<PAGE>
 
                                                               EXHIBIT NO. 10.47



                                                               Execution Version



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                         CAPITAL CONTRIBUTION GUARANTEE

                                      by

                                EME TRI GEN BV
 
                                      and

                            EDISON MISSION ENERGY,
                                  Guarantors
                                
                                  in favor of

                           TRI ENERGY COMPANY LIMITED


                                      and

                           THE SANWA BANK, LIMITED,
                           as Equity Facility Agent


================================================================================
<PAGE>
 
                        CAPITAL CONTRIBUTION GUARANTEE

         THIS CAPITAL CONTRIBUTION GUARANTEE (this "Guarantee"), dated as of
                                                    ---------
June 30, 1998, is made by EME Tri Gen BV, a corporation organized and validly
existing under the laws of The Netherlands ("ETG" or the "Sponsor"), having its
principal address at Croeselaan 18, 3521 CB Utrecht, The Netherlands and Edison
Mission Energy, a corporation organized and validly existing under the laws of
the State of California ("EME" and together with ETG, the "Guarantors"), having
                                                           ----------
its principal address at 18101 Von Karman Ave., Suite 1700, Irvine, California
92612-1046 U.S.A., in favor of Tri Energy Company Limited, a limited liability
company organized and existing under the laws of Thailand (the "Borrower"),
                                                                --------
having its registered address at 16th Fl., Grand Amarin Tower, New Petchburi
Road, Ratchathewi, Bangkok, 10320 Thailand and The Sanwa Bank, Limited, a
banking institution organized under the laws of Japan, acting by and through its
Tokyo head office, as Equity Facility Agent (in such capacity, together with its
successors and assigns in such capacity, the "Equity Facility Agent") for the
                                              ---------------------
Equity Bridge Lenders under the Financing Documents.

    WITNESSETH:
    ----------

         A.  The Guarantors. ETG is a sponsor of the Borrower. EME is the parent
             --------------                                                   
corporation of ETG.

         B.  Common Terms Agreement. The Borrower has entered into that certain
             ----------------------
Amended and Restated Common Terms Agreement, dated as of June 30, 1998, among
the Borrower, Credit Suisse First Boston, as Documentation and Coordination
Agent and Syndication Agent, the Sanwa Bank, Limited, as Facility Agent, Equity
Facility Agent, Offshore Collateral Agent and Technical Agent, Tokyo-Mitsubishi
International (Singapore) Ltd., as Insurance Agent, The Sumitomo Bank, Limited,
as Onshore Collateral Agent, Citibank, N.A., as a Letter of Credit Facility
Lender and a Working Capital Facility Lender, Siam City Bank Public Company
Limited, as Guarantee Facility Lender and a Working Capital Facility Lender, The
Industrial Finance Corporation of Thailand, as a Working Capital Facility
Lender, and NationsBank, N.A., as a Letter of Credit Facility Lender, and all
financial institutions and trusts that from time to time become Lenders pursuant
to the terms of the Credit Agreement. The Common Terms Agreement sets forth
certain common provisions regarding the Loans, including (i) the conditions
precedent to the initial drawdown and conditions precedent to subsequent
drawdowns of the Credit Facilities and the conditions precedent to the Credit
Facility Conversion, (ii) representations and covenants of the Borrower running
in favor of the Financing Parties, (iii) common Events of Default, and (iv)
reporting and insurance requirements for the Project.

         C.  Financing Documents. The Borrower has entered into (i) that certain
             -------------------
Equity Bridge Loan Credit Agreement with the Equity Bridge Lenders, the
Documentation and Coordination Agent, the Facility Agent, the Equity Facility
Agent and Banpu Gas (solely for purposes of Section 2.5.3 thereof), pursuant to
                                            --------------                     
which the Equity Bridge Lenders will provide Equity Bridge Loans to the Borrower
during the construction phase of the Project, which are to be guaranteed in part
by this Guarantee, (ii) the Credit Agreements with the Lenders and the Agents
party thereto, and (iii) certain other Financing Documents.

         D.  Condition to Lending. It is a condition precedent to the Equity
             --------------------
Bridge Lenders' obligation to make the Equity Bridge Loan Facility available to
the Borrower under the Common Terms Agreement and the Equity Bridge Loan Credit
Agreement and the Lenders'

                                      -2-
<PAGE>
 
obligations to make the other Credit Facilities available to the Borrower under
the Common Terms Agreement and the other Credit Agreements that the Guarantors
enter into this Guarantee.

     AGREEMENT
     ---------

         NOW, THEREFORE, in consideration of the premises set forth above and
other good and valuable consideration, receipt of which is hereby acknowledged,
and as an inducement to the Equity Bridge Lenders to enter into the Equity
Bridge Loan Credit Agreement with the Borrower, and to the Lenders to enter into
all other Financing Documents, the Guarantors hereby agree as follows:

         1.    Capitalized Terms. Capitalized terms used but not otherwise
               -----------------
defined herein shall have the respective meanings given them in Section 1 of
Schedule 1 to the Common Terms Agreement, and the Principles of Construction
contained in Section 2 of Schedule 1 to the Common Terms Agreement shall apply
hereto.

         2.    Guarantee of Obligations.
               ------------------------

          (a) The Guarantors hereby, jointly and severally, unconditionally and
irrevocably guarantee to the Equity Bridge Lenders and the Equity Facility Agent
(for the benefit of the Equity Bridge Lenders) to make on or before the Equity
Bridge Loan Repayment Date, whether by acceleration or otherwise, aggregate
capital contributions to the Capital Contributions Account of the Borrower equal
to twenty-five percent (25%) (the "EME Guaranteed Percentage") of all
                                   -------------------------
obligations of the Borrower under the Equity Bridge Loan Credit Agreement and
allocable to the Equity Bridge Loans under any other applicable Financing
Documents (but, for the avoidance of doubt, not including (i) any obligations by
the Borrower in favor of the Offshore Lenders to repay amounts drawn from the
Offshore Loans and used to pay interest due on the Equity Bridge Loans, or (ii)
any amounts owed by the Borrower to any Hedge Provider under Interest Rate
Hedging Agreements entered into by the Borrower with respect to the Equity
Bridge Loans) whether for interest, fees, expenses or otherwise, together with
all expenses incurred by the Equity Facility Agent or the Equity Bridge Lenders
in enforcing any of such obligations or the terms hereof, including reasonable
fees and expenses of legal counsel, but specifically limited solely to amounts
due to the Equity Facility Agent and the Equity Bridge Lenders and not to
include any amounts owed by the Borrower to other Persons under or based upon
any other Financing Documents (the EME Guaranteed Percentage of the total of
such obligations of the Borrower is referred to herein as the "Guaranteed
                                                               ---------- 
Obligations"). The Guarantors agree that if for any reason whatsoever the
-------------
Borrower fails or is unable duly, punctually and fully to pay any such
Guaranteed Obligations, the Guarantors shall, upon demand by the Equity Facility
Agent (acting at the instructions of the Equity Bridge Lenders), make aggregate
capital contributions to the Borrower in the amount of such Guaranteed
Obligations by deposit of such capital contributions into the Capital
Contributions Account within five (5) Business Days after the date of demand,
without regard to any exercise or non-exercise by the Equity Facility Agent or
the Equity Bridge Lenders of any right, remedy, power or privilege under or in
respect of the Equity Bridge Loan Credit Agreement or any other Financing
Document against the Borrower. The Borrower acknowledges and agrees that, upon
receipt of such capital contributions, the Offshore Collateral Agent shall be
obligated to transfer immediately to the Equity Facility Agent the amount of
such capital contributions in payment of the Guaranteed Obligations pursuant to
Section 2.1.8 of the Disbursement Agreement to enable the Borrower to repay the
Equity Bridge Loans. Each payment made by a Guarantor pursuant to this Section
2(a) in respect of the Guaranteed Obligations shall be deemed to be a capital
contribution by the Sponsor to the Borrower. Upon receipt of such capital
contribution, the Borrower agrees promptly to issue shares of its Capital Stock
to the Sponsor in respect of such capital contribution, in accordance with
Section 5.2 of the Shareholders' Agreement and the Charter Documents, and the
Sponsor shall, and EME shall cause the Sponsor to, execute Pledge Agreements
with respect to

                                      -3-
<PAGE>
 
such shares of Capital Stock; provided, however, that the failure of the
                              --------  -------                              
Borrower to deliver such shares of Capital Stock shall not excuse the
Guarantors' obligations hereunder.

          (b) The obligations of the Guarantors under this Guarantee are the
Guarantors' primary obligations and are an absolute, unconditional, continuing
and irrevocable guarantee of payment and not of collectibility or performance
and are in no way conditioned on or contingent upon any attempt to enforce in
whole or in part the Borrower's obligations under the Equity Bridge Loan Credit
Agreement or the obligations of any Person under any of the other Financing
Documents. The obligations of the Guarantors under this Guarantee are not, and
shall not be, subject to any defense or right of set-off, counterclaim,
deduction, diminution, abatement, recoupment, suspension, deferment or reduction
or any other legal or equitable defense which the Guarantors have or hereafter
may have, against any other Person (including the Borrower) for any reason
whatsoever (including any action, failure to act or circumstance which
constitutes, or might constitute or be construed as, an equitable or legal
discharge of any or all of the Borrower's obligations under the Equity Bridge
Loan Credit Agreement); provided that nothing in this Guarantee shall affect
                        --------                                           
any right the Guarantors may have against any of the Equity Bridge Lenders or
the Equity Facility Agent arising out of any gross negligence or willful
misconduct of any such Person under the Equity Bridge Loan Credit Agreement,
the Common Terms Agreement or this Guarantee. Each failure by the Borrower to
pay any Guaranteed Obligations shall give rise to a separate cause of action
hereunder, and separate suits may be brought hereunder as each cause of action
arises.

          (c) The Equity Facility Agent, acting pursuant to the Equity Bridge
Loan Credit Agreement or the Equity Bridge Lenders may, at any time and from
time to time without the consent of or notice to the Guarantors, except such
notice as may be required by the Financing Documents or Applicable Law, which
cannot be waived, without incurring responsibility to the Guarantors, without
impairing or releasing the obligations of the Guarantors hereunder, upon or
without any terms or conditions and in whole or in part, (i) change, by mutual
agreement with the Borrower, the manner, place and terms of payment or change or
extend the time of payment of, renew or alter any Guaranteed Obligations or any
obligations (including any hereunder) incurred directly or indirectly in respect
hereof, or in any manner by mutual agreement with the Borrower modify, amend or
supplement the terms of the Equity Bridge Loan Credit Agreement or any
documents, instruments or agreements executed in connection therewith (other
than any document to which either Guarantor is a party), and the guarantee
herein undertaken shall apply to the Guaranteed Obligations as so changed,
extended, renewed, modified, amended, supplemented or altered; (ii) exercise or
refrain from exercising any rights against the Borrower or others (including the
Guarantors), whether under the Financing Documents or otherwise, or otherwise
act or refrain from acting; (iii) add or release any other guarantor or other
Person from its obligations under any of the Financing Documents without
obtaining the consent of the Guarantors, and without affecting or impairing the
obligations of the Guarantors hereunder; (iv) settle or compromise any
Guaranteed Obligations and/or any obligations and liabilities (including any of
those hereunder) incurred directly or indirectly in respect thereof or hereof,
and may subordinate the payment of all or any part thereof to the payment of any
obligations and liabilities which may be due to the Equity Bridge Lenders or
others; (v) sell, exchange, release, surrender, realize upon or otherwise deal
with in any manner or in any order any property or assets by whomsoever pledged,
transferred, or assigned to secure or howsoever securing the Guaranteed
Obligations or any liabilities or obligations (including any of those hereunder)
incurred directly or indirectly in respect thereof or hereof and/or any offset
thereagainst; (vi) apply any sums by whomsoever paid or howsoever realized to
the obligations of the Borrower under the Equity Bridge Loan Credit Agreement in
the manner provided for therein regardless of what obligations and liabilities
remain unpaid; (vii) consent to or waive any breach of, or any act, omission or
default under, the Financing Documents or any of such other instruments or
agreements, or with the mutual agreement of the Borrower and (when such
Guarantor is a party thereto) each respective Guarantor, amend, modify or
supplement the Financing Documents or any

                                      -4-
<PAGE>
 
of such other instruments or agreements; and/or (viii) act or fail to act in any
manner referred to in this Guarantee which may deprive the Guarantors of any
right it may otherwise have had to subrogation or reimbursement against the
Borrower to recover full indemnity for any payments made pursuant to this
Guarantee or of its right of contribution against any other party.

          (d) No invalidity, irregularity or unenforceability of any or all of
the obligations or liabilities hereby guaranteed shall affect, impair, or be a
defense to this Guarantee.

          (e) This is a continuing Guarantee and all obligations to which it
applies or may apply under the terms hereof shall be conclusively presumed to
have been created in reliance hereon. The Guarantors hereby waive any right to
revoke this Guarantee, and acknowledges that this Guarantee is continuing in
nature and applies to all Guaranteed Obligations, whether existing now or in the
future. In the event that, notwithstanding the provisions of this Section 2,
                                                                  ---------
this Guarantee shall be deemed revocable pursuant to Applicable Law, then any
such revocation shall become effective only upon receipt by the Equity Facility
Agent of written notice of revocation signed by the Guarantors. No revocation or
termination hereof shall affect in any manner rights arising under this
Guarantee with respect to Guaranteed Obligations arising prior to receipt by the
Equity Facility Agent of written notice of such revocation or termination and
the sole effect of revocation and termination hereof shall be to exclude from
this Guarantee all Guaranteed Obligations thereafter arising which are
unconnected with Guaranteed Obligations theretofore arising or transactions
theretofore entered into.

          (f) Each Guarantor acknowledges and agrees that (i) it will benefit,
directly and indirectly, if the Equity Bridge Lenders enter into the Equity
Bridge Loan Credit Agreement with the Borrower and (ii) the obligations of such
Guarantor hereunder are being incurred concurrently with the obligations of the
Borrower under the Financing Documents.

          (g) The obligations of each Guarantor hereunder shall remain
unchanged and in full force and effect in accordance with the terms hereof
notwithstanding any transfer or other disposition of any interest (whether
direct or indirect) in the Sponsor or any transfer or other disposition by the
Sponsor of its interest in the Borrower.

          (h) Anything in this Guarantee or in any other Financing Document to
the contrary notwithstanding, the maximum liability of each Guarantor under this
Guarantee shall in no event exceed the amount that can be guaranteed by each
Guarantor under applicable U.S. federal and state laws relating to the
insolvency of debtors.

         3.  Waiver. To the fullest extent permitted by Applicable Law, each
             ------  
Guarantor hereby expressly waives and relinquishes all rights and remedies
accorded by Applicable Law to sureties or guarantors and agrees not to assert or
take advantage of any such rights or remedies, including (i) any right to
require the Equity Facility Agent or the Equity Bridge Lenders to proceed
against the Borrower or any other Person or to proceed against or exhaust any
security held by the Equity Facility Agent, on behalf of the Equity Bridge
Lenders, or by the Equity Bridge Lenders at any time or to pursue any other
remedy in the Equity Facility Agent's or the Equity Bridge Lenders' power before
proceeding against such Guarantor; (ii) any right to elect trial by jury, the
benefit of the statute of limitations in any action hereunder or in any action
for the collection or performance of any obligations hereunder or of the
Borrower under the Equity Bridge Loan Credit Agreement; (iii) any defense to
any indebtedness or obligation based on a statute of limitations (as to the time
period within which an action may be brought); (iv) any defense that may arise
by reason of the incapacity, lack of power or authority, dissolution, merger or
termination of the Borrower or any other Person or the failure of the Equity
Facility Agent or the Equity Bridge Lenders to file or enforce a claim against
the estate (in administration, bankruptcy or any other proceeding) of the
Borrower or any other Person; (v) any defense based on any act, failure to act,

                                      -5-
<PAGE>
 
delay or omission whatsoever on the part of the Borrower, the Equity Facility
Agent or the Equity Bridge Lenders or the failure of the Borrower, the Equity
Facility Agent or the Equity Bridge Lenders to do any act or thing or to observe
or perform any covenant, condition or agreement to be observed or performed by
it under the Financing Documents; (vi) diligence, demand, presentment, protest
and notice of any kind, including notice of acceptance of this Guarantee and of
any obligation to which it applies or may apply, and notice of the existence,
creation or incurrence of any new or additional indebtedness or obligation or of
any default, indulgence, enforcement or other action or non-action on the part
of the Borrower, any endorser or creditor of each Guarantor or the Borrower or
on the part of any other Person under this or any other instrument in connection
with any obligation or evidence of indebtedness held by the Equity Facility
Agent, on behalf of the Equity Bridge Lenders, or the Equity Bridge Lenders as
collateral or in connection with any obligations hereunder; (vii) any defense
based upon an election of remedies by the Equity Facility Agent or the Equity
Bridge Lenders, including an election to proceed by non-judicial rather than
judicial foreclosure, which destroys or otherwise impairs the subrogation rights
of the such Guarantor or the right of such Guarantor to proceed against the
Borrower for reimbursement; (viii) any defense based upon any statute or rule of
law which provides that the obligation of a surety must be neither larger in
amount nor in other respects more burdensome than that of the principal; (ix)
any duty on the part of the Equity Facility Agent or the Equity Bridge Lenders
to disclose to such Guarantor any facts that the Equity Facility Agent or the
Equity Bridge Lenders may now or hereafter know about the Borrower, such
Guarantor or any other Person, regardless of whether the Equity Facility Agent
or the Equity Bridge Lenders have reason to believe that any such facts
materially increase the risk beyond that which such Guarantor intends to assume,
or have reason to believe that such facts are unknown to such Guarantor, or have
a reasonable opportunity to communicate such facts to such Guarantor, since each
Guarantor acknowledges that such Guarantor is fully responsible for being and
keeping informed of the financial condition of the Borrower and of all
circumstances bearing on the risk of non-payment of any obligations and
liabilities hereby guaranteed; (x) the fact that EME may at any time in the
future transfer or dispose of all or part of its direct or indirect interest in
the Sponsor and the Sponsor may at any time in the future transfer or dispose of
all or part of its direct or indirect interest in the Borrower; (xi) any defense
based on any change in the time, manner or place of any payment under, or in any
other term of, the Equity Bridge Loan Credit Agreement or any other amendment,
renewal, extension, acceleration, compromise or waiver of or any consent or
departure from the terms of the Equity Bridge Loan Credit Agreement ; and (xii)
any defense based on any offset against any amounts which may be owed by any
Person to such Guarantor for any reason whatsoever. No delay on the part of the
Equity Facility Agent or the Equity Bridge Lenders in exercising any of their
rights (including those hereunder) and no partial or single exercise thereof and
no action or non-action by the Equity Facility Agent or the Equity Bridge
Lenders, with or without notice to such Guarantor or anyone else, shall
constitute a waiver of any rights or shall affect or impair this Guarantee.

         4.  Subrogation. Until the indefeasible payment and satisfaction in
             -----------
full of all Guaranteed Obligations or termination of this Guarantee pursuant to
Section 18, each Guarantor agree not to assert any claim or other rights which
----------
it may now have or hereafter acquire, directly or indirectly, against the
Borrower that arise from the existence or performance of such Guarantor's
obligations under this Guarantee, including any claim, remedy or right of
subrogation, reimbursement, exoneration, contribution, indemnification, any
right to participate in any claim, right or remedy of the Equity Facility Agent
or the Equity Bridge Lenders against the Borrower or the Sponsor, or any
security now or hereafter held by the Equity Facility Agent or the Equity Bridge
Lenders, whether or not such claim, remedy or right arises in equity or under
contract, statute or common law, by any payment made hereunder or otherwise,
including the right to take or receive from the Borrower or the Sponsor,
directly or indirectly, in cash or other property or by set-off or in any other
manner, payment or security on account of such claim or other rights.

          5.  Bankruptcy.
              ----------

                                      -6-
<PAGE>
 
          (a) So long as any of the Guaranteed Obligations remain outstanding,
the Guarantors shall not, without the prior written consent of the Equity
Facility Agent, commence, or join with any other Person in commencing, any
bankruptcy, reorganization, or insolvency proceeding against the Borrower. The
obligations of the Guarantors under this Guarantee shall not be altered, limited
or affected by any proceeding, voluntary or involuntary, involving the
bankruptcy, reorganization, insolvency, receivership, liquidation or arrangement
of the Borrower, or by any defense which the Borrower may have by reason of any
order, decree or decision of any court or administrative body resulting from any
such proceeding.

          (b) So long as any of the Guaranteed Obligations remain outstanding,
to the extent of such Guaranteed Obligations, the Guarantors shall file, in any
bankruptcy or other proceeding in which the filing of claims is required or
permitted by law, all claims which the Guarantors may have against the Borrower
relating to any indebtedness of the Borrower to the Guarantors and each
Guarantor hereby assigns to the Equity Facility Agent, on behalf of the Equity
Bridge Lenders, all rights of such Guarantor thereunder. If the Guarantors do
not file any such claim, the Equity Facility Agent, as attorney-in-fact for such
party, is hereby authorized to do so in the name of the Guarantors or, in the
Equity Facility Agent's discretion, to assign the claim to a nominee, to cause
proofs of claim to be filed in the name of the Equity Facility Agent's nominee
and to vote or otherwise deal with such party's interests in connection with or
with respect to all matters in any proceeding. The foregoing power of attorney
is coupled with an interest and cannot be revoked. The Equity Facility Agent or
its nominee(s) shall have the sole right to accept or reject any plan proposed
in any such proceeding and to take any other action, which a party filing a
claim is entitled to take. In all such cases, whether in administration,
bankruptcy or otherwise, the Person authorized to pay such a claim shall pay the
same to the Equity Facility Agent, and, to the full extent necessary for that
purpose, each Guarantor hereby assigns to the Equity Facility Agent all of its
rights to all such payments or distributions to which such Guarantor would
otherwise be entitled; provided, however, that the obligations hereunder shall
                       --------  -------
not be satisfied except to the extent that the Equity Facility Agent receives
cash by reason of any such payment or distribution. If the Equity Facility Agent
receives anything hereunder other than cash, the same shall be held as
collateral for amounts due under this Guarantee.

          (c) Without limiting the generality of any of the foregoing provisions
of this Guarantee, each Guarantor irrevocably waives, to the fullest extent
permitted by Applicable Law and for the benefit of, and as a separate
undertaking with the Equity Facility Agent and each Equity Bridge Lender, any
defense to the performance of this Guarantee which may be available to such
Guarantor as a consequence of any proceeding seeking to adjudicate the Borrower
as bankrupt or insolvent or seeking liquidation, winding up, reorganization,
arrangement, protection, relief or composition of the Borrower or the debts of
the Borrower under any law relating to bankruptcy, insolvency or reorganization
or relief or protection of debtors.

         6.  Subordination. Except as otherwise specifically provided in this
             -------------
Guarantee, all existing and future indebtedness of the Borrower to the
Guarantors and the right of the Guarantors to withdraw any capital invested by
the Guarantors in the Borrower, are hereby subordinated to the prior and
indefeasible payment in full of all Guaranteed Obligations. Without the prior
written consent of the Equity Facility Agent, such subordinated indebtedness
shall not be paid or withdrawn in whole or in part, nor shall either Guarantor
accept any payment of or on account of any such indebtedness or as a withdrawal
of capital while this Guarantee is in effect. If any amount shall be paid to the
Guarantors in violation of this Guarantee, and there are outstanding Guaranteed
Obligations, such amount shall be deemed to have been paid to the Guarantors for
the benefit of, and held in trust for the Equity Facility Agent and the Equity
Bridge Lenders, and the Guarantors shall cause the same to be paid to the Equity
Facility Agent for the benefit of the Equity

                                      -7-
<PAGE>
 
Bridge Lenders immediately upon demand by the Equity Facility Agent to be
credited and applied toward payment of the outstanding Guaranteed Obligations,
whether matured or unmatured.

      7.  Taxes.
          -----

          (a)  All sums payable by the Guarantors under this Guarantee shall be
paid (i) free of any restriction or condition, (ii) free and clear of and
(except to the extent required by law) without any deduction or withholding on
account of any taxes, levies, imposts, duties or other charges of whatever
nature (excluding taxes on the overall net income or franchise taxes imposed on
the Equity Facility Agent or the Equity Bridge Lenders by the jurisdiction of
their incorporation or in which their lending offices are located) (all such
non-excluded taxes and other amounts being hereinafter referred to as "taxes")
and (iii) without deduction or withholding (except to the extent required by
Applicable Law) on account of any other amount, whether by way of setoff or
otherwise.

          (b)  If (i) either Guarantor is required by law to make any deduction
or withholding on account of any such taxes or other amount as is referred to in
Section 7(a) from any sum paid or payable by such Guarantor under this Guarantee
------------                                                                   
or (ii) any other party to any of the Financing Documents (or any Person on its
behalf) is required by Applicable Law to make any deduction or withholding from,
or (except on account of taxes on the overall net income or franchise taxes
imposed on the Equity Facility Agent or the Equity Bridge Lenders by their
jurisdiction of incorporation or the jurisdiction in which their lending offices
are located) any payment on or calculated by reference to the amount of, any sum
payable by such Guarantor under this Guarantee:

               (w) each Guarantor shall notify the Equity Facility Agent of any
such requirement or any change in any such requirement as soon as it becomes
aware of it;

               (x) each Guarantor shall pay any such taxes or other amount
before the date on which penalties attach thereto, such payment to be made (if
the liability is imposed on any other party to any of the Financing Documents)
on behalf of and in the name of that party; and

               (y) the sum payable by the Guarantors in respect of which the
relevant deduction, withholding or payment is required shall be increased to the
extent necessary to ensure that, after the making of that deduction, withholding
or payment, that party receives on the due date and retains (free from any
liability in respect of any such deduction, withholding or payment including
additional income taxes payable as a consequence of the payment of any
additional amounts) a net sum equal to what it would have received and so
retained had no such deduction, withholding or payment been required or made.

      8.  Representations and Warranties of the Guarantors. The Guarantors
          ------------------------------------------------ 
make the representations and warranties contained in this Section 8 for the
                                                          ---------         
benefit of the Equity Facility Agent and each Equity Bridge Lender. Each such
representation and warranty shall be deemed made as of the date hereof, as of
the date of Financial Close and as of the date of each subsequent Disbursement
under the Equity Bridge Loan Credit Agreement , as applicable, except with
respect to those representations and warranties which by their express terms
relate solely to an earlier date. The representations and warranties contained
herein shall survive the execution and delivery of this Guarantee.

          (a) Organization and Existence. Each Guarantor is a corporation duly
              --------------------------                                    
organized, validly existing and in good standing under the laws of the
jurisdiction of its formation and has the corporate power and authority to
execute and deliver this Guarantee and to perform its

                                      -8-
<PAGE>
 
obligations under this Guarantee and is in good standing in each jurisdiction
material to the Project in which the character of the properties owned or leased
by it or in which the transaction of its business as presently conducted or
proposed to be conducted makes such qualification necessary or desirable.

          (b) Corporate Action. Each Guarantor has taken all necessary corporate
              ----------------
action to authorize its execution and delivery of this Guarantee and the
performance of its obligations under this Guarantee and this Guarantee has or by
the date of Financial Close will have been duly authorized, executed and
delivered.

          (c) Binding Effect. This Guarantee constitutes the legal, valid and
              --------------
binding obligation of each Guarantor, enforceable against each Guarantor, in
accordance with its terms, except to the extent the enforceability thereof may
be limited by applicable bankruptcy, insolvency and other similar laws affecting
creditors' rights generally and by general equitable principles regardless of
whether the issue of enforceability is considered in a proceeding in equity or
at law.

          (d) No Breach. The execution, delivery and performance of this
              ---------
Guarantee by each Guarantor will not (i) violate any organizational documents of
such Guarantor; (ii) require any consent or approval (including any approval of
any Governmental Authority) which has not been obtained; (iii) result in any
contravention or violation of any Applicable Law; or (iv) result in any
contravention or violation or breach of any provision of, or constitute a
default under, or result in the creation or imposition of any Lien on any of the
assets of such Guarantor (except as contemplated hereunder) pursuant to the
provisions of, any mortgage, indenture, contract, agreement or other undertaking
to which such Guarantor is a party or which purports to be binding upon such
Guarantor or upon any of its assets.

          (e) No Defaults. Neither Guarantor is in default under any term of
              -----------
this Guarantee or any other agreement to which it is a party which could
reasonably be expected to have a Material Adverse Effect.

          (f) No Litigation. There is no pending or, to its knowledge,
              -------------
threatened, action or proceeding at law or in equity affecting either Guarantor
before any court, Governmental Authority or arbitrator, which, if adversely
determined, could, either individually or in the aggregate, reasonably be
expected to materially impair its ability to perform the obligations under this
Agreement.

          (g) Financial Statements. All financial statements of EME delivered in
              --------------------
accordance with Section 3.1.16 or 5.4.3 of the Common Terms Agreement are and,
           --------------------   -----
in the case of financial statements to be delivered after the date hereof, will
be, true, correct and complete in all respects as of the date of such
statements.

          (h) Tax Information. Each Guarantor has filed, or caused to be filed,
              ---------------
all tax and informational returns that are required to have been filed by it in
all jurisdictions, which failure could reasonably be expected to have a Material
Adverse Effect, and has paid all taxes shown to be due and payable on such
returns and all any other taxes and assessments payable by it, to the extent the
same have become due and payable (other than those taxes that it is contesting
in good faith and by appropriate proceedings, with adequate, segregated reserves
established for such taxes in accordance with generally accepted accounting
principles in the jurisdiction of its incorporation, if applicable), the failure
of which to pay could reasonably be expected to have a Material Adverse Effect.
To the extent such taxes are not due, each Guarantor has established reserves
that are adequate for the payment thereof and are as required by generally
accepted

                                      -9-
<PAGE>
 
accounting principles in the jurisdiction of its incorporation, except to the
extent that the failure to establish such reserves would not be reasonably
expected to have a Material Adverse Effect.

          (i) No Fees. Other than amounts that have been paid in full or will
              -------
have been paid in full by the Borrower, the Sponsor or the Guarantors prior to
Financial Close, no fees or taxes, including stamp, transaction, registration or
similar taxes, are required to be paid in connection with the execution and
delivery of this Guarantee.

          (j) Compliance with Applicable Law. None of the Guarantors or any of
              ------------------------------
such Guarantor's officers, directors, employees, agents or affiliates, acting on
such Guarantor's behalf, has taken any action in connection with the Project
that violates any Applicable Laws, including the Corrupt Practices Laws, the
violation of which could be reasonably expected to have a Material Adverse
Effect.

          (k) Pension Plans.
              -------------

              (i)   The withdrawal by either Guarantor or any of such
Guarantor's Subsidiaries or any entity under common control within the meaning
of Section 4001 of ERISA from all Multiemployer Plans in which they participate
would not have a Material Adverse Effect on the consolidated financial condition
of such Guarantor and its Subsidiaries taken as a whole.

              (ii)  Neither Guarantor has been notified that any Multiemployer
Plan to which it or any of its Subsidiaries or any entity under common control
within the meaning of Section 4001 contributed is either in reorganization or
insolvent.

              (iii) All single employer plans which are subject to ERISA
maintained by either Guarantor, its Subsidiaries or any entity under common
control within the meaning of Section 4001 of ERISA are in material compliance
with all applicable requirements of ERISA. The sum of the value of all accrued
benefits vested under all single employer plans as of December 31, 1906 did not
exceed the value of the assets of such plans allocable to such vested benefits
as determined by the plan actuaries.

          (l) Investment Company Act of 1940. Neither Guarantor is an
              ------------------------------
"investment company" or a company "controlled" by an "investment company,"
within the meaning of the Investment Company Act of 1940.

          (m) Regulation. Neither of the Guarantors nor such Guarantor's
              ----------                                                
Affiliates is or will be, solely as a result of the participation by such party
separately or as a group in the transactions contemplated hereby or by any other
Financing Document, or as a result of the ownership, use or operation of the
Project, subject to regulation by any Governmental Authority of the United
States as a "public utility," an "electric utility," an "electric utility
holding company," a "public utility holding company," a "holding company," or an
"electric corporation" or a Subsidiary or Affiliate of any of the foregoing;
provided, however, that Edison International, the ultimate parent of EME, will
--------  -------
continue to be subject to an annual reporting requirement and other requirements
applicable to holding companies exempt under Section 3 of PUHCA, pursuant to
Sections 3, 9(a)(2), 10, 16, 26, 32 and 33 of PUHCA, and that Southern
California Edison Company, a wholly-owned subsidiary of Edison International and
an Affiliate of EME, as a public utility company that is an "associate company"
of a foreign utility company within the meaning of Section 2(a)(10) of PUHCA,
may be subject to reporting requirements prescribed by the Securities and
Exchange Commission pursuant to Section 33(e)(1) of PUHCA. The Guarantors are
not subject to regulation as a "subsidiary company" or an "affiliate" of a
holding company under (and as defined in) PUHCA. Neither Guarantor has taken any
action which, (i) if and so long as the

                                      -10-
<PAGE>
 
owner and operator of the Project is an "exempt wholesale generator" under
Section 32 of PUHCA, could reasonably be expected to result in the Project
failing to meet the definition of an "eligible facility" under paragraph
32(a)(2) of PUHCA or (ii) if and so long as the owner and operator of the
Project is a "foreign utility company" under Section 33 of PUHCA, could
reasonably be expected to result in the Project not satisfying the requirements
set forth in paragraph 33(a)(3) of PUHCA.

          (n) Margin Stock. No Guarantor is engaged in the business of extending
              ------------                                                    
credit for the purpose of purchasing or carrying margin stock within the meaning
of Regulations G, T and X issued by the Board of Governors of the Federal
Reserve System.

          (o) Conditions Precedent. Upon the execution and delivery hereof,
              -------------------- 
there are no conditions precedent to the effectiveness of this Guarantee that
have not been satisfied or waived.

      9.  Covenants of the Guarantor. So long as any of the Guaranteed
          -------------------------- 
Obligations are outstanding, each Guarantor hereby covenants and agrees that it
shall faithfully observe and fulfill, and shall cause to be observed and
fulfilled, each and all of the following covenants:

          (a) Governmental Approvals. It will maintain in full force and effect
              ----------------------                                         
all approvals or authorizations or Permits from any Governmental Authority that
are required to be obtained by it with respect to this Guarantee (if any) and
will obtain any that may become necessary in the future.

          (b) Compliance with Applicable Law. It will comply in all respects
              ------------------------------
with all Applicable Laws to which it may be subject, the noncompliance with
which could be reasonably expected to have a Material Adverse Effect.

          (c) Financial Statements. As soon as available, EME will deliver to
              --------------------                                         
the Facility Agent copies of the annual (which shall be audited) and quarterly
financial statements (consisting of a balance sheet and the related statements
of income and cash flows) in accordance with the requirements of Section 5.4.3
                                                                 -------------
of the Common Terms Agreement.

          (d) Litigation. Promptly, and in any event within five (5) Business
              ----------                                                     
Days after an Authorized Officer obtains knowledge thereof, each Guarantor will
give to the Equity Facility Agent and the Facility Agent notice of the
occurrence of any event or of any litigation or governmental proceeding pending
(i) against it or any of its Affiliates which could, either individually or in
the aggregate, reasonably be expected to have a Material Adverse Effect.

          (e) Transfer of Interests. It shall not permit a Change of Control as
              ---------------------  
a result of actions taken by the Sponsor in contravention of Section 6.19 of the
                                                             ------------      
Common Terms Agreement or a transfer of interests in contravention of Section
                                                                      -------
23.13 of the Power Purchase Agreement.
-----                                

          (f) Regulation. It shall not take any action which could reasonably
              ----------                                                     
be expected to result in (i) it being subject to regulation by any Governmental
Authority of the United States as a "public utility," an "electric utility," an
"electric utility holding company," a "public utility holding company," a
"holding company," or an "electric corporation" or a Subsidiary or Affiliate of
any of the foregoing, (ii) it being subject to regulation as a "subsidiary
company" or an "affiliate" of a holding company under (and as defined in) PUHCA
or (iii) if and so long as the owner and operator of the Project is an "exempt
wholesale generator" under Section 32 of PUHCA, the Project failing to meet the
definition of an "eligible facility" under paragraph 32(a)(2) of PUHCA, or, if
and so long as the owner and operator of the Project is a "foreign utility
company" under Section 33 of PUHCA, the Project is not satisfying the
requirements set forth in paragraph

                                      -11-
<PAGE>
 
32(a)(3) of PUHCA; provided, however, that Edison International, the ultimate
                   --------  -------
parent of EME, will continue to be subject to an annual reporting requirement
and other requirements applicable to holding companies exempt under Section 3 of
PUHCA, pursuant to Sections 3, 9(a)(2), 10, 16, 26, 32 and 33 of PUHCA, and that
Southern California Edison Company, a wholly-owned subsidiary of Edison
International and an Affiliate of EME, as a public utility company that is an
"associate company" of a foreign utility company within the meaning of Section
2(a)(10) of PUHCA, may be subject to reporting requirements prescribed by the
Securities and Exchange Commission pursuant to Section 33(e)(1) of PUHCA.

          (g) Corporate Existence. Each Guarantor shall preserve and maintain in
              -------------------
full force and effect its corporate existence, rights (charter and statutory),
franchises and privileges and qualify and remain qualified, as a corporation in
good standing in each jurisdiction in which such qualification is from time to
time necessary, except for such jurisdictions where the failure to so qualify
would not have a Material Adverse Effect; provided, however, that neither
                                          --------  -------                   
Guarantor shall be required to preserve any right, privilege or franchise if the
board of directors thereof shall determine in good faith that such right,
privilege or franchise is no longer useful in the conduct of the business of
such Guarantor, and the loss thereof is not disadvantageous in any material
respect to the Equity Facility Agent and the Equity Bridge Lenders.

          (h) Notice of Defaults. Promptly upon any Specified Officer (as
              ------------------                                       
defined below) of either Guarantor obtaining knowledge thereof, such Guarantor
shall give notice to the Equity Facility Agent of any development, including any
litigation, investigation or proceeding affecting such Guarantor, which has a
Material Adverse Effect, could reasonably be expected to have a Material Adverse
Effect or, in the case of any litigation, investigation or other proceeding,
which could, if adversely decided, reasonably be expected to have a Material
Adverse Effect. For the purpose of this Section 9(h), the term "Specified
                                        ------------            ---------
Officer" shall mean the Chairman, any Vice Chairman, the President, the Chief
-------                                                                    
Executive Officer, the Chief Financial Officer, any Senior Vice President, any
Vice President, the Secretary, the Treasurer or equivalent officers of such
Guarantor.

          (i) Merger, Acquisition or Sales of Assets. Neither Guarantor shall
              --------------------------------------                       
consolidate or merge into, or transfer its properties and assets substantially
as an entirety to, another Person, unless (i) the surviving Person, if other
than such Guarantor, or the transferee, assumes by supplemental agreement
satisfactory in form and substance to the Equity Bridge Lenders all the
Guaranteed Obligations and (ii) after giving effect to such assumption, there
would not exist any Default or Event of Default.

          (j) Further Assurances. It will deliver such other documents and other
              ------------------                                              
information reasonably requested by the Equity Facility Agent.

     10.  Action by Equity Facility Agent.
          -------------------------------

          (a) The Equity Facility Agent shall be entitled to rely on any notice
received by it from the Equity Bridge Lenders stating that an Event of Default
shall have occurred under the Financing Documents and shall not be under any
duty or responsibility to make any independent verification of such statement.
Notwithstanding any provisions to the contrary in this Guarantee, if any action
to be taken by the Equity Facility Agent under this Guarantee is to be taken on
a day which is not a Business Day, such action shall be taken on the next
succeeding Business Day.

          (b) Each Guarantor hereby agrees to pay all costs, including
reasonable attorneys' fees, incurred with respect to the enforcement of such
provisions of this Guarantee against such Guarantor, which enforcement costs,
regardless of when incurred, shall be payable by

                                      -12-
<PAGE>
 
such Guarantor on the earlier of (i) the date on which a judgment shall be
obtained against such Guarantor with respect to this Guarantee and (ii) the date
on which such Guarantor and the Equity Facility Agent shall have otherwise
resolved (including by way of settlement) any dispute with respect to the
enforcement of this Guarantee against such Guarantor.

     11.  Successors and Assigns.
          ----------------------

          (a) This Guarantee shall be binding upon, and inure to the benefit of,
the parties hereto and their respective successors or permitted assigns.

          (b) Notwithstanding any transfer of its interests permitted under
Section 6.19 of the Common Terms Agreement, Section 23.13 of the Power Purchase
------------                                -------------                     
Agreement or any other provision of the Financing Documents, each Guarantor
shall remain liable for any and all of its obligations under this Guarantee and
shall not assign its obligations hereunder to any other Person without the
written consent of the Required Equity Voting Parties, and any purported
assignment in violation of this provision shall be void.

          (c) The Equity Facility Agent and any Equity Bridge Lender may
transfer, assign or grant its rights hereunder in connection with an assignment
or transfer of all or any part of its interest in the Guaranteed Obligations
held by it to any other Person in accordance with the provisions of the
Financing Documents; provided that any such assignee has agreed to be bound by
                     --------                                                
the terms of the Financing Documents, including this Guarantee.

     12.  Interpretation. The section headings in this Guarantee are for the
          --------------                                                  
convenience of reference only and shall not affect the meaning or construction
of any provision hereof.

     13.  Notices.  All notices and other communications provided for
          -------
hereunder shall be made in the English language and (a) in writing (including
telecopier) and (b) telecopied or sent by overnight courier (if for inland
delivery) or international courier (if for overseas delivery) to a party hereto
at its address and contact number specified below, or at such other address and
contact number as is designated by such party in a written notice to the other
parties hereto or, if not specified below, at the address and contact number for
such Person set forth in Schedule 16 of the Common Terms Agreement.
                         -----------                           

          All such notices and communications shall be effective (a) if sent by
telecopier, when sent (on receipt of confirmation) and (b) if sent by courier,
(i) one day after timely deposit with an overnight courier if for inland
delivery and (ii) five (5) days after timely deposit with an international
courier if for overseas delivery; provided, however, that no notice or
                                  --------  -------                        
communication to any Lender or Agent shall be effective until received by such
Lender or Agent.

                  (a)  The address of EME is:

                       Edison Mission Energy
                       18101 Von Karman Ave., Suite 1700
                       Irvine California 92612-1046 U.S.A.
                       Attention:  General Counsel
                       Telephone No.: 1-949-752-5588
                       Telecopier No.: 1-949-752-1420

                  (b)  The address of ETG is:

                       EME Tri Gen BV

                                      -13-
<PAGE>
 
                     Croeselaan 18
                     3521 CB Utrecht
                     The Netherlands
                     Attention:  Ms. Hetty Solberg
                     Telephone No.: 31-30-216-1944
                     Telecopier No.: 31-30-216-1250

                (c)  The address of TECO is:

                     Tri Energy Company Limited
                     1550 Grand Amarin Tower, 16th Floor
                     New Petchburi Road  
                     Ratchathewi, Makkasan
                     Bangkok 10320 Thailand
                     Attention:  Khun Rawi Corsiri
                                         President
                     Telephone No.: (662) 207-0307
                     Telecopier No.: (662) 207-0315

                (d)  The address of the Equity Facility Agent is:

                     The Sumitomo Bank, Limited
                     11th Floor, Ramaland Building
                     952 Rama IV Road
                     Kwaeng Suriyawong
                     Khet Bangrak
                     Bangkok 10500
                     Thailand
                     Telephone No.: (662) 632-9210
                     Telecopier No.: (662) 632-9208
                     Attention: Mr. Anuphap Tharavanij, Assistant Vice President
                                Mr. Shouichi Yamashiro, Assistant Vice President

     14.  Amendments. Notwithstanding anything contained herein that may be
          ----------                                                     
construed to the contrary, this Guarantee may be amended only in writing with
the written consent of the Equity Facility Agent and each Guarantor.

     15.  English Language. This Guarantee is made in the English language.
          ----------------                                               
Any translation of this Guarantee not approved by the Equity Facility Agent
shall have no legal validity.

     16.  Jurisdiction.
          ------------

              (a) THIS GUARANTEE SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK OTHER THAN THE CONFLICT OF
LAWS RULES THEREOF (EXCEPT SECTION 5-1401 OF THE NEW YORK GENERAL OBLIGATIONS
LAW). ANY LEGAL ACTION OR PROCEEDING AGAINST EACH GUARANTOR WITH RESPECT TO THIS
GUARANTEE, ANY CREDIT AGREEMENT, OR ANY OTHER FINANCING DOCUMENT (AS DEFINED IN
SCHEDULE 1 OF THE COMMON TERMS AGREEMENT) TO WHICH IT IS A PARTY MAY BE BROUGHT
----------                                                         
IN THE COURTS OF THE STATE OF NEW YORK IN THE COUNTY OF NEW YORK OR OF THE
UNITED STATES FOR THE SOUTHERN DISTRICT OF NEW YORK AND, BY EXECUTION AND
DELIVERY OF THIS GUARANTEE, EACH GUARANTOR HEREBY IRREVOCABLY ACCEPTS FOR ITSELF
AND IN RESPECT OF ITS

                                      -14-
<PAGE>
 
PROPERTY, GENERALLY AND UNCONDITIONALLY, THE JURISDICTION OF THE AFORESAID
COURTS. EACH GUARANTOR AGREES THAT A JUDGMENT, AFTER EXHAUSTION OF ALL AVAILABLE
APPEALS, IN ANY SUCH ACTION OR PROCEEDING SHALL BE CONCLUSIVE AND BINDING UPON
IT, AND MAY BE ENFORCED IN ANY OTHER JURISDICTION, INCLUDING BY A SUIT UPON SUCH
JUDGMENT, A CERTIFIED COPY OF WHICH SHALL BE CONCLUSIVE EVIDENCE OF THE
JUDGMENT. EACH GUARANTOR HEREBY IRREVOCABLY DESIGNATES, APPOINTS AND EMPOWERS CT
CORPORATION SYSTEM, WITH OFFICES ON THE DATE HEREOF AT 1633 BROADWAY, NEW YORK,
NEW YORK 10019, AS ITS DESIGNEE, APPOINTEE AND AGENT WITH RESPECT TO ANY ACTION
OR PROCEEDING IN NEW YORK TO RECEIVE, ACCEPT AND ACKNOWLEDGE FOR AN ON ITS
BEHALF, AND IN RESPECT OF ITS PROPERTY, SERVICE OF ANY AND ALL LEGAL PROCESS,
SUMMONS, NOTICES AND DOCUMENTS WHICH MAY BE SERVED IN ANY SUCH ACTION OR
PROCEEDING AND AGREES THAT THE FAILURE OF SUCH AGENT TO GIVE ANY ADVICE OF ANY
SUCH SERVICE OF PROCESS TO SUCH GUARANTOR SHALL NOT IMPAIR OR AFFECT THE
VALIDITY OF SUCH SERVICE OR OF ANY BASED THEREON. IF FOR ANY REASON SUCH
DESIGNEE, APPOINTEE AND AGENT SHALL CEASE TO BE AVAILABLE TO ACT AS SUCH, EACH
GUARANTOR AGREES TO DESIGNATE A NEW DESIGNEE, APPOINTEE AND AGENT IN NEW YORK
CITY ON THE TERMS AND FOR THE PURPOSES OF THIS PROVISION ACCEPTABLE TO THE
EQUITY FACILITY AGENT AND THE EQUITY BRIDGE LENDERS. EACH GUARANTOR FURTHER
IRREVOCABLY CONSENTS TO THE SERVICE OF PROCESS OUT OF ANY OF THE AFOREMENTIONED
COURTS IN ANY SUCH ACTION OR PROCEEDING BY THE MAILING OF COPIES THEREOF BY
REGISTERED OR CERTIFIED MAIL, POSTAGE PREPAID, TO SUCH GUARANTOR AND CT
CORPORATION SYSTEM, AT THEIR RESPECTIVE ADDRESSES SET FORTH ABOVE AND IN SECTION
                                                                         -------
13, SUCH SERVICE TO BECOME EFFECTIVE TEN (10) DAYS AFTER SUCH MAILING. NOTHING
--                                                                          
HEREIN SHALL AFFECT THE RIGHT OF ANY PARTY HERETO TO SERVE PROCESS IN ANY OTHER
MANNER PERMITTED BY LAW OR TO COMMENCE LEGAL PROCEEDINGS OR OTHERWISE PROCEED
AGAINST SUCH GUARANTOR IN THAILAND OR IN ANY OTHER COURT OR TRIBUNAL HAVING
JURISDICTION.

          (b) EACH GUARANTOR HEREBY IRREVOCABLY WAIVES ANY OBJECTION WHICH IT
MAY NOW OR HEREAFTER HAVE TO THE LAYING OF VENUE OF ANY OF THE AFORESAID ACTIONS
OR PROCEEDINGS ARISING OUT OF OR IN CONNECTION WITH THIS OR ANY OTHER FINANCING
DOCUMENT BROUGHT IN THE COURTS REFERRED TO IN SECTION 16(a) ABOVE AND HEREBY
                                              -------------                
FURTHER IRREVOCABLY WAIVES AND AGREES NOT TO PLEAD OR CLAIM IN ANY SUCH COURT
THAT ANY SUCH ACTION OR PROCEEDING BROUGHT IN ANY SUCH COURT HAS BEEN BROUGHT IN
AN INCONVENIENT FORUM.

          (c) EACH OF THE PARTIES HERETO HEREBY IRREVOCABLY WAIVES ALL RIGHT TO
TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT OF OR
RELATING TO ANY OF THE FINANCING DOCUMENTS OR THE TRANSACTIONS CONTEMPLATED
THEREBY.

      17. Judgment Currency.
          -----------------

          (a) The Guarantors' obligations hereunder to make payments in Dollars
(the "Obligation Currency") shall not be discharged or satisfied by any tender
      -------------------                                                  
or recovery pursuant to any judgment expressed in or converted into any currency
other than the Obligation Currency, except to the extent that such tender or
recovery results in the effective receipt by the Equity Facility Agent or the
Equity Bridge Lenders, as applicable, of the full amount of the Obligation

                                      -15-
<PAGE>
 
Currency expressed to be payable to such party under this Guarantee. If for the
purpose of obtaining or enforcing judgment against the Guarantors in any court
or in any jurisdiction, it becomes necessary to convert into or from any
currency other than the Obligation Currency (such other currency being
hereinafter referred to as the "Judgment Currency") an amount due in the
                                -----------------                    
Obligation Currency, the conversion shall be made, at the Dollar Equivalent, in
the case of Baht, and, in the case of other currencies, at the rate of exchange
(as quoted by the Facility Agent which shall be market competitive or if the
Facility Agent fails to quote a rate of exchange on such currency, by a known
dealer in such currency designated by the Facility Agent) determined, in each
case, as of the day on which the judgment is given (such Business Day being
hereinafter referred to as the "Judgment Currency Conversion Date").
                                ---------------------------------

          (b) If there is a change in the rate of exchange prevailing between
the Judgment Currency Conversion Date and the date of actual payment of the
amount due, the Guarantors covenant to pay, or cause to be paid, such additional
amounts, if any (but in any event not a lesser amount), as may be necessary to
ensure that the amount paid in the Judgment Currency, when converted at the rate
of exchange prevailing on the date of payment, will produce the amount of the
Obligation Currency which could have been purchased with the amount of Judgment
Currency stipulated in the judgment or judicial award at the rate of exchange
prevailing on the Judgment Currency Conversion Date.

          (c) For purposes of determining the Dollar Equivalent or rate of
exchange under this Section 17, such amounts shall include any premium and costs
                    ----------                                                
payable in connection with the purchase of the Obligation Currency.


     18.  Termination; Reinstatement of Guarantee.
          ---------------------------------------

          (a) Subject to the provisions of Section 18(b), this Guarantee shall
                                           -------------                    
terminate upon the indefeasible payment and satisfaction in full of all
Guaranteed Obligations and termination of all Commitments under the Equity
Bridge Loan Facility.

          (b) Notwithstanding the provisions of Section 18(a), this Guarantee
                                                -------------              
shall be reinstated if at any time following the termination of this Guarantee
under Section 18(a), any payment by each Guarantor under this Guarantee is
      -------------                                                     
rescinded or must otherwise be returned by the Equity Facility Agent or any
other Person upon the insolvency, bankruptcy, reorganization, dissolution or
liquidation of such Guarantor or otherwise, and is so rescinded or returned to
the Person making such payment, all as though such payment had not been made.
Such period of reinstatement shall continue until satisfaction of the conditions
contained in, and shall continue to be subject to, the provisions hereof,
including this Section 18.
               ----------

     19.  Interest. Any amount required to be paid by the Guarantors pursuant to
          --------
the terms hereof shall bear interest at the Default Rate or the maximum rate
permitted by law, whichever is less, from the date due until paid in full.

     20.  Entire Agreement. This Guarantee, including the documents referred
          ----------------                                                
to herein, embodies the entire agreement and understanding of the parties hereto
and supersedes all prior agreements and understandings of the parties hereto
relating to the subject matter herein contained.

     21.  Execution in Counterparts. This Guarantee may be signed in one or
          -------------------------                                      
more duplicate counterparts, and when executed and delivered by all of the
parties listed below shall constitute a single binding agreement. Any party
hereto may execute this Guarantee by signing any such counterpart (including by
facsimile). Signature pages may be detached from multiple separate

                                      -16-
<PAGE>
 
counterparts and attached to a single counterpart so that all signatures are
physically attached to the same counterpart.

         22.  Severability. Any provision of this Guarantee which is prohibited
              ------------                                                   
or unenforceable in any jurisdiction shall, as to such jurisdiction, be
ineffective to the extent of such prohibition or unenforceability, but shall not
invalidate the remaining provisions of this Guarantee or affect such provision
in any other jurisdiction.

         23.  Joint and Several Liability. The obligations of the Guarantors
              ---------------------------                                 
under this Guarantee shall be joint and several.

                                      -17-
<PAGE>
 
          IN WITNESS WHEREOF, each Guarantor has caused this Capital 
Contribution Guarantee to be duly executed and delivered as of the day and year
first written above.


                                                EDISON MISSION ENERGY,
                                                as a Guarantor

                                                By: /s/ ROBERT E. DRISCOLL
                                                   -----------------------
                                                Name: Robert E. Driscoll
                                                Title: Vice President

                      
                                                EME TRI GEN BV,
                                                as a Guarantor

                                                By: /s/ ROBERT E. DRISCOLL
                                                   -----------------------
                                                Name: Robert E. Driscoll
                                                Title: Attorney


AGREED AND ACCEPTED:

THE SANWA BANK, LIMITED, as
Equity Facility Agent for the
Equity Bridge Lenders


By: 
    ---------------------------
Name: 
      -------------------------
Title: 
       ------------------------


ACKNOWLEDGED AND AGREED as to Section 2 only:

TRI ENERGY COMPANY LIMITED,
as the Borrower

By: /s/ RAWI CORSIRI
   ----------------------------
Name:  RAWI CORSIRI
     --------------------------
Title: Director & President
      -------------------------
                                           [LOGO OF TRI ENERGY COMPANY LIMITED]

By:  /s/ MARTIN DENIS CONSIDINE
   ----------------------------
Name: MARTIN DENIS CONSIDINE
     --------------------------
Title: DIRECTOR
      -------------------------

<PAGE>
 
 
    IN WITNESS WHEREOF, each Guarantor has caused this Capital Contribution
Guarantee to be duly executed and delivered as of the day and year first written
above.

                                                        EDISON MISSION ENERGY,
                                                        as a Guarantor


                                                        By:
                                                            --------------------
                                                        Name: Robert E. Driscoll
                                                        Title: Vice President


                                                        EME TRI GEN BV,
                                                        as a Guarantor


                                                        By:
                                                            --------------------
                                                        Name: Robert E. Driscoll
                                                        Title: Attorney




AGREED AND ACCEPTED:

THE SANWA BANK, LIMITED, as
Equity Facility Agent for the 
Equity Bridge Lenders

By: /s/ Yoshihiro Kubo
   -----------------------
Name:  YOSHIHIRO KUBO
     ---------------------
Title: MANAGER
      --------------------

ACKNOWLEDGED AND AGREED as to Section 2 only:

TRI ENERGY COMPANY LIMITED
as the Borrower

By:
   -----------------------
Name:
     ---------------------
Title:
      --------------------



By:
   -----------------------
Name:
     ---------------------
Title:
      --------------------