NEWS FOR IMMEDIATE RELEASE
                                                          Contact: James Spiezio
                                                        Beacon Power Corporation
                                                                    978-694-9121
                                                         spiezio@beaconpower.com


                BEACON POWER ANNOUNCES FIRST-QUARTER 2004 RESULTS
                              AND FILES FORM 10-K/A

     Wilmington,  MA - May 14, 2004 - Beacon Power Corporation (Nasdaq: BCON), a
development  stage company that  designs,  develops,  configures  and offers for
sale,  sustainable  energy  storage and power  conversion  systems  that provide
highly  reliable,   high-quality,   environmentally  friendly,   uninterruptible
electric power,  today announced that it has filed its quarterly  report on Form
10Q its  financial  results  for the first  quarter  ended March 31, 2004 and an
amended  2003  Form  10-K  on Form  10-K/A  with  the  Securities  and  Exchange
Commission.

     For the first quarter of 2004, the Company  reported revenue of $57,408 and
a net loss of $2.1  million,  or ($0.05) per share,  compared with a net loss in
the first  quarter of 2003 of $2.2  million,  or ($0.05)  per share.  During the
first quarter of 2004,  the Company  incurred costs of $1.0 million in R&D, $1.1
million in SG&A and  recorded  depreciation  of  $46,587.  At March 31, 2004 the
Company had $7.1 million in cash and cash  equivalents.  The  Company's  working
capital was $7.1 million.

     The Company also filed a Form 10-K/A to reflect  accounting  adjustments to
its balance sheet.  The balance  sheets for the years ending  December 31, 2003,
2002 and 2001 were  adjusted.  The  adjustments  did not  affect  the net losses
reported on the Consolidated Statement of Operations and did not have a material
affect on the balance sheet as a whole.

     "We are very  pleased to report  revenue for the first time on sales of our
Smart Power M5 power conversion  systems.  We are optimistic about the continued
and  increasing  sales  prospects of this  product as we continue our  installer
certification  program along with expanded  sales and marketing  efforts,"  said
Bill Capp,  president and CEO. "We are also encouraged by the consistent  record
of trouble free installations and by repeat orders from distributors.

     "In addition to our photovoltaic  products,  we are excited by the positive
reaction we are receiving to the Smart Energy Matrix product opportunity. Beacon
Power recently became a member of the PJM Regional Transmission  Organization as
a step towards providing regulation  services.  Regulation services are critical
to the stable  operation of the North  American  electrical  grid, and reached a
record high market price in 2003. We believe that the Smart Energy Matrix,  with
its low  operating  costs and  uniquely  fast  response  can become an important
participant in this critical and growing market."



About Beacon Power Corporation

     Beacon Power Corporation  designs and develops  sustainable  energy storage
and power  conversion  solutions  that provide  reliable  electric power for the
renewable energy,  telecommunications,  distributed  generation and UPS markets.
Beacon's  latest  product is the Smart Power M5, a 5-kilowatt  power  conversion
system  for  grid-connect  solar  power  applications.  The Smart  Power M5 is a
UL-approved,   "all-in-one"  power  conversion  system  incorporating   multiple
high-performance components in one unit that delivers instantaneous power in the
event of a grid  outage.  Beacon is also known for its  advanced  flywheel-based
Smart Energy systems,  designed to provide  reliable,  environmentally  friendly
power quality  solutions for electric utility  transmission and distribution and
other applications.


     For more information, please contact James Spiezio, Chief Financial Officer
at  Beacon  Power  Corporation,  tel.  978.694.9121;  fax  978.694.9127;   email
spiezio@beaconpower.com,or  send mail to 234 Ballardvale Street,  Wilmington, MA
01887. Visit Beacon Power on the Internet at www.beaconpower.com

Safe Harbor  Statements under the Private  Securities  Litigation  Reform Act of
1995:

Material  contained in this press  release may include  statements  that are not
historical facts and are considered  "forward-looking" within the meaning of the
Private  Securities   Litigation  Reform  Act  of  1995.  These  forward-looking
statements reflect Beacon Power Corporation's  current views about future events
and financial performances.  These forward-looking  statements are identified by
the use of terms and phrases such as "believe," "expect," "plan,"  "anticipate,"
and similar expressions identifying forward-looking statements. Investors should
not rely on forward-looking  statements because they are subject to a variety of
risks,  uncertainties,  and other  factors  that could cause  actual  results to
differ  materially from Beacon Power  Corporation's  expectation.  These factors
include:  a short  operating  history;  a  history  of  losses  and  anticipated
continued  losses from operations;  a need to raise additional  capital combined
with  a  questionable  ability  to do  so;  conditions  in  target  markets;  no
experience manufacturing any product on a commercial basis; the company has only
recently entered into the renewable energy market through its inverter products,
and hence, has only limited  experience in this sector;  the dependence of sales
on the achievement of product development and commercialization  milestones; the
uncertainty of the political and economic climate of any foreign  countries into
which Beacon hopes to sell, including the uncertainty of enforcing contracts and
the  potential  substantial  fluctuation  in  currency  exchange  rates in those
countries; significant technological challenges to successfully complete product
development;  dependence on  third-party  suppliers;  intense  competition  from
companies with greater financial resources;  possible government regulation that
would impede the ability to market products;  possible product  liability claims
and  the  negative   publicity  which  could  result;  any  failure  to  protect
intellectual  property;  the possible  need in the future to hire and retain key
executives;  the recent volatility in the stock price of companies  operating in
the same sector;  the power of controlling  shareholders and the limited ability
of others to influence  the outcome of matters put to the vote of  shareholders.
These factors are  elaborated  upon and other factors may be disclosed from time
to time in Beacon Power  Corporation's  filings with the Securities and Exchange
Commission.  Beacon Power  Corporation  expressly does not undertake any duty to
update forward-looking statements.



                     BEACON POWER CORPORATION AND SUBSIDIARY
                      CONSOLIDATED STATEMENTS OF OPERATIONS

                                        Three months ended March 31,
                                             2004           2003
                                         -----------    -----------
Revenue ..............................   $    57,408    $      --
Cost of goods sold ...................        75,779           --
                                         -----------    -----------
Gross profit .........................       (18,371)          --

Operating expenses:
   Selling, general and administrative     1,076,262      1,218,648
   Research and development ..........     1,048,240        958,907
   Depreciation and amortization .....        46,587         99,689
                                         -----------    -----------
          Total operating expenses ...     2,171,089      2,277,244
                                         -----------    -----------
Loss from operations .................    (2,189,460)    (2,277,244)
Other income(expense), net ...........        40,733         47,869
                                         -----------    -----------
Loss to common shareholders ..........   $(2,148,727)   $(2,229,375)
                                         ===========    ===========
Loss per share, basic and diluted          $   (0.05)     $   (0.05)
                                         ===========    ===========
Weighted-average common shares
 outstanding                              43,121,702     42,812,897
                                         ===========    ===========




                     BEACON POWER CORPORATION AND SUBSIDIARY
                           CONSOLIDATED BALANCE SHEETS

                                                       March 31,      December 31,
                                                         2004            2003
                                                    -------------    -------------
Assets
Current assets:
                                                               
 Cash and cash equivalents ......................   $   7,096,242    $   8,909,261
 Accounts receivable, trade .....................          97,972          128,133
 Inventory ......................................         606,786          238,684
 Prepaid expenses and other current assets ......         594,339          773,226
 Investments ....................................       1,187,500        1,163,758
                                                    -------------    -------------
   Total current assets .........................       9,582,839       11,213,062

Property and equipment, net .....................         342,940          357,180
Restricted cash .................................         405,232          405,232
Other assets ....................................          73,060           91,325
                                                    -------------    -------------

Total assets ....................................   $  10,404,071    $  12,066,799
                                                    =============    =============

Liabilities and Stockholders' Equity
Current liabilities:
 Accounts payable ...............................   $     365,159    $     148,075
 Accrued compensation and benefits ..............         216,563          156,000
 Other accrued expenses .........................         582,664          664,527
 Restructuring reserve ..........................       1,320,305        1,406,191
                                                    -------------    -------------
   Total current liabilities ....................       2,484,691        2,374,793

Stockholders' equity:
 Common stock ...................................         431,375          431,075
 Deferred stock compensation ....................        (451,669)        (832,639)
 Additional paid-in-capital .....................     133,791,498      133,796,667
 Deficit accumulated during the development stage    (125,752,164)    (123,603,437)
 Less: treasury stock, at cost ..................         (99,660)         (99,660)
                                                    -------------    -------------
   Total stockholders' equity ...................       7,919,380        9,692,006

Total liabilities and stockholders' equity ......   $  10,404,071    $  12,066,799
                                                    =============    =============