<PAGE>   1
                                                             EXHIBIT 4-179
 
                                                             CONFORMED COPY
 
                           THE DETROIT EDISON COMPANY
                              (2000 Second Avenue,
                            Detroit, Michigan 48226)
 
                                       TO
                             BANKERS TRUST COMPANY
                              (Four Albany Street,
                           New York, New York 10015)
 
                                              AS TRUSTEE
 
                            ------------------------
 
                                   INDENTURE
                            Dated as of May 15, 1991
 
                            ------------------------
 
                   SUPPLEMENTAL TO MORTGAGE AND DEED OF TRUST
                          DATED AS OF OCTOBER 1, 1924
 
                                 PROVIDING FOR
 
  (A) GENERAL AND REFUNDING MORTGAGE BONDS, 1991 SERIES DP, DUE AUGUST 1, 2021
 
                                      AND
 
                         (B) RECORDING AND FILING DATA
<PAGE>   2
 
                                        i
 
                               TABLE OF CONTENTS*
 
                            ------------------------
 
                                                                  PAGE
                                                                  ----
PARTIES.....................................................        1
RECITALS
  Original Indenture and Supplementals......................        1
  Issue of Bonds under Indenture............................        1
  Bonds heretofore issued...................................        1
  Reason for creation of new series.........................        5
  Bonds to be 1991 Series DP................................        5
  Further Assurance.........................................        6
  Authorization of Supplemental Indenture...................        6
  Consideration for Supplemental Indenture..................        6

                                    PART I.
                      CREATION OF TWO HUNDRED NINETY-FIRST
                                SERIES OF BONDS
                     GENERAL AND REFUNDING MORTGAGE BONDS,
                                 1991 SERIES DP
Sec. 1. Terms of Bonds of 1991 Series DP....................        6
Sec. 2. Redemption of Bonds of 1991 Series DP...............        8
Sec. 3. Redemption in Event of Acceleration.................        9
Sec. 4. Consent.............................................       10
Sec. 5. Form of Bonds of 1991 Series DP.....................       10
        Form of Trustee's Certificate.......................       15

                                    PART II.
                           RECORDING AND FILING DATA
Recording and filing of Original Indenture..................       15
Recording and filing of Supplemental Indentures.............       15
Recording of Certificates of Provision for Payment..........       20

                                   PART III.
                                  THE TRUSTEE
Terms and conditions of acceptance of trust by Trustee......       20

                                    PART IV.
                                 MISCELLANEOUS
Confirmation of Series 318(c) of Trust Indenture Act........       20
Execution in Counterparts...................................       20
Testimonium.................................................       21
Execution...................................................       21
Acknowledgements............................................       22
Affidavit as to consideration and good faith................       23
 
------------------------
* This Table of Contents shall not have any bearing upon the interpretation of
  any of the terms or provisions of this Indenture.
<PAGE>   3
 
                                        1
 
PARTIES.              SUPPLEMENTAL INDENTURE, dated as of the fifteenth day of
                    May, in the year one thousand nine hundred and ninety-one,
                    between THE DETROIT EDISON COMPANY, a corporation organized
                    and existing under the laws of the State of Michigan and a
                    transmitting utility (hereinafter called the "Company"),
                    party of the first part, and BANKERS TRUST COMPANY, a
                    corporation organized and existing under the laws of the
                    State of New York, having its corporate trust office at Four
                    Albany Street, in the Borough of Manhattan, The City and
                    State of New York, as Trustee under the Mortgage and Deed of
                    Trust hereinafter mentioned (hereinafter called the
                    "Trustee"), party of the second part.
 
ORIGINAL              WHEREAS, the Company has heretofore executed and delivered
INDENTURE AND       its Mortgage and Deed of Trust (hereinafter referred to as
SUPPLEMENTALS.      the "Original Indenture"), dated as of October 1, 1924, to
                    the Trustee, for the security of all bonds of the Company
                    outstanding thereunder, and pursuant to the terms and
                    provisions of the Original Indenture, indentures dated as
                    of, respectively, June 1, 1925, August 1, 1927, February 1,
                    1931, June 1, 1931, October 1, 1932, September 25, 1935,
                    September 1, 1936, November 1, 1936, February 1, 1940,
                    December 1, 1940, September 1, 1947, March 1, 1950, November
                    15, 1951, January 15, 1953, May 1, 1953, March 15, 1954, May
                    15, 1955, August 15, 1957, June 1, 1959, December 1, 1966,
                    October 1, 1968, December 1, 1969, July 1, 1970, December
                    15, 1970, June 15, 1971, November 15, 1971, January 15,
                    1973, May 1, 1974, October 1, 1974, January 15, 1975,
                    November 1, 1975, December 15, 1975, February 1, 1976, June
                    15, 1976, July 15, 1976, February 15, 1977, March 1, 1977,
                    June 15, 1977, July 1, 1977, October 1, 1977, June 1, 1978,
                    October 15, 1978, March 15, 1979, July 1, 1979, September 1,
                    1979, September 15, 1979, January 1, 1980, April 1, 1980,
                    August 15, 1980, August 1, 1981, November 1, 1981, June 30,
                    1982, August 15, 1982, June 1, 1983, October 1, 1984, May 1,
                    1985, May 15, 1985, October 15, 1985, April 1, 1986, August
                    15, 1986, November 30, 1986, January 31, 1987, April 1,
                    1987, August 15, 1987, November 30, 1987, June 15, 1989,
                    July 15, 1989, December 1, 1989, February 15, 1990, November
                    1, 1990, April 1, 1991 and May 1, 1991 supplemental to the
                    Original Indenture, have heretofore been entered into
                    between the Company and the Trustee (the Original Indenture
                    and all indentures supplemental thereto together being
                    hereinafter sometimes referred to as the "Indenture"); and
 
ISSUE OF              WHEREAS, the Indenture provides that said bonds shall be
BONDS UNDER         issuable in one or more series, and makes provision that the
INDENTURE.          rates of interest and dates for the payment thereof, the
                    date of maturity or dates of maturity, if of serial
                    maturity, the terms and rates of optional redemption (if
                    redeemable), the forms of registered bonds without coupons
                    of any series and any other provisions and agreements in
                    respect thereof, in the Indenture provided and permitted, as
                    the Board of Directors may determine, may be expressed in a
                    supplemental indenture to be made by the Company to the
                    Trustee thereunder; and
 
BONDS HERETOFORE      WHEREAS, bonds in the principal amount of Five billion 
ISSUED.             seven hundred twenty-three million three hundred sixty-
                    seven thousand dollars ($5,723,367,000) have heretofore been
                    issued under the Indenture as follows, viz:
 
<TABLE>
                            <S>    <C>                               <C>
                              (1)  Bonds of Series A                 -- Principal Amount $26,016,000,
                              (2)  Bonds of Series B                 -- Principal Amount $23,000,000,
                              (3)  Bonds of Series C                 -- Principal Amount $20,000,000,
                              (4)  Bonds of Series D                 -- Principal Amount $50,000,000,
                              (5)  Bonds of Series E                 -- Principal Amount $15,000,000,
                              (6)  Bonds of Series F                 -- Principal Amount $49,000,000,
                              (7)  Bonds of Series G                 -- Principal Amount $35,000,000,
                              (8)  Bonds of Series H                 -- Principal Amount $50,000,000,
                              (9)  Bonds of Series I                 -- Principal Amount $60,000,000,
                             (10)  Bonds of Series J                 -- Principal Amount $35,000,000,
                             (11)  Bonds of Series K                 -- Principal Amount $40,000,000,
                             (12)  Bonds of Series L                 -- Principal Amount $24,000,000,
</TABLE>
<PAGE>   4
 
                                        2
 
<TABLE>
<CAPTION>
 
                        <S>        <C>                               <C>
                             (13)  Bonds of Series M                 -- Principal Amount $40,000,000,
                             (14)  Bonds of Series N                 -- Principal Amount $40,000,000,
                             (15)  Bonds of Series O                 -- Principal Amount $60,000,000,
                             (16)  Bonds of Series P                 -- Principal Amount $70,000,000,
                             (17)  Bonds of Series Q                 -- Principal Amount $40,000,000,
                             (18)  Bonds of Series W                 -- Principal Amount $50,000,000,
                             (19)  Bonds of Series BB                -- Principal Amount $50,000,000,
                             (20)  Bonds of Series CC                -- Principal Amount $50,000,000,
                             (21)  Bonds of Series UU                -- Principal Amount $100,000,000,
                          (22-29)  Bonds of Series DDP Nos. 1-8      -- Principal Amount $6,400,000,
                          (30-41)  Bonds of Series FFR Nos. 1-12     -- Principal Amount $8,000,000,
                          (42-56)  Bonds of Series GGP Nos. 1-6 and
                                   8-16                              -- Principal Amount $8,355,000,
                          (57-70)  Bonds of Series IIP Nos. 1-6 and
                                   8-15                              -- Principal Amount $490,000,
                          (71-76)  Bonds of Series JJP Nos. 1-6      -- Principal Amount $690,000,
                          (77-82)  Bonds of Series KKP Nos. 1-6      -- Principal Amount $1,590,000,
                          (83-97)  Bonds of Series LLP Nos. 1-7 and
                                   8-15                              -- Principal Amount $8,850,000,
                         (98-110)  Bonds of Series NNP Nos. 1-6 and
                                   8-14                              -- Principal Amount $8,450,000,
                        (111-119)  Bonds of Series OOP Nos. 1-9      -- Principal Amount $3,015,000,
                        (120-133)  Bonds of Series QQP Nos. 1-8 and
                                   10-15                             -- Principal Amount $9,710,000,
                        (134-140)  Bonds of Series TTP Nos. 1-7      -- Principal Amount $385,000,
                             (141) Bonds of 1980 Series A            -- Principal Amount $50,000,000,
                        (142-158)  Bonds of 1980 Series CP Nos.
                                   1-12 and 13-17                    -- Principal Amount $26,000,000,
                        (159-169)  Bonds of 1980 Series DP Nos.
                                   1-11                              -- Principal Amount $10,750,000,
                        (170-174)  Bonds of 1981 Series AP Nos. 1-5  -- Principal Amount $4,000,000,
                            (175)  Bonds of 1985 Series A            -- Principal Amount $35,000,000
</TABLE>
 
                 all of which have either been retired and cancelled, or no
                 longer represent obligations of the Company, having been called
                 for redemption and funds necessary to effect the payment,
                 redemption and retirement thereof having been deposited with
                 the Trustee as a special trust fund to be applied for such
                 purpose;
 
                 (176) Bonds of Series R in the principal amount of One hundred
                 million dollars ($100,000,000), all of which are outstanding at
                 the date hereof;
 
                 (177) Bonds of Series S in the principal amount of One hundred
                 fifty million dollars ($150,000,000), all of which are
                 outstanding at the date hereof;
 
                 (178) Bonds of Series T in the principal amount of Seventy-five
                 million dollars ($75,000,000), all of which are outstanding at
                 the date hereof;
 
                 (179) Bonds of Series U in the principal amount of Seventy-five
                 million dollars ($75,000,000), all of which are outstanding at
                 the date hereof;
 
                 (180) Bonds of Series V in the principal amount of One hundred
                 million dollars ($100,000,000), all of which are outstanding at
                 the date hereof;
 
                 (181) Bonds of Series X in the principal amount of One hundred
                 million dollars ($100,000,000), all of which are outstanding at
                 the date hereof;
 
                 (182) Bonds of Series Y in the principal amount of Sixty
                 million dollars ($60,000,000), all of which are outstanding at
                 the date hereof;
 
                 (183) Bonds of Series Z in the principal amount of One hundred
                 million dollars ($100,000,000), all of which are outstanding at
                 the date hereof;
 
                 (184) Bonds of Series AA in the principal amount of One hundred
                 million dollars ($100,000,000), all of which are outstanding at
                 the date hereof;
<PAGE>   5
 
                                        3
 
                 (185) Bonds of Series DDP No. 9 in the principal amount of
                 Seven million nine hundred five thousand dollars ($7,905,000),
                 of which Two million four hundred thousand dollars ($2,400,000)
                 principal amount have heretofore been retired and Five million
                 five hundred five thousand dollars ($5,505,000) principal
                 amount are outstanding at the date hereof;
 
                 (186) Bonds of Series EE in the principal amount of Fifty
                 million dollars ($50,000,000), of which Thirty-five million
                 dollars ($35,000,000) principal amount have heretofore been
                 retired and Fifteen million dollars ($15,000,000) principal
                 amount are outstanding at the date hereof;
 
                 (187-188) Bonds of Series FFR Nos. 13-14 in the principal
                 amount of Thirty-seven million six hundred thousand dollars
                 ($37,600,000), all of which are outstanding at the date hereof;
 
                 (189-195) Bonds of Series GGP Nos. 7 and 17-22 in the principal
                 amount of Thirty-three million nine hundred forty-five thousand
                 dollars ($33,945,000), of which Three million two hundred
                 thousand dollars ($3,200,000) principal amount have heretofore
                 been retired and Thirty million seven hundred forty-five
                 thousand dollars ($30,745,000) principal amount are outstanding
                 at the date hereof;
 
                 (196) Bonds of Series HH in the principal amount of Fifty
                 million dollars ($50,000,000), all of which are outstanding at
                 the date hereof;
 
                 (197-198) Bonds of Series MMP and MMP No. 2 in the principal
                 amount of Five million four hundred thirty thousand dollars
                 ($5,430,000), of which One million three hundred eighty
                 thousand dollars ($1,380,000) principal amount have heretofore
                 been retired and Four million fifty thousand dollars
                 ($4,050,000) principal amount are outstanding at the date
                 hereof;
 
                 (199-206) Bonds of Series IIP Nos. 7 and 16-22 in the principal
                 amount of Three million two hundred sixty thousand dollars
                 ($3,260,000), of which Two hundred twenty thousand dollars
                 ($220,000) principal amount have heretofore been retired and
                 Three million forty thousand dollars ($3,040,000) principal
                 amount are outstanding at the date hereof;
 
                 (207-208) Bonds of Series JJP Nos. 7-8 in the principal amount
                 of Six million one hundred sixty thousand dollars ($6,160,000),
                 of which Six hundred twenty thousand dollars ($620,000)
                 principal amount have heretofore been retired and Five million
                 five hundred forty thousand dollars ($5,540,000) are
                 outstanding at the date hereof;
 
                 (209-214) Bonds of Series KKP Nos. 7-12 in the principal amount
                 of One hundred twenty-three million seven hundred ninety
                 thousand dollars ($123,790,000), of which One million three
                 hundred thousand dollars ($1,300,000) principal amount have
                 heretofore been retired and One hundred twenty-two million four
                 hundred ninety thousand dollars ($122,490,000) are outstanding
                 at the date hereof;
 
                 (215-222) Bonds of Series NNP Nos. 7 and 15-21 in the principal
                 amount of Thirty-nine million five hundred thousand
                 ($39,500,000), of which Two million four hundred seventy-five
                 thousand dollars ($2,475,000) principal amount have heretofore
                 been retired and Thirty-seven million twenty-five thousand
                 dollars ($37,025,000) principal amount are outstanding at the
                 date hereof;
 
                 (223-231) Bonds of Series OOP Nos. 10-18 in the principal
                 amount of Fifteen million eight hundred sixty-five thousand
                 dollars ($15,865,000), of which Two hundred eighty thousand
                 dollars ($280,000) principal amount have heretofore been
                 retired and Fifteen million five hundred eighty-five thousand
                 dollars ($15,585,000) are outstanding at the date hereof;
 
                 (232) Bonds of Series PP in the principal amount of Seventy
                 million dollars ($70,000,000), all of which are outstanding at
                 the date hereof;
<PAGE>   6
 
                                        4
 
                 (233-237) Bonds of Series QQP Nos. 9 and 16-19 in the principal
                 amount of Three million nine hundred forty thousand dollars
                 ($3,940,000), all of which are outstanding at the date hereof;
 
                 (238) Bonds of Series RR in the principal amount of Seventy
                 million dollars ($70,000,000), all of which are outstanding at
                 the date hereof;
 
                 (239) Bonds of Series SS in the principal amount of One hundred
                 fifty million dollars ($150,000,000), of which Ninety million
                 dollars ($90,000,000) principal amount have heretofore been
                 retired and Sixty million dollars ($60,000,000) principal
                 amount are outstanding at the date hereof;
 
                 (240-247) Bonds of Series TTP Nos. 8-15 in the principal amount
                 of Three million four hundred fifteen thousand dollars
                 ($3,415,000), all of which are outstanding at the date hereof;
 
                 (248) Bonds of 1980 Series B in the principal amount of One
                 hundred million dollars ($100,000,000), of which Sixty-six
                 million five hundred thousand dollars ($66,500,000) principal
                 amount have heretofore been retired and Thirty-three million
                 five hundred thousand dollars ($33,500,000) principal amount
                 are outstanding at the date hereof;
 
                 (249-256) Bonds of 1980 Series CP Nos. 18-25 in the principal
                 amount of Nine million dollars ($9,000,000), all of which are
                 outstanding at the date hereof;
 
                 (257-267) Bonds of 1981 Series AP Nos. 6-16 in the principal
                 amount of One hundred twenty million dollars ($120,000,000),
                 all of which are outstanding at the date hereof;
 
                 (268) Bonds of 1984 Series AP in the principal amount of Two
                 million four hundred thousand dollars ($2,400,000), all of
                 which are outstanding at the date hereof;
 
                 (269) Bonds of 1984 Series BP in the principal amount of Seven
                 million seven hundred fifty thousand dollars ($7,750,000), all
                 of which are outstanding at the date hereof;
 
                 (270) Bonds of 1985 Series B in the principal amount of Fifty
                 million dollars ($50,000,000), all of which are outstanding at
                 the date hereof;
 
                 (271) Bonds of 1986 Series A in the principal amount of Two
                 hundred million dollars ($200,000,000), all of which are
                 outstanding at the date hereof;
 
                 (272) Bonds of 1986 Series B in the principal amount of One
                 hundred million dollars ($100,000,000), all of which are
                 outstanding at the date hereof;
 
                 (273) Bonds of 1986 Series C in the principal amount of Two
                 hundred million dollars ($200,000,000), all of which are
                 outstanding at the date hereof;
 
                 (274) Bonds of 1987 Series A in the principal amount of Three
                 hundred million dollars ($300,000,000), all of which are
                 outstanding at the date hereof;
 
                 (275) Bonds of 1987 Series B in the principal amount of One
                 hundred seventy-five million dollars ($175,000,000), all of
                 which are outstanding at the date hereof;
 
                 (276) Bonds of 1987 Series C in the principal amount of Two
                 hundred twenty-five million dollars ($225,000,000), all of
                 which are outstanding at the date hereof;
 
                 (277) Bonds of 1987 Series D in the principal amount of Two
                 hundred fifty million dollars ($250,000,000), all of which are
                 outstanding at the date hereof;
 
                 (278) Bonds of 1987 Series E in the principal amount of One
                 hundred fifty million dollars ($150,000,000), all of which are
                 outstanding at the date hereof;
 
                 (279) Bonds of 1987 Series F in the principal amount of Two
                 hundred million dollars ($200,000,000), all of which are
                 outstanding at the date hereof;
 
                 (280) Bonds of 1989 Series A in the principal amount of Three
                 hundred million dollars ($300,000,000), all of which are
                 outstanding at the date hereof;
<PAGE>   7
 
                                        5
 
                 (281) Bonds of 1989 Series BP in the principal amount of
                 Sixty-six million five hundred sixty-five thousand
                 ($66,565,000), all of which are outstanding at the date hereof;
 
                 (282) Bonds of 1990 Series A in the principal amount of One
                 hundred ninety-four million six hundred forty-nine thousand
                 ($194,649,000) of which Twelve million five hundred fifty-eight
                 thousand ($12,558,000) principal amount have heretofore been
                 retired and One hundred eighty-two million ninety-one thousand
                 ($182,091,000) principal amount are outstanding at the date
                 hereof;
 
                 (283) Bonds of 1990 Series B in the principal amount of Two
                 hundred fifty-six million nine hundred thirty-two thousand
                 ($256,932,000) of which Nineteen million thirty-two thousand
                 ($19,032,000) principal amount have heretofore been retired and
                 Two hundred thirty-seven million nine hundred thousand
                 ($237,900,000) principal amount are outstanding at the date
                 hereof;
 
                 (284) Bonds of 1990 Series C in the principal amount of
                 Eighty-five million four hundred seventy-five thousand
                 ($85,475,000) of which Six million eight hundred thirty-eight
                 thousand ($6,838,000) principal amount have heretofore been
                 retired and Seventy-eight million six hundred thirty-seven
                 thousand ($78,637,000) principal amount are outstanding at the
                 date hereof;
 
                 (285) Bonds of 1991 Series AP in the principal amount of
                 Thirty-two million three hundred seventy-five thousand
                 ($32,375,000), all of which are outstanding at the date hereof;
 
                 (286) Bonds of 1991 Series BP in the principal amount of
                 Twenty-five million nine hundred ten thousand ($25,910,000),
                 all of which are outstanding at the date hereof; and
 
                 (287) Bonds of 1991 Series CP in the principal amount of
                 Thirty-two million eight hundred thousand ($32,800,000), all of
                 which are outstanding at the date hereof;
 
                 and, accordingly, of the bonds so issued, Four billion three
                 hundred seventy-two million eight hundred sixty-three thousand
                 dollars ($4,372,863,000) principal amount are outstanding at
                 the date hereof; and
 
REASON FOR         WHEREAS, the City of Superior, Wisconsin has agreed to
CREATION OF      issue and sell $37,600,000 principal amount of its Limited
NEW SERIES.      Obligation Refunding Revenue Bonds (Midwest Energy Resources
                 Company Project), Series E-1991 (Collateralized) so as to
                 provide funds for the refunding of certain Dock or Wharf
                 Revenue Bonds previously issued to finance a project of the
                 Midwest Energy Resources Company ("Midwest"), a wholly owned
                 subsidiary of The Detroit Edison Company; and
 
                   WHEREAS, Midwest and The Detroit Edison Company (the
                 "Company") have entered into a Loan Agreement, dated as of
                 May 1, 1991, with the City of Superior, Wisconsin in order
                 to refund the previously issued bonds, and pursuant to such
                 Loan Agreement the Company has agreed to issue its General
                 and Refunding Mortgage Bonds under the Indenture in order
                 further to secure its obligations under such Loan Agreement;
                 and
 
                   WHEREAS, for such purposes the Company desires to issue a
                 new series of bonds to be issued under the Indenture and to
                 be authenticated and delivered pursuant to Section 8 of
                 Article III of the Indenture; and
 
BONDS TO BE        WHEREAS, the Company desires by this Supplemental
1991 SERIES DP   Indenture to create such new series of bonds, to be
                 designated "General and Refunding Mortgage Bonds, 1991
                 Series DP"; and
<PAGE>   8
 
                                        6
 
FURTHER               WHEREAS, the Original Indenture, by its terms, includes in
ASSURANCE.          the property subject to the lien thereof all of the estates
                    and properties, real, personal and mixed, rights, privileges
                    and franchises of every nature and kind and wheresoever
                    situate, then or thereafter owned or possessed by or
                    belonging to the Company or to which it was then or at any
                    time thereafter might be entitled in law or in equity
                    (saving and excepting, however, the property therein
                    specifically excepted or released from the lien thereof),
                    and the Company therein covenanted that it would, upon
                    reasonable request, execute and deliver such further
                    instruments as may be necessary or proper for the better
                    assuring and confirming unto the Trustee all or any part of
                    the trust estate, whether then or thereafter owned or
                    acquired by the Company (saving and excepting, however,
                    property specifically excepted or released from the lien
                    thereof); and
 
AUTHORIZATION         WHEREAS, the Company in the exercise of the powers and
OF SUPPLEMENTAL     authority conferred upon and reserved to it under and by
INDENTURE.          virtue of the provisions of the Indenture, and pursuant to
                    resolutions of its Board of Directors has duly resolved and
                    determined to make, execute and deliver to the Trustee a
                    supplemental indenture in the form hereof for the purposes
                    herein provided; and
 
                      WHEREAS, all conditions and requirements necessary to make
                    this Supplemental Indenture a valid and legally binding
                    instrument in accordance with its terms have been done,
                    performed and fulfilled, and the execution and delivery
                    hereof have been in all respects duly authorized;
 
CONSIDERATION         NOW, THEREFORE, THIS INDENTURE WITNESSETH: That The
FOR SUPPLEMENTAL    Detroit Edison Company, in consideration of the premises and
INDENTURE.          of the covenants contained in the Indenture and of the sum
                    of One Dollar ($1.00) and other good and valuable
                    consideration to it duly paid by the Trustee at or before
                    the ensealing and delivery of these presents, the receipt
                    whereof is hereby acknowledged, hereby covenants and agrees
                    to and with the Trustee and its successors in the trusts
                    under the Original Indenture and in said indentures
                    supplemental thereto as follows:
 
                                    PART I.
                      CREATION OF TWO HUNDRED NINETY-FIRST
                                SERIES OF BONDS.
                     GENERAL AND REFUNDING MORTGAGE BONDS,
                                 1991 SERIES DP
 
CERTAIN TERMS         SECTION 1. The Company hereby creates the Two hundred
OF BONDS OF         Ninety-first series of bonds to be issued under and secured
1991 SERIES DP      by the Original Indenture as amended to date and as further
                    amended by this Supplemental Indenture, to be designated,
                    and to be distinguished from the bonds of all other series,
                    by the title "General and Refunding Mortgage Bonds, 1991
                    Series DP" (elsewhere herein referred to as the "bonds of
                    1991 Series DP"). The aggregate principal amount of bonds of
                    1991 Series DP shall be limited to Thirty-seven million six
                    hundred thousand dollars ($37,600,000), except as provided
                    in Sections 7 and 13 of Article II of the Original Indenture
                    with respect to exchanges and replacements of bonds.
<PAGE>   9
 
                                        7
 
                      Each bond of 1991 Series DP is to be irrevocably assigned
                    to, and registered in the name of, NBD Bank, N.A., as
                    trustee, or a successor trustee (said trustee or any
                    successor trustee being hereinafter referred to as the
                    "Superior Trust Indenture Trustee"), under the Trust
                    Indenture, dated as of May 1, 1991 (hereinafter called the
                    "Superior Trust Indenture"), between the City of Superior,
                    Wisconsin (hereinafter called "Superior"), and the Superior
                    Trust Indenture Trustee, to secure payment of the City of
                    Superior, Wisconsin Limited Obligation Refunding Revenue
                    Bonds (Midwest Energy Resources Company Project), Series
                    E-1991 (Collateralized) (hereinafter called the "Superior
                    Revenue Bonds"), issued by Superior under the Superior Trust
                    Indenture, the proceeds of which will be provided for the
                    refunding of certain bonds which Midwest will refund
                    pursuant to the provisions of the Loan Agreement, dated as
                    of May 1, 1991 (hereinafter called the "Superior
                    Agreement"), between Midwest, the Company and Superior.

                      The bonds of 1991 Series DP shall be issued as registered
                    bonds without coupons in denominations of a multiple of
                    $5,000. The bonds of 1991 Series DP shall be issued in the
                    aggregate principal amount of $37,600,000, shall mature on
                    August 1, 2021 and shall bear interest, payable
                    semi-annually on February 1 and August 1 of each year
                    (commencing August 1, 1991), at the rate of 6.9%, until the
                    principal thereof shall have become due and payable and
                    thereafter until the Company's obligation with respect to
                    the payment of said principal shall have been discharged as
                    provided in the Indenture.

                      The bonds of 1991 Series DP shall be payable as to
                    principal, premium, if any, and interest as provided in the
                    Indenture, but only to the extent and in the manner herein
                    provided. The bonds of 1991 Series DP shall be payable, both
                    as to principal and interest, at the office or agency of the
                    Company in the Borough of Manhattan, The City and State of
                    New York, in any coin or currency of the United States of
                    America which at the time of payment is legal tender for
                    public and private debts.

                      Except as provided herein, each bond of 1991 Series DP
                    shall be dated the date of its authentication and interest
                    shall be payable on the principal represented thereby from
                    the February 1 or August 1 next preceding the date thereof
                    to which interest has been paid on bonds of 1991 Series DP,
                    unless the bond is authenticated on a date to which interest
                    has been paid, in which case interest shall be payable from
                    the date of authentication, or unless the date of
                    authentication is prior to August 1, 1991, in which case
                    interest shall be payable from May 1, 1991.

                      The bonds of 1991 Series DP in definitive form shall be,
                    at the election of the Company, fully engraved or shall be
                    lithographed or printed in authorized denominations as
                    aforesaid and numbered 1 and upwards (with such further
                    designation as may be appropriate and desirable to indicate
                    by such designation the form, series and denominations of
                    bonds of 1991 Series DP). Until bonds of 1991 Series DP in
                    definitive form are ready for delivery, the Company may
                    execute, and upon its request in writing the Trustee shall
                    authenticate and deliver in lieu thereof, bonds of 1991
                    Series DP in temporary form, as provided in Section 10 of
                    Article II of the Indenture. Temporary bonds of 1991 Series
                    DP, if any, may be printed and may be issued in authorized
                    denominations in substantially the form of definitive bonds
                    of 1991 Series DP, but with such omissions, insertions and
                    variations as may be appropriate for temporary bonds, all as
                    may be determined by the Company.
<PAGE>   10
 
                                        8
 
                     Bonds of 1991 Series DP shall not be assignable or
                   transferable except as may be required to effect a transfer
                   to any successor trustee under the Superior Trust Indenture,
                   or, subject to compliance with applicable law, as may be
                   involved in the course of the exercise of rights and
                   remedies consequent upon an Event of Default under the
                   Superior Trust Indenture. Any such transfer shall be made
                   upon surrender thereof for cancellation at the office or
                   agency of the Company in the Borough of Manhattan, The City
                   and State of New York, together with a written instrument of
                   transfer (if so required by the Company or by the Trustee)
                   in form approved by the Company duly executed by the holder
                   or by its duly authorized attorney. Bonds of 1991 Series DP
                   shall in the same manner be exchangeable for a like
                   aggregate principal amount of bonds of 1991 Series DP upon
                   the terms and conditions specified herein and in Section 7
                   of Article II of the Indenture. The Company waives its
                   rights under Section 7 of Article II of the Indenture not to
                   make exchanges or transfers of bonds of 1991 Series DP,
                   during any period of ten days next preceding any redemption
                   date for such bonds.
 
                     Bonds of 1991 Series DP, in definitive and temporary form,
                   may bear such legends as may be necessary to comply with any
                   law or with any rules or regulations made pursuant thereto
                   or as may be specified in the Superior Agreement.
 
                     Upon payment of the principal or premium, if any, or
                   interest on the Superior Revenue Bonds, whether at maturity
                   or prior to maturity by redemption or otherwise, or upon
                   provision for the payment thereof having been made in
                   accordance with Section 204 of the Superior Trust Indenture,
                   bonds of 1991 Series DP in a principal amount equal to the
                   principal amount of such Superior Revenue Bonds, shall, to
                   the extent of such payment of principal, premium or
                   interest, be deemed fully paid and the obligation of the
                   Company thereunder to make such payment shall forthwith
                   cease and be discharged, and, in the case of the payment of
                   principal and premium, if any, such bonds shall be
                   surrendered for cancellation or presented for appropriate
                   notation to the Trustee.
 
REDEMPTION           SECTION 2. Bonds of 1991 Series DP shall be redeemed on
OF BONDS OF        the respective dates and in the respective principal amounts
1991 SERIES DP     which correspond to the redemption dates for, and the
                   principal amounts to be redeemed of, the Superior Revenue
                   Bonds.

                     In the event the Company elects to redeem any Superior
                   Revenue Bonds prior to maturity in accordance with the
                   provisions of the Superior Trust Indenture, the Company
                   shall on the same date redeem bonds of 1991 Series DP in
                   principal amounts and at redemption prices corresponding to
                   the Superior Revenue Bonds so redeemed. The Company agrees
                   to give the Trustee notice of any such redemption of bonds
                   of 1991 Series DP on the same date as it gives notice of
                   redemption of Superior Revenue Bonds to the Superior Trust
                   Indenture Trustee.
<PAGE>   11
 
                                        9
 
REDEMPTION           SECTION 3. In the event of an Event of Default under the
OF BONDS OF        Superior Trust Indenture and the acceleration of all
1991 SERIES        Superior Revenue Bonds, the bonds of 1991 Series DP shall be
DP IN EVENT OF     redeemable in whole upon receipt by the Trustee of a written
ACCELERATION       demand (hereinafter called a "Redemption Demand") from the
OF SUPERIOR        Superior Trust Indenture Trustee stating that there has
BONDS.             occurred under the Superior Trust Indenture both an Event of
                   Default and a declaration of acceleration of payment of
                   principal, accrued interest and premium, if any, on the
                   Superior Revenue Bonds, specifying the last date to which
                   interest on the Superior Revenue Bonds has been paid (such
                   date being hereinafter referred to as the "Initial Interest
                   Accrual Date") and demanding redemption of the bonds of said
                   series. The Trustee shall, within five days after receiving
                   such Redemption Demand, mail a copy thereof to the Company
                   marked to indicate the date of its receipt by the Trustee.
                   Promptly upon receipt by the Company of such copy of a
                   Redemption Demand, the Company shall fix a date on which it
                   will redeem the bonds of said series so demanded to be
                   redeemed (hereinafter called the "Demand Redemption Date").
                   Notice of the date fixed as the Demand Redemption Date shall
                   be mailed by the Company to the Trustee at least ten days
                   prior to such Demand Redemption Date. The date to be fixed
                   by the Company as and for the Demand Redemption Date may be
                   any date up to and including the earlier of (x) the 60th day
                   after receipt by the Trustee of the Redemption Demand or (y)
                   the maturity date of such bonds first occurring following
                   the 20th day after the receipt by the Trustee of the
                   Redemption Demand; provided, however, that if the Trustee
                   shall not have received such notice fixing the Demand
                   Redemption Date on or before the 10th day preceding the
                   earlier of such dates, the Demand Redemption Date shall be
                   deemed to be the earlier of such dates. The Trustee shall
                   mail notice of the Demand Redemption Date (such notice being
                   hereinafter called the "Demand Redemption Notice") to the
                   Superior Trust Indenture Trustee not more than ten nor less
                   than five days prior to the Demand Redemption Date.
 
                     Each bond of 1991 Series DP shall be redeemed by the
                   Company on the Demand Redemption Date therefore upon
                   surrender thereof by the Superior Trust Indenture Trustee to
                   the Trustee at a redemption price equal to the principal
                   amount thereof plus accrued interest thereon at the rate
                   specified for such bond from the Initial Interest Accrual
                   Date to the Demand Redemption Date plus an amount equal to
                   the aggregate premium, if any, due and payable on such
                   Demand Redemption Date on all Superior Revenue Bonds;
                   provided, however, that in the event of a receipt by the
                   Trustee of a notice that, pursuant to Section 606 of the
                   Superior Trust Indenture, the Superior Trust Indenture
                   Trustee has terminated proceedings to enforce any right
                   under the Superior Trust Indenture, then any Redemption
                   Demand shall thereby be rescinded by the Superior Trust
                   Indenture Trustee, and no Demand Redemption Notice shall be
                   given, or, if already given, shall be automatically
                   annulled; but no such rescission or annulment shall extend
                   to or affect any subsequent default or impair any right
                   consequent thereon.
 
                     Anything herein contained to the contrary notwithstanding,
                   the Trustee is not authorized to take any action pursuant to
                   a Redemption Demand and such Redemption Demand shall be of
                   no force or effect, unless it is executed in the name of the
                   Superior Trust Indenture Trustee by its President or one of
                   its Vice Presidents.
<PAGE>   12
 
                                       10
 
CONSENT.              SECTION 4. The holders of the bonds of 1991 Series DP, by
                    their acceptance of and holding thereof, consent and agree
                    that bonds of any series may be issued which mature on a
                    date or dates later than October 1, 2024 and also consent to
                    the deletion from the first paragraph of Section 5 of
                    Article II of the Indenture of the phrase "but in no event
                    later than October 1, 2024". Such holders further agree that
                    (a) such consent shall, for all purposes of Article XV of
                    the Indenture and without further action on the part of such
                    holders, be deemed the affirmative vote of such holders at
                    any meeting called pursuant to said Article XV for the
                    purpose of approving such deletion, and (b) such deletion
                    shall become effective at such time as not less than
                    eighty-five per cent (85%) in principal amount of bonds
                    outstanding under the Indenture shall have consented thereto
                    substantially in the manner set forth in this Section 4, or
                    in writing, or by affirmative vote cast at a meeting called
                    pursuant to said Article XV, or by any combination thereof.
 
FORM OF BONDS         SECTION 5. The bonds of 1991 Series DP and the form of
OF 1991 SERIES DP   Trustee's Certificate to be endorsed on such bonds shall be
                    substantially in the following forms, respectively:
<PAGE>   13
 
                                       11
 
                             [FORM OF FACE OF BOND]
 
                           THE DETROIT EDISON COMPANY
                      GENERAL AND REFUNDING MORTGAGE BOND
                    1991 SERIES DP, 6.9% DUE AUGUST 1, 2021
 
                 Notwithstanding any provisions hereof or in the Indenture,
               this bond is not assignable or transferable except as may be
               required to effect a transfer to any successor trustee under
               the Trust Indenture, dated as of May 1, 1991, between the
               City of Superior, Wisconsin and NBD Bank, N.A., as trustee,
               or, subject to compliance with applicable law, as may be
               involved in the course of the exercise of rights and
               remedies consequent upon an Event of Default under said
               Trust Indenture.

                 $.........                                    No..........

                 THE DETROIT EDISON COMPANY (hereinafter called the
               "Company"), a corporation of the State of Michigan, for
               value received, hereby promises to pay to NBD Bank, N.A., as
               trustee, or registered assigns, at the Company's office or
               agency in the Borough of Manhattan, The City and State of
               New York, the principal sum of            dollars ($)       
               in lawful money of the United States of America on the date
               specified in the title hereof and interest thereon at the
               rate specified in the title hereof, in like lawful money,
               from May 1, 1991, and after the first payment of interest on
               bonds of this Series has been made or otherwise provided
               for, from the most recent date to which interest has been
               paid or otherwise provided for, semi-annually on February 1
               and August 1 of each year (commencing August 1, 1991), until
               the Company's obligation with respect to payment of said
               principal shall have been discharged, all as provided, to
               the extent and in the manner specified in the Indenture
               hereinafter mentioned on the reverse hereof and in the
               supplemental indenture pursuant to which this bond has been
               issued.

                 Under a Trust Indenture, dated as of May 1, 1991
               (hereinafter called the "Superior Trust Indenture"), between
               the City of Superior, Wisconsin (hereinafter called
               "Superior"), and NBD Bank, N.A., as trustee (hereinafter
               called the "Superior Trust Indenture Trustee"), Superior has
               issued Limited Obligation Refunding Revenue Bonds (Midwest
               Energy Resources Company Project), Series E-1991
               (Collateralized) (hereinafter called the "Superior Revenue
               Bonds"). This bond was originally issued to Superior and
               simultaneously irrevocably assigned to the Superior Trust
               Indenture Trustee so as to secure the payment of the
               Superior Revenue Bonds. Payments of principal of, or
               premium, if any, or interest on, Superior Revenue Bonds
               shall constitute like payments on this bond as further
               provided herein and in the supplemental indenture pursuant
               to which this bond has been issued.
 
                 Reference is hereby made to such further provisions of this
               bond set forth on the reverse hereof and such further provisions
               shall for all purposes have the same effect as though set forth
               at this place.

                 This bond shall not be valid or become obligatory for any
               purpose until Bankers Trust Company, the Trustee under the
               Indenture hereinafter mentioned on the reverse hereof, or its
               successor thereunder, shall have signed the form of certificate
               endorsed hereon.
<PAGE>   14
 
                                       12
 
 
                 IN WITNESS WHEREOF, THE DETROIT EDISON COMPANY has caused
               this instrument to be executed by its Chairman of the Board
               and its Executive Vice President and Chief Financial Officer
               or a Vice President, with their manual or facsimile
               signatures, and its corporate seal, or a facsimile thereof,
               to be impressed or imprinted hereon and the same to be
               attested by its Secretary or an Assistant Secretary with his
               or her manual or facsimile signature.


               Dated:                         THE DETROIT EDISON COMPANY
                                 
                                              By ............................
                                                 Chairman of the Board
                                   
                                                 ............................
                                                 Executive Vice President
                                                 and Chief Financial Officer
              
               
               Attest:

               ............................
               Secretary
<PAGE>   15
 
                                       13
 
                           [FORM OF REVERSE OF BOND]
 
                 This bond is one of an authorized issue of bonds of the
               Company, unlimited as to amount except as provided in the
               Indenture hereinafter mentioned or any indentures
               supplemental thereto, and is one of a series of General and
               Refunding Mortgage Bonds known as 1991 Series DP, limited to
               an aggregate principal amount of $37,600,000, except as
               otherwise provided in the Indenture hereinafter mentioned.
               This bond and all other bonds of said series are issued and
               to be issued under, and are all equally and ratably secured
               (except insofar as any sinking, amortization, improvement or
               analogous fund, established in accordance with the
               provisions of the Indenture hereinafter mentioned, may
               afford additional security for the bonds of any particular
               series and except as provided in Section 3 of Article VI of
               said Indenture) by an Indenture, dated as of October 1,
               1924, duly executed by the Company to Bankers Trust Company,
               a corporation of the State of New York, as Trustee, to which
               Indenture and all indentures supplemental thereto (including
               the Supplemental Indenture dated as of May 15, 1991)
               reference is hereby made for a description of the properties
               and franchises mortgaged and conveyed, the nature and extent
               of the security, the terms and conditions upon which the
               bonds are issued and under which additional bonds may be
               issued, and the rights of the holders of the bonds and of
               the Trustee in respect of such security (which Indenture and
               all indentures supplemental thereto, including the
               Supplemental Indenture dated as of May 15, 1991, are
               hereinafter collectively called the "Indenture"). As
               provided in the Indenture, said bonds may be for various
               principal sums and are issuable in series, which may mature
               at different times, may bear interest at different rates and
               may otherwise vary as in said Indenture provided. With the
               consent of the Company and to the extent permitted by and as
               provided in the Indenture, the rights and obligations of the
               Company and of the holders of the bonds and the terms and
               provisions of the Indenture, or of any indenture
               supplemental thereto, may be modified or altered in certain
               respects by affirmative vote of at least eighty-five percent
               (85%) in amount of the bonds then outstanding, and, if the
               rights of one or more, but less than all, series of bonds
               then outstanding are to be affected by the action proposed
               to be taken, then also by affirmative vote of at least
               eighty-five percent (85%) in amount of the series of bonds
               so to be affected (excluding in every instance bonds
               disqualified from voting by reason of the Company's interest
               therein as specified in the Indenture); provided, however,
               that, without the consent of the holder hereof, no such
               modification or alteration shall, among other things, affect
               the terms of payment of the principal of or the interest on
               this bond, which in those respects is unconditional.

                 The holders of the bonds of 1991 Series DP, by their
               acceptance of and holding thereof, consent and agree that
               bonds of any series may be issued which mature on a date or
               dates later than October 1, 2024 and also consent to the
               deletion from the first paragraph of Section 5 of Article II
               of the Indenture of the phrase "but in no event later than
               October 1, 2024,". Such holders further agree that (a) such
               consent shall, for all purposes of Article XV of the
               Indenture and without further action on the part of such
               holders, be deemed the affirmative vote of such holders at
               any meeting called pursuant to said Article XV for the
               purpose of approving such deletion, and (b) such deletion
               shall become effective at such time as not less than
               eighty-five per cent (85%) in principal amount of bonds
               outstanding under the Indenture shall have consented thereto
               substantially in the manner set forth in Section 4 of Part I
               of the Supplemental Indenture dated as of May 15, 1991, or
               in writing, or by affirmative vote cast at a meeting called
               pursuant to said Article XV, or by any combination thereof.

                 This bond is redeemable upon the terms and conditions set
               forth in the Indenture, including provision for redemption
               upon demand of the Superior Trust Indenture Trustee
               following the occurrence of an Event of Default under the
               Superior Trust Indenture and the acceleration of the
               principal of the Superior Revenue Bonds.
<PAGE>   16
 
                                       14
 
                 Under the Indenture, funds may be deposited with the
               Trustee (which shall have become available for payment), in
               advance of the redemption date of any of the bonds of 1991
               Series DP (or portions thereof), in trust for the redemption
               of such bonds (or portions thereof) and the interest due or
               to become due thereon, and thereupon all obligations of the
               Company in respect of such bonds (or portions thereof) so to
               be redeemed and such interest shall cease and be discharged,
               and the holders thereof shall thereafter be restricted
               exclusively to such funds for any and all claims of
               whatsoever nature on their part under the Indenture or with
               respect to such bonds (or portions thereof) and interest.

                 In case an event of default, as defined in the Indenture,
               shall occur, the principal of all the bonds issued
               thereunder may become or be declared due and payable, in the
               manner, with the effect and subject to the conditions
               provided in the Indenture.

                 Upon payment of the principal of, or premium, if any, or
               interest on, the Superior Revenue Bonds, whether at maturity
               or prior to maturity by redemption or otherwise or upon
               provision for the payment thereof having been made in
               accordance with Article IV of the Superior Trust Indenture,
               bonds of 1991 Series DP in a principal amount equal to the
               principal amount of such Superior Revenue Bonds and having
               both a corresponding maturity date and interest rate shall,
               to the extent of such payment of principal, premium or
               interest, be deemed fully paid and the obligation of the
               Company thereunder to make such payment shall forthwith
               cease and be discharged, and, in the case of the payment of
               principal and premium, if any, such bonds of said series
               shall be surrendered for cancellation or presented for
               appropriate notation to the Trustee.

                 This bond is not assignable or transferable except as may
               be required to effect a transfer to any successor trustee
               under the Superior Trust Indenture, or, subject to
               compliance with applicable law, as may be involved in the
               course of the exercise of rights and remedies consequent
               upon an Event of Default under the Superior Trust Indenture.
               Any such transfer shall be made by the registered holder
               hereof, in person or by his attorney duly authorized in
               writing, on the books of the Company kept at its office or
               agency in the Borough of Manhattan, The City and State of
               New York, upon surrender and cancellation of this bond, and
               thereupon, a new registered bond of the same series of
               authorized denominations for a like aggregate principal
               amount will be issued to the transferee in exchange
               therefor, and this bond with others in like form may in like
               manner be exchanged for one or more new bonds of the same
               series of other authorized denominations, but of the same
               aggregate principal amount, all as provided and upon the
               terms and conditions set forth in the Indenture, and upon
               payment, in any event, of the charges prescribed in the
               Indenture.

                 No recourse shall be had for the payment of the principal
               of or the interest on this bond, or for any claim based
               hereon or otherwise in respect hereof or of the Indenture,
               or of any indenture supplemental thereto, against any
               incorporator, or against any past, present or future
               stockholder, director or officer, as such, of the Company,
               or of any predecessor or successor corporation, either
               directly or through the Company or any such predecessor or
               successor corporation, whether for amounts unpaid on stock
               subscriptions or by virtue of any constitution, statute or
               rule of law, or by the enforcement of any assessment or
               penalty or otherwise howsoever; all such liability being, by
               the acceptance hereof and as part of the consideration for
               the issue hereof, expressly waived and released by every
               holder or owner hereof, as more fully provided in the
               Indenture.
<PAGE>   17
 
                                       15
 
 
                           [FORM OF TRUSTEE'S CERTIFICATE]
 
FORM OF               This bond is one of the bonds, of the series designated
TRUSTEE'S           therein, described in the within-mentioned Indenture.
CERTIFICATE.
 
                                              BANKERS TRUST COMPANY,
 
                                                             as Trustee
 
                                              By ...........................
                                                 Authorized Officer
 
                                    PART II.
                           RECORDING AND FILING DATA
 
RECORDING AND         The Original Indenture and indentures supplemental
FILING OF ORIGINAL  thereto have been recorded and/or filed and Certificates of
INDENTURE.          Provision for Payment have been recorded as hereinafter set
                    forth.
                      The Original Indenture has been recorded as a real
                    estate mortgage and filed as a chattel mortgage in the
                    offices of the respective Registers of Deeds of certain
                    counties in the State of Michigan as set forth in the
                    Supplemental Indenture dated as of September 1, 1947, has
                    been recorded as a real estate mortgage in the office of the
                    Register of Deeds of Genesee County, Michigan as set forth
                    in the Supplemental Indenture dated as of May 1, 1974, has
                    been filed in the Office of the Secretary of State of
                    Michigan on November 16, 1951 and has been filed and
                    recorded in the office of the Interstate Commerce Commission
                    on December 8, 1969.
 
RECORDING AND         Pursuant to the terms and provisions of the Original
FILING OF           Indenture, indentures supplemental thereto heretofore
SUPPLEMENTAL        entered into have been recorded as a real estate mortgage
INDENTURES.         and/or filed as a chattel mortgage or as a financing
                    statement in the offices of the respective Registers of
                    Deeds of certain counties in the State of Michigan, the
                    Office of the Secretary of State of Michigan and the Office
                    of the Interstate Commerce Commission, as set forth in
                    supplemental indentures as follows:


<TABLE>
<CAPTION>
                                                                                             RECORDED AND/OR
                                                                                          FILED AS SET FORTH IN
                                   SUPPLEMENTAL                      PURPOSE OF               SUPPLEMENTAL
                                    INDENTURE                       SUPPLEMENTAL                INDENTURE
                                   DATED AS OF                       INDENTURE                DATED AS OF:
                                   ------------                     ------------          ---------------------
                        <S>                                 <C>                           <C>
                        June 1, 1925(a)(b)................  Series B Bonds                February 1, 1940
                        August 1, 1927(a)(b)..............  Series C Bonds                February 1, 1940
                        February 1, 1931(a)(b)............  Series D Bonds                February 1, 1940
                        June 1, 1931(a)(b)................  Subject Properties            February 1, 1940
                        October 1, 1932(a)(b).............  Series E Bonds                February 1, 1940
                        September 25, 1935(a)(b)..........  Series F Bonds                February 1, 1940
                        September 1, 1936(a)(b)...........  Series G Bonds                February 1, 1940
                        November 1, 1936(a)(b)............  Subject Properties            February 1, 1940
                        February 1, 1940(a)(b)............  Subject Properties            September 1, 1947
                        December 1, 1940(a)(b)............  Series H Bonds and Ad-        September 1, 1947
                                                              ditional Provisions
                        September 1, 1947(a)(b)(c)........  Series I Bonds,               November 15, 1951
                                                              Subject Properties and
                                                              Additional Provisions
                        March 1, 1950(a)(b)(c)............  Series J Bonds                November 15, 1951
                                                              and Additional Provisions
                        November 15, 1951(a)(b)(c)........  Series K Bonds                January 15, 1953
                                                              Additional Provisions and
                                                              Subject Properties
                        January 15, 1953(a)(b)............  Series L Bonds                May 1, 1953
                        May 1, 1953(a)....................  Series M Bonds                March 15, 1954
                                                              and Subject Properties
                        March 15, 1954(a)(c)..............  Series N Bonds                May 15, 1955
                                                              and Subject Properties
</TABLE>
<PAGE>   18
 
                                       16
 
<TABLE>
<CAPTION>
                                                                                                           RECORDED AND/OR
                                                                                                         FILED AS SET FORTH IN
                                   SUPPLEMENTAL                                PURPOSE OF                    SUPPLEMENTAL
                                    INDENTURE                                 SUPPLEMENTAL                     INDENTURE
                                   DATED AS OF                                 INDENTURE                     DATED AS OF:
                                   ------------                               ------------               ---------------------
                                 <S>                                         <C>                           <C>
                                  May 15, 1955(a)(c)........................  Series O Bonds                 August 15, 1957
                                                                                and Subject Properties
                                  August 15, 1957(a)(c).....................  Series P Bonds                 June 1, 1959
                                                                                Additional Provisions and
                                                                                Subject Properties
                                  June 1, 1959(a)(c)........................  Series Q Bonds                 December 1, 1966
                                                                                and Subject Properties
                                  December 1, 1966(a)(c)....................  Series R Bonds                 October 1, 1968
                                                                                Additional Provisions and
                                                                                Subject Properties
                                  October 1, 1968(a)(c).....................  Series S Bonds                 December 1, 1969
                                                                                and Subject Properties
                                  December 1, 1969(a)(c)....................  Series T Bonds                 July 1, 1970
                                                                                and Subject Properties
                                  July 1, 1970(c)...........................  Series U Bonds                 December 15, 1970
                                                                                and Subject Properties
                                  December 15, 1970(c)......................  Series V and                   June 15, 1971
                                                                                Series W Bonds
                                  June 15, 1971(c)..........................  Series X Bonds                 November 15, 1971
                                                                                and Subject Properties
                                  November 15, 1971(c)......................  Series Y Bonds                 January 15, 1973
                                                                                and Subject Properties
                                  January 15, 1973(c).......................  Series Z Bonds                 May 1, 1974
                                                                                and Subject Properties
                                  May 1, 1974...............................  Series AA Bonds                October 1, 1974
                                                                                and Subject Properties
                                  October 1, 1974...........................  Series BB Bonds                January 15, 1975
                                                                                and Subject Properties
                                  January 15, 1975..........................  Series CC Bonds                November 1, 1975
                                                                                and Subject Properties
                                  November 1, 1975..........................  Series DDP Nos. 1-9 Bonds and  December 15, 1975
                                                                                Subject Properties
                                  December 15, 1975.........................  Series EE Bonds                February 1, 1976
                                                                                and Subject Properties
                                  February 1, 1976..........................  Series FFR Nos. 1-13 Bonds     June 15, 1976
                                  June 15, 1976.............................  Series GGP Nos. 1-7 Bonds and  July 15, 1976
                                                                                Subject Properties
                                  July 15, 1976.............................  Series HH Bonds                February 15, 1977
                                                                                and Subject Properties
                                  February 15, 1977.........................  Series MMP Bonds and Subject   March 1, 1977
                                                                                Properties
                                  March 1, 1977.............................  Series IIP Nos. 1-7 Bonds,     June 15, 1977
                                                                                Series JJP Nos. 1-7 Bonds,
                                                                                Series KKP Nos. 1-7 Bonds
                                                                                and Series LLP Nos. 1-7
                                                                                Bonds
                                  June 15, 1977.............................  Series FFR No. 14 Bonds and    July 1, 1977
                                                                                Subject Properties
                                  July 1, 1977..............................  Series NNP Nos. 1-7 Bonds and  October 1, 1977
                                                                                Subject Properties
</TABLE>
<PAGE>   19
 
                                       17
 
<TABLE>
<CAPTION>
                                                                                                  RECORDED AND/OR
                                                                                               FILED AS SET FORTH IN
                                   SUPPLEMENTAL                           PURPOSE OF               SUPPLEMENTAL
                                    INDENTURE                            SUPPLEMENTAL                INDENTURE
                                   DATED AS OF                            INDENTURE                DATED AS OF:
                                   ------------                          ------------          ---------------------
                        <S>                                         <C>                            <C>
                         October 1, 1977...........................  Series GGP Nos. 8-22 Bonds     June 1, 1978
                                                                       and Series OOP Nos. 1-17
                                                                       Bonds and Subject
                                                                       Properties
                         June 1, 1978..............................  Series PP Bonds,               October 15, 1978
                                                                       Series QQP Nos. 1-9 Bonds
                                                                       and Subject Properties
                         October 15, 1978..........................  Series RR Bonds                March 15, 1979
                                                                       and Subject Properties
                         March 15, 1979............................  Series SS Bonds                July 1, 1979
                                                                       and Subject Properties
                         July 1, 1979..............................  Series IIP Nos. 8-22 Bonds,    September 1, 1979
                                                                       Series NNP Nos. 8-21 Bonds
                                                                       and Series TTP Nos. 1-15
                                                                       Bonds and Subject
                                                                       Properties
                         September 1, 1979.........................  Series JJP No. 8 Bonds,        September 15, 1979
                                                                       Series KKP No. 8 Bonds,
                                                                       Series LLP Nos. 8-15 Bonds,
                                                                       Series MMP No. 2 Bonds and
                                                                       Series OOP No. 18 Bonds and
                                                                       Subject Properties
                         September 15, 1979........................  Series UU Bonds                January 1, 1980
                         January 1, 1980...........................  1980 Series A Bonds and        April 1, 1980
                                                                       Subject Properties
                         April 1, 1980.............................  1980 Series B Bonds            August 15, 1980
                         August 15, 1980...........................  Series QQP Nos. 10-19 Bonds,   August 1, 1981
                                                                       1980 Series CP Nos. 1-12
                                                                       Bonds and 1980 Series DP
                                                                       No. 1-11 Bonds and Subject
                                                                       Properties
                         August 1, 1981............................  1980 Series CP Nos. 13-25      November 1, 1981
                                                                       Bonds and Subject
                                                                       Properties
                         November 1, 1981..........................  1981 Series AP Nos. 1-12       June 30, 1982
                                                                       Bonds
                         June 30, 1982.............................  Article XIV Reconfirmation     August 15, 1982
                         August 15, 1982...........................  1981 Series AP Nos. 13-14 and  June 1, 1983
                                                                       Subject Properties
                         June 1, 1983..............................  1981 Series AP Nos. 15-16 and  October 1, 1984
                                                                       Subject Properties
                         October 1, 1984...........................  1984 Series AP and 1984        May 1, 1985
                                                                       Series BP Bonds and Subject
                                                                       Properties
                         May 1, 1985...............................  1985 Series A Bonds            May 15, 1985
                         May 15, 1985..............................  1985 Series B Bonds and        October 15, 1985
                                                                       Subject Properties
                         October 15, 1985..........................  Series KKP No. 9 Bonds and     April 1, 1986
                                                                       Subject Properties
</TABLE>
<PAGE>   20
 
                                       18
 
<TABLE>
<CAPTION>
                                                                                                  RECORDED AND/OR
                                                                                               FILED AS SET FORTH IN
                                   SUPPLEMENTAL                           PURPOSE OF               SUPPLEMENTAL
                                    INDENTURE                            SUPPLEMENTAL                INDENTURE
                                   DATED AS OF                            INDENTURE                DATED AS OF:
                                   ------------                          ------------          ---------------------
                        <S>                                         <C>                           <C>
                         April 1, 1986.............................  1986 Series A and Subject      August 15, 1986
                                                                       Properties
                         August 15, 1986...........................  1986 Series B and Subject      November 30, 1986
                                                                       Properties
                         November 30, 1986.........................  1986 Series C                  January 31, 1987
                         January 31, 1987..........................  1987 Series A                  April 1, 1987
                         April 1, 1987.............................  1987 Series B and 1987 Series  August 15, 1987
                                                                       C
                         August 15, 1987...........................  1987 Series D and 1987 Series  November 30, 1987
                                                                       E and Subject Properties
                         November 30, 1987.........................  1987 Series F                  June 15, 1989
                         June 15, 1989.............................  1989 Series A                  July 15, 1989
                         July 15, 1989.............................  Series KKP No. 10              December 1, 1989
                         December 1, 1989..........................  Series KKP No. 11 and 1989     February 15, 1990
                                                                       Series BP
                         February 15, 1990.........................  1990 Series A, 1990 Series B,  November 1, 1990
                                                                       1990 Series C, 1990 Series
                                                                       D, 1990 Series E and 1990
                                                                       Series F
                         November 1, 1990..........................  Series KKP No. 12              April 1, 1991
                         April 1, 1991.............................  1991 Series AP                 May 1, 1991
                         May 1, 1991...............................  1991 Series BP and 1991        May 15, 1991
                                                                       Series CP
 </TABLE>

                 ------------------------------------------
                 (a) See Supplemental Indenture dated as of July 1, 1970 for
                     Interstate Commerce Commission filing and recordation
                     information.
 
                 (b) See Supplemental Indenture dated as of May 1, 1953 for
                     Secretary of State of Michigan filing information.
 
                 (c) See Supplemental Indenture dated as of May 1, 1974 for
                     County of Genesee, Michigan recording and filing
                     information.
<PAGE>   21
 
                                       19
 
                   Further, pursuant to the terms and provisions of the
               Original Indenture, a Supplemental Indenture dated as of May
               1, 1991 providing for the terms of bonds to be issued
               thereunder of 1991 Series BP and 1991 Series CP has
               heretofore been entered into between the Company and the
               Trustee and has been filed in the Office of the Secretary of
               State of Michigan as a financing statement on May 17, 1991
               (Filing No. 11440B), has been filed and recorded in the
               Office of the Interstate Commerce Commission (Recordation
               No. 5485-SSS), and has been recorded as a real estate
               mortgage in the offices of the respective Register of Deeds
               of certain counties in the State of Michigan, as follows:
 
<TABLE>
<CAPTION>
                                                                  LIBER OF
                                                                  MORTGAGES
                                                                  OR COUNTY
                     COUNTY                  RECORDED              RECORDS            PAGE
                     ------                  --------             ---------           ----
         <S>                             <C>                      <C>               <C>
         Genesee.......................      May 17, 1991            2645           305-337
         Huron.........................      May 17, 1991             556            64-96
         Ingham........................      May 17, 1991            1879           233-235
         Lapeer........................      May 17, 1991             716           174-206
         Lenawee.......................      May 17, 1991            1155           687-719
         Livingston....................      May 17, 1991            1474           366-398
         Macomb........................      May 17, 1991            5104           362-394
         Mason.........................      May 17, 1991             404           667-699
         Monroe........................      May 17, 1991            1163           399-431
         Oakland.......................      May 17, 1991           11869           763-795
         Sanilac.......................      May 17, 1991             417           836-868
         St. Clair.....................      May 17, 1991             990            26-58
         Tuscola.......................      May 17, 1991             612           734-766
         Washtenaw.....................      May 17, 1991            2495           295-327
         Wayne.........................      May 17, 1991           25124           863-895
</TABLE>
<PAGE>   22
 
                                       20
 
RECORDING OF            All the bonds of Series A which were issued under the
CERTIFICATES        Original Indenture dated as of October 1, 1924, and of
OF PROVISION        Series B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, W,
FOR PAYMENT.        BB, CC, DDP Nos. 1-8, FFR Nos. 1-12, GGP Nos. 1-6 and 8-16,
                    IIP Nos. 1-6 and 8-15, JJP Nos. 1-6, KKP Nos. 1-6, LLP Nos.
                    1-7 and 8-15, NNP Nos. 1-6 and 8-14, OOP Nos. 1-9, QQP Nos.
                    1-8 and 10-15 and TTP Nos. 1-7, UU, 1980 Series A, 1980
                    Series CP Nos. 1-17, 1980 Series DP Nos. 1-11, 1981 Series
                    AP Nos. 1-5 and 1985 Series A which were issued under
                    Supplemental Indentures dated as of, respectively, June 1,
                    1925, August 1, 1927, February 1, 1931, October 1, 1932,
                    September 25, 1935, September 1, 1936, December 1, 1940,
                    September 1, 1947, November 15, 1951, January 15, 1953, May
                    1, 1953, March 15, 1954, May 15, 1955, August 15, 1957,
                    December 15, 1970, October 1, 1974, January 15, 1975,
                    November 1, 1975, February 1, 1976, June 15, 1976, October
                    1, 1977, March 1, 1977, July 1, 1979, March 1, 1977, March
                    1, 1977, March 1, 1977, September 1, 1979, July 1, 1977,
                    July 1, 1979, September 15, 1979, October 1, 1977, June 1,
                    1978, October 1, 1977, July 1, 1979, January 1, 1980, August
                    15, 1980, November 1, 1981 and May 1, 1985 have matured or
                    have been called for redemption and funds sufficient for
                    such payment or redemption have been irrevocably deposited
                    with the Trustee for that purpose; and Certificates of
                    Provision for Payment have been recorded in the offices of
                    the respective Registers of Deeds of certain counties in the
                    State of Michigan, with respect to all bonds of Series A, B,
                    C, D, E, F, G, H, K, L, M, O, W, BB, CC, DDP Nos. 1 and 2,
                    FFR Nos. 1-3, GGP Nos. 1 and 2, IIP No. 1, JJP No. 1, KKP
                    No. 1, LLP No. 1 and GGP No. 8.
                    
                                   PART III.
                                  THE TRUSTEE.
TERMS AND               The Trustee hereby accepts the trust hereby declared and
CONDITIONS OF       provided, and agrees to perform the same upon the terms and
ACCEPTANCE OF       conditions in the Original Indenture, as amended to date and
TRUST BY TRUSTEE.   as supplemented by this Supplemental Indenture, and in this
                    Supplemental Indenture set forth, and upon the following
                    terms and conditions:
                        The Trustee shall not be responsible in any manner
                    whatsoever for and in respect of the validity or sufficiency
                    of this Supplemental Indenture or the due execution hereof
                    by the Company or for or in respect of the recitals
                    contained herein, all of which recitals are made by the
                    Company solely.

                                    PART IV.
                                 MISCELLANEOUS.
CONFIRMATION OF         Except to the extent specifically provided therein, no
SECTION 318(C) OF   provision of this supplemental indenture or any future
TRUST INDENTURE     supplemental indenture is intended to modify, and the
ACT                 parties do hereby adopt and confirm, the provisions of
                    Section 318(c) of the Trust Indenture Act which amend and
                    supercede provisions of the Indenture in effect prior to
                    November 15, 1990.

EXECUTION IN            THIS SUPPLEMENTAL INDENTURE MAY BE SIMULTANEOUSLY
COUNTERPARTS.       EXECUTED IN ANY NUMBER OF COUNTERPARTS, EACH OF WHICH WHEN
                    SO EXECUTED SHALL BE DEEMED TO BE AN ORIGINAL; BUT SUCH
                    COUNTERPARTS SHALL TOGETHER CONSTITUTE BUT ONE AND THE SAME
                    INSTRUMENT.
<PAGE>   23
 
                                       21
 
 
TESTIMONIUM.            IN WITNESS WHEREOF, THE DETROIT EDISON COMPANY AND
                    BANKERS TRUST COMPANY HAVE CAUSED THESE PRESENTS TO BE
                    SIGNED IN THEIR RESPECTIVE CORPORATE NAMES BY THEIR
                    RESPECTIVE CHAIRMEN OF THE BOARD, PRESIDENTS, VICE
                    PRESIDENTS, ASSISTANT VICE PRESIDENTS, TREASURERS OR
                    ASSISTANT TREASURERS AND IMPRESSED WITH THEIR RESPECTIVE
                    CORPORATE SEALS, ATTESTED BY THEIR RESPECTIVE SECRETARIES OR
                    ASSISTANT SECRETARIES, ALL AS OF THE DAY AND YEAR FIRST
                    ABOVE WRITTEN.
 
                                               THE DETROIT EDISON COMPANY,

                    (Corporate Seal)           By /s/    C. C. ARVANI
                                                  --------------------------
                                                      C. C. Arvani
                                                  Assistant Treasurer
 
EXECUTION.          Attest:

                    /s/    SUSAN M. BEALE
                    ----------------------------
                          Susan M. Beale
                            Secretary
        
                    Signed, sealed and delivered by THE DETROIT
                    EDISON COMPANY, in the presence of
        
                    /s/        JANE E. LENART
                    ----------------------------  
                           Jane E. Lenart

                    /s/       JANET A. SCULLEN
                    ----------------------------
                    Janet A. Scullen

                    (Corporate Seal)
                                               BANKERS TRUST COMPANY,
                                               
                                               By /s/     SANDRA SHIRLEY
                                               --------------------------------
                                                        Sandra Shirley
                                                    Assistant Vice President

                    Attest:

                    /s/   JOHN J. MAZZUCA
                    ---------------------------
                          John J. Mazzuca
                        Assistant Secretary
                  
                    Signed, sealed and delivered by
                    BANKERS TRUST COMPANY, in the
                    presence of
                  
                    /s/      ERIC HAWNER
                    ---------------------------
                           Eric Hawner

                    /s/    SIROJNI DINDIAL
                    ---------------------------
                    Sirojni Dindial
<PAGE>   24
 
                                       22
 
                    STATE OF MICHIGAN
                                      SS.:
                    COUNTY OF WAYNE
ACKNOWLEDGMENT        On this 29th day of May, 1991, before me, the subscriber,
OF EXECUTION        a Notary Public within and for the County of Wayne, in the
BY COMPANY.         State of Michigan, personally appeared C. C. Arvani, to me
                    personally known, who, being by me duly sworn, did say that
                    he does business at 2000 Second Avenue, Detroit, Michigan
                    48226 and is the Assistant Treasurer of THE DETROIT EDISON
                    COMPANY, one of the corporations described in and which
                    executed the foregoing instrument; that he knows the
                    corporate seal of the said corporation and that the seal
                    affixed to said instrument is the corporate seal of said
                    corporation; and that said instrument was signed and sealed
                    in behalf of said corporation by authority of its Board of
                    Directors and that he subscribed his name thereto by like
                    authority; and said C. C. Arvani, acknowledged said
                    instrument to be the free act and deed of said corporation.
 
                                               /s/    PEARL E. KOTTER
                                            -------------------------------
                    (Notarial Seal)          Pearl E. Kotter, Notary Public
                                                    Macomb County, MI
                                                (Acting in Wayne County)
                                          My Commission Expires August 23, 1993
 

                    STATE OF NEW YORK
                                        SS.:
                    COUNTY OF NEW YORK
 
ACKNOWLEDGMENT        On this 24th day of May, 1991, before me, the subscriber,
OF EXECUTION        a Notary Public within and for the County of New York, in 
BY TRUSTEE.         the State of New York, personally appeared Sandra Shirley, 
                    to me personally known, who, being by me duly sworn, did 
                    say that her business office is located at Four Albany
                    Street, New York, New York 10015, and she is Assistant Vice
                    President of BANKERS TRUST COMPANY, one of the corporations
                    described in and which executed the foregoing instrument;
                    that she knows the corporate seal of the said corporation
                    and that the seal affixed to said instrument is the
                    corporate seal of said corporation; and that said
                    instrument was signed and sealed in behalf of said
                    corporation by authority of its Board of Directors and that
                    she subscribed her name thereto by like authority; and said
                    Sandra Shirley acknowledged said instrument to be the free
                    act and deed of said corporation.

                    (Notarial Seal)
                                            /s/        MARIA A. JOHNSON
                                            --------------------------------
                                                      Maria A. Johnson
                                            Notary Public, State of New York
                                                       No. 4851727
                                                 Qualified in Nassau County
                                           Certificate filed in New York County
                                           Commission Expires February 3, 1992
<PAGE>   25
 
                                       23
 
                    STATE OF MICHIGAN
                                      SS.:
                    COUNTY OF WAYNE

AFFIDAVIT AS TO       C. C. Arvani, being duly sworn, says: that he is the
CONSIDERATION       Assistant Treasurer of THE DETROIT EDISON COMPANY, the
AND GOOD FAITH.     Mortgagor named in the foregoing instrument, and that he has
                    knowledge of the facts in regard to the making of said
                    instrument and of the consideration therefor; that the
                    consideration for said instrument was and is actual and
                    adequate, and that the same was given in good faith for the
                    purposes in such instrument set forth.

                                             /s/           C. C. ARVANI
                                             -------------------------------
                                                       C. C. Arvani

                    Sworn to before me this 29th day of
                    May, 1991
 
                    /s/       PEARL E. KOTTER
                    ---------------------------------
                     Pearl E. Kotter, Notary Public
                             Macomb County, MI
                        (Acting in Wayne County)
                   My Commission Expires August 23, 1993
 
                    (Notarial Seal)

                         This instrument was drafted by Frances B. Rohlman,
                    Esq., 2000 Second Avenue, Detroit, Michigan 48226