
     have been specifically bargained for between the Parties.

7.   CONFIDENTIALITY.

7.1  "Confidential Information" means any information: (i) disclosed by one
     Party (the "Disclosing Party") to any other Party (the "Receiving Party"),
     which, if in written, graphic, machine-readable or other tangible form is
     marked as "Confidential" or "Proprietary", or which, if disclosed orally or
     by demonstration, is identified at the time of initial disclosure as
     confidential and reduced to writing and marked "Confidential" within [****]
     of such disclosure; or (ii) which is otherwise referred to as Confidential
     Information under this Agreement or any License Agreement.

7.2  Notwithstanding Section 7.1 above, Confidential Information shall exclude
     information that: (i) was independently developed by the Receiving Party
     without using any of the Disclosing Party's Confidential Information; (ii)
     becomes known to the Receiving Party, without restriction, from a source
     other than the Disclosing Party that had a right to disclose it; (iii) was
     in the public domain at the time it was disclosed or becomes in the public
     domain through no act or omission of the Receiving Party; or (iv) was
     rightfully known to the Receiving Party, without restriction, at the time
     of disclosure.

7.3  The Receiving Party shall treat as confidential all of the Disclosing
     Party's Confidential Information and shall not use such Confidential
     Information except as expressly permitted under this Agreement. Without
     limiting the foregoing, the Receiving Party shall use at least the same
     degree of care that it uses to prevent the disclosure of its own
     confidential information of like importance, but in no event with less than
     reasonable care, to prevent the disclosure of the Disclosing Party's
     Confidential Information, subject to Section 7.4 below.

7.4  Notwithstanding anything herein to the contrary, a Receiving Party has the
     right to disclose Confidential Information without the prior written
     consent of the Disclosing Party: (i) as required by


                                       -5-

<PAGE>

     any court or other Governmental Authority, or any stock exchange where a
     Party's shares are listed; (ii) as otherwise required by law, or (iii) as
     advisable or required in connection with any government or regulatory
     filings. If a Receiving Party believes that it will be compelled by a court
     or other authority to disclose Confidential Information of the Disclosing
     Party, it shall give the Disclosing Party prompt written notice so that the
     Disclosing Party may take steps to oppose such disclosure.

8.   CAPACITY.

     In the event SGSIL from time to time experiences limited delivery capacity
     as a result of Force Majeure (as defined in Section 9) or as a result of
     demand for Products by Customer in excess of the maximum quantity amounts
     set out in Section 3 and Attachment 2 (a "Limited Capacity Period"), SGSIL
     shall use its [****] efforts to allocate delivery of Products to Customer
     and SGSIL's other customers in proportion to Customer's and other
     customers' relative orders for forecasted amounts of Products and their
     orders for Products in excess of forecasted amounts. Notwithstanding
     anything to the contrary in this Agreement, Customer agrees that such
     [****] efforts by SGSIL shall constitute adequate performance of SGSIL's
     obligations under this Agreement during a Limited Capacity Period.

9.   FORCE MAJEURE.

9.1  Neither party shall be considered in default in the performance of its
     obligations hereunder to the extent that the performance of these
     obligations is prevented or delayed by Force Majeure. The term "Force
     Majeure" is hereby defined as the following: acts of God; plant accidents;
     strikes; lockouts or other similar industrial disturbances; acts of public
     enemies; orders or restraints of any kind from any Governmental Authority
     (except when such governmental action results from a Party's failure or
     refusal to comply with any applicable law, rule or regulation); acts of
     terrorism; war, insurrection or riots; earthquakes, fires, storms or other
     natural disasters.

9.2  In case of Force Majeure according to Section 9.1 either party shall
     promptly notify the other party and shall use its [****] efforts to
     minimize the consequences.

9.3  For the duration and to the extent of Force Majeure, the Parties will be
     released from their obligations under this Agreement. The Term shall be
     extended for an amount of time equal to the period during which the Parties
     were released from their obligations under this Agreement.

10.  SUSPENSION OF PERFORMANCE - TERMINATION.

10.1 This Agreement may terminate in the event that the parties mutually agree
     in writing to terminate this Agreement (subject to the Master Joint Venture
     Agreement).

     Either Party may suspend its performance under this Agreement for a
     material breach or default of any of the terms, conditions or covenants of
     this Agreement by the other, provided that such suspension of performance
     may be made only following written notice of such breach with reference to
     this Section 10.1 and the expiration of a [****] period during which period
     the other party has failed to cure such breach after such notice. Such
     suspension of performance shall not affect any delivery under a Blanket
     Purchase Order for a delivery date that is prior to the date of suspension
     of performance or an additional purchase order accepted by SGSIL prior to
     the date of suspension of performance. The suspension of performance shall
     not prejudice the rights or liabilities of the Parties with respect to
     Product sold, or any indebtedness then owing by either party to the other.


                                       -6-

<PAGE>

     No single instance of suspension of performance may exceed [****], nor must
     performance be suspended by one Party more than [****] in any [****] period
     under the Agreement. Should an event occur, that might otherwise give a
     Party the right to suspend performance had it not already done so [****] in
     the last [****], the Party may instead elect to terminate the Agreement
     according to the rules of article 10.2 to the extent these are applicable.

10.2 Either Party may terminate this Agreement, effective immediately, without
     liability for said termination, upon written notice to the other Party, if
     any of the following events occur:

     (i)  The other files a voluntary petition in bankruptcy or is adjudged
          bankrupt;

     (ii) A court assumes jurisdiction of the assets of the other under a
          federal reorganization act;

     (iii) A trustee or receiver is appointed by a court for all or a
          substantial portion of the assets of the other;

     (iv) The other becomes insolvent or suspends its business;

     (v)  The other makes an assignment of its assets for the benefit of its
          creditors, except as required in the ordinary course of business; or

     Notwithstanding the generality of the foregoing, the Parties agree that in
     the event of a termination by SGSIL pursuant to this Section 10.2, such
     termination shall also automatically terminate the then-current Blanket
     Purchase Order, and any deliveries thereunder, and any additional purchase
     orders received from Customer, and SGSIL shall have no obligation to
     deliver Products pursuant to any such terminated Blanket Purchase Order or
     additional purchase order.

11.  MISCELLANEOUS.

11.1 Other than as expressly otherwise provided herein, this Agreement shall not
     be assignable or otherwise transferable by any Party hereto without the
     prior written consent of all the other parties hereto, and any purported
     assignment or other transfer without such consent shall be void and
     unenforceable; provided, however, that any Party may assign this Agreement:

     (a)  to any of its Affiliates so long as it will be made at the same time
          as a transfer of its Shares to such Affiliate specifically permitted
          by the Master Joint Venture Agreement;

     (b)  in connection with the sale by a Party of all of the Shares
          beneficially owned by such Party as specifically provided by the
          Master Joint Venture Agreement, including by way of the Change of
          Control of such Party.

     (c)  For the avoidance of doubt, neither Party shall be obligated to obtain
          the consent of the other Party (under this Section 11.1) solely by
          virtue of a Change of Control of such Party.

11.2 In the event any provision of this Agreement shall be declared
     unenforceable or invalid by a legal authority having jurisdiction over the
     Agreement and the Parties, the validity of the remaining provisions shall
     not in any way be affected or impaired thereby. The Parties shall in good
     faith work together toward replacing the ineffective or invalid provisions
     with valid provisions, which fulfill the economic purpose of the
     ineffective or invalid provision.


                                       -7-

<PAGE>

11.3 Any amendment, addition, deletion, alteration or change of this Agreement
     shall only be valid if in writing and executed by each of the Parties. The
     following listed documents shall be the only documents attached to this
     Supply Agreement:

     [ ]  Attachment 1 - Specifications

     [ ]  Attachment 2 - Supply Forecasts, Minimum and Maximum [****]
          Quantities, Pricing and Product Mix

     [ ]  Attachment 3 - Addresses and Contact Persons

     [ ]  Attachment 4 - Blanket Purchase Order

11.4 This Agreement shall be null and void, and SGIL shall have no obligations
     whatsoever hereunder, unless the parties thereto sign and execute the
     Master Joint Venture Agreement, on the date indicated, in such a way as to
     give it full legal effect under German law, including, but not limited to,
     notarising it. Furthermore, no obligations shall be binding for SGIL until
     such a time as the initial share transfer regulated by the Master Joint
     Venture Agreement article 2.2 (a) and (b) have been completed according to
     the further regulation of the Master Joint Venture Agreement article 2.2
     (d).

12.  TERM.

     Except as otherwise extended pursuant to a force majeure under Section 9.3,
     or earlier terminated pursuant to Section 4.2 or Section 10, this Agreement
     will be effective on the date executed by both of the Parties and will
     endure for an initial period of seven (7) years and, thereafter, shall be
     automatically extended for consecutive periods of one year, unless either
     Party provides to the other Party written notice of its intent to terminate
     this Agreement as of the next occurring expiration date, which notice shall
     be given not less than [****] prior to such expiration date. The initial
     seven (7) year term of this Agreement, and any extensions thereof pursuant
     to this Section 12 shall be referred to herein as the "Term."

13.  APPLICABLE LAW.

     The law applicable to this Agreement is set forth in Section 16.

14.  NOTICES.

     All notices called for under this Agreement shall be in writing. Notice
     shall be deemed effective if sent registered mail to the address listed in
     Attachment 3 or to such other address as either party may, from time to
     time, by written notice provide to the other Party. Notice shall also be
     effective if actually received by any method that produces a hard copy
     record, including facsimile transmissions and e-mail with confirmation of
     receipt.

15.  GOVERNING LANGUAGE.

     The parties hereby confirm that they have agreed that all written documents
     between them shall be prepared in the English language only and such
     language shall be the governing language.

16.  DISPUTE RESOLUTION.

     All disputes arising in connection with this Agreement or its validity or
     any agreement provided herein which cannot be resolved by mutual agreement
     of the Parties shall be finally settled in accordance with the Arbitration
     Rules of the American Arbitration Association (AAA) without recourse to the
     ordinary courts of law. The place of arbitration is New York, New York. The
     arbitral


                                       -8-

<PAGE>

     tribunal consists of three arbitrators. The law of the State of New York is
     applicable to the dispute. The language of the arbitral proceedings is
     English.

17.  PATENT INDEMNITY.

     SGSIL warrants that the sale or use of the Products does not infringe or
     misappropriate any third party's patents, trademarks, trade secrets or
     other proprietary rights (collectively, "PROPRIETARY RIGHTS"). SGSIL will
     hold Customer harmless from all costs, losses, damages and liability which
     may be awarded against Customer on account of the infringement of such
     third party's Proprietary Rights by the Products, provided SGSIL is given
     prompt notice by Customer of any pending or threatened infringement claim
     and is allowed to control the defense and settlement of any such claim.
     SGSIL shall have the right to settle any such infringement claim on the
     terms and conditions it deems advisable. SGSIL shall not be liable for any
     infringement claims or costs or damages incurred as a result of any suit or
     proceeding based upon a claim that: (i) the infringement was caused by a
     combination of the PRODUCT with another product not supplied by SGSIL or
     which other product was specified by Customer and not otherwise provided by
     SGSIL, where the Product otherwise does not infringe or (ii) if the PRODUCT
     was modified after delivery to Customer, where the unmodified Product does
     not infringe.

18.  COMPLIANCE WITH FOREIGN LAWS.

     Customer shall obtain all licenses, permits and approvals required by any
     United States law or regulation with respect to the export of the Products
     to Customer's facility outside the United States under this Agreement.
     Subject to Section 19, Customer agrees that, after the Products arrive at
     Customer's facility, Customer will not re-export the Products except in
     compliance with United States export laws and regulations. Customer shall
     be responsible for formal compliance with those export laws and
     regulations. In addition, Customer expressly assumes responsibility for
     determining the need for and obtaining import licenses, currency exchange
     approvals and any other governmental approvals that may be necessary to
     permit the import of the Products into Germany. Customer is responsible for
     full compliance with all applicable laws or regulations in countries other
     than the United States concerning the export, sales or use of the Customer
     products incorporating the Products sold hereunder. Customer will indemnify
     and hold SGSIL harmless from any costs, liabilities or damages that result
     from any failure by Customer to comply with such laws.

19.  USE OF PRODUCTS.

     Customer agrees that the Products sold and delivered to Customer hereunder
     are to be used solely for use in Customer's own photovoltaic products and
     are not to be resold or used by Customer for any other purpose or in any
     other manner whatsoever.

20.  QUESTIONABLE PAYMENTS.

     Customer shall at all times comply, and shall cause its directors,
     officers, employees and agents to abide by and comply, in all respects,
     with the United States Foreign Corrupt Practices Act (15 U.S.C.
     Sections 78dd-1, 78dd 2, 78dd-3 and 78m, as amended) and all United States
     governmental agency regulations applying or interpreting said Act and, to
     the extent applicable in any non-U.S. jurisdiction, with the Convention on
     Combating Bribery of Foreign Public Officials in International Business
     Transactions (Dec. 18, 1997, 37 I.L.M 1 (1998), and/or the European Union
     Convention on the Fight Against Corruption Involving Officials of the
     European Communities or Officials of the Member States of the European
     Union (O.J. No. C195, 25.06.1997, May 26, 1997), or any similar treaty,
     convention, law or regulation applicable in the jurisdiction in question.


                                       -9-

<PAGE>

IN WITNESS WHEREOF, SGSIL and Customer have caused this Agreement to be executed
by their duly authorized officer or representative, as of the date and year set
forth below.

SOLAR GRADE SILICON LLC                 EVERGREEN SOLAR, INC


BY:                                     BY:
    ---------------------------------       ------------------------------------
PRINT NAME:                             PRINT NAME:
            -------------------------               ----------------------------
ITS:                                    ITS:
     --------------------------------        -----------------------------------
DATE:                                   DATE:
      -------------------------------         ----------------------------------


                                      -10-

<PAGE>

ATTACHMENT 1 - SPECIFICATIONS

                 TO SUPPLY AGREEMENT BETWEEN SGSIL AND CUSTOMER

See attached Specifications of each Product listed below, as previously sent to
Customer electronically in PDF Format, and as hereafter amended, from time to
time, by mutual agreement of the Parties in accordance with the Agreement:

PRODUCTS:

Either:

     [****]


                                      -11-

<PAGE>

           ATTACHMENT 2 - SUPPLY FORECASTS, MINIMUM AND MAXIMUM [****]
                       QUANTITIES, PRICING AND PRODUCT MIX
                 TO SUPPLY AGREEMENT BETWEEN SGSIL AND CUSTOMER

[****]


                                      -12-

<PAGE>

                  ATTACHMENT 3 - ADDRESSES AND CONTACT PERSONS
                 TO SUPPLY AGREEMENT BETWEEN SGSIL AND CUSTOMER

<TABLE>
<CAPTION>
              SGSIL                             CUSTOMER
              -----                             --------
<S>                                 <C>
CONTRACT HOLDER:                    CONTRACT HOLDER:
Goran Bye, CEO                      Shall be as provided by Customer
Solar Grade Silicon LLC             in writing.
3322 Road, "N" N.E.,
Moses Lake, Washington 98837, USA

CONTRACT MANAGER:                   CONTRACT MANAGER:
Kurt Levens, Director of Sales &    Leo Oei
Marketing

CONTRACT ADMINISTRATOR:             CONTRACT ADMINISTRATOR:
Ms. Sharon Palmerton                Richard Chleboski
</TABLE>


                                      -13-

<PAGE>

                      ATTACHMENT 4 - BLANKET PURCHASE ORDER


                                      -14-