<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)