<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM PLUG POWER'S
BALANCE SHEETS AND STATEMENTS OF OPERATIONS, AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>

                                                                        
<PERIOD-TYPE>                   6-MOS                   YEAR                     6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1998              DEC-31-1999
<PERIOD-START>                             JUN-27-1997             JAN-01-1998              JAN-01-1999
<PERIOD-END>                               DEC-31-1997             DEC-31-1998              JUN-30-1999
<CASH>                                       3,080,181               3,993,122               17,242,734
<SECURITIES>                                         0                       0                        0
<RECEIVABLES>                                  803,557               1,285,261                1,016,402
<ALLOWANCES>                                         0                       0                        0
<INVENTORY>                                     20,911                  14,647                   53,087
<CURRENT-ASSETS>                             3,917,288               5,293,030               18,340,750
<PP&E>                                         854,421               3,202,776                8,947,265
<DEPRECIATION>                               (116,808)               (449,284)                (804,752)
<TOTAL-ASSETS>                               4,846,566               8,093,435               37,232,815
<CURRENT-LIABILITIES>                        1,249,906               2,600,738                4,771,235
<BONDS>                                              0                       0                        0
<PREFERRED-MANDATORY>                                0                       0                        0
<PREFERRED>                                          0                       0                        0
<COMMON>                                             0                       0                        0
<OTHER-SE>                                   9,500,000              21,012,000               55,410,182
<TOTAL-LIABILITY-AND-EQUITY>                 4,846,566               8,093,435               37,232,815
<SALES>                                              0                       0                        0
<TOTAL-REVENUES>                             1,193,530               6,541,040                3,695,535
<CGS>                                                0                       0                        0
<TOTAL-COSTS>                                1,226,443               8,863,845                5,117,834
<OTHER-EXPENSES>                             5,973,550               7,386,374               13,880,430
<LOSS-PROVISION>                                     0                       0                        0
<INTEREST-EXPENSE>                                   0                       0                        0
<INCOME-PRETAX>                            (5,903,340)             (9,615,963)             (15,084,696)
<INCOME-TAX>                                         0                       0                        0
<INCOME-CONTINUING>                        (5,903,340)             (9,615,963)             (15,084,696)
<DISCONTINUED>                                       0                       0                        0
<EXTRAORDINARY>                                      0                       0                        0
<CHANGES>                                            0                       0                        0
<NET-INCOME>                               (5,903,340)             (9,615,963)             (15,084,696)
<EPS-BASIC>                                     (0.62)                  (0.71)                   (0.71)
<EPS-DILUTED>                                   (0.62)                  (0.71)                   (0.71)