Dear Sir or Madam

June 26, 2008

Evergreen Solar, Inc.

138 Bartlett Street

Marlboro, Massachusetts 01752

Telephone No.: (508) 357-2221

Facsimile No.: (646) 885-9546]

Lehman Brothers OTC Derivatives Inc., acting as principal

c/o Lehman Brothers Inc.

745 Seventh Avenue

New York, New York 10019

Attention: Andrew Yare, Capital Markets Contracts — Legal

Telephone No.: 646-333-9493

Facsimile No.: 646-885-9546 (United States of America)

Global Deal ID: [  ]

General Terms:

Agent:

LBI is acting as agent on behalf of Party A and Party B for the Transaction. LBI has no obligations, by guarantee, endorsement or otherwise, with respect to the performance of the Transaction by either party.

Trade Date:

June 26, 2008

Option Style:

“Modified American” as set forth under “Procedures for Exercise” below.

Option Type:

Call

Seller:

Party A

Buyer:

Party B

Shares:


Number of Options:

The common stock of Evergreen Solar, Inc. (the “ Issuer ”), par value USD0.01 per share, Ticker: ESLR

325,000, provided that if Lehman Brothers Inc. as representative of the Initial Purchasers (as defined in the Underwriting Agreement dated as of June 26, 2008 between Party B and Lehman Brothers Inc. as representative of the underwriters party thereto (the “ Underwriting Agreement ”)), exercises the option to purchase additional Convertible Notes pursuant to Section 2 of the Underwriting Agreement, the Number of Options hereunder shall be automatically increased, effective upon payment by Party B of the Additional Premium on the Additional Premium Payment Date, by the Applicable Percentage times the number of Convertible Notes in denominations of USD1,000 principal amount issued pursuant to such exercise (such Convertible Notes, the “ Additional Convertible Notes ”). For the avoidance of doubt, the Number of Options shall be reduced by the number of any Options exercised or terminated by Party B. In no event will the Number of Options be less than zero.

Option Entitlement:

As of any date, a number equal to the Conversion Rate as of such date (as defined in the Indenture, but without regard to any adjustments to the Conversion Rate pursuant to Section 9.04(b) or Section 9.05(h) of the Indenture) for each Convertible Note.

Applicable Percentage:

100%

Number of Shares:

The product of the Number of Options and the Option Entitlement.

Strike Price:

USD $12.1125

Cap Price:

USD$19.00

Premium:

USD59,247,500 (Premium per Option: USD182.3) which shall be paid as (i) an upfront premium of USD34,385,000 on the Initial Premium Payment Date and (ii) 9 subsequent equal installments of USD2,762,500 where one such installment is paid on each Premium Payment Date (each, an “ Installment Premium ”), provided that if the Number of Options is increased pursuant to the proviso to the definition of “Number of Options” above, (A) Party B shall pay on the Additional Premium Payment Date an additional premium (the “ Additional Premium ”) equal to the product of (1) the quotient of the number of Options by which the Number of Options is so increased divided by the Number of Options prior to such increase (such quotient, the “ Upsize Percentage ”) multiplied by (2) USD34,385,000 and (B) each of the 9 remaining Installment Premiums shall be increased by an amount equal to the product of (x) the Installment Premium multiplied by (y) the Upsize Percentage.

Initial Premium Payment Date:

4 Currency Business Days after the Trade Date

Premium Payment Dates:

January 15 and July 15 of each year commencing on January 15, 2009 and ending on January 15, 2013; provided that if any such day is not a Currency Business Day, the applicable Premium Payment Date shall be the immediately following Currency Business Day.

Additional Premium Payment Date:

The closing date for the purchase and sale of the Additional Convertible Notes.

Exchange:

NASDAQ Global Market

Related Exchange(s):

All Exchanges

Market Disruption Event:

The definition of “Market Disruption Event” in Section 6.3(a) of the Equity Definitions is hereby amended by deleting the words “at any time during the one-hour period that ends at the relevant Valuation Time, Latest Exercise Time, Knock-in Valuation Time or Knock-out Valuation Time, as the case may be” and

inserting the words “at any time on any Averaging Date for an aggregate one half hour period or a period of any duration if such period occurs in the one-hour period that ends at the relevant Valuation Time, Latest Exercise Time, Knock-in Valuation Time or Knock-out Valuation Time, as the case may be” after the word “material,” in the third line thereof.

Disrupted Day:

The definition of “Disrupted Day” in Section 6.4 of the Equity Definitions shall be amended by adding the following sentence after the first sentence: “A Scheduled Trading Day on which a Related Exchange fails to open during its regular trading session will not be a Disrupted Day if the Calculation Agent determines that such failure will not have a material adverse impact on Party A’s ability to unwind any related hedging transactions related to the Transaction.”

Procedure for Exercise :

Exercise Period:

Notwithstanding anything to the contrary in the Equity Definitions, an Exercise Period shall occur with respect to an Option hereunder only if such Option is an Exercisable Option (as defined below) and the Exercise Period shall be, in respect of any Exercisable Option, the period commencing on, and including, the relevant Conversion Date and ending on, but excluding, the first Averaging Date in respect of such Conversion Date; provided that in respect of any Exercisable Options relating to Convertible Notes for which the relevant Conversion Date occurs during the period beginning on, and including, the 25th scheduled trading day prior to the Expiration Date, the final day of the Exercise Period shall be the Scheduled Trading Day immediately prior to the Expiration Date (such Exercise Period, the “ Final Exercise Period ”).

Conversion Date:

With respect to any conversion of Convertible Notes, the date on which the holder of such Convertible Notes satisfies all of the requirements for conversion thereof as set forth in Section 9.02 of the Indenture.

Exercisable Options:

Upon the occurrence of a Conversion Date, a number of Options equal to (x) the Applicable Percentage times (y) the number of Convertible Notes in denominations of USD1,000 principal amount converted on such Conversion Date.

Expiration Time:

The Valuation Time

Expiration Date:

July 15, 2013

Multiple Exercise:

Applicable, as described under “Exercisable Options” above.

Automatic Exercise:

Applicable; and means that, in respect of any Exercise Period other than the Final Exercise Period, a number of Options not previously exercised hereunder equal to the number of Exercisable Options shall be deemed to be exercised on the relevant Averaging Dates to which such Options relate and, in respect of the Final Exercise Period, all Options not previously exercised shall be deemed exercised on the relevant Averaging Dates to which such Options relate; provided that in each case, if a Notice of Exercise is required, such Options shall be deemed exercised only to the extent that Party B has provided a Notice of Exercise to Party A (in each case, such number of Options deemed exercised, the “ Exercised Options ”); provided further that, with respect to Exercised Options relating to an Exercise Period occurring prior to the Final Exercise Period (an “ Early Conversion ”), Automatic Exercise means that an Additional Termination Event shall be deemed to occur with respect to a portion of the Transaction relating to a number of Options equal to the number of such Exercised Options, as provided in clause (i) under “Additional Termination Events” below; provided further that to the extent the number of Exercised Options relating to any Conversion Date is less than the number of Exercisable Options relating to such Conversion Date, Party B shall be deemed to make to Party A on the date it provided the related Notice of Exercise to Party A (or, if no such notice is provided, the final day of such Exercise Period) the representations and warranties contained in paragraphs (g) and (i) under “Additional Representations and Warranties of Party B” below as if the reference therein to “at the time of placing any order with respect to the Transaction” were replaced with “as of the date of the related Notice of Exercise (or, if no such notice is provided, the final day of the related Exercise Period).”

Notice of Exercise:

Notwithstanding anything to the contrary in the Equity Definitions, in order to exercise any Exercisable Options in respect of any Conversion Date occurring prior to the Final Exercise Period, Party B must notify Party A in writing before 5:00 p.m. (New York City time) on the Scheduled Trading Day prior to the first scheduled Averaging Date for the Exercisable Options being exercised of (i) the number of such Options, and (ii) such first scheduled Averaging Date and the scheduled Settlement Date.

Valuation:

Valuation Time:

At the close of trading on the Exchange, without regard

to extended or after hours trading.

Averaging Dates:

(x) For any Exercised Option relating to an Exercise Period occurring prior to the Final Exercise Period, the 20 consecutive Scheduled Trading Days commencing on and including the third “Settlement Period Trading Day” (as defined in the Indenture) following the relevant Conversion Date, or (y) for any Exercisable Option relating to the Final Exercise Period, the 20 consecutive Scheduled Trading Days commencing on, and including, the 22 ^nd Scheduled Trading Day immediately preceding the Expiration Date.

Averaging Date Market Disruption:

Modified Postponement; provided that, notwithstanding anything to the contrary in the Equity Definitions and in addition to the provisions of Section 6.7(c)(iii) of the Equity Definitions, if any Averaging Date is a Disrupted Day, the Calculation Agent may assign additional dates to be Averaging Dates and/or make adjustments to the number of Options to which each Averaging Date relates (including increasing such number or reducing such number to zero with respect to one or more Averaging Dates).

Relevant Price:

For any Averaging Date, the VWAP Price for such Averaging Date.

VWAP Price:

For any Exchange Business Day, the dollar volume weighted average price per Share for that Exchange Business Day based on transactions executed during that Exchange Business Day on the Exchange, as reported on Bloomberg Page “ESLR <Equity> AQR” (or any successor thereto), or in the event such price is not so reported on such Exchange Business Day for any reason, as reasonably determined by the Calculation Agent.

Settlement Terms:

Settlement Currency:

USD

Settlement Date:

For any Exercised Option, the date Shares will be delivered with respect to the Convertible Notes related to such Exercised Options, under the terms of the Indenture.

Settlement Method Election:

Not Applicable

Settlement Method:

Physical Settlement

Physical Settlement:

With respect to any Exercised Options, a relevant portion of the Transaction shall expire on each Averaging Date with respect to a number of Options equal to the relevant number of Exercised Options divided by the number of scheduled Averaging Dates, rounded down to the nearest whole number, except the

portion relating to the last such Averaging Date shall equal such relevant number of Exercised Options minus the number of Options relating to all preceding Averaging Dates relating to such Exercised Options (in each case subject to adjustment by the Calculation Agent in respect of any Disrupted Day). On the Settlement Date relating to the relevant Exercised Options, Party A shall deliver to Party B the aggregate Number of Shares to be Delivered for all related Averaging Dates and pay to Party B any Fractional Share Amount resulting from such aggregation (valued at the Relevant Price for the last Averaging Date).

Number of Shares to be Delivered:

An amount of Shares equal to the Physical Settlement Amount for such Averaging Date divided by the Relevant Price for such Averaging Date.

Physical Settlement Amount:

For each Averaging Date, an amount, as calculated by the Calculation Agent, equal to (i) the Strike Price Differential for such Averaging Date, multiplied by (ii) the number of Options to which such Averaging Date relates, multiplied by (iii) the Option Entitlement as of such Averaging Date.

Strike Price Differential:

For each Averaging Date, if the Relevant Price for such Averaging Date is (a) greater than the Strike Price and less than or equal to the Cap Price, an amount equal to the excess of the Relevant Price for such Averaging Date over the Strike Price, (b) greater than the Cap Price, an amount equal to the excess of the Cap Price over the Strike Price, or (c) less than or equal to the Strike Price, zero.

Other Applicable Provisions in Respect of Physical Settlement:

The representations and agreements contained in Section 9.11 of the Equity Definitions shall be modified by excluding any representations therein relating to restrictions, obligations, limitations or requirements under applicable securities laws that exist as a result of the fact that Party B is the issuer of the Shares.

Share Adjustments:

Potential Adjustment Events:

Notwithstanding Section 11.2(e) of the Equity Definitions, a “Potential Adjustment Event” means an occurrence of any event or condition, as set forth in Section 9.05 of the Indenture, that would result in an adjustment to the Conversion Rate of the Convertible Notes; provided that in no event shall there be any adjustment hereunder as a result of an adjustment to the Conversion Rate pursuant to Section 9.04(b) or Section 9.05(h) of the Indenture.

Method of Adjustment:

Calculation Agent Adjustment; which means, notwithstanding anything to the contrary in the Equity Definitions, upon any adjustment to the Conversion Rate of the Convertible Notes pursuant to the Indenture (other than pursuant to Section 9.04(b) or Section 93.05(h) of the Indenture) (i) the Calculation Agent shall make a corresponding adjustment to any of the Strike Price, Number of Options and the Option Entitlement and (ii) the Calculation Agent may, but is not required to, make any adjustment consistent with the Calculation Agent Adjustment set forth in Section 11.2(c) of the Equity Definitions to the Cap Price or any other variable relevant to the exercise, settlement or payment for the Transaction to preserve the fair value of the Options to Party A after taking into account the effect of such Potential Adjustment Event; provided , that adjustments may be made to account for changes in volatility, expected dividends, stock loan rate and liquidity relevant to the Shares or to the Transaction; provided further , that in no event shall the Cap Price be less than the Strike Price.

Extraordinary Events:

Merger Events:

Notwithstanding Section 12.1(b) of the Equity Definitions, a “Merger Event” means the occurrence of any event or condition set forth in Section 9.06(a) or Section 9.06(b) of the Indenture.

Tender Offers:

Applicable; provided that notwithstanding Section 12.1(d) of the Equity Definitions, a “Tender Offer” means the occurrence of any event or condition set forth in Section 9.05(f) or clauses (1) or (2) of the definition of Fundamental Change in Section 2 of the Indenture.

Consequence of Merger Events/Tender Offers:

Notwithstanding Sections 12.2 and 12.3 of the Equity Definitions, upon the occurrence of a Merger Event or a Tender Offer:

(i) the Calculation Agent shall make a corresponding adjustment in respect of any adjustment under the Indenture to any one or more of the nature of the Shares, Strike Price, Number of Options and the Option Entitlement; provided , however , that such adjustment shall be made without regard to any adjustment to the Conversion Rate for the issuance of additional shares as set forth in Section 9.04(b) or Section 9.05(h) of the Indenture; and

(ii) the Calculation Agent may, in its sole discretion, make any adjustment consistent with the Modified Calculation Agent Adjustment set forth in Section

12.2(e) or 12.3(d) of the Equity Definitions, as applicable, to the Cap Price or any other variable relevant to the exercise, settlement or payment for the Transaction;

provided, further, that, for the avoidance of doubt, adjustments shall be made pursuant to the provisions of subparagraphs (i) and (ii) above regardless of whether any Merger Event or Tender Offer gives rise to an Early Conversion; and

provided further that, notwithstanding the foregoing, with respect to any Majority Tender Offer, Party A may elect for Cancellation and Payment (Calculation Agent Determination) to apply. “ Majority Tender Offer ” means a Tender Offer as defined in Section 12.1(d) of the Equity Definitions that results in the relevant entity or person purchasing, or otherwise obtaining or having the right to obtain, by conversion or other means, 50% or greater than 50% of the outstanding voting shares of the Issuer, as determined by the Calculation Agent, based upon the making of filings with governmental or self-regulatory agencies or such other information as the Calculation Agent deems relevant.

Modified Calculation Agent
Adjustment:

For greater certainty, the definition of “Modified Calculation Adjustment” in Sections 12.2 and 12.3 of the Equity Definitions shall be amended by adding the following italicized language after the stipulated parenthetical provision:

“(including adjustments to account for changes in volatility, expected dividends, stock loan rate or liquidity relevant to the Shares or to the Transaction) from the Announcement Date to the Merger Date (Section 12.2) or Tender Offer Date (Section 12.3) .”

Announcement Event:

If an Announcement Event occurs, the Calculation Agent will determine the economic effect of the Announcement Event on the theoretical value of the Transaction (including without limitation any change in volatility, expected dividends, stock loan rate or liquidity relevant to the Shares or to the Transaction) from the Announcement Date to the Expiration Date. If such economic effect is material, the Calculation Agent may, in its sole discretion, adjust the terms of the Transaction to reflect such economic effect. “ Announcement Event ” shall mean the occurrence of (i) the first public announcement of an intention to engage in a transaction that may lead to a Merger Event, (ii) the first public announcement of an intention to purchase or otherwise obtain the requisite number of shares that may lead to a Tender Offer or (iii) in each

case, any subsequent amendment to or withdrawal of such announcement.

Composition of Combined Consideration:

Not Applicable

Nationalization, Insolvency or Delisting:

Cancellation and Payment

     (Calculation Agent Determination)

Delisting:

The definition of “Delisting” in Section 12.6 of the Equity Definitions shall be deleted in its entirety and replaced with the following: ‘“Delisting” means that the Exchange announces that pursuant to the rules of such Exchange, the Shares cease (or will cease) to be listed, traded or publicly quoted on the Exchange for any reason (other than a Merger Event or Tender Offer) and are not immediately re-listed, re-traded or re-quoted on the New York Stock Exchange, the American Stock Exchange, the NASDAQ Global Select Market or the NASDAQ Global Market (or their respective successors)”

Additional Disruption Events:

Change in Law:

Applicable

Failure to Deliver:

Applicable

Insolvency Filing:

Applicable

The definition of “Insolvency Filing” in Section 12.9 of the Equity Definitions shall be amended by deleting the clause “provided that such proceedings instituted or petitions presented by creditors and not consented to by the Issuer shall not be deemed an Insolvency Filing” at the end of such definition and replacing it with the following: “; or it has instituted against it a proceeding seeking a judgment of insolvency or bankruptcy or any other relief under any bankruptcy or insolvency law or other similar law affecting creditors’ rights, or a petition is presented for its winding-up or liquidation by a creditor and such proceeding is not dismissed, discharged, stayed or restrained in each case within thirty (30) days of