Document:

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                                                                    Exhibit 4.5

                  PROMISSORY NOTE, dated as of August 24, 2000, (this "NOTE") by
EDISON MISSION ENERGY, a California corporation (the "BORROWER"), in favor of
MIDWEST GENERATION, LLC, a Delaware limited liability company (the "LENDER").

                  The Borrower, for value received, hereby promises to pay to
the order of the Lender, the sum of FOUR HUNDRED NINETY NINE MILLION FOUR
HUNDRED FIFTY THOUSAND EIGHT HUNDRED DOLLARS ($499,450,800) (the "LOAN") in
accordance with the terms hereof.

1.       INTEREST. The Borrower agrees to pay to the Lender interest in respect
         of the unpaid principal amount of the Loan from the date hereof until
         the Loan shall be paid in full at an interest rate per annum equal to
         8.30%, the initial interest payment to be made on November 24, 2000,
         payments thereafter payable in arrears on each 2nd day of January and
         July, until paid in full (unless such day is not a Business Day, in
         which event on the immediately preceding Business Day) (each a "PAYMENT
         DATE"); PROVIDED, HOWEVER, that any principal amount not paid when due
         and, to the extent permitted by applicable law, any interest not paid
         when due, in each case whether at stated maturity, by required
         prepayment, declaration, acceleration, demand or otherwise (both before
         as well as after judgment), shall bear interest payable upon demand
         (or, if no demand is made, on the last Business Day of each month) at a
         rate that is 2% per annum in excess of the rate of interest otherwise
         payable with respect to the Loan. Interest on the Loan should be
         computed on the basis of a year of 360 days and twelve 30-day months.
         In computing interest, the date of the making of the Loan applicable to
         the Loan shall be included, and the date of repayment of the Loan shall
         be excluded. In no event shall the interest rate payable on the Loan
         exceed the maximum rate of interest permitted to be charged under
         applicable law.

2.       PRINCIPAL: REPAYMENT ON THE FINAL MATURITY DATE. The Borrower agrees to
         pay to the Lender the principal of the Loan in a series of installments
         on the respective dates and in the respective amounts as set forth in
         SCHEDULE 1 hereto on each Payment Date. All amounts of principal and
         interest thereon and any other amounts outstanding hereunder shall be
         repaid in full on the Final Maturity Date. The principal of the Loan
         may not be prepaid. Amounts borrowed hereunder and subsequently repaid
         or (to the extent permitted) prepaid may not be reborrowed.

3.       PAYMENTS. The Borrower agrees to make payments of principal and
         interest in respect of this Note in lawful money of the United States
         of America in same day

                                    EME NOTE

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         funds not later than 12:00 Noon (New York City time), without set-off
         (except as expressly provided in this Note), or counterclaim, free and
         clear of taxes. Each payment made hereunder shall be credited first to
         interest and fees then due and the remainder of such payment shall be
         credited to principal, and interest shall thereupon cease to accrue
         upon the principal so credited. Each of the Lender and any subsequent
         holder of this Note agrees, by its acceptance hereof, that before
         disposing of this Note or any part hereof it will make a notation
         hereon of all amounts advanced and all principal and interest payments
         previously made hereunder; PROVIDED, HOWEVER, that the failure to make
         a notation of the Loan or payment made on this Note shall not limit or
         otherwise affect the obligation of the Borrower hereunder with respect
         to payments of principal or interest on this Note.

4.       THE LOAN.

                           (a) COMMITMENT TO MAKE THE LOAN; BORROWING MECHANICS.
The Borrower shall deliver notice (a "NOTICE OF BORROWING") to Lender no later
than 12:00 Noon (New York City time) at least one Business Day in advance of the
Closing Date. Such Notice of Borrowing shall specify (i) the amount of the Loan,
(ii) that no Event of Default or event that, after notice or after any
applicable grace period has lapsed, or both, would constitute an Event of
Default has occurred and is continuing and (iii) that the condition to funding
set forth in Section 4(c), have been satisfied as of such date. The Lender shall
have no obligation to make the Loan requested hereunder unless it receives a
Notice of Borrowing in accordance with the terms of this Section. Upon funding
of the Loan by the Lender in accordance with this Note pursuant to any such
Notice of Borrowing, the Borrower shall have effected a borrowing hereunder in
the amount of the Loan. A Notice of Borrowing shall be irrevocable on and after
2:00 p.m (New York City time) on the date the Notice of Borrowing is received
and the Borrower shall be bound to make a borrowing in accordance therewith. The
Lender shall make the proceeds of the Loan available to the Borrower on the
Closing Date by causing an amount of same day funds equal to the amount of the
Loan to be credited to such account of the Borrower as the Borrower shall
specify to the Lender.

                           (b) ADJUSTMENTS FOR WITHHOLDING, CAPITAL ADEQUACY,
ETC. If the effect of the adoption, effectiveness, phase-in or applicability
after the date hereof of any law, rule or regulation (including without
limitation any reserve requirement or tax, duty, charge or withholding on or
from payments due from the Borrower (but excluding taxation on the net income or
profits or the Lender)), or any change therein or in the interpretation or
administration thereof by any governmental authority, central bank or comparable
agency charged with the interpretation or administration thereof, is to reduce
the rate of return on the capital of the Lender with respect to this Note or to
increase the

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cost to the Lender of making or maintaining amounts available under this Note,
then the Borrower shall pay to the Lender such additional amount or amounts as
will compensate the Lender on an after-tax basis for such reduction or increase.

                           (c) CONDITION TO THE LOAN. The obligations of the
Lender to make the Loan hereunder are subject to delivery by the Borrower of the
Notice of Borrowing.

5.       REPRESENTATIONS AND WARRANTIES.

                  In order to induce the Lender to make the Loan, the Borrower
makes the following representations and warranties:

                  (1) The Borrower (i) is validly organized and existing and in
good standing under the laws of the State of California, (ii) has all requisite
power and authority to conduct its business substantially as currently conducted
by it and (iii) has all requisite power and authority to enter into and perform
its obligations under this Note, except, with respect to clauses (ii) and (iii)
to the extent that the failure to comply therewith would not reasonably be
expected to have a material adverse effect on the Borrower's ability to perform
its obligations under this Note.

                  (2) This Note constitutes the Borrower's legal, valid and
binding obligation enforceable in accordance with its terms (except as may be
limited by bankruptcy, insolvency or other similar laws affecting the
enforcement of creditors' rights generally and general principles of equity).

                  (3) The execution, delivery and performance by the Borrower of
this Note do not: (i) contravene its Articles of Incorporation or By-laws, (ii)
contravene any law, governmental regulation, court decree or order or material
contractual obligation binding on or affecting it or (iii) result in, or require
the creation or imposition of, any lien on any of its properties.

                  (4) No part of the proceeds of the Loan will be used by the
Borrower to purchase or carry any Margin Stock (as defined in Regulations T, U
or X of the Federal Reserve Board) or for the purpose of reducing or retiring
any indebtedness originally incurred to purchase or carry a margin security or
margin stock or for any other purpose which might cause any of the transactions
contemplated by this Note to constitute a "purpose credit" within the meaning of
such Regulation T, U or X or for the purpose of purchasing or carrying any
security, and the Borrower has not taken and will not take any action in
connection with any of the transactions contemplated by this Note that would
involve a violation of such Regulation T, U or X, or any other regulation of the
Federal Reserve Board.

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6.       BORROWER COVENANTS.

         The Borrower covenants and agrees that until the Loan and all other
obligations under this Note are paid in full: (a) the Borrower shall furnish to
the Lender such information or documents (financial or otherwise) relating to
the Borrower's ability to perform under this Note in the possession of the
Borrower as the Lender may from time to time reasonably request; (b) the
Borrower shall keep proper books of record and account in which full, true and
correct entries in conformity with GAAP shall be made of all dealings and
transactions in relation to this Note; and (c) the Borrower shall comply with
all applicable laws, rules, statutes, regulations, decrees and orders of, and
all applicable restrictions imposed by, all governmental bodies, domestic or
foreign, in respect of the conduct of its business and the ownership of its
property, except where such noncompliance would not be reasonably be expected to
have a material adverse effect on the Borrower's ability to perform its
obligations under this Note.

7.       EVENTS OF DEFAULT.

                  Each of the following events, acts, occurrences or conditions
shall constitute an "EVENT OF DEFAULT" under this Note:

                           (a) The Borrower shall default in the payment when
due of any principal of the Loan or the Borrower shall default (and such default
shall continue unremedied for five Business Days) in the payment when due of
interest on the Loan.

                           (b) Any representation or warranty made by the
Borrower herein or in any certificate or statement delivered pursuant hereto is
or shall be incorrect when made in any material respect.

                           (c) The Borrower shall fail to perform or observe any
other agreement or covenant set forth herein or obligation arising hereunder and
such failure shall continue unremedied for a period of thirty days after written
notice thereof shall have been given to the Borrower by the Lender.

                           (d) The Borrower shall:

                                    (i) become insolvent or generally fail to
                  pay, or admit in writing its inability or unwillingness to
                  pay, debts as they become due;

                                    (ii) apply for, consent to, or acquiesce in,
                  the appointment of a trustee, receiver, sequestrator or other
                  custodian for the Borrower or a substantial portion of its
                  property, or make a general assignment for the benefit of
                  creditors;

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                                    (iii) in the absence of such application,
                  consent or acquiescence, permit or suffer to exist the
                  appointment of a trustee, receiver, sequestration or other
                  custodian for the Borrower or for a substantial part of its
                  property, and such trustee, receiver, sequestration or other
                  custodian shall not be discharged within sixty days, PROVIDED
                  that nothing in this Note shall prohibit or restrict any right
                  the Lender may have under applicable law to appear in any
                  court conducting any relevant proceeding during such sixty-day
                  period to preserve, protect and defend its rights under this
                  Note (and the Borrower shall not object to any such
                  appearance);

                                    (iv) permit or suffer to exist the
                  commencement of any bankruptcy, reorganization, debt
                  arrangement or other case or proceeding under any bankruptcy
                  or insolvency law, or any dissolution, winding up or
                  liquidation proceeding, in respect of the Borrower, and, if
                  any such case or proceeding is not commenced by the Borrower,
                  such case or proceeding shall be consented to or acquiesced in
                  by the Borrower or shall result in the entry of an order for
                  relief or shall remain for sixty days undismissed, PROVIDED
                  that nothing in this Note shall prohibit or restrict any right
                  the Lender may have under applicable law to appear in any
                  court conducting any such case or proceeding during such
                  sixty-day period to preserve, protect and defend its rights
                  under this Note (and the Borrower shall not object to any such
                  appearance); or

                                    (v) take any corporate action authorizing,
                  or in furtherance of, any of the foregoing.

                           (e) A default shall occur in the payment when due
(subject to any applicable grace period), whether by acceleration or otherwise,
of any indebtedness of the Borrower (other than indebtedness incurred under this
Note) or a default shall occur in the performance or observance of any
obligation or condition with respect to such indebtedness if the effect of such
default is to accelerate the maturity of any such indebtedness or such default
shall continue unremedied for any applicable period of time sufficient to permit
the holder or holders of such indebtedness, or any trustee or agent for such
holders, to cause such indebtedness to become due and payable prior to its
expressed maturity, in either case, such indebtedness having a principal amount,
individually or in the aggregate, in excess of $20,000,000 (other than
indebtedness described in clause (a) above).

                           (f) Any judgment or order for the payment of money in
excess of $50,000,000 (taking into account any insurance proceeds payable under
a policy where

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the insurer has accepted coverage without reservation) shall be rendered against
the Borrower and either:

                                    (i) enforcement proceedings shall have been
                  commenced by any creditor upon such judgment or order; or

                                    (ii) there shall be any period of fifteen
                  consecutive days during which a stay of enforcement of such
                  judgment or order, by reason of a pending appeal or otherwise,
                  shall not be in effect.

8.       REMEDIES.

                  Upon the occurrence and during the continuance of any Event of
Default, the Lender may in its sole discretion (except in the case of an Event
of Default occurring under Section 7(d) above, in which case the following will
occur automatically) declare the unpaid principal amount of and any and all
accrued and unpaid interest on the Loan and any and all other obligations under
this Note to be, and the same shall thereupon be, immediately due and payable
with all additional interest from time to time accrued thereon and without
presentation, demand, or protest or other requirements of any kind (including,
without limitation, valuation and appraisement, diligence, presentment, notice
of intent to demand or accelerate and notice of acceleration), all of which are
hereby expressly waived by the Borrower. The Borrower is hereby authorized at
any time and from time to time, to the fullest extent permitted by law, to
set-off and apply any and all payments made with respect to Basic Lease Rent by
the Borrower to Powerton Trust I under the Guaranty Agreement dated as of August
17, 2000 by the Borrower in favor of Powerton Trust I (as the same may be
amended from time to time, the "EME GUARANTY"), against the obligations of the
Borrower due this Note, provided, however, that following the occurrence of a
Specified Event under and as defined in the EME Powerton (TI) Pledge Agreement,
dated as of August 17, 2000, between the Lender and Citibank, N.A., as
Collateral Agent, the Borrower shall not be entitled to set-off payments made by
the Borrower under the EME Guaranty.

9.       INDEMNIFICATION.

                  The Borrower shall pay all out-of-pocket costs and expenses of
all parties hereto in connection with the negotiation, preparation, execution,
delivery, amendment or waiver of this Note, in connection with the preservation
of rights under, and enforcement of, this Note, or in connection with any
restructuring or rescheduling of the obligations hereunder. The Borrower shall
indemnify the Lender, its officers, directors, partners, stockholders,
employees, representatives and agents (each, an "INDEMNITEE") from, and hold
each of them harmless against, any and all losses, liabilities, claims, damages,
expenses, obligations, penalties, actions, judgments, suits, costs or
disbursements of any

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kind or nature whatsoever (including, without limitation, the fees and
disbursements of counsel for such Indemnitee in connection with any
investigative, administrative or judicial proceeding commenced or threatened,
whether or not such Indemnitee shall be designated a party thereto) that may at
any time (including, without limitation, at any time following the payment of
the obligations) be imposed on, asserted against or incurred by any Indemnitee
as a result of, or arising out of, or in any way related to or by reason of, (i)
any of the transactions contemplated hereby or the execution, delivery or
performance of this Note and (ii) the exercise by the Lender of its rights and
remedies hereunder (but excluding, as to any Indemnitee, any such losses,
liabilities, claims, damages, expenses, obligations, penalties, actions,
judgments, suits, costs or disbursements incurred solely by reason of the gross
negligence or willful misconduct of such Indemnitee as finally determined by a
court of competent jurisdiction). The Borrower's obligations under this
paragraph shall survive the termination of this Note and the payment of the
obligations hereunder.

10.      DEFINITIONS.

         "BUSINESS DAY" shall mean any day on which federal and state chartered
banks in Wilmington, Delaware and New York are open for commercial banking
business.

         "CLOSING DATE" shall mean August 24, 2000.

         "FINAL MATURITY DATE" shall mean January 2, 2016.

         "PARTY" or "PARTIES" shall mean the Borrower and, by virtue of its
acceptance of this Note, the Lender.

11.      MISCELLANEOUS.

                  No failure or delay on the part of the Lender in exercising
any right, power or privilege hereunder and no course of dealing between the
parties hereto shall operate as a waiver thereof; nor shall any single or
partial exercise of any right, power or privilege hereunder preclude any other
or further exercise thereof or the exercise of any other right, power or
privilege hereunder. The rights and remedies herein expressly provided are
cumulative and not exclusive of any rights or remedies which the Lender would
otherwise have. No notice to the Borrower in any case shall entitle the Borrower
to any other or further notice in similar or other circumstances or constitute a
waiver of the rights of the Lender to any other or further action in any
circumstances without notice.

                  This Note shall be binding upon and shall inure to the benefit
of the parties hereto and their respective successors and assigns; PROVIDED,
HOWEVER, that (i) the Borrower shall not assign its obligations under this Note
without the prior written consent

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of the Lender and (ii) the Lender shall give a prior written notice to the
Borrower of any assignment of this Note.

                  This Note may be amended, modified or waived only by an
instrument in writing signed by the Lender and Borrower.

                  THIS NOTE AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES
HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND BE GOVERNED BY THE LAWS OF
THE STATE OF NEW YORK.

                  ANY LITIGATION BASED HEREON, OR ARISING OUT OF, UNDER, OR IN
CONNECTION WITH, THIS NOTE, OR ANY COURSE OF CONDUCT, COURSE OF DEALING,
STATEMENTS (WHETHER VERBAL OR WRITTEN) OR ACTIONS OF ANY PARTY HERETO SHALL BE
BROUGHT AND MAINTAINED EXCLUSIVELY IN THE COURTS OF THE STATE OF NEW YORK OR IN
THE UNITED STATES DISTRICT COURT FOR THE SOUTHERN DISTRICT OF NEW YORK. EACH
PARTY HERETO HEREBY EXPRESSLY AND IRREVOCABLY SUBMITS TO THE JURISDICTION OF THE
COURTS OF THE STATE OF NEW YORK AND OF THE UNITED STATES DISTRICT COURT FOR THE
SOUTHERN DISTRICT OF NEW YORK FOR THE PURPOSE OF ANY SUCH LITIGATION AS SET
FORTH ABOVE AND IRREVOCABLY AGREES TO BE BOUND BY ANY JUDGMENT RENDERED THEREBY
IN CONNECTION WITH SUCH LITIGATION. EACH PARTY HERETO FURTHER IRREVOCABLY
CONSENTS TO THE SERVICE OF PROCESS BY REGISTERED MAIL, POSTAGE PREPAID, OR BY
PERSONAL SERVICE WITHIN OR WITHOUT THE STATE OF NEW YORK. EACH PARTY HERETO
HEREBY EXPRESSLY AND IRREVOCABLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY LAW,
ANY OBJECTION WHICH IT MAY HAVE OR HEREAFTER MAY HAVE TO THE LAYING OF VENUE OF
ANY SUCH LITIGATION BROUGHT IN ANY SUCH COURT REFERRED TO ABOVE AND ANY CLAIM
THAT ANY SUCH LITIGATION HAS BEEN BROUGHT IN AN INCONVENIENT FORUM. TO THE
EXTENT THAT ANY PARTY HERETO HAS OR HEREAFTER MAY ACQUIRE ANY IMMUNITY FROM
JURISDICTION OF ANY COURT OR FROM ANY LEGAL PROCESS (WHETHER THROUGH SERVICE OR
NOTICE, ATTACHMENT PRIOR TO JUDGMENT, ATTACHMENT IN AID OF EXECUTION OR
OTHERWISE) WITH RESPECT TO ITSELF OR ITS PROPERTY, SUCH PARTY HEREBY IRREVOCABLY
WAIVES SUCH IMMUNITY IN RESPECT OF ITS OBLIGATIONS UNDER THIS NOTE.

                  EACH PARTY HEREBY KNOWINGLY, VOLUNTARILY AND INTENTIONALLY
WAIVES ANY RIGHTS IT MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY LITIGATION
BASED HEREON, OR ARISING OUT OF, UNDER, OR IN CONNECTION WITH, THIS NOTE, OR ANY
COURSE OF CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN)

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OR ACTIONS OF ANY PARTY HERETO. EACH PARTY ACKNOWLEDGES AND AGREES THAT IT HAS
RECEIVED FULL AND SUFFICIENT CONSIDERATION FOR THIS PROVISION AND THAT THIS
PROVISION IS A MATERIAL INDUCEMENT FOR THE OTHER PARTIES HERETO.

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                  IN WITNESS WHEREOF, the Borrower has caused its duly
authorized officer to execute and deliver this Note as of the date first above
written.

                                        EDISON MISSION ENERGY

                                        By:    /s/ John P. Finneran, Jr.
                                           -------------------------------
                                          Name:  John P. Finneran, Jr.
                                          Title: Vice President

                                        Notice Address:

                                        18101 Von Karman Avenue
                                        Suite 1700
                                        Irvine, CA  92616
                                        Attention:  General Counsel
                                        Telecopier No.:  (949) 752-1420

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                                                                      SCHEDULE I
                                                                PAYMENT SCHEDULE

                                       11<PAGE>

                                                                  Exhibit 4.5.1

SCHEDULE IDENTIFYING SUBSTANTIALLY IDENTICAL AGREEMENT(S)  TO EXHIBIT 4.5
-------------------------------------------------------------------------

Promissory Note ($285,849,200 ), dated as of August 24, 2000, by Edison Mission
Energy in favor of Midwest Generation, LLC.

         This Promissory Note differs from Exhibit 4.17 in the following
respects:

         In the Remedies section, Edison Mission Energy is authorized to set off
         and apply all payments made with respect to Basic Lease Rent by Edison
         Mission Energy to Powerton Trust II, against the obligations due under
         the Note.

         The Final Maturity Date is January 2, 2015

Promissory Note ($369,961,200 ), dated as of August 24, 2000, by Edison Mission
Energy in favor of Midwest Generation, LLC.

         This Promissory Note differs from Exhibit 4.17 in the following
respects:

         In the Remedies section, Edison Mission Energy is authorized to set off
         and apply all payments made with respect to Basic Lease Rent by Edison
         Mission Energy to Joliet Trust I, against the obligations due under the
         Note.

         The Final Maturity Date is July 2, 2014

Promissory Note ($211,738,800 ), dated as of August 24, 2000, by Edison Mission
Energy in favor of Midwest Generation, LLC.

         This Promissory Note differs from Exhibit 4.17 in the following
respects:

         In the Remedies section, Edison Mission Energy is authorized to set off
         and apply all payments made with respect to Basic Lease Rent by Edison
         Mission Energy to Joliet Trust II, against the obligations due under
         the Note.

         The Final Maturity Date is July 2, 2014

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