<PAGE>

                                                                    Exhibit 12-A

                        Delmarva Power & Light Company

                      Ratio of Earnings to Fixed Charges
                      ----------------------------------
                        (Dollars in Thousands)


<TABLE>
<CAPTION>
                                                                   Year Ended December 31,
                                            ----------------------------------------------------------------------
                                                2000             1999          1998          1997         1996
                                            -------------   --------------  -----------   -----------  -----------
<S>                                         <C>            <C>             <C>            <C>         <C>
Income before extraordinary item            $    141,816    $      142,179  $   112,410   $   105,709  $   116,187
                                            ------------    --------------  -----------   -----------  -----------

Income taxes                                      81,510            95,321       72,276        72,155       78,340
                                            ------------    --------------  -----------   -----------  -----------

Fixed charges:
     Interest on long-term debt
        including amortization of
        discount, premium and
        expense                                   77,178            77,790       81,132        78,350       69,329
     Other interest                                7,512             6,117        9,328        12,835       12,516
     Preferred dividend require-
        ments of a subsidiary
        trust                                      5,687             5,687        5,688         5,687        1,390
                                            ------------    --------------  -----------   -----------  -----------
Total fixed charges                               90,377            89,594       96,148        96,872       83,235
                                            ------------    --------------  -----------   -----------  -----------

Nonutility capitalized interest                      -                  -           -            (208)        (311)
                                            ------------    --------------  -----------   -----------  -----------

Earnings before extraordinary
     item, income taxes, and
     fixed charges                          $    313,703    $      327,094  $   280,834   $   274,528  $   277,451
                                            ============    ==============  ===========   ===========  ===========

Ratio of earnings to fixed charges                  3.47              3.65         2.92          2.83         3.33
</TABLE>

For purposes of computing the ratio, earnings are income before extraordinary
item plus income taxes and fixed charges, less nonutility capitalized interest.
Fixed charges consist of interest on long- and short-term debt, amortization of
debt discount, premium, and expense, dividends on preferred securities of a
subsidiary trust, plus the estimated interest component of rentals.