UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 8-K
                                 CURRENT REPORT
                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934

        Date of report (Date of earliest event reported): April 22, 2005

                            BEACON POWER CORPORATION
               (Exact Name of Registrant as Specified in Charter)

        DELAWARE                       001-16171                 04-3372365
(State or Other Jurisdiction of  (Commission File Number)      (IRS Employer
        Incorporation)                                      Identification No.)

         234 BALLARDVALE STREET
             WILMINGTON, MA                                   01887
 (Address of Principal Executive Offices)                   (Zip Code)

        Registrant's telephone number, including area code: 978-694-9121


     Check the  appropriate  box below if the Form 8-K  filing  is  intended  to
simultaneously  satisfy the filing obligation of the registrant under any of the
following provisions:

     [X] Written  communications  pursuant to Rule 425 under the  Securities Act
(17 CFR 230.425)

     [X] Soliciting  material pursuant to Rule 14a-12 under the Exchange Act (17
CFR 240.14a-12)

     [ ]  Pre-commencement  communications  pursuant to Rule 14d-2(b)  under the
Exchange Act (17 CFR 240.14d-2(b))

     [ ]  Pre-commencement  communications  pursuant to Rule 13e-4(c)  under the
Exchange Act (17 CFR 240.13e-4(c))



Section 1 - Registrant's Business and Operations

Item 1.01 Entry into a Material Definitive Agreement.

Arrangement Agreement

     On  April  22,  2005,  Beacon  Power  Corporation   ("Beacon")  and  Beacon
Acquisition Co., a wholly-owned subsidiary of Beacon ("Acquisitionco"),  entered
into an Arrangement  Agreement  with NxtPhase T&D  Corporation  ("NxtPhase")  to
purchase all of the outstanding  capital  securities of NxtPhase.  NxtPhase is a
privately-held  Canadian  corporation  that  supplies  digital  and fiber  optic
products for electric  power and grid  monitoring and control.  The  Arrangement
Agreement contemplates a plan of arrangement among the parties under Section 192
of the Canada Business Corporations Act.

     Beacon  obtained the option to acquire  NxtPhase from Perseus 2000,  L.L.C.
("Perseus  2000"),  the largest  shareholder  of NxtPhase  and an  affiliate  of
Perseus Capital, L.L.C. ("Perseus Capital"),  the largest stockholder of Beacon.
Perseus-affiliated  entities  have two  directors  on the boards of directors of
each of Beacon and NxtPhase. Perseus 2000 obtained the option in connection with
the NxtPhase Class A preferred  share  financing in November 2004, and has since
assigned that option to Beacon.

     Upon  consummation  of  the  Arrangement  and  subject  to  the  terms  and
conditions of the Arrangement Agreement, (i) NxtPhase will become a wholly-owned
subsidiary of Beacon and (ii) each NxtPhase common share and each NxtPhase Class
A preferred  share will be converted  into the right to receive shares of Beacon
common  stock  based  on a  formula  set  forth  in the  Arrangement  Agreement.
(Although  those  NxtPhase  shares,  if  any,  issued  in  connection  with  the
Investment  Agreement  as further  described  below,  are subject to a different
formula as set forth in the Arrangement  Agreement.) Beacon anticipates  issuing
approximately   15.7  million  shares  of  its  common  stock  to  the  NxtPhase
shareholders,  which  number  of  shares  may be  adjusted  as set  forth in the
Arrangement Agreement. In addition,  immediately after the effective time of the
Arrangement,  Beacon will issue to the employees of NxtPhase  Beacon  restricted
stock units covering 2.7 million shares of Beacon common stock.

     Beacon,  Acquisitionco  and NxtPhase have made  customary  representations,
warranties and covenants in the Arrangement  Agreement,  including among others,
covenants (i) to cause  stockholder  meetings to be held to consider approval of
the  Arrangement  and the other  transactions  contemplated  by the  Arrangement
Agreement,  (ii) for  NxtPhase to conduct its  business in the  ordinary  course
between the execution of the Arrangement  Agreement and the  consummation of the
Arrangement and (iii) for each party to provide access to its books and records.

     Consummation of the Arrangement is subject to customary closing conditions,
including (i) approval of the holders of Beacon  common stock,  (ii) approval of
the holders of NxtPhase common shares and preferred shares, (iii) absence of any
law or order prohibiting the closing and (iv) subject to certain exceptions, the
accuracy of representations and warranties.  The Arrangement  Agreement contains
certain termination rights for both Beacon and NxtPhase.

     In connection  with the  execution of the  Arrangement  Agreement,  certain
shareholders  of NxtPhase  entered  into  agreements  with  Beacon and  NxtPhase
containing representations,  warranties and covenants,  including, among others,
representations  as to ownership of NxtPhase  shares and the accuracy of certain
statements in the Arrangement Agreement.  In addition, the NxtPhase shareholders
agreed to indemnify Beacon, subject to certain limitations, upon certain events,
including,  among others, a misrepresentation,  breach of warranty or failure to
perform any covenant.

     The foregoing  descriptions of the  Arrangement  Agreement and the NxtPhase
shareholder  agreements do not purport to be complete and are qualified in their
entirety by reference to the  Arrangement  Agreement,  which is filed as Exhibit
2.1 hereto, and the Form of NxtPhase  Shareholder  Agreement,  which is filed as
Exhibit 10.1, and are incorporated into this report by reference.

Investment Agreement

     Beacon,  Perseus Capital and Perseus 2000 Expansion Fund, L.L.C.  ("Perseus
2000 Expansion") entered into an Investment Agreement dated as of April 22, 2005
whereby  (i)  Beacon  will issue and sell to Perseus  2000  Expansion  1,666,667
shares of Beacon common stock (the "Initial Issuance"),  (ii) Beacon will extend
the term of a preexisting warrant issued to Perseus Capital by two years so that
it  expires  on  May  23,  2007  rather  than  on May  23,  2005  (the  "Warrant
Extension"),  (iii) Perseus 2000 Expansion agrees,  until September 30, 2005, to
purchase on demand  Beacon  common  stock  having a maximum  aggregate  value of
$1,500,000 at $0.84 per share (the "Additional Investment Call Option") and (iv)
Perseus  2000  Expansion  will have the  option to assign to Beacon its right to
make a maximum  investment of $1,500,000 in NxtPhase (the  "NxtPhase  Investment
Option"),  which will be granted in connection  with a Preferred  Stock Purchase
Agreement  among  NxtPhase  and  certain  of  its  existing  Class  A  preferred
shareholders.  In the case of the  NxtPhase  Investment  Option,  if  exercised,
Perseus 2000 Expansion would purchase shares of Beacon common stock at $0.84 per
share and Beacon would use the proceeds  thereof to purchase  shares of NxtPhase
Class A preferred shares at the price per share and upon the other terms thereof
as stated in the assigned Preferred Stock Purchase Agreement. Any amounts of the
NxtPhase  Investment  Option that are not actually  invested in NxtPhase Class A
preferred  shares prior to the  consummation  of the  transactions  contemplated
under  the  Arrangement  Agreement  will  be  added  to  and  become  additional
availability under the Additional Investment Call Option.

     In  addition,  in  connection  with the Initial  Issuance  and the original
amount of the Additional  Investment  Call Option,  Beacon will issue to Perseus
2000  Expansion  a warrant  (the  "Warrant")  for the number of shares of Beacon
common  stock equal to the  product of (i)  806,400  divided by (ii) a per share
purchase  price of $1.0080,  which price may be adjusted  from time to time.  In
connection with the NxtPhase  Investment  Option,  if exercised,  or if any such
unused amounts are added to the Additional  Investment Call Option,  Beacon will
issue to Perseus 2000  Expansion an additional  warrant for the number of shares
of Beacon  common stock equal to the quotient  obtained by dividing (i) 27.9491%
of the  investment  amount and (ii) $1.0080.  The warrants will have an exercise
price of $1.0080 per share of Beacon common stock.

     The  closing of the  transactions  contemplated  by the  Initial  Issuance,
including  the  issuance of the  Warrant,  and the Warrant  Extension  will take
place,  subject to  certain  conditions,  on May 13,  2005 or such other date as
agreed by the  parties.  At this time,  Beacon  will  enter into a  Registration
Rights  Agreement  for the  registration  of the shares of Beacon  common  stock
issuable pursuant to the Initial Issuance, the Additional Investment Call Option
and the  Warrant.  The  Additional  Investment  Call Option may be  exercised by
Beacon requesting an additional closing to Perseus 2000 Expansion.

     The NxtPhase  Investment  Option,  if  exercised,  will  require  Beacon to
purchase NxtPhase Class A preferred shares using the funds received from Perseus
2000 Expansion.  If the Arrangement with NxtPhase is not consummated or does not
occur  within a certain  period,  Beacon  will  transfer  its  NxtPhase  Class A
preferred  shares to Perseus  2000  Expansion  and Perseus 2000  Expansion  will
transfer  its  Beacon  common  stock  issued  in  connection  with the  NxtPhase
Investment Option to Beacon.

     The foregoing  description of the Investment  Agreement does not purport to
be complete and is  qualified  in its  entirety by  reference to the  Investment
Agreement,  which is filed as Exhibit 10.2 hereto, and is incorporated into this
report by reference.

Item 8.01         Other Events

     On April 25, 2005,  Beacon issued a press release  announcing the execution
of the Arrangement Agreement.  The press release is attached as Exhibit 99.1 and
is incorporated herein by reference.

     Stockholders  are  urged  to  read  the  joint  proxy  statement/prospectus
regarding the proposed transaction,  when it becomes available,  because it will
contain important  information.  Stockholders will be able to obtain free copies
of the joint proxy  statement/prospectus,  as well as other  filings  containing
information  about Beacon and NxtPhase,  without  charge,  at the SEC's Internet
site  (http://www.sec.gov).  These  documents may also be obtained for free from
Beacon by  directing  a request to Beacon  Power  Corporation,  234  Ballardvale
Street, Wilmington,  Massachusetts 01887, Attention:  Secretary.  Beacon and its
directors and executive  officers and other members of management  and employees
may be deemed to be  participants  in the  solicitation  of  proxies  from their
respective  shareholders  in respect of the proposed  transactions.  Information
regarding  Beacon's  directors and  executive  officers is available in Beacon's
proxy  statement for its 2004 annual  meeting of  shareholders,  which was filed
with the SEC on November 10, 2004.

     Additional   information   regarding  the   interests  of  such   potential
participants  will be included in the joint proxy  statement/prospectus  and the
other relevant documents filed with the SEC when they become available.

Section 9 - Financial Statements and Exhibits

Item 9.01 Financial Statements and Exhibits.

(c) Exhibits

          2.1  Arrangement  Agreement  dated as of April 22,  2005 among  Beacon
               Power  Corporation,  Beacon  Acquisition  Co.  and  NxtPhase  T&D
               Corporation   (the  schedules  and  exhibits  have  been  omitted
               pursuant to Item 601(b)(2) of Regulation S-K).

          10.1 Form of NxtPhase Shareholder Agreement.

          10.2 Investment  Agreement  dated as of April 22,  2005  among  Beacon
               Power  Corporation,  Perseus  Capital,  L.L.C.  and Perseus  2000
               Expansion Fund, L.L.C.

          99.1 Press release of Beacon Power Corporation dated April 25, 2005.





                                    Signature

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.


                                       BEACON POWER CORPORATION



Date:  April 25, 2005                  By: /s/ F. William Capp
                                           ----------------------
                                       Name:  F. William Capp
                                       Title:  President and Chief Executive
                                               Officer





                                  Exhibit Index
                                  -------------

Exhibit No.      Description
- -----------      -----------

  2.1          Arrangement  Agreement  dated as of April 22,  2005 among  Beacon
               Power  Corporation,  Beacon  Acquisition  Co.  and  NxtPhase  T&D
               Corporation   (the  schedules  and  exhibits  have  been  omitted
               pursuant to Item 601(b)(2) of Regulation S-K).

  10.1         Form of NxtPhase Shareholder Agreement.

  10.2         Investment  Agreement  dated as of April 22,  2005  among  Beacon
               Power  Corporation,  Perseus  Capital,  L.L.C.  and Perseus  2000
               Expansion Fund, L.L.C.

  99.1         Press release of Beacon Power Corporation dated April 25, 2005.