NEITHER THESE SECURITIES NOR THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND ANY APPLICABLE STATE SECURITIES LAWS AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS AS EVIDENCED BY A LEGAL OPINION OF COUNSEL TO THE TRANSFEROR TO SUCH EFFECT, THE SUBSTANCE OF WHICH SHALL BE REASONABLY ACCEPTABLE TO THE COMPANY. THESE SECURITIES AND THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES MAY BE PLEDGED IN CONNECTION WITH A BONA FIDE MARGIN ACCOUNT SECURED BY SUCH SECURITIES.

R EAL G OODS S OLAR , I NC .

W ARRANT T O P URCHASE C OMMON S TOCK

Warrant No.:             

Date of Issuance: June 3, 2013 (“ Issuance Date ”)

Real Goods Solar, Inc., a Colorado corporation (the “ Company ”), hereby certifies that, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged,                     , the registered holder hereof or its permitted assigns (the “ Holder ”), is entitled, subject to the terms set forth below, to purchase from the Company, at the Exercise Price (as defined below) then in effect, upon exercise of this Warrant to Purchase Common Stock (including any Warrants to Purchase Common Stock issued in exchange, transfer or replacement hereof, the “ Warrant ”), at any time or times on or after the Issuance Date, but not after 11:59 p.m., New York time, on the Expiration Date (as defined below),              (subject to adjustment as provided herein) fully paid and non-assessable shares of Common Stock (as defined below) (the “ Warrant Shares ”). Except as otherwise defined herein, capitalized terms in this Warrant shall have the meanings set forth in Section 15. Capitalized terms used and not otherwise defined herein that are defined in the Securities Purchase Agreement (as defined below) will have the respective meanings given such terms in the Securities Purchase Agreement. This Warrant is one of the Warrants to Purchase Common Stock (the “ SPA Warrants ”) issued pursuant to that certain Securities Purchase Agreement, dated as of May 24, 2013, by and among the Company and the investors (the “ Buyers ”) referred to therein, as amended from time to time (the “ Securities Purchase Agreement ”).

2

1. EXERCISE OF WARRANT .

(a) Mechanics of Exercise . Subject to the terms and conditions hereof (including, without limitation, the limitations set forth in Section 1(f)), this Warrant may be exercised by the Holder on any day on or after the Issuance Date, in whole or in part, by delivery (whether via facsimile or otherwise) of a written notice, in the form attached hereto as Exhibit A (the “ Exercise Notice ”), of the Holder’s election to exercise this Warrant. Within one (1) Trading Day following an exercise of this Warrant as aforesaid, the Holder shall deliver payment to the Company of an amount equal to the Exercise Price in effect on the date of such exercise multiplied by the number of Warrant Shares as to which this Warrant was so exercised (the “ Aggregate Exercise Price ”) in cash or via wire transfer of immediately available funds unless the Holder notifies the Company in such Exercise Notice that such exercise was made pursuant to a Cashless Exercise (as defined in Section 1(d)) to the extent permitted by Section 1(d). The Holder shall not be required to deliver the original of this Warrant in order to effect an exercise hereunder. Execution and delivery of an Exercise Notice with respect to less than all of the Warrant Shares shall have the same effect as cancellation of the original of this Warrant and issuance of a new Warrant evidencing the right to purchase the remaining number of Warrant Shares. Execution and delivery of an Exercise Notice for all of the then-remaining Warrant Shares shall have the same effect as cancellation of the original of this Warrant after delivery of the Warrant Shares in accordance with the terms hereof. On or before the first (1 ^st ) Trading Day following the date on which the Company has received an Exercise Notice, the Company shall transmit by facsimile an acknowledgment of confirmation of receipt of such Exercise Notice, in the form attached hereto as Exhibit B , to the Holder and the Company’s transfer agent (the “ Transfer Agent ”). On or before the later of (i) the third (3 ^rd ) Trading Day following the date on which the Company has received such Exercise Notice, and (ii) the second (2 ^nd ) Trading Day following the date on which the Company has received the Aggregate Purchase Price, the Company shall (X) provided that the Transfer Agent is participating in The Depository Trust Company (“ DTC ”) Fast Automated Securities Transfer Program, upon the request of the Holder, credit such aggregate number of shares of Common Stock to which the Holder is entitled pursuant to such exercise to the Holder’s or its designee’s balance account with DTC through its Deposit/Withdrawal at Custodian system, or (Y) if the Transfer Agent is not participating in the DTC Fast Automated Securities Transfer Program, issue and deliver to the Holder or, at the Holder’s instruction pursuant to the Exercise Notice, the Holder’s agent or designee, in each case, sent by reputable overnight courier to the address as specified in the applicable Exercise Notice, a certificate, registered in the Company’s share register in the name of the Holder or its designee (as indicated in the applicable Exercise Notice), for the number of shares of Common Stock to which the Holder is entitled pursuant to such exercise. Upon delivery of an Exercise Notice, the Holder shall be deemed for all corporate purposes to have become the holder of record of the Warrant Shares with respect to which this Warrant has been exercised, irrespective of the date such Warrant Shares are credited to the Holder’s DTC account or the date of delivery of the certificates evidencing such Warrant Shares (as the case may be). If this Warrant is submitted in connection with any exercise pursuant to this Section 1(a) and the number of Warrant Shares represented by this Warrant submitted for exercise is greater than the number of Warrant Shares being acquired upon an exercise, then, at the request of the Holder, the Company shall as soon as practicable and in no event later than three (3) Business Days after any exercise and at its own expense, issue and deliver to the Holder (or its designee) a new Warrant (in accordance with Section 6(d)) representing the right to purchase the number of Warrant Shares purchasable immediately prior to such exercise under this Warrant, less the number of Warrant Shares with respect to which this Warrant is exercised. No fractional shares of Common Stock are to be issued upon the exercise of this Warrant, but rather the number of shares of Common

3

Stock to be issued shall be rounded up to the nearest whole number. The Company shall pay any and all taxes and fees which may be payable with respect to the issuance and delivery of Warrant Shares upon exercise of this Warrant. The Company shall not, however, be required to pay any such tax which may be payable in respect of any transfer involved in the issuance and delivery of Common Stock in any name other than that of the Holder of this Warrant. Notwithstanding the foregoing, except in the case where an exercise of this Warrant is validly made pursuant to a Cashless Exercise (as defined in Section 1(d)), the Company’s failure to deliver Warrant Shares to the Holder on or prior to the second (2nd) Trading Day after the Company’s receipt of the Aggregate Exercise Price shall not be deemed to be a breach of this Warrant. Notwithstanding any provision of this Warrant to the contrary, no more than the number of Warrant Shares eligible to be issued pursuant to the limitation in Section 1(f) below shall be exercisable hereunder.

(b) Exercise Price . For purposes of this Warrant, “ Exercise Price ” means $2.75, subject to adjustment as provided herein.

(c) Company’s Failure to Timely Deliver Securities . If the Company shall fail, for any reason or for no reason, to issue to the Holder within the later of (i) three (3) Trading Days after receipt of the applicable Exercise Notice and (ii) two (2) Trading Days after the Company’s receipt of the Aggregate Exercise Price (or valid notice of a Cashless Exercise) (such later date, the “ Share Delivery Deadline ”), a certificate for the number of shares of Common Stock to which the Holder is entitled and register such shares of Common Stock on the Company’s share register or to credit the Holder’s balance account with DTC for such number of shares of Common Stock to which the Holder is entitled upon the Holder’s exercise of this Warrant (as the case may be) (a “ Delivery Failure ”), and if on or after such Share Delivery Deadline the Holder (or any other Person in respect, or on behalf, of the Holder) purchases (in an open market transaction or otherwise) shares of Common Stock to deliver in satisfaction of a sale by the Holder of all or any portion of the number of shares of Common Stock, or a sale of a number of shares of Common Stock equal to all or any portion of the number of shares of Common Stock, issuable upon such exercise that the Holder so anticipated receiving from the Company, then, in addition to all other remedies available to the Holder, the Company shall, within three (3) Business Days after the Holder’s request and in the Holder’s discretion, either (i) pay cash to the Holder in an amount equal to the Holder’s total purchase price (including brokerage commissions and other out-of-pocket expenses, if any) for the shares of Common Stock so purchased (including, without limitation, by any other Person in respect, or on behalf, of the Holder) (the “ Buy-In Price ”), at which point the Company’s obligation to so issue and deliver such certificate or credit the Holder’s balance account with DTC for the number of shares of Common Stock to which the Holder is entitled upon the Holder’s exercise hereunder (as the case may be) (and to issue such shares of Common Stock) shall terminate, or (ii) promptly honor its obligation to so issue and deliver to the Holder a certificate or certificates representing such shares of Common Stock or credit the Holder’s balance account with DTC for the number of shares of Common Stock to which the Holder is entitled upon the Holder’s exercise hereunder (as the case may be) and pay cash to the Holder in an amount equal to the excess (if any) of the Buy-In Price over the product of (A) such number of shares of Common Stock multiplied by (B) the lowest Closing Sale Price of the Common Stock on any Trading Day during the period commencing on the date of the applicable Exercise Notice and ending on the date of such issuance and payment under this clause (ii).

4

(d) Cashless Exercise . Notwithstanding anything contained herein to the contrary (other than Section 1(f) below), if at any time of exercise hereof a Registration Statement (as defined in the Registration Rights Agreement) is not effective (or the prospectus contained therein is not available for use on a continuous basis) for the resale by the Holder of the Warrant Shares then being exercised at market prices from time to time, then the Holder may, in its sole discretion, exercise this Warrant in whole or in part and, in lieu of making the cash payment otherwise contemplated to be made to the Company upon such exercise in payment of the Aggregate Exercise Price, elect instead to receive upon such exercise the “Net Number” of shares of Common Stock determined according to the following formula (a “ Cashless Exercise ”):

Net Number = (A x B) - (A x C)

                                                         D

For purposes of the foregoing formula:

A= the total number of shares with respect to which this Warrant is then being exercised.

B=the quotient of (x) the sum of the VWAP of the Common Stock of each of the five (5) Trading Days ending at the close of business on the Principal Market immediately prior to the time of exercise as set forth in the applicable Exercise Notice, divided by (y) five (5).

C= the Exercise Price then in effect for the applicable Warrant Shares at the time of such exercise.

D= as applicable: (i) the Closing Sale Price of the Common Stock on the Trading Day immediately preceding the date of the applicable Exercise Notice if such Exercise Notice is (1) both executed and delivered pursuant to Section 1(a) hereof on a day that is not a Trading Day or (2) both executed and delivered pursuant to Section 1(a) hereof on a Trading Day prior to the opening of “regular trading hours” (as defined in Rule 600(b)(64) of Regulation NMS promulgated under the federal securities laws) on such Trading Day, (ii) the Bid Price of the Common Stock as of the time of the Holder’s execution of the applicable Exercise Notice if such Exercise Notice is executed during “regular trading hours” on a Trading Day and is delivered within two (2) hours thereafter pursuant to Section 1(a) hereof, or (iii) the Closing Sale Price of the Common Stock on the date of the applicable Exercise Notice if the date of such Exercise Notice is a Trading Day and such Exercise Notice is both executed and delivered pursuant to Section 1(a) hereof after the close of “regular trading hours” on such Trading Day.

(e) Disputes . In the case of a dispute as to the determination of the Exercise Price or the arithmetic calculation of the number of Warrant Shares to be issued pursuant to the terms hereof, the Company shall promptly issue to the Holder the number of Warrant Shares that are not disputed and resolve such dispute in accordance with Section 12.

5

(f) Limitations on Exercises .

(i) Notwithstanding anything to the contrary contained in this Warrant, this Warrant shall not be exercisable by the Holder hereof, to the extent (but only to the extent) that after giving effect to such exercise the Holder (together with any of its affiliates) would beneficially own in excess of 4.99% (the “ Maximum Percentage ”) of the Common Stock. To the extent the above limitation applies, the determination of whether this Warrant shall be exercisable (vis-à-vis other convertible, exercisable or exchangeable securities owned by the Holder or any of its affiliates) and of which such securities shall be convertible, exercisable or exchangeable (as the case may be, as among all such securities owned by the Holder) shall, subject to such Maximum Percentage limitation, be determined on the basis of the first submission to the Company for conversion, exercise or exchange (as the case may be). No prior inability to exercise this Warrant pursuant to this paragraph shall have any effect on the applicability of the provisions of this paragraph with respect to any subsequent determination of exercisability. For the purposes of this paragraph, beneficial ownership and all determinations and calculations (including, without limitation, with respect to calculations of percentage ownership) shall be determined in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), and the rules and regulations promulgated thereunder. The provisions of this paragraph shall be implemented in a manner otherwise than in strict conformity with the terms of this paragraph to correct this paragraph (or any portion hereof) which may be defective or inconsistent with the intended Maximum Percentage beneficial ownership limitation herein contained or to make changes or supplements necessary or desirable to properly give effect to such Maximum Percentage limitation. The limitations contained in this paragraph shall apply to a successor Holder of this Warrant. The holders of Common Stock shall be third party beneficiaries of this paragraph and the Company may not waive this paragraph without the consent of holders of a majority of its Common Stock. For any reason at any time, upon the written or oral request of the Holder, the Company shall within one (1) Business Day confirm orally and in writing to the Holder the number of shares of Common Stock then outstanding, including by virtue of any prior conversion or exercise of convertible or exercisable securities into Common Stock, including, without limitation, pursuant to this Warrant or securities issued pursuant to the Securities Purchase Agreement. At any time the Holder may increase or decrease the Maximum Percentage to any other percentage not in excess of 9.99% as specified in a written notice by the Holder to the Company (subject to the Company’s consent to any such increase, not to be unreasonably withheld); provided that (i) any such increase will not be effective until the 61st day after such notice is delivered to the Company, and (ii) any such increase or decrease will apply only to the Holder sending such notice and not to any other holder of SPA Warrants.

(ii) Principal Market Regulation . The Company shall not issue any shares of Common Stock upon the exercise of this Warrant if the issuance of such shares of Common Stock (taken together with the Shares and the issuance of such shares of Common Stock upon exercise of the SPA Warrants) would exceed the aggregate number of shares of Common Stock which the Company may issue upon exercise of the SPA Warrants without breaching the Company’s obligations under the rules or regulations of the Principal Market (the number of shares which may be issued without violating such rules and regulations, the “ Exchange Cap ”), except that such limitation shall not apply in

6

the event that the Company (A) obtains the approval of its shareholders as required by the applicable rules of the Principal Market for issuances of shares of Common Stock in excess of such amount or (B) obtains a written opinion from outside counsel to the Company that such approval is not required, which opinion shall be reasonably satisfactory to the Holder. Until such approval or such written opinion is obtained, no Buyer shall be issued in the aggregate, upon exercise of the Warrants, shares of Common Stock in an amount greater than the product of (i) the Exchange Cap as of the Issuance Date multiplied by (ii) the quotient of (1) the number of Shares issued to such Buyer pursuant to the Securities Purchase Agreement on the Closing Date (as defined in the Securities Purchase Agreement) divided by (2) the aggregate number of Shares issued to all Investors pursuant to the Securities Purchase Agreement on the Closing Date (with respect to each Buyer, the “ Exchange Cap Allocation ”). In the event that any Buyer shall sell or otherwise transfer any of such Buyer’s SPA Warrants, the transferee shall be allocated a pro rata portion of such Buyer’s Exchange Cap Allocation with respect to such portion of such SPA Warrants so transferred, and the restrictions of the prior sentence shall apply to such transferee with respect to the portion of the Exchange Cap Allocation so allocated to such transferee. Upon exercise in full of a holder’s SPA Warrants, the difference (if any) between such holder’s Exchange Cap Allocation and the number of shares of Common Stock actually issued to such holder upon such holder’s exercise in full of such SPA Warrants shall be allocated to the respective Exchange Cap Allocations of the remaining holders of SPA Warrants on a pro rata basis in proportion to the shares of Common Stock underlying the SPA Warrants then held by each such holder of SPA Warrants. In the event that the Company is prohibited from issuing any shares of Common Stock pursuant to this Section 1(f)(ii) (the “ Exchange Cap Shares ”), in lieu of issuing and delivering such Exchange Cap Shares to the Holder, the Company shall pay cash to the Holder in exchange for the cancellation of such portion of this Warrant exercisable into such Exchange Cap Shares (the “ Exchange Cap Payment Amount ”) at a price equal to the sum of (x) the product of (A) such number of Exchange Cap Shares and (B) the greatest Closing Sale Price of the Common Stock on any Trading Day during the period commencing on the date the Holder delivers the applicable Exercise Notice with respect to such Exchange Cap Shares to the Company and ending on the date of such payment under this Section 1(f)(ii) and (y) to the extent the Holder purchases (in an open market transaction or otherwise) shares of Common Stock to deliver in satisfaction of a sale by the Holder of Exchange Cap Shares, any brokerage commissions and other out-of-pocket expenses, if any, of the Holder incurred in connection therewith.

(g) Insufficient Authorized Shares . The Company shall at all times keep reserved for issuance under this Warrant a number of shares of Common Stock at least equal to 135% of the maximum number of shares of Common Stock as shall be necessary to satisfy the Company’s obligation to issue shares of Common Stock hereunder (without regard to any limitation otherwise contained herein with respect to the number of shares of Common Stock that may be acquirable upon exercise of this Warrant). If, notwithstanding the foregoing, and not in limitation thereof, at any time while any of the SPA Warrants remain outstanding the Company does not have a sufficient number of authorized and unreserved shares of Common Stock to satisfy its obligation to reserve for issuance upon exercise of the SPA Warrants at least a number of shares of Common Stock (the “ Required Reserve Amount ”) equal to the number of shares of Common Stock as shall from time to time be necessary to effect the exercise of all of the SPA

7

Warrants then outstanding (an “ Authorized Share Failure ”), then the Company shall promptly take all action reasonably necessary to increase the Company’s authorized shares of Common Stock to an amount sufficient to allow the Company to reserve the Required Reserve Amount for all the SPA Warrants then outstanding. Without limiting the generality of the foregoing sentence, as soon as practicable after the date of the occurrence of an Authorized Share Failure, but in no event later than sixty (60) days after the occurrence of such Authorized Share Failure, the Company shall hold a meeting of its shareholders for the approval of an increase in the number of authorized shares of Common Stock. In connection with such meeting, the Company shall provide each shareholder with a proxy statement and shall use its reasonable best efforts to solicit its shareholders’ approval of such increase in authorized shares of Common Stock and to cause its board of directors to recommend to the shareholders that they approve such proposal. In the event that the Company is prohibited from issuing shares of Common Stock upon an exercise of this Warrant due to the failure by the Company to have sufficient shares of Common Stock available out of the authorized but unissued shares of Common Stock (such unavailable number of shares of Common Stock, the “ Authorization Failure Shares ”), in lieu of delivering such Authorization Failure Shares to the Holder, the Company shall pay cash in exchange for the cancellation of such portion of this Warrant exercisable into such Authorized Failure Shares at a price equal to the sum of (i) the product of (x) such number of Authorization Failure Shares and (y) the greatest Closing Sale Price of the Common Stock on any Trading Day during the period commencing on the date the Holder delivers the applicable Exercise Notice with respect to such Authorization Failure Shares to the Company and ending on the date of such issuance and payment under this Section 1(g) and (ii) to the extent the Holder purchases (in an open market transaction or otherwise) shares of Common Stock to deliver in satisfaction of a sale by the Holder of Authorization Failure Shares, any brokerage commissions and other out-of-pocket expenses, if any, of the Holder incurred in connection therewith.

2. ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF WARRANT SHARES . The Exercise Price and number of Warrant Shares issuable upon exercise of this Warrant are subject to adjustment from time to time as set forth in this Section 2.

(a) Stock Dividends and Splits . Without limiting any provision of Section 2(b) or Section 3, if the Company, at any time on or after the Issuance Date, (i) pays a stock dividend on one or more classes of its then outstanding shares of Common Stock or otherwise makes a distribution on any class of capital stock that is payable in shares of Common Stock, (ii) subdivides (by any stock split, stock dividend, recapitalization or otherwise) one or more classes of its then outstanding shares of Common Stock into a larger number of shares or (iii) combines (by combination, reverse stock split or otherwise) one or more classes of its then outstanding shares of Common Stock into a smaller number of shares, then in each such case the Exercise Price shall be multiplied by a fraction of which the numerator shall be the number of shares of Common Stock outstanding immediately before such event and of which the denominator shall be the number of shares of Common Stock outstanding immediately after such event. Any adjustment made pursuant to clause (i) of this paragraph shall become effective immediately after the record date for the determination of shareholders entitled to receive such dividend or distribution, and any adjustment pursuant to clause (ii) or (iii) of this paragraph shall become effective immediately after the effective date of such subdivision or combination. If any event requiring an adjustment under this paragraph occurs during the period that an Exercise Price is calculated hereunder, then the calculation of such Exercise Price shall be adjusted appropriately to reflect such event.

8

(b) Adjustment Upon Issuance of Shares of Common Stock . If and whenever on or after the Issuance Date, the Company issues or sells, or in accordance with this Section 2 is deemed to have issued or sold, any shares of Common Stock (including the issuance or sale of shares of Common Stock owned or held by or for the account of the Company, but excluding any Excluded Securities issued or sold or deemed to have been issued or sold) for a consideration per share (the “ New Issuance Price ”) less than a price equal to the Exercise Price in effect immediately prior to such issue or sale or deemed issuance or sale (such Exercise Price then in effect is referred to as the “ Applicable Price ”) (the foregoing a “ Dilutive Issuance ”), then immediately after such Dilutive Issuance, the Conversion Price then in effect shall be reduced to an amount equal to the product of (A) the Conversion Price in effect immediately prior to such Dilutive Issuance and (B) the quotient determined by dividing (1) the sum of (I) the product derived by multiplying the Conversion Price in effect immediately prior to such Dilutive Issuance and the number of Common Stock Deemed Outstanding immediately prior to such Dilutive Issuance plus (II) the net consideration, if any, received by the Company upon such Dilutive Issuance (as determined and, if applicable, adjusted, pursuant to Section 2(b)(ii) below), by (2) the product derived by multiplying (I) the Conversion Price in effect immediately prior to such Dilutive Issuance by (II) the sum of (x) the number of Common Stock Deemed Outstanding immediately prior to such Dilutive Issuance plus (y) the number of shares of Common Stock issued (or deemed issued in such Dilutive Issuance pursuant to Sections 2(b)(i) and 2(b)(ii) below, regardless of whether such Options or Convertible Securities are actually convertible or exercisable at such time, but excluding any shares of Common Stock issued (or deemed issued pursuant to Sections 2(b)(i) and 2(b)(ii) below) under any Secondary Securities (as defined below), if any). For all purposes of the foregoing (including, without limitation, determining the adjusted Conversion Price and consideration per share under this Section 2(b)), the following shall be applicable:

(i) Issuance of Options . If the Company in any manner grants or sells any Options and the lowest price per share for which one share of Common Stock is issuable upon the exercise of any such Option or upon conversion, exercise or exchange of any Convertible Securities issuable upon exercise of any such Option is less than the Applicable Price, then such share of Common Stock shall be deemed to be outstanding and to have been issued and sold by the Company at the time of the granting or sale of such Option for such price per share. For purposes of this Section 2(b)(i), the “lowest price per share for which one share of Common Stock is issuable upon the exercise of any such Options or upon conversion, exercise or exchange of any Convertible Securities issuable upon exercise of any such Option” shall be equal to (1) the lower of (x) the sum of the lowest amounts of consideration (if any) received or receivable by the Company with respect to any one share of Common Stock upon the granting or sale of such Option, upon exercise of such Option and upon conversion, exercise or exchange of any Convertible Security issuable upon exercise of such Option and (y) the lowest exercise price set forth in such Option for which one share of Common Stock is issuable upon the exercise of any such Options or upon conversion, exercise or exchange of any Convertible Securities issuable upon exercise of any such Option minus (2) the sum of all amounts paid or payable to the holder of such Option (or any other Person) upon the

9

granting or sale of such Option, upon exercise of such Option and upon conversion, exercise or exchange of any Convertible Security issuable upon exercise of such Option plus the value of any other consideration received or receivable by, or benefit conferred on, the holder of such Option (or any other Person). Except as contemplated below, no further adjustment of the Exercise Price shall be made upon the actual issuance of such shares of Common Stock or of such Convertible Securities upon the exercise of such Options or upon the actual issuance of such shares of Common Stock upon conversion, exercise or exchange of such Convertible Securities.

(ii) Issuance of Convertible Securities . If the Company in any manner issues or sells any Convertible Securities and the lowest price per share for which one share of Common Stock is issuable upon the conversion, exercise or exchange thereof is less than the Applicable Price, then such share of Common Stock shall be deemed to be outstanding and to have been issued and sold by the Company at the time of the issuance or sale of such Convertible Securities for such price per share. For the purposes of this Section 2(b)(ii), the “lowest price per share for which one share of Common Stock is issuable upon the conversion, exercise or exchange thereof” shall be equal to (1) the lower of (x) the sum of the lowest amounts of consideration (if any) received or receivable by the Company with respect to one share of Common Stock upon the issuance or sale of the Convertible Security and upon conversion, exercise or exchange of such Convertible Security and (y) the lowest conversion price set forth in such Convertible Security for which one share of Common Stock is issuable upon conversion, exercise or exchange thereof minus (2) the sum of all amounts paid or payable to the holder of such Convertible Security (or any other Person) upon the issuance or sale of such Convertible Security plus the value of any other consideration received or receivable by, or benefit conferred on, the holder of such Convertible Security (or any other Person). Except as contemplated below, no further adjustment of the Exercise Price shall be made upon the actual issuance of such shares of Common Stock upon conversion, exercise or exchange of such Convertible Securities, and if any such issue or sale of such Convertible Securities is made upon exercise of any Options for which adjustment of this Warrant has been or is to be made pursuant to other provisions of this Section 2(b), except as contemplated below, no further adjustment of the Exercise Price shall be made by reason of such issue or sale.

(iii) Change in Option Price or Rate of Conversion . If the purchase or exercise price provided for in any Options, the additional consideration, if any, payable upon the issue, conversion, exercise or exchange of any Convertible Securities, or the rate at which any Convertible Securities are convertible into or exercisable or exchangeable for shares of Common Stock, increases or decreases at any time, the Exercise Price in effect at the time of such increase or decrease shall be adjusted to the Exercise Price which would have been in effect at such time had such Options or Convertible Securities provided for such increased or decreased purchase price, additional consideration or increased or decreased conversion rate, as the case may be, at the time initially granted, issued or sold. For purposes of this Section 2(b)(iii), if the terms of any Option or Convertible Security that was outstanding as of the date of issuance of this Warrant are increased or decreased in the manner described in the immediately preceding sentence, then such Option or Convertible Security and the shares of Common Stock deemed issuable upon exercise, conversion or exchange thereof shall be deemed to have been issued as of the date of such increase or decrease. No adjustment pursuant to this Section 2(b) shall be made if such adjustment would result in an increase of the Exercise Price then in effect.

10

(iv) Calculation of Consideration Received . If any Option and/or Convertible Security and/or Adjustment Right is issued in connection with the issuance or sale or deemed issuance or sale of any other securities of the Company (as determined by the Holder, the “ Primary Security ”, and such Option and/or Convertible Security and/or Adjustment Right, the “ Secondary Securities ”), together comprising one integrated transaction, the Primary Security issued or sold in such integrated transaction shall be deemed to have been issued for consideration equal to the difference of (A) the aggregate consideration received by the Company to purchase such Primary Security and Secondary Securities, minus (B) the product of (x) solely with respect to the Secondary Securities, the sum of (I) the Black Scholes Consideration Value of such Option, if any, (II) the fair market value (as determined by the Holder) or the Black Scholes Consideration Value, as applicable, of such Adjustment Right, if any, and (III) the fair market value (as determined by the Holder) of such Convertible Security, if any, in each case, as determined on a per share basis in accordance with this Section 2(b)(iv) and (y) the aggregate number of shares of Common Stock issued (or deemed issued pursuant to Sections 2(a)(i) and 2(a)(ii) above, regardless of whether such Options or Convertible Securities are actually convertible or exercisable at such time) in such Dilutive Issuance pursuant to such Secondary Securities. If any shares of Common Stock, Options or Convertible Securities are issued or sold or deemed to have been issued or sold for cash, the consideration received therefor will be deemed to be the net amount of consideration received by the Company therefor. If any shares of Common Stock, Options or Convertible Securities are issued or sold for a consideration other than cash, the amount of such consideration received by the Company will be the fair value of such consideration, except where such consideration consists of publicly traded securities, in which case the amount of consideration received by the Company for such securities will be the arithmetic average of the VWAPs of such security for each of the five (5) Trading Days immediately preceding the date of receipt. If any shares of Common Stock, Options or Convertible Securities are issued to the owners of the non-surviving entity in connection with any merger in which the Company is the surviving entity, the amount of consideration therefor will be deemed to be the fair value of such portion of the net assets and business of the non-surviving entity as is attributable to such shares of Common Stock, Options or Convertible Securities, as the case may be. The fair value of any consideration other than cash or publicly traded securities will be determined jointly by the Company and the Holder. If such parties are unable to reach agreement within ten (10) days after the occurrence of an event requiring valuation (the “ Valuation Event ”), the fair value of such consideration will be determined within five (5) Trading Days after the tenth (10 ^th ) day following such Valuation Event by an independent, reputable appraiser jointly selected by the Company and the Holder. The determination of such appraiser shall be final and binding upon all parties absent manifest error and the fees and expenses of such appraiser shall be borne by the Company.

11

(v) Record Date . If the Company takes a record of the holders of shares of Common Stock for the purpose of entitling them (A) to receive a dividend or other distribution payable in shares of Common Stock, Options or in Convertible Securities or (B) to subscribe for or purchase shares of Common Stock, Options or Convertible Securities, then such record date will be deemed to be the date of the issue or sale of the shares of Common Stock deemed to have been issued or sold upon the declaration of such dividend or the making of such other distribution or the date of the granting of such right of subscription or purchase (as the case may be).

(c) Number of Warrant Shares . Simultaneously with any adjustment to the Exercise Price pursuant to paragraphs (a) or (b) of this Section 2, the number of Warrant Shares that may be purchased upon exercise of this Warrant shall be increased or decreased proportionately, so that after such adjustment the aggregate Exercise Price payable hereunder for the adjusted number of Warrant Shares shall be the same as the aggregate Exercise Price in effect immediately prior to such adjustment (without regard to any limitations on exercise contained herein).

(d) Other Events . In the event that the Company (or any Subsidiary) shall take any action to which the provisions hereof are not strictly applicable, or, if applicable, would not operate to protect the Holder from dilution or if any event occurs of the type contemplated by the provisions of this Section 2 but not expressly provided for by such provisions (including, without limitation, the granting of stock appreciation rights, phantom stock rights or other rights with equity features), then the Company’s board of directors shall in good faith determine and implement an appropriate adjustment in the Exercise Price and the number of Warrant Shares (if applicable) so as to protect the rights of the Holder, provided that no such adjustment pursuant to this Section 2(d) will increase the Exercise Price or decrease the number of Warrant Shares as otherwise determined pursuant to this Section 2.

(e) Calculations . All calculations under this Section 2 shall be made by rounding to the nearest cent or the nearest 1/100 ^th of a share, as applicable. The number of shares of Common Stock outstanding at any given time shall not include shares owned or held by or for the account of the Company, and the disposition of any such shares shall be considered an issue or sale of Common Stock.

3. PURCHASE RIGHTS; FUNDAMENTAL TRANSACTIONS .

(a) Purchase Rights . In addition to any adjustments pursuant to Section 2 above, if at any time the Company grants, issues or sells any Options, Convertible Securities or rights to purchase stock, warrants, securities or other property pro rata to the record holders of the Common Stock (the “ Purchase Rights ”), then the Holder will be entitled to acquire, upon the terms applicable to such Purchase Rights, the aggregate Purchase Rights which the Holder could have acquired if the Holder had held the number of shares of Common Stock acquirable upon complete exercise of this Warrant (without regard to any limitations on exercise hereof, including without limitation, the Maximum Percentage) immediately before the date on which a record is taken for the grant, issuance or sale of such Purchase Rights, or, if no such record is taken, the date as of which the record holders of shares of Common Stock are to be determined for the grant, issue or sale of such Purchase Rights (provided, however, to the extent that the Holder’s right to participate in any such Purchase Right would result in the Holder exceeding the Maximum Percentage, then the Holder shall not be entitled to participate in such Purchase Right to such extent (or beneficial ownership of such shares of Common Stock as a result of such Purchase Right to such extent) and such Purchase Right to such extent shall be held in abeyance for the Holder until such time, if ever, as its right thereto would not result in the Holder exceeding the Maximum Percentage).

12

(b) Fundamental Transactions . The Company shall not enter into or be party to a Fundamental Transaction unless the Successor Entity assumes in writing all of the obligations of the Company under this Warrant and the other Transaction Documents in accordance with the provisions of this Section 3(b) pursuant to written agreements in form and substance satisfactory to the Holder and approved by the Holder prior to such Fundamental Transaction, including agreements to deliver to the Holder in exchange for this Warrant a security of the Successor Entity evidenced by a written instrument substantially similar in form and substance to this Warrant, including, without limitation, which is exercisable for a corresponding number of shares of capital stock equivalent to the shares of Common Stock acquirable and receivable upon exercise of this Warrant (without regard to any limitations on the exercise of this Warrant) prior to such Fundamental Transaction, and with an exercise price which applies the exercise price hereunder to such shares of capital stock (but taking into account the relative value of the shares of Common Stock pursuant to such Fundamental Transaction and the value of such shares of capital stock, such adjustments to the number of shares of capital stock and such exercise price being for the purpose of protecting the economic value of this Warrant immediately prior to the consummation of such Fundamental Transaction). Upon the consummation of each Fundamental Transaction, the Successor Entity shall succeed to, and be substituted for (so that from and after the date of the applicable Fundamental Transaction, the provisions of this Warrant and the other Transaction Documents referring to the “Company” shall refer instead to the Successor Entity), and may exercise every right and power of the Company and shall assume all of the obligations of the Company under this Warrant and the other Transaction Documents with the same effect as if such Successor Entity had been named as the Company herein. Upon consummation of each Fundamental Transaction, the Successor Entity shall deliver to the Holder confirmation that there shall be issued upon exercise of this Warrant (or other securities, cash, assets or other property (except such items still issuable under Section 3(a) above, which shall continue to be receivable thereafter) (without regard to any limitations on the exercise of this Warrant). Notwithstanding the foregoing, and without limiting Section 1(f) hereof, the Holder may elect, at its sole option, by delivery of written notice to the Company to waive this Section 3(b) to permit the Fundamental Transaction without the assumption of this Warrant.

(c) Black Scholes Value .

(i) Fundamental Transaction Redemption by the Holder . Notwithstanding the provisions of Section 3(b) above, at the request of the Holder delivered at any time commencing on the earliest to occur of (x) the public disclosure of any “person” or “group” (as these terms are used for purposes of Sections 13(d) and 14(d) of the Exchange Act and the rules and regulations promulgated thereunder), other than Gaiam, Inc. or Riverside Renewable Energy Investment LLC, becoming the “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of 50% of the aggregate ordinary voting power represented by issued and outstanding Voting Stock of the Company (a “ Change of Control ”), (y) the consummation of any Change of Control and (z) the Holder first becoming aware of any Change of Control, through the date that

13

is twenty (20) days after the public disclosure of the consummation of such Fundamental Transaction by the Company pursuant to a Current Report on Form 8-K filed with the Securities and Exchange Commission (“ SEC ”), the Company or the Successor Entity (as the case may be) shall purchase this Warrant from the Holder on the date of such request by paying to the Holder cash in an amount equal to the Black Scholes Value.

(ii) Going Private Redemption by the Company . Notwithstanding the foregoing and the provisions of Section 3(b) above, at any time after the date of the public disclosure of a Fundamental Transaction in which neither the Successor Entity nor its Parent Entity in such Fundamental Transaction is a publicly traded corporation with common equity that is quoted on or listed for trading on an Eligible Market (a “ Going Private Transaction ”), the Company may, at its option, redeem this Warrant in full, not in part, from the Holder on the date of consummation of such Going Private Transaction (the “ Going Private Date ”) by paying to the Holder cash in an amount equal to the Going Private Black Scholes Value (the “ Going Private Redemption Amount ”, and such redemption, a “ Going Private Redemption ”). The Company may exercise its right to require redemption under this Section 3(c)(ii) by delivering an irrevocable written notice thereof by facsimile and overnight courier to all, but not less than all, of the holders of SPA Warrants (the “ Going Private Redemption Notice ” and the date all of the holders of SPA Warrants received such notice is referred to as the “ Going Private Redemption Notice Date ”). The Company may deliver only one Going Private Redemption Notice in any sixty (60) day period. The Going Private Redemption Notice shall (x) state the date on which the Going Private Redemption shall occur (the “ Going Private Redemption Date ”) which date shall not be less than thirty (30) calendar days nor more than sixty (60) calendar days following the Going Private Redemption Notice Date and (y) state the Going Private Redemption Amount (with back-up calculations) which is being redeemed in such Going Private Redemption from the Holder and all of the other holders of the SPA Warrants pursuant to this Section 3(c)(ii) (and analogous provisions under the other SPA Warrants) on the Going Private Redemption Date. Until the Going Private Redemption Amount is paid in full, this Warrant may be exercised, in whole or in part, by the Holder into Common Stock pursuant to Section 1. In the event the Holder elects to exercise any portion of this Warrant after the Going Private Redemption Notice Date, the Going Private Black Scholes Value of the portion so exercised shall be deducted from the Going Private Redemption Amount the Company shall pay to the Holder on the Going Private Date.

(d) Application . The provisions of this Section 3 shall apply similarly and equally to successive Fundamental Transactions and Corporate Events and shall be applied as if this Warrant (and any such subsequent warrants) were fully exercisable and without regard to any limitations on the exercise of this Warrant (provided that the Holder shall continue to be entitled to the benefit of the Maximum Percentage, applied however with respect to shares of capital stock registered under the

(e) Exchange Act and thereafter receivable upon exercise of this Warrant (or any such other warrant)).

14

4. NONCIRCUMVENTION . The Company hereby covenants and agrees that the Company will not, by amendment of its articles of incorporation, bylaws or through any reorganization, transfer of assets, consolidation, merger, scheme of arrangement, dissolution, issue or sale of securities, or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, and will at all times in good faith carry out all the provisions of this Warrant and take all action as may be required to protect the rights of the Holder. Without limiting the generality of the foregoing, the Company (i) shall not increase the par value of any shares of Common Stock receivable upon the exercise of this Warrant above the Exercise Price then in effect, (ii) shall take all such actions as may be necessary or appropriate in order that the Company may validly and legally issue fully paid and non-assessable shares of Common Stock upon the exercise of this Warrant, and (iii) shall, in accordance with Section 1(g) above, so long as any of the Spa Warrants are outstanding, take all action necessary to reserve and keep available out of its authorized and unissued shares of Common Stock, solely for the purpose of effecting the exercise of the Spa Warrants, the maximum number of shares of Common Stock as shall from time to time be necessary to effect the exercise of the Spa Warrants then outstanding (without regard to any limitations on exercise).

5. WARRANT HOLDER NOT DEEMED A SHAREHOLDER . Except as otherwise specifically provided herein, the Holder, solely in its capacity as a holder of this Warrant, shall not be entitled to vote or receive dividends or be deemed the holder of share capital of the Company for any purpose, nor shall anything contained in this Warrant be construed to confer upon the Holder, solely in its capacity as the holder of this Warrant, any of the rights of a shareholder of the company or any right to vote, give or withhold consent to any corporate action (whether any reorganization, issue of stock, reclassification of stock, consolidation, merger, conveyance or otherwise), receive notice of meetings, receive dividends or subscription rights, or otherwise, prior to the issuance to the Holder of the Warrant shares which it is then entitled to receive upon the due exercise of this Warrant. In addition, nothing contained in this Warrant shall be construed as imposing any liabilities on the Holder to purchase any securities (upon exercise of this Warrant or otherwise) or as a shareholder of the Company, whether such liabilities are asserted by the Company or by creditors of the Company. Notwithstanding this Section 5, the Company shall provide the Holder with copies of the same notices and other information (that are not filed with or furnished to the SEC) given to the shareholders of the Company generally, contemporaneously with the giving thereof to the shareholders.

6. REISSUANCE OF WARRANTS .

(a) Transfer of Warrant . If this Warrant is to be transferred, the Holder shall surrender this Warrant to the Company, whereupon the Company will forthwith issue and deliver upon the order of the Holder a new Warrant (in accordance with Section 6(d)), registered as the Holder may request, representing the right to purchase the number of Warrant Shares being transferred by the Holder and, if less than the total number of Warrant Shares then underlying this Warrant is being transferred, a new Warrant (in accordance with Section 6(d)) to the Holder representing the right to purchase the number of Warrant Shares not being transferred.

15

(b) Lost, Stolen or Mutilated Warrant . Upon receipt by the Company of evidence reasonably satisfactory to the Company of the loss, theft, destruction or mutilation of this Warrant (as to which a written certification and the indemnification contemplated below shall suffice as such evidence), and, in the case of loss, theft or destruction, of any indemnification undertaking by the Holder to the Company in customary and reasonable form and, in the case of mutilation, upon surrender and cancellation of this Warrant, the Company shall execute and deliver to the Holder a new Warrant (in accordance with Section 6(d)) representing the right to purchase the Warrant Shares then underlying this Warrant.

(c) Exchangeable for Multiple Warrants . This Warrant is exchangeable, upon the surrender hereof by the Holder at the principal office of the Company, for a new Warrant or Warrants (in accordance with Section 6(d)) representing in the aggregate the right to purchase the number of Warrant Shares then underlying this Warrant, and each such new Warrant will represent the right to purchase such portion of such Warrant Shares as is designated by the Holder at the time of such surrender; provided, however, no warrants for fractional shares of Common Stock shall be given.

(d) Issuance of New Warrants . Whenever the Company is required to issue a new Warrant pursuant to the terms of this Warrant, such new Warrant (i) shall be of like tenor with this Warrant, (ii) shall represent, as indicated on the face of such new Warrant, the right to purchase the Warrant Shares then underlying this Warrant (or in the case of a new Warrant being issued pursuant to Section 6(a) or Section 6(c), the Warrant Shares designated by the Holder which, when added to the number of shares of Common Stock underlying the other new Warrants issued in connection with such issuance, does not exceed the number of Warrant Shares then underlying this Warrant), (iii) shall have an issuance date, as indicated on the face of such new Warrant which is the same as the Issuance Date, and (iv) shall have the same rights and conditions as this Warrant.

7. NOTICES . Whenever notice is required to be given under this Warrant, unless otherwise provided herein, such notice shall be given in accordance with Section 6.3 of the Securities Purchase Agreement. The Company shall provide the Holder with prompt written notice of all actions taken pursuant to this Warrant, including in reasonable detail a description of such action and the reason therefor. Without limiting the generality of the foregoing, the Company will give written notice to the Holder (i) immediately upon each adjustment of the Exercise Price and the number of Warrant Shares, setting forth in reasonable detail, and certifying, the calculation of such adjustment(s) and (ii) at least fifteen (15) days prior to the date on which the Company closes its books or takes a record (A) with respect to any dividend or distribution upon the shares of Common Stock, (B) with respect to any grants, issuances or sales of any Options, Convertible Securities or rights to purchase stock, warrants, securities or other property to holders of shares of Common Stock or (C) for determining rights to vote with respect to any Fundamental Transaction, dissolution or liquidation, provided in each case that such information shall be made known to the public prior to or in conjunction with such notice being provided to the Holder and (iii) at least five (5) Trading Days prior to the consummation of any Fundamental Transaction. To the extent that any notice provided hereunder constitutes, or contains, material, non-public information regarding the Company or any of its Subsidiaries, the Company shall simultaneously file such notice with the SEC pursuant to a Current Report on Form 8-K. It is expressly understood and agreed that the time of execution specified by the Holder in each Exercise Notice shall be definitive and may not be disputed or challenged by the Company.

16

8. AMENDMENT AND WAIVER . Except as otherwise provided herein, the provisions of this Warrant (other than Section 1(f)) may be amended and the Company may take any action herein prohibited, or omit to perform any act herein required to be performed by it, only if the Company has obtained the written consent of all Holders of the then issued and outstanding aggregate number of Shares and Warrant Shares; provided, however, with respect to any amendment that proposes to (i) decrease the number of shares into which this Warrant or the SPA Warrants, collectively, are exercisable into or (ii) increase the exercise price of this Warrant or the SPA Warrants, collectively, the Company must also obtain the written consent of the Holder. The Holder shall be entitled, at its option, to the benefit of any amendment of any other SPA Warrant. No consideration shall be offered or paid to the Holder to amend or consent to a waiver or modification of any provision of this Warrant unless the same consideration is also offered to all of the holders of the other SPA Warrants. No waiver shall be effective unless it is in writing and signed by an authorized representative of the waiving party.

9. SEVERABILITY . If any provision of this Warrant is prohibited by law or otherwise determined to be invalid or unenforceable by a court of competent jurisdiction, the provision that would otherwise be prohibited, invalid or unenforceable shall be deemed amended to apply to the broadest extent that it would be valid and enforceable, and the invalidity or unenforceability of such provision shall not affect the validity of the remaining provisions of this Warrant so long as this Warrant as so modified continues to express, without material change, the original intentions of the parties as to the subject matter hereof and the prohibited nature, invalidity or unenforceability of the provision(s) in question does not substantially impair the respective expectations or reciprocal obligations of the parties or the practical realization of the benefits that would otherwise be conferred upon the parties. The parties will endeavor in good faith negotiations to replace the prohibited, invalid or unenforceable provision(s) with a valid provision(s), the effect of which comes as close as possible to that of the prohibited, invalid or unenforceable provision(s).

10. GOVERNING LAW . This Warrant shall be governed by and construed and enforced in accordance with, and all questions concerning the construction, validity, interpretation and performance of this Warrant shall be governed by, the internal laws of the State of New York, without giving effect to any choice of law or conflict of law provision or rule (whether of the State of New York or any other jurisdictions) that would cause the application of the laws of any jurisdictions other than the State of New York. The Company hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in The City of New York, Borough of Manhattan, for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is brought in an inconvenient forum or that the venue of such suit, action or proceeding is improper. Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law. Nothing contained herein shall be deemed or operate to preclude the Holder from bringing suit or taking other legal action against the Company in any other jurisdiction to collect on the Company’s obligations to the Holder or to enforce a judgment or other court ruling in favor of the Holder. THE COMPANY HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE TO, AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION WITH OR ARISING OUT OF THIS WARRANT OR ANY TRANSACTION CONTEMPLATED HEREBY.

17

11. CONSTRUCTION; HEADINGS . This Warrant shall be deemed to be jointly drafted by the Company and the Holder and shall not be construed against any Person as the drafter hereof. The headings of this Warrant are for convenience of reference and shall not form part of, or affect the interpretation of, this Warrant. Terms used in this Warrant but defined in the other Transaction Documents shall have the meanings ascribed to such terms on the Closing Date in such other Transaction Documents unless otherwise consented to in writing by the Holder.

12. DISPUTE RESOLUTION . In the case of a dispute as to the determination of the Exercise Price, the Closing Sale Price, the Bid Price or fair market value or the arithmetic calculation of the number of Warrant Shares (as the case may be), the Company or the Holder (as the case may be) shall submit the disputed determinations or arithmetic calculations (as the case may be) via facsimile (i) within two (2) Business Days after receipt of the applicable notice giving rise to such dispute to the Company or the Holder (as the case may be) or (ii) if no notice gave rise to such dispute, at any time after the Holder learned of the circumstances giving rise to such dispute (including, without limitation, as to whether any issuance or sale or deemed issuance or sale was an issuance or sale or deemed issuance or sale of Excluded Securities). If the Holder and the Company are unable to agree upon such determination or calculation (as the case may be) of the Exercise Price, the Closing Sale Price, the Bid Price or fair market value or the number of Warrant Shares (as the case may be) within three (3) Business Days of such disputed determination or arithmetic calculation being submitted to the Company or the Holder (as the case may be), then the Company shall, within two (2) Business Days submit via facsimile (a) the disputed determination of the Exercise Price, the Closing Sale Price, the Bid Price or fair market value (as the case may be) to an independent, reputable investment bank selected by the Company and reasonably acceptable to the Holder or (b) the disputed arithmetic calculation of the number of Warrant Shares to the Company’s independent, outside accountant. The Company shall cause the investment bank or the accountant (as the case may be) to perform the determinations or calculations (as the case may be) and notify the Company and the Holder of the results no later than ten (10) Business Days from the time it receives such disputed determinations or calculations (as the case may be). Such investment bank’s or accountant’s determination or calculation (as the case may be) shall be binding upon all parties absent manifest error. The loser of the dispute shall pay the fees and out of pocket expenses of such investment bank or accountant.

13. REMEDIES, CHARACTERIZATION, OTHER OBLIGATIONS, BREACHES AND INJUNCTIVE RELIEF . The remedies provided in this Warrant shall be cumulative and in addition to all other remedies available under this Warrant and the other Transaction Documents, at law or in equity (including a decree of specific performance and/or other injunctive relief), and nothing herein shall limit the right of the Holder to pursue actual damages for any failure by the Company to comply with the terms of this Warrant. The Company covenants to the Holder that there shall be no characterization concerning this instrument other than as expressly provided herein. Amounts set forth or provided for herein with respect to payments, exercises and the like (and the computation thereof) shall be the amounts to be received by the Holder and shall not, except as expressly provided herein, be subject to any other obligation of the Company (or the performance thereof). The Company acknowledges that a breach by it of its obligations

18

hereunder will cause irreparable harm to the Holder and that the remedy at law for any such breach may be inadequate. The Company therefore agrees that, in the event of any such breach or threatened breach, the holder of this Warrant shall be entitled, in addition to all other available remedies, to an injunction restraining any breach, without the necessity of showing economic loss and without any bond or other security being required. The Company shall provide all information and documentation to the Holder that is requested by the Holder to enable the Holder to confirm the Company’s compliance with the terms and conditions of this Warrant (including, without limitation, compliance with Section 2 hereof). The issuance of shares and certificates for shares as contemplated hereby upon the exercise of this Warrant shall be made without charge to the Holder or such shares for any issuance tax or other costs in respect thereof, provided that the Company shall not be required to pay any tax which may be payable in respect of any transfer involved in the issuance and delivery of any certificate in a name other than the Holder or its agent on its behalf.

14. TRANSFER . This Warrant may be offered for sale, sold, transferred or assigned without the consent of the Company, except as may otherwise be required by Section 2(e) of the Securities Purchase Agreement.

15. CERTAIN DEFINITIONS . For purposes of this Warrant, the following terms shall have the following meanings:

(a) “ Adjustment Right ” means any right granted with respect to any securities issued in connection with, or with respect to, any issuance or sale (or deemed issuance or sale in accordance with Section 2) of shares of Common Stock (other than rights of the type described in Section 3 hereof) that could result in a decrease in the net consideration received by the Company in connection with, or with respect to, such securities (including, without limitation, any cash settlement rights, cash adjustment or other similar rights).

(b) “ Approved Stock Plan ” means any employee benefit plan which has been approved by the board of directors of the Company prior to or subsequent to the date hereof pursuant to which shares of Common Stock and standard options to purchase Common Stock may be issued to any employee, officer or director for services provided to the Company in their capacity as such.

(c) “ Bid Price ” means, for any security as of the particular time of determination, the bid price for such security on the Principal Market as reported by Bloomberg as of such time of determination, or, if the Principal Market is not the principal securities exchange or trading market for such security, the bid price of such security on the principal securities exchange or trading market where such security is listed or traded as reported by Bloomberg as of such time of determination, or if the foregoing does not apply, the bid price of such security in the over-the-counter market on the electronic bulletin board for such security as reported by Bloomberg as of such time of determination, or, if no bid price is reported for such security by Bloomberg as of such time of determination, the average of the bid prices of any market makers for such security as reported in the “pink sheets” by OTC Markets Group Inc. (formerly Pink Sheets LLC) as of such time of determination. If the Bid Price cannot be calculated for a security as of the particular time of determination on any of the foregoing bases, the Bid Price of such security as of such time of determination shall be the fair market value as mutually determined by the

19

Company and the Holder. If the Company and the Holder are unable to agree upon the fair market value of such security, then such dispute shall be resolved in accordance with the procedures in Section 12. All such determinations shall be appropriately adjusted for any stock dividend, stock split, stock combination or other similar transaction during such period.

(d) “ Black Scholes Consideration Value ” means the value of the applicable Option, Convertible Security or Adjustment Right (as the case may be) as of the date of issuance thereof calculated using the Black Scholes Option Pricing Model obtained from the “OV” function on Bloomberg utilizing (i) an underlying price per share equal to the Closing Sale Price of the Common Stock on the Trading Day immediately preceding the public announcement of the execution of definitive documents with respect to the issuance of such Option or Convertible Security (as the case may be), (ii) a risk-free interest rate corresponding to the U.S. Treasury rate for a period equal to the remaining term of such Option, Convertible Security or Adjustment Right (as the case may be) as of the date of issuance of such Option, Convertible Security or Adjustment Right (as the case may be), (iii) a zero cost of borrow and (iv) an expected volatility equal to the lesser of 100% and the 100 day volatility obtained from the HVT function on Bloomberg (determined utilizing a 365 day annualization factor) as of the Trading Day immediately following the date of issuance of such Option, Convertible Security or Adjustment Right (as the case may be).

(e) “ Black Scholes Value ” means the value of the unexercised portion of this Warrant remaining on the date of the Holder’s request pursuant to Section 3(c), which value is calculated using the Black Scholes Option Pricing Model obtained from the “OV” function on Bloomberg utilizing (i) an underlying price per share equal to the greater of (1) the highest Closing Sale Price of the Common Stock during the period beginning on the Trading Day immediately preceding the announcement of the applicable Fundamental Transaction (or the consummation of the applicable Fundamental Transaction, if earlier) and ending on the Trading Day of the Holder’s request pursuant to Section 3(c) and (2) the sum of the price per share being offered in cash in the applicable Fundamental Transaction (if any) plus the value of the non-cash consideration being offered in the applicable Fundamental Transaction (if any), (ii) a strike price equal to the Exercise Price in effect on the date of the Holder’s request pursuant to Section 3(c), (iii) a risk-free interest rate corresponding to the U.S. Treasury rate for a period equal to the greater of (1) the remaining term of this Warrant as of the date of the Holder’s request pursuant to Section 3(c) and (2) the remaining term of this Warrant as of the date of consummation of the applicable Fundamental Transaction or as of the date of the Holder’s request pursuant to Section 3(c) if such request is prior to the date of the consummation of the applicable Fundamental Transaction, (iv) a zero cost of borrow and (v) an expected volatility equal to the lesser of 100% and the 100 day volatility obtained from the HVT function on Bloomberg (determined utilizing a 365 day annualization factor) as of the Trading Day immediately prior to the date of the consummation of the applicable Fundamental Transaction.

(f) “ Bloomberg ” means Bloomberg, L.P.

(g) “ Business Day ” means any day other than Saturday, Sunday or other day on which commercial banks in The City of New York are authorized or required by law to remain closed.

20

(h) “ Closing Sale Price ” means, for any security as of any date, the last closing trade price for such security on the Principal Market, as reported by Bloomberg, or, if the Principal Market begins to operate on an extended hours basis and does not designate the closing trade price, then the last trade price of such security prior to 4:00:00 p.m., New York time, as reported by Bloomberg, or, if the Principal Market is not the principal securities exchange or trading market for such security, the last trade price of such security on the principal securities exchange or trading market where such security is listed or traded as reported by Bloomberg, or if the foregoing does not apply, the last trade price of such security in the over-the-counter market on the electronic bulletin board for such security as reported by Bloomberg, or, if no last trade price is reported for such security by Bloomberg, the average of the ask prices of any market makers for such security as reported in the “pink sheets” by OTC Markets Group Inc. (formerly Pink Sheets LLC). If the Closing Sale Price cannot be calculated for a security on a particular date on any of the foregoing bases, the Closing Sale Price of such security on such date shall be the fair market value as mutually determined by the Company and the Holder. If the Company and the Holder are unable to agree upon the fair market value of such security, then such dispute shall be resolved in accordance with the procedures in Section 12. All such determinations shall be appropriately adjusted for any stock dividend, stock split, stock combination or other similar transaction during such period.

(i) “ Common Stock ” means (i) the Company’s shares of class A common stock, $0.0001 par value per share, and (ii) any capital stock into which such class A common stock shall have been changed or any share capital resulting from a reclassification of such common stock.

(j) “ Common Stock Deemed Outstanding ” means, at any given time, the number of shares of Common Stock actually outstanding at such time, but excluding any shares of Common Stock owned or held by or for the account of the Company.

(k) “ Convertible Securities ” means any stock or other security (other than Options) that is at any time and under any circumstances, directly or indirectly, convertible into, exercisable or exchangeable for, or which otherwise entitles the holder thereof to acquire, any shares of Common Stock.

(l) “ Eligible Market ” means The New York Stock Exchange, the NYSE MKT, the Nasdaq Global Select Market, the Nasdaq Global Market or the Principal Market.

(m) “ Excluded Securities ” means (i) shares of Common Stock or standard options to purchase Common Stock issued to directors, officers or employees of the Company in their capacity as such pursuant to an Approved Stock Plan (as defined below), provided that (A) all such issuances (taking into account the shares of Common Stock issuable upon exercise of such options) after the date hereof pursuant to this clause (i) do not, in the aggregate, exceed more than 10% of the Common Stock issued and outstanding immediately prior to the date hereof and (B) none of such options are amended to increase the number of shares issuable thereunder and none of the terms or conditions of any such options are otherwise materially changed in any manner that adversely affects any of the Buyers; (ii) shares of Common Stock issued upon the conversion or exercise of Convertible Securities (other than standard options to purchase Common Stock issued pursuant to an Approved Stock Plan that are covered by clause (i) above)

21

issued prior to the date hereof, provided that the conversion price of any such Convertible Securities (other than standard options to purchase Common Stock issued pursuant to an Approved Stock Plan that are covered by clause (i) above) is not lowered, none of such Convertible Securities (other than standard options to purchase Common Stock issued pursuant to an Approved Stock Plan that are covered by clause (i) above) are amended to increase the number of shares issuable thereunder and none of the terms or conditions of any such Convertible Securities (other than standard options to purchase Common Stock issued pursuant to an Approved Stock Plan that are covered by clause (i) above) are otherwise materially changed in any manner that adversely affects any of the Buyers; (iii) the shares of Common Stock issuable upon exercise of the SPA Warrants as in effect as of the Closing Date, (iv) the shares of Common Stock or Options issued in connection with strategic alliances, strategic partnerships, and merger and acquisition transactions, provided, that (A) the primary purpose of such issuance is not to raise capital as determined in good faith by the Board of Directors of the Company, (B) the purchaser or acquirer of the securities in such issuance solely consists of either (x) the actual participants in such strategic alliance or strategic partnership, (y) the actual owners of such assets or securities acquired in such merger and acquisition transactions, or (z) the shareholders, partners or members of the foregoing Persons, and (C) the number or amount of securities issued to such Person by the Company shall not be disproportionate (as determined in good faith by the Board of Directors of the Company) to either (x) the fair market value of such Person’s actual contribution to such strategic alliance or strategic partnership or (y) the proportional ownership of such assets or securities to be acquired by the Company, as applicable; (v) the shares of Common Stock or Options issued to financial institutions or lessors in connection with commercial credit arrangements, equipment financings or similar transactions (excluding any shares of Common Stock issuable upon conversion or exercise of any Convertible Securities), and (vi) shares of Common Stock or Options issued to vendors to settle bona fide trade liabilities.

(n) “ Expiration Date ” means the date that is the fifth (5 ^th ) anniversary of the Issuance Date or, if such date falls on a day other than a Business Day or on which trading does not take place on the Principal Market (a “ Holiday ”), the next date that is not a Holiday.

(o) “ Fundamental Transaction ” means (i) a transaction or series of related transactions pursuant to which the Company, directly or indirectly (1) consolidates or merges with or into (whether or not the Company is the surviving corporation) any other Person, or (2) sells, leases, licenses, assigns, transfers, conveys or otherwise disposes of all or substantially all of the Company’s properties or assets to any other Person, determined on either a quantitative or qualitative basis, or (3) allows any other Person, other than Gaiam, Inc. or Riverside Renewable Energy Investment LLC, to make a purchase, tender or exchange offer that is accepted by the holders of more than 50% of the outstanding shares of Voting Stock of the Company (not including any shares of Voting Stock of the Company held by the Person or Persons making or party to, or associated or affiliated with the Persons making or party to, such purchase, tender or exchange offer), or (4) consummates a stock or share purchase agreement or other business combination (including, without limitation, a reorganization, recapitalization, spin-off or scheme of arrangement) with any other Person whereby such other Person acquires more than 50% of the outstanding shares of Voting Stock of the Company (not including any shares of Voting Stock of the Company held by the other Person or other Persons making or party to, or associated or affiliated with the other Persons making or party to, such stock or share purchase agreement or

22

other business combination), or (ii) any “person” or “group” (as these terms are used for purposes of Sections 13(d) and 14(d) of the Exchange Act and the rules and regulations promulgated thereunder) , other than Gaiam, Inc. or Riverside Renewable Energy Investment LLC, is or shall become the “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of 50% of the aggregate ordinary voting power represented by issued and outstanding Voting Stock of the Company.

(p) “ Going Private Black Scholes Value ” means the value of the unexercised portion of this Warrant remaining on the Going Private Redemption Notice Date, which value is calculated using the Black Scholes Option Pricing Model obtained from the “OV” function on Bloomberg utilizing (i) an underlying price per share equal to the greater of (1) the highest Closing Sale Price of the Common Stock during the period beginning on the Trading Day immediately preceding the announcement of the applicable Going Private Transaction (or the consummation of the applicable Going Private Transaction, if earlier) and ending on the Going Private Redemption Notice Date and (2) the sum of the price per share being offered in cash in the applicable Going Private Transaction (if any) plus the value of the non-cash consideration being offered in the applicable Going Private Transaction (if any), (ii) a strike price equal to the Exercise Price in effect on the Going Private Redemption Notice Date, (iii) a risk-free interest rate corresponding to the U.S. Treasury rate for a period equal to the greater of (1) the remaining term of this Warrant as of the Going Private Redemption Notice Date and (2) the remaining term of this Warrant as of the Going Private Redemption Notice Date, (iv) a zero cost of borrow and (v) an expected volatility equal to the lesser of 100% and the 100 day volatility obtained from the HVT function on Bloomberg (determined utilizing a 365 day annualization factor) as of the Trading Day immediately prior to the date of the consummation of the applicable Going Private Transaction.

(q) “ Options ” means any rights, warrants or options to subscribe for or purchase shares of Common Stock or Convertible Securities.

(r) “ Parent Entity ” of a Person means an entity that, directly or indirectly, controls the applicable Person and whose common stock or equivalent equity security is quoted or listed on an Eligible Market, or, if there is more than one such Person or Parent Entity, the Person or Parent Entity with the largest public market capitalization as of the date of consummation of the Fundamental Transaction.

(s) “ Person ” means an individual, a limited liability company, a partnership, a joint venture, a corporation, a trust, an unincorporated organization, any other entity or a government or any department or agency thereof.

(t) “ Principal Market ” means The Nasdaq Capital Market.

(u) “ Registration Rights Agreement ” means that certain registration rights agreement, dated as of the Closing Date, by and among the Company and the initial Holder relating to, among other things, the registration of the resale of the shares of Common Stock issuable upon exercise of the SPA Warrants, as it may be amended from time to time.

23

(v) “ Successor Entity ” means the Person (or, if so elected by the Holder, the Parent Entity) formed by, resulting from or surviving any Fundamental Transaction or the Person (or, if so elected by the Holder, the Parent Entity) with which such Fundamental Transaction shall have been entered into.

(w) “ Trading Day ” means any day on which the Common Stock is traded on the Principal Market, or, if the Principal Market is not the principal trading market for the Common Stock, then on the principal securities exchange or securities market on which the Common Stock is then traded, provided that “Trading Day” shall not include any day on which the Common Stock is scheduled to trade on such exchange or market for less than 4.5 hours or any day that the Common Stock is suspended from trading during the final hour of trading on such exchange or market (or if such exchange or market does not designate in advance the closing time of trading on such exchange or market, then during the hour ending at 4:00:00 p.m., New York time) unless such day is otherwise designated as a Trading Day in writing by the Holder.

(x) “ Voting Stock ” of a Person means capital stock of such Person of the class or classes pursuant to which the holders thereof have the general voting power to elect, or the general power to appoint, at least a majority of the board of directors, managers or trustees of such Person (irrespective of whether or not at the time capital stock of any other class or classes shall have or might have voting power by reason of the happening of any contingency).

(y) “ VWAP ” means, for any security as of any date, the dollar volume-weighted average price for such security on the Principal Market (or, if the Principal Market is not the principal trading market for such security, then on the principal securities exchange or securities market on which such security is then traded) during the period beginning at 9:30:01 a.m., New York time, and ending at 4:00:00 p.m., New York time, as reported by Bloomberg through its “Volume at Price” function or, if the foregoing does not apply, the dollar volume-weighted average price of such security in the over-the-counter market on the electronic bulletin board for such security during the period beginning at 9:30:01 a.m., New York time, and ending at 4:00:00 p.m., New York time, as reported by Bloomberg, or, if no dollar volume-weighted average price is reported for such security by Bloomberg for such hours, the average of the highest closing bid price and the lowest closing ask price of any of the market makers for such security as reported in the “pink sheets” by OTC Markets Group Inc. (formerly Pink Sheets LLC). If VWAP cannot be calculated for such security on such date on any of the foregoing bases, the VWAP of such security on such date shall be the fair market value as mutually determined by the Company and the Holder. If the Company and the Holder are unable to agree upon the fair market value of such security, then such dispute shall be resolved in accordance with the procedures in Section 12. All such determinations shall be appropriately adjusted for any stock dividend, stock split, stock combination or other similar transaction during such period.

[ signature page follows ]

24

IN WITNESS WHEREOF, the Company has caused this Warrant to Purchase Common Stock to be duly executed as of the Issuance Date set out above.

EXHIBIT A

EXERCISE NOTICE

TO BE EXECUTED BY THE REGISTERED HOLDER TO EXERCISE THIS

WARRANT TO PURCHASE COMMON STOCK

REAL GOODS SOLAR, INC.

The undersigned holder hereby exercises the right to purchase                                          of the shares of Common Stock (“ Warrant Shares ”) of Real Goods Solar, Inc., a Colorado corporation (the “ Company ”), evidenced by Warrant to Purchase Common Stock No.                      (the “ Warrant ”). Capitalized terms used herein and not otherwise defined shall have the respective meanings set forth in the Warrant.

1. Form of Exercise Price . The Holder intends that payment of the Exercise Price shall be made as:

In the event that the Holder has elected a Cashless Exercise with respect to some or all of the Warrant Shares to be issued pursuant hereto, the Holder hereby represents and warrants that (i) this Exercise Notice was executed by the Holder at                      [a.m.][p.m.] on the date set forth below and (ii) if applicable, the Bid Price as of such time of execution of this Exercise Notice was $        .

2. Payment of Exercise Price . In the event that the Holder has elected a Cash Exercise with respect to some or all of the Warrant Shares to be issued pursuant hereto, the Holder shall pay the Aggregate Exercise Price in the sum of $                     to the Company in accordance with the terms of the Warrant.

3. Delivery of Warrant Shares . The Company shall deliver to Holder, or its designee or agent as specified below,                      Warrant Shares in accordance with the terms of the Warrant. Delivery shall be made to Holder, or for its benefit, to the following address: