<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEETS OF TELEGEN CORPORATION AS OF DECEMBER 31, 1998 AND
1997 AND THE CONSOLIDATED STATEMENT OF OPERATIONS FOR THE YEARS ENDED DECEMBER
31, 1998 AND 1997 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<S> <C> <C>
<PERIOD-TYPE> 12-MOS 12-MOS
<FISCAL-YEAR-END> DEC-31-1998 DEC-31-1997
<PERIOD-START> JAN-01-1998 JAN-01-1997
<PERIOD-END> DEC-31-1998 DEC-31-1997
<CASH> 14 275,891
<SECURITIES> 0 0
<RECEIVABLES> 0 66,000
<ALLOWANCES> 0 66,000
<INVENTORY> 0 75,760
<CURRENT-ASSETS> 14 610,249
<PP&E> 1,106,669 2,253,008
<DEPRECIATION> 672,772 706,825
<TOTAL-ASSETS> 433,911 2,231,614
<CURRENT-LIABILITIES> 3,675,215 2,901,366
<BONDS> 0 0
0 0
0 0
<COMMON> 23,385,796 16,031,336
<OTHER-SE> (22,493,460) (17,501,088)
<TOTAL-LIABILITY-AND-EQUITY> 433,911 2,231,614
<SALES> 57,900 463,486
<TOTAL-REVENUES> 57,900 1,038,402
<CGS> 264,578 234,292
<TOTAL-COSTS> 264,578 328,085
<OTHER-EXPENSES> 3,333,676 11,431,110
<LOSS-PROVISION> 0 0
<INTEREST-EXPENSE> 1,115,493 89,364
<INCOME-PRETAX> (4,991,562) (10,455,911)
<INCOME-TAX> 800 0
<INCOME-CONTINUING> (4,992,372) (10,455,911)
<DISCONTINUED> 0 0
<EXTRAORDINARY> 0 536,179
<CHANGES> 0 0
<NET-INCOME> (4,992,372) (9,919,732)
<EPS-BASIC> (6.93) (30.16)
<EPS-DILUTED> (6.93) (28.61)
</TABLE>