<TABLE> <S> <C>
<PAGE>
<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>
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> JUN-30-2000
<CASH> 110,797,623
<SECURITIES> 11,242,180
<RECEIVABLES> 4,632,854
<ALLOWANCES> 0
<INVENTORY> 2,606,335
<CURRENT-ASSETS> 132,187,557
<PP&E> 32,294,033
<DEPRECIATION> (3,546,471)
<TOTAL-ASSETS> 190,391,950
<CURRENT-LIABILITIES> 10,115,747
<BONDS> 0
0
0
<COMMON> 435,159
<OTHER-SE> 173,474,226
<TOTAL-LIABILITY-AND-EQUITY> 190,391,950
<SALES> 0
<TOTAL-REVENUES> 5,350,557
<CGS> 0
<TOTAL-COSTS> 7,390,300
<OTHER-EXPENSES> 33,084,660
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> 154,615
<INCOME-PRETAX> (35,279,018)
<INCOME-TAX> 0
<INCOME-CONTINUING> (35,279,018)
<DISCONTINUED> 0
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> (35,279,018)
<EPS-BASIC> (0.82)
<EPS-DILUTED> (0.82)
</TABLE>