<Page>

                                                                    Exhibit 12.1

EME Homer City Generation LP
Ratio of Earnings to Fixed Charges (000's)

<Table>
<Caption>
                                                        Year Ended    Year Ended  Nine Months Ended  Nine Months Ended
                                                       December 31,  December 31,   September 30,      September 30,
                                                          2000          1999            2001               2000
                                                       ---------------------------------------------------------------
                                                                                              
EARNINGS:

Income (loss) before income taxes and extraordinary
       item (1999)                                        (3,563)        4,290          57,545              9,489
Adjustments:
       Fixed charges, as below                           149,149       105,860         112,438            111,367
       Interest capitalized                              (10,282)       (1,779)         (9,651)            (6,873)
                                                       ---------------------------------------------------------------

Earnings as adjusted                                     135,304       108,371         160,332            113,983
                                                       ===============================================================

FIXED CHARGES:

Interest on indebtedness (expense and capitalized)       148,936       105,593         112,248            111,207
Interest portion on rental expense                           213           267             190                160
                                                       ---------------------------------------------------------------
                                                         149,149       105,860         112,438            111,367
                                                       ===============================================================

Ratio of Earnings to Fixed Charges                  (a)      --           1.02            1.43               1.02
</Table>

(a)    For the year ended December 31, 2000, there was a fixed charge deficiency
       of $13,845

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EME Homer City Generation LP
Ratio of Earnings to Fixed Charges (000's)
Pro forma

<Table>
<Caption>
                                                                            Year Ended  Nine Months Ended
                                                                           December 31,   September 30,
                                                                              2000           2001
                                                                            ---------      ---------
                                                                                     
PRO FORMA EARNINGS:

Historical income (loss) before income taxes                                $  (3,563)     $  57,545

Pro forma earnings adjustments due to sale-leaseback:
   Elimination of interest on debt to be repaid with proceeds from sale
   Additional interest expense from lease financing                          (105,000)       (79,000)

Adjustments:
       Fixed charges, as below                                                243,867        181,787
       Interest capitalized - none                                                 --             --
                                                                            ---------      ---------

Earnings as adjusted                                                        $ 135,304      $ 160,332
                                                                            =========      =========


PRO FORMA FIXED CHARGES:

Historical interest on indebtedness                                         $ 148,936      $ 112,248

Pro forma interest adjustments due to sale-leaseback:
   Elimination of interest on debt to be repaid with proceeds from sale       (10,282)        (9,651)
   Additional interest expense from lease financing                           105,000         79,000

Historical interest portion on rental expense                                     213            190
                                                                            ---------      ---------
                                                                            $ 243,867      $ 181,787
                                                                            =========      =========

Pro forma ratio of Earnings to Fixed Charges                                       -- (a)         -- (a)
</Table>

(a)      For the year ended December 31. 2000 and for the nine month period
         ended September 30, 2001, there was a pro forma fixed charge deficiency
         of $108,563 and $21,455, respectively.