EXHIBIT 10.9  NEITHER THIS WARRANT NOR THE COMMON STOCK ISSUABLE UPON EXERCISE HEREOF
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, ACCCORDINGLY, 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 COMPLIANCE WITH APPLICABLE STATE
SECURITIES LAWS OR BLUE SKY LAWS.  BEACON POWER CORPORATION  WARRANT  Warrant No. L-1
  
  Dated:
  July 23, 2007  Beacon Power Corporation, a Delaware corporation (the Company), hereby certifies that, for
value received, GFI Tyngsboro, LLC, a limited liability company organized under
the laws of the Commonwealth of Massachusetts, or its registered assigns in
accordance with Section 13 (the Holder), is entitled to purchase from the Company up to a total
of five-hundred thousand (500,000) shares of common stock, $0.01 par value per
share (the Common Stock), of
the Company (each such share, a Warrant
Share and all such shares, the Warrant
Shares) at an exercise price equal to $1.77 per share (as adjusted from
time to time as provided in Section 8, the Exercise Price), at any time and from time to time on and after
the date hereof and through and including the seventh (7th) anniversary of the date hereof (the Expiration Date), subject to the
terms and conditions set forth herein.  This
Warrant and 150,000 shares of Common Stock (the Lease Shares) are being
issued on the date hereof in connection with the entering into of that certain
Lease dated the date hereof (the Lease) between the Company and the Holder
with respect to the premises located at 65 Middlesex Road, Tyngsborough,
Massachusetts.  1.Registration of Warrant. The Company shall register this Warrant, upon
records to be maintained by the Company for that purpose (the Warrant Register), in the name of the
record Holder hereof from time to time. The Company may deem and treat the
registered Holder of this Warrant as the absolute owner hereof for the purpose
of any exercise hereof or any distribution to the Holder, and for all other
purposes, absent actual notice to the contrary.  2.Registration of Transfers. The Company shall register the transfer
of any portion of this Warrant in accordance with Section 13 in the
Warrant Register, upon surrender of this Warrant, with the Form of
Assignment attached hereto duly completed and signed, to the Companys transfer
agent or to the Company at its address specified herein. Upon any such
registration or transfer, a new warrant to purchase Common Stock, in
substantially the form of this Warrant


(any such new warrant, a New Warrant), evidencing the portion
of this Warrant so transferred shall be issued to the transferee and a New
Warrant evidencing the remaining portion of this Warrant not so transferred, if
any, shall be issued to the transferring Holder. The acceptance of the New
Warrant by the transferee thereof shall be deemed the acceptance by such
transferee of all of the rights and obligations of a holder of a Warrant.  3.Exercise and Duration of Warrants.  (a)This Warrant shall be exercisable by the registered
Holder at any time and from time to time on or after the date hereof to and
including the Expiration Date provided
that the representations and warranties set forth in Section 14 are true,
and that the covenants set forth in Section 14 have been satisfied, at the
time of such exercise. At 6:30 P.M., Eastern time on the Expiration Date,
the portion of this Warrant not exercised prior thereto shall be and become
void and of no value.  (b)A Holder may exercise this Warrant by delivering to
the Company (i) an exercise notice, in the form attached hereto (the Exercise Notice), appropriately
completed and duly signed, and (ii) payment of the Exercise Price for the
number of Warrant Shares as to which this Warrant is being exercised, and the
date such items are delivered to the Company (as determined in accordance with
the notice provisions hereof) is an Exercise
Date. The Holder shall not be required to deliver the original Warrant
in order to effect an exercise hereunder. Upon the execution and delivery of
the Exercise Notice, the Company shall issue a New Warrant to the Holder
evidencing the right to purchase the remaining number of Warrant Shares.  (c)The Company shall have a sufficient number of
authorized but unissued and otherwise unreserved shares of Common Stock
available to issue the Warrant Shares upon exercise of the Warrant.  4.Delivery of Warrant Shares.  (a)Upon exercise of this Warrant, the Company shall
promptly issue or cause to be issued and cause to be delivered to the Holder a
certificate for the Warrant Shares issuable upon such exercise. Such
certificate shall bear a restrictive legend substantially the same as the
legend first set forth above.  The Holder
shall be deemed to have become holder of record of such Warrant Shares as of
the Exercise Date.  (b)This Warrant is exercisable, either in its entirety
or, from time to time from the Date hereof, for a portion of the number of
Warrant Shares. Upon surrender of this Warrant following one or more partial
exercises, the Company shall issue or cause to be issued, at its expense, a New
Warrant evidencing the right to purchase the remaining number of Warrant
Shares.  5.Charges, Taxes and Expenses. Issuance and delivery of certificates
for Warrant Shares shall be made without charge to the Holder for any issue or
transfer tax, withholding tax, transfer agent fee or other incidental tax or
expense in respect of the issuance of such certificates, all of which taxes and
expenses shall be paid by the Company. The Holder shall be responsible for all
other tax liability that may arise as a result of holding this Warrant or


receiving Warrant Shares
upon exercise hereof or transferring either this Warrant or the Warrant Shares.  6.Replacement of Warrant. If this Warrant is mutilated, lost, stolen or
destroyed, the Company shall issue or cause to be issued in exchange and
substitution for and upon cancellation hereof, or in lieu of and substitution
for this Warrant, a New Warrant, but only upon receipt of evidence reasonably
satisfactory to the Company of such loss, theft or destruction and customary
and reasonable bond or indemnity, if requested. Applicants for a New Warrant
under such circumstances shall also comply with such other reasonable
regulations and procedures and pay such other reasonable third-party costs as
the Company may prescribe.  7.Reservation of Warrant Shares. The Company shall at all times reserve
and keep available out of the aggregate of its authorized but unissued and
otherwise unreserved Common Stock, solely for the purpose of enabling it to
issue Warrant Shares upon exercise of this Warrant as herein provided, the
number of Warrant Shares which are then issuable and deliverable upon the
exercise of this entire Warrant, free from preemptive rights or any other
contingent purchase rights of persons other than the Holder (taking into
account the adjustments and restrictions of Section 8).  The Company covenants that all Warrant Shares
so issuable and deliverable shall, upon issuance and the payment of the
applicable Exercise Price in accordance with the terms hereof, be duly and
validly authorized, issued and fully paid and nonassessable. The Company will
take all such actions as may be necessary to assure that such shares of Common
Stock may be issued as provided herein without violation of any applicable law
or regulation, or of any requirements of any securities exchange or automated
quotation system upon which the Common Stock may be listed.  8.Certain Adjustments. 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.  (a)Stock Dividends and Splits. If the Company, at any time while this
Warrant is outstanding, (i) pays a stock dividend on its Common Stock or
otherwise makes a distribution on any class of capital stock that is payable in
shares of Common Stock, (ii) subdivides outstanding shares of Common Stock
into a larger number of shares, or (iii) combines 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. See also Section 8(c).  Any adjustment made pursuant to clause (i) of
this paragraph shall become effective immediately after the record date for the
determination of stockholders 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.  (b)Fundamental Transactions. If, at any time while this Warrant is
outstanding, (i) the Company effects any merger or consolidation of the
Company with or into another person and the Company is not the surviving party,
(ii) the Company effects any sale of all or substantially all of its
assets in one or a series of related transactions, (iii) any tender offer
or exchange offer (whether by the Company or another person) is completed
pursuant to which


holders of Common Stock
are permitted to tender or exchange their shares for other securities, cash or
property, or (iv) the Company effects any reclassification of the Common
Stock or any compulsory share exchange pursuant to which the Common Stock is
effectively converted into or exchanged for other securities, cash or property
(other than as a result of a subdivision or combination of shares of Common
Stock covered by Section 8(a) above) (in any such case, a Fundamental Transaction), then the
Holder shall have the right thereafter to receive, upon exercise of this
Warrant, the same amount and kind of securities, cash or property as it would
have been entitled to receive upon the occurrence of such Fundamental
Transaction if it had been, immediately prior to such Fundamental Transaction, the
holder of the number of Warrant Shares then issuable upon exercise in full of
this Warrant (the Alternate
Consideration). The aggregate Exercise Price for this Warrant will not
be affected by any such Fundamental Transaction, but the Company shall apportion
such aggregate Exercise Price among the Alternate Consideration in a reasonable
manner reflecting the relative value of any different components of the
Alternate Consideration. If holders of Common Stock are given any choice as to
the securities, cash or property to be received in a Fundamental Transaction,
then the Holder shall be given the same choice as to the Alternate
Consideration it receives upon any exercise of this Warrant following such
Fundamental Transaction. If, in the case of any Fundamental Transaction, the
Alternate Consideration includes shares of stock, other securities, other
property or assets of a person other than the Company or any such successor or
purchasing person, as the case may be, in such Fundamental Transaction, then such
written agreement shall also be executed by such other person and shall contain
such additional provisions to protect the interests of the Holder as the Board
of Directors of the Company shall reasonably consider necessary by reason of
the foregoing. At the Holders request, any successor to the Company or
surviving entity in such Fundamental Transaction shall issue to the Holder a
new warrant consistent with the foregoing provisions and evidencing the Holders
right to purchase the Alternate Consideration for the aggregate Exercise Price
upon exercise thereof. The terms of any agreement pursuant to which a
Fundamental Transaction is completed shall include terms requiring any such
successor or surviving entity to comply with the provisions of this Section 8(b) and
insuring that the Warrant (or any such replacement security) will be similarly
adjusted upon any subsequent transaction analogous to a Fundamental
Transaction.  (c)Number of Warrant Shares. Simultaneously with any adjustments to
the Exercise Price pursuant to paragraph (a) of this Section, 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 increased or decreased
number of Warrant Shares shall be the same as the aggregate Exercise Price in
effect immediately prior to such adjustment.  (d)Calculations. All calculations under this Section 8
shall be made to the nearest cent or the nearest 1/100thof 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.  (e)Notice of Adjustments. Upon the occurrence of each adjustment pursuant to
this Section 8, the Company at its expense will promptly compute
such adjustment in accordance with the terms of this Warrant and prepare a
certificate setting forth such adjustment, including


a statement of the
adjusted Exercise Price and adjusted number or type of Warrant Shares or other
securities issuable upon exercise of this Warrant (as applicable), describing
the transactions giving rise to such adjustments and showing in detail the
facts upon which such adjustment is based. Upon written request, the Company
will promptly deliver a copy of each such certificate to the Holder and to the
Companys transfer agent.  (f)Notice of Corporate Events. If the Company (i) declares a
dividend or any other distribution of cash, securities or other property in
respect of its Common Stock, including without limitation any granting of
rights or warrants to subscribe for or purchase any capital stock of the
Company or any Subsidiary, (ii) authorizes or approves, enters into any
agreement contemplating or solicits stockholder approval for any Fundamental
Transaction or (iii) authorizes the voluntary dissolution, liquidation or
winding up of the affairs of the Company, then the Company shall deliver to the
Holder a notice describing the material terms and conditions of such
transaction, at least 20 calendar days prior to the applicable record or
effective date on which a person would need to hold Common Stock in order to participate
in or vote with respect to such transaction, and the Company will take all
steps reasonably necessary in order to insure that the Holder is given the
practical opportunity to exercise this Warrant prior to such time so as to
participate in or vote with respect to such transaction; provided, however,
that the failure to deliver such notice or any defect therein shall not affect
the validity of the corporate action required to be described in such notice.  9.Payment of Exercise Price. The Holder shall pay the Exercise Price
in immediately available funds  10.Fractional Shares. The Company shall not be required to issue or cause
to be issued fractional Warrant Shares on the exercise of this Warrant. If any
fraction of a Warrant Share would, except for the provisions of this Section,
be issuable upon exercise of this Warrant, the number of Warrant Shares to be
issued will be rounded up to the nearest whole share.  11.Notices. Any and all notices or other communications or
deliveries hereunder (including without limitation any Exercise Notice) shall
be in writing and shall be deemed given and effective on the earliest of (i) the
date of transmission, if such notice or communication is delivered via
facsimile at the facsimile number specified in this Section prior to 6:30 p.m.
(New York City time) on a Trading Day, (ii) the next Trading Day after the
date of transmission, if such notice or communication is delivered via
facsimile at the facsimile number specified in this Section on a day that
is not a Trading Day or later than 6:30 p.m. (New York City time) on any
Trading Day, (iii) the Trading Day following the date of mailing, if sent
by nationally recognized overnight courier service, or (iv) upon actual
receipt by the party to whom such notice is required to be given. Trading Day
means (a) any day on which the Common Stock is listed and traded on the
Nasdaq Stock Market, or (b) if the Common Stock is not then listed and
traded on the Nasdaq Stock Market, then a day on which trading occurs on either
the New York Stock Exchange or the American Stock Exchange (together with the
Nasdaq Stock Market, each an Eligible Market) (or any successor thereto), or (c) if
trading ceases to occur on an Eligible Market (or any successor thereto), any
day other than Saturday, Sunday or other day on which commercial banks in New
York City are authorized or required by law to remain closed.


12.The address for such notices or communications shall
be as set forth below:  (a)if to the Company, at the office of the Company, 65
Middlesex Road, Tyngsboro, MA, Attention: 
James Spiezio, with copies to Edwards Angell Palmer & Dodge
LLP, 111 Huntington Avenue, Boston, Massachusetts 02199, Attention:  Albert Sokol, or  (b) if to the
Holder, c/o GFI Partners, 133 Pearl Street, Suite 400 Boston, MA 02110,
Attn: Steven E. Goodman with a copy to Henshon Parker Vyadro, P.C. 84 State
Street, Suite 760 Boston, MA  02109
Attn: F. Robert Parker, Jr.  13.Warrant Agent. The Company shall serve as warrant agent under this
Warrant. Upon 30 days notice to the Holder, the Company may appoint a new
warrant agent. Any corporation into which the Company or any new warrant agent
may be merged or any corporation resulting from any consolidation to which the
Company or any new warrant agent shall be a party or any corporation to which
the Company or any new warrant agent transfers substantially all of its
corporate trust or shareholders services business shall be a successor warrant
agent under this Warrant without any further act. Any such successor warrant
agent shall promptly cause notice of its succession as warrant agent to be
mailed (by first class mail, postage prepaid) to the Holder at the Holders
last address as shown on the Warrant Register.  14.Transferability.  This Warrant may not be
assigned by the Company except to a successor in the event of a Fundamental
Transaction.  NO INTEREST IN THIS WARRANT MAY BE SOLD, ASSIGNED OR OTHERWISE
TRANSFERRED BY THE HOLDER WITHOUT THE PRIOR WRITTEN CONSENT OF THE COMPANY, NOT
TO BE UNREASONABLY WITHHELD IN THE EVENT THAT HOLDER COMPLIES WITH THIS
CLAUSE.  NEITHER THIS WARRANT NOR THE
COMMON STOCK ISSUABLE UPON EXERCISE HEREOF 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, ACCCORDINGLY, MAY NOT BE SOLD,
TRANSFERRED, ASSIGNED OR OFFERED FOR SAME 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 COMPLIANCE WITH APPLICABLE STATE
SECURITIES LAWS OR BLUE SKY LAWS, TO BE DOCUMENTED IN PART BY THE HOLDER
PROVIDING THE COMPANY WITH AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE
COMPANY STATING THAT SUCH SALE, TRANSFER OR ASSIGNMENT IS EXEMPT FROM THE
REGISTRATION REQUIREMENTS OF THE SECURITIES ACT.


15.Holders Representations, Warranties and Covenants  (a)At the time the Holder was offered the Warrant Shares
and Lease Shares, it was, and on the date hereof, it is, and on the date of any
exercise hereof, the Holder will be, an accredited investor as defined in Rule 501(a) under
the Securities Act.  (b)Holder has such knowledge, sophistication and
experience in business and financial matters so as to be capable of evaluating
the merits and risks of the investment in this Warrant, the Lease Shares and
the Warrant Shares and has so evaluated the merits and risks of such investment
and shall evaluate such merits and risks before any exercise hereof.  Holder is able to bear the economic risk of
an investment in the Warrant, the Lease Shares and the Warrant Shares indefinitely
and is able to afford a complete loss of such investment.  (c)The Holder is purchasing this Warrant and the Lease
Shares, and upon any exercise hereof will purchase the Warrant Shares, for the
Holders account and not for the account of any other person, and without a
view to the distribution thereof.  The
Holder acknowledges that this Warrant and the Lease Shares are, and the Warrant
Shares will be, restricted securities (as that term is defined in Rule 144
under the Securities Act) and may not be resold except pursuant to an effective
registration statement or pursuant to an exemption from the registration
requirements of the Securities Act and in accordance with all applicable state
laws.  16.Registration Rights for the Lease Shares. 
The Company shall, at its sole expense, prepare and file a registration
statement (the Registration Statement) with the Securities and Exchange
Commission within 30 days after the date of this Warrant (subject to reasonable
extension at the Companys discretion, but in any event for no more than 30
additional days) to register the Lease Shares within a commercially reasonable
time.  The Company shall endeavor in good
faith and diligently to cause the Registration Statement to be declared
effective by the Securities and Exchange Commission, and shall endeavor to keep
it continuously effective under the Securities Act until the earlier of (i) the
first anniversary of the date hereof or (ii) the date all of the Lease
Shares have been sold publicly.  17.Miscellaneous  (a)The Company will not, by amendment of its governing
documents or through any reorganization, transfer of assets, consolidation,
merger, 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, but will at all times in good faith assist in the carrying out of
all such terms and in the taking of all such action as may be necessary or
appropriate in order to protect the rights of the Holder against impairment.
Without limiting the generality of the foregoing, the Company (i) will not
increase the par value of any Warrant Shares above the amount payable therefor
on such exercise, (ii) will take all such action as may be reasonably
necessary or appropriate in order that the Company may validly and legally
issue fully paid and nonassessable Warrant Shares on the exercise of this
Warrant, and (iii) will not close its shareholder books or records in any
manner which interferes with the timely exercise of this Warrant.  (b)GOVERNING LAW; VENUE; WAIVER OF JURY TRIAL. ALL
QUESTIONS CONCERNING THE CONSTRUCTION, VALIDITY, ENFORCEMENT AND INTERPRETATION
OF THIS WARRANT SHALL BE GOVERNED BY AND CONSTRUED AND ENFORCED IN ACCORDANCE
WITH THE INTERNAL LAWS OF


THE COMMONWEALTH OF
MASSACHUSETTS WITHOUT REGARD TO THE PRINCIPLES OF CONFLICTS OF LAW THEREOF.
EACH PARTY AGREES THAT ALL LEGAL PROCEEDINGS CONCERNING THE INTERPRETATIONS,
ENFORCEMENT AND DEFENSE OF THE TRANSACTIONS CONTEMPLATED BY ANY OF THE
TRANSACTION DOCUMENTS (WHETHER BROUGHT AGAINST A PARTY HERETO OR ITS RESPECTIVE
AFFILIATES, DIRECTORS, OFFICERS, SHAREHOLDERS, EMPLOYEES OR AGENTS) SHALL BE
COMMENCED EXCLUSIVELY IN THE STATE AND FEDERAL COURTS SITTING IN THE CITY OF
BOSTON, MASSACHUSETTS. EACH PARTY HERETO HEREBY IRREVOCABLY SUBMITS TO THE
EXCLUSIVE JURISDICTION OF THE STATE AND FEDERAL COURTS SITTING IN THE CITY OF
BOSTON, MASSACHUSETTS FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN
CONNECTION HEREWITH OR WITH ANY TRANSACTION CONTEMPLATED HEREBY OR DISCUSSED
HEREIN (INCLUDING WITH RESPECT TO THE ENFORCEMENT OF ANY OF THIS WARRANT), 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 IMPROPER. EACH PARTY
HERETO HEREBY IRREVOCABLY WAIVES PERSONAL SERVICE OF PROCESS AND CONSENTS TO
PROCESS BEING SERVED IN ANY SUCH SUIT, ACTION OR PROCEEDING BY MAILING A COPY
THEREOF VIA REGISTERED OR CERTIFIED MAIL OR OVERNIGHT DELIVERY (WITH EVIDENCE
OF DELIVERY) TO SUCH PARTY AT THE ADDRESS IN EFFECT FOR NOTICES TO IT UNDER
THIS WARRANT AND AGREES THAT SUCH SERVICE SHALL CONSTITUTE GOOD AND SUFFICIENT
SERVICE OF PROCESS AND NOTICE THEREOF. NOTHING CONTAINED HEREIN SHALL BE DEEMED
TO LIMIT IN ANY WAY ANY RIGHT TO SERVE PROCESS IN ANY MANNER PERMITTED BY LAW.
EACH PARTY HERETO HEREBY IRREVOCABLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY
APPLICABLE LAW, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING
ARISING OUT OF OR RELATING TO THIS WARRANT OR ANY OF THE TRANSACTION DOCUMENTS
OR THE TRANSACTIONS CONTEMPLATED HEREBY OR THEREBY. IF EITHER PARTY SHALL
COMMENCE AN ACTION OR PROCEEDING TO ENFORCE ANY PROVISIONS OF THIS WARRANT OR
ANY TRANSACTION DOCUMENT, THEN THE PREVAILING PARTY IN SUCH ACTION OR
PROCEEDING SHALL BE REIMBURSED BY THE OTHER PARTY FOR ITS REASONABLE ATTORNEYS
FEES AND OTHER REASONABLE COSTS AND EXPENSES INCURRED WITH THE INVESTIGATION,
PREPARATION AND PROSECUTION OF SUCH ACTION OR PROCEEDING.  (c)The headings herein are for convenience only, do not
constitute a part of this Warrant and shall not be deemed to limit or affect
any of the provisions hereof.  (d)In case any one or more of the provisions of this
Warrant shall be invalid or unenforceable in any respect, the validity and
enforceability of the remaining terms and provisions of this Warrant shall not
in any way be affected or impaired thereby and the parties will attempt in good
faith to agree upon a valid and enforceable provision which shall be a
commercially reasonable substitute therefor, and upon so agreeing, shall
incorporate such substitute provision in this Warrant.


(e)The holder of this Warrant shall have no rights as a
stockholder of the Company by virtue of holding this Warrant.  (f)This Warrant shall be binding on and inure to the
benefit of the parties hereto and their respective successors and assigns
pursuant to transfers in accordance with Section 13. Subject to the
preceding sentence, nothing in this Warrant shall be construed to give to any
person other than the Company and the Holder any legal or equitable right,
remedy or cause of action under this Warrant.  (g)This Warrant may be amended only in writing signed by
the Company and the Holder and their successors and assigns pursuant to
transfers in accordance with Section 13.


IN WITNESS WHEREOF, the Company has caused this
Warrant to be duly executed by its authorized officer as of the date first
indicated above.   BEACON POWER CORPORATIONBy:
  /s/ James M. SpiezioName:  James M. SpiezioTitle:  CFOGFI TYNGSBORO, LLCBy:
  /s/ Steven E. GoodmanName:  Steven E. GoodmanTitle:  Manager


FORM OF EXERCISE NOTICE  (To be executed by the Holder to exercise the right to
purchase shares of Common Stock under the foregoing Warrant)  To:Beacon Power Corporation  The undersigned is the Holder of Warrant No.               
(the Warrant) issued by Beacon
Power Corporation, a Delaware corporation (the Company). Capitalized terms used herein and not otherwise defined
have the respective meanings set forth in the Warrant.  1.The Warrant is currently
exercisable to purchase a total of
                            
Warrant Shares.  2.The undersigned Holder
hereby exercises its right to purchase
                              
Warrant Shares pursuant to the Warrant.  3.The holder shall pay the sum
of
$                        
to the Company in accordance with the terms of the Warrant.  4.Pursuant to this exercise,
the Company shall deliver to the holder
                              
Warrant Shares in accordance with the terms of the Warrant.  5.Following this exercise, the
Warrant shall be exercisable to purchase a total of
                            
Warrant Shares.  6.The representations and
warranties set forth in Section 14 of the Warrant are true, and the
covenants set forth in Section 14 of the Warrant have been satisfied, on
the date hereof.  Dated:   ,
  Name of Holder:(Print)By:Name:Title:(Signature must conform in all respects to name of holder as
  specified on the face of the Warrant)


FORM OF
ASSIGNMENT  [To be completed and signed only upon transfer of
Warrant]  FOR VALUE RECEIVED, the undersigned hereby sells,
assigns and transfers unto                                                                 
the right represented by the within Warrant to purchase
                        
shares of Common Stock of Beacon Power Corporation to which the within Warrant
relates and appoints
                                
attorney to transfer said right on the books of Beacon Power Corporation with
full power of substitution in the premises.  Dated:   ,(Signature
  must conform in all respects to name of holder as specified on the face of
  the Warrant)Address of TransfereeIn the presence of: