Exhibit 10.36



                  PARTNERSHIP INTEREST PLEDGE AGREEMENT (CLC)
                  -------------------------------------------


                           Dated as of May 28, 1999


                                     Among


                      CAITHNESS ACQUISITION COMPANY, LLC,
                     a Delaware limited liability company,

                     CAITHNESS GEOTHERMAL 1980 LTD., L.P.,
                        a Delaware limited partnership,


                                      and


                     U.S. BANK TRUST NATIONAL ASSOCIATION,
                              as Collateral Agent


                               TABLE OF CONTENTS
                               -----------------


                                                                      Page
                                                                      ----
                                                                   
PREFACE.............................................................   1

AGREEMENT...........................................................   1

1. Definitions......................................................   2

2. Assignment, Pledge and Grant of Security Interest................   3

3. Documents........................................................   3

4. Events of Default................................................   5

5. Remedies.........................................................   5

6. Remedies Cumulative; Delay Not Waiver............................   7

7. Covenants and Representations of Pledgors........................   8

8. Certain Consents and Waivers.....................................  11

9. CLC's Consent and Covenants......................................  13

10. Attorney-in-Fact................................................  13

11. Place of Business; Location of Records..........................  14

12. Perfection; Further Assurances..................................  14




                                                                   
13. Continuing Assignment and Security Interest; Transfer of Loans..  15

14. Liability.......................................................  16

15. Attorneys' Fees.................................................  16

16. Severability....................................................  16

17. Successors and Assigns..........................................  16

18. Headings........................................................  16

19. Governing Law...................................................  16

20. Time............................................................  16

21. References to Other Documents...................................  17

22. Reinstatement...................................................  17

23. Statute of Limitations..........................................  17

24. Entire Agreement................................................  17

25. Counterparts....................................................  17

26. Waiver of Jury Trial............................................  17

27. Regarding the Collateral Agent..................................  18


                                      ii


                               COSO LAND COMPANY


                     PARTNERSHIP INTEREST PLEDGE AGREEMENT

          This Partnership Interest Pledge Agreement ("Agreement"), dated as of
                                                       ---------
May 28, 1999, is entered into by and among COSO LAND COMPANY, a California
general partnership ("CLC"), CAITHNESS ACQUISITION COMPANY, LLC, a Delaware
                      ---
limited liability company ("CAC"), CAITHNESS GEOTHERMAL 1980 LTD., L.P.,
                            ---
("CAG") a Delaware limited partnership (each of CAC and CAG a "Pledgor," and,
  ---                                                          -------
collectively, the "Pledgors"), and U.S. BANK TRUST NATIONAL ASSOCIATION in its
                   --------
capacity as collateral agent ("Collateral Agent") for U.S. BANK TRUST NATIONAL
                               ----------------
ASSOCIATION in its capacity as trustee ("Trustee") for the holders of all
                                         -------
secured notes issued pursuant to that certain Indenture dated as of May 28, 1999
(the "Indenture") among the Trustee, COSO FINANCE PARTNERS, a California general
      ---------
partnership ("Navy I"), COSO ENERGY DEVELOPERS, a California general partnership
              ------
("BLM"), COSO POWER DEVELOPERS, a California general partnership ("Navy II"
  ---                                                              -------
together with BLM and Navy I the "Guarantors,"), and CAITHNESS COSO FUNDING
                                  ----------
CORP., a Delaware corporation (the "Issuer") (such notes, the "Senior Secured
                                    ------                     --------------
Notes" and the holders thereof, the "Holders of the Senior Secured Notes"), and
- -----                                -----------------------------------
all Permitted Additional Senior Lenders (as defined in the Indenture).

                                    PREFACE
                                    -------

     A.  Issuer has, as of the date of this Agreement, issued $413,000,000
of the Senior Secured Notes, the proceeds of which will be used to make loans to
the Guarantors.

     B.  Pledgors are the general partners of CLC pursuant to that certain
Amended Joint Venture Agreement of COSO LAND COMPANY, dated as of June 1, 1983
(the "Partnership Agreement").
      ---------------------

     C.  Pursuant to a Guarantee dated as of even date herewith (the
"Guarantee"), the Pledgors have guaranteed to Trustee and the Holders of the
 ---------
Senior Secured Notes the payment and performance of Issuer's obligations under
the Senior Secured Notes and the Indenture.

     D.  As a condition precedent to the sale of the Senior Secured Notes,
CLC and the Pledgors are required to have executed this Agreement as security
for the payment and performance of Guarantors' obligations under the Guarantee.

                                   AGREEMENT
                                   ---------


          In consideration of the premises herein and for other good and
valuable consideration, the receipt and adequacy of which are hereby
acknowledged, CLC and the Pledgors hereby agree with Collateral Agent for the
benefit of Trustee, the Holders of the Senior Secured Notes and the Permitted
Additional Senior Lenders, if any, as follows:

          1.   Definitions.
               -----------

          (a)  Unless otherwise defined, all capitalized terms used herein which
are defined in the Indenture shall have their respective meanings therein
defined, and all terms, defined in the UCC shall have the respective meanings
given to those terms in the UCC.

          (b)  "UCC" shall mean the Uniform Commercial Code as the same may,
                ---
from time to time, be in effect in the State of New York; provided, however, in
the event that, by reason of mandatory provisions of law, any or all of the
attachment, perfection or priority of the security interest in any Collateral is
governed by the Uniform Commercial Code as in effect in a jurisdiction other
than the State of New York, the term "UCC" shall mean the Uniform Commercial
Code as in effect in such other jurisdiction for purposes of the provisions
hereof relating to such attachment, perfection or priority and for purposes of
definitions related to such provisions.

          (c)  "Qualifying Facility" shall mean a qualifying small power
                -------------------
production facility in accordance with PURPA and the rules and regulations of
FERC under PURPA relating thereto.

          (d)  "FPA" shall mean the Federal Power Act of 1925, as amended.
                ---

          (e)  "PUHCA" shall mean the Public Utility Holding Company Act of
                -----
1935, as amended.

          (f)  "PURPA" shall mean the Public Utility Regulatory Policies Act of
                -----
1978, as amended, and the regulations promulgated thereunder.

                                       2


          2.   Assignment, Pledge and Grant of Security Interest.
               -------------------------------------------------

          (a)  To secure the timely payment and performance of the Obligations
(as defined below), each Pledgor hereby assigns and pledges to Collateral Agent
for the benefit of the Trustee, the Holders of the Senior Secured Notes and all
Permitted Additional Senior Lenders, if any, and grants to Collateral Agent for
the benefit of the Trustee, the Holders of the Senior Secured Notes and all
Permitted Additional Senior Lenders, if any, a security interest in all the
estate, right, title and interest of each such Pledgor, now owned or hereafter
acquired, in, to and under any and all of the following (the "Collateral"):
                                                              ----------

     Such Pledgor's partnership interest in CLC, including without limitation
     such Pledgor's (i) rights to receive all income, gain, profit, loss or
     other items allocated or distributed to such Pledgor under the Partnership
     Agreement, (ii) rights to receive all distributions of any nature
     whatsoever by the Pledgors with respect to such partnership interest; (iii)
     capital or ownership interest, including capital accounts, in CLC, and all
     accounts, deposits or credits of any kind with CLC, (iv) voting rights in
     or rights to control or direct the affairs of CLC, (v) right, title and
     interest, as a partner in CLC, in or to any and all of CLC's assets or
     properties, (vi) other rights, title and interest in or to CLC, and all
     rights to receive income, profit or other distributions from CLC, of any
     nature whatsoever, in each case, as such rights are derived from such
     Pledgor's partnership interests in CLC, (vii) claims for damages arising
     out of or for breach of or default relating to the Collateral, and (viii)
     rights to terminate, amend, supplement, modify or waive performance under
     the Partnership Agreement, to perform thereunder and to compel performance
     and otherwise exercise all remedies thereunder, along with all of the
     proceeds of any of the above and all General Intangibles (as such term is
     defined in the UCC) constituting any of the above.

          (b)  This Agreement and all of the Collateral secure the payment and
performance of Guarantors' obligations under the Guarantee, including, but not
limited to, the payment of all amounts owed to Collateral Agent, Trustee, the
Holders of the Senior Secured Notes and the Permitted Additional Senior Lenders,
if any, of every kind and description (whether or not evidenced by any note or
instrument and whether or not for the payment of money), direct or indirect,
absolute or contingent, due or to become due, now existing or hereafter arising,
pursuant to the terms of the Guarantee, including all interest, fees, charges,
expenses, attorney's fees and accountant's fees (all such obligations being
herein called the "Obligations").
                   -----------

          3.   Documents.
               ---------

                                       3


          (a)  At any time and from time to time upon the request of Collateral
Agent, each Pledgor will (i) deliver and pledge to Collateral Agent, endorsed
and/or accompanied by such evidence of assignment and transfer, in such form and
substance, as Collateral Agent may request, any and all instruments, documents,
chattel paper and/or general intangibles relating to the Collateral as
Collateral Agent may specify; (ii) give, execute, deliver, file and/or record
any notice, statement, instrument, document, agreement or other papers that may
be reasonably necessary, as Collateral Agent may reasonably request, in order to
create, preserve, perfect or validate the assignment and security interest
granted pursuant hereto or to enable Collateral Agent to exercise and enforce
its rights hereunder or with respect to such assignment and security interest;
and (iii) keep and stamp or otherwise mark any and all documents and its
individual books and records relating to Collateral in such manner as Collateral
Agent may require.

          (b)  Each Pledgor agrees that, from time to time, at the expense of
the relevant Pledgor, such Pledgor will promptly execute and deliver all further
instruments and documents, and take all further action that may be necessary or
required, or that Collateral Agent may reasonably request, in order to perfect
and protect the assignment and security interest granted or intended to be
granted hereby or to enable the Collateral Agent to exercise and enforce its
rights and remedies hereunder with respect to any Collateral. Without limiting
the generality of the foregoing, each Pledgor will execute and file such
financing or continuation statements or amendments thereto and such other
instruments, endorsements or notices as may be necessary or required, or as the
Collateral Agent may reasonably request, in order to perfect and preserve the
assignments and security interests granted or purported to be granted hereby.
Notwithstanding the foregoing, Collateral Agent shall have no obligation in
respect of filing such statements or the perfection or preservation of such
security interests.

          (c)  If any default by any Pledgor under the Partnership Agreement
shall occur, Collateral Agent shall, at its option, be permitted (but shall not
be obligated) to remedy any such default by giving written notice of such intent
to CLC and the relevant Pledgor. Collateral Agent shall have a period of sixty
(60) days after giving such notice in which to cure such default. In the event
that any such default (except monetary defaults) shall not be reasonably curable
within such 60 day period, neither CLC nor any Person acting on behalf of CLC,
including without limitation a general partner of CLC, shall exercise any
remedies thereunder if Collateral Agent shall, within such 60 day period,
initiate action to cure such default and proceed diligently to the curing
thereof. Any cure by Collateral Agent of a Pledgor's default under the
Partnership Agreement shall not be construed as an assumption by Collateral
Agent, Trustee, any of the Holders of the Senior Secured Notes or any Permitted
Additional Senior Lender of any obligations, covenants or agreements of any
Pledgor under the Partnership Agreement, and neither Collateral Agent, Trustee,
the Holders of the Senior Secured Notes nor any Permitted Additional Senior
Lender shall be liable for any action taken pursuant to this Section 3(c) to
cure any such default. This

                                       4


Agreement shall not be deemed to release or to affect in any way the obligations
of any Pledgor under the Partnership Agreement.

          4.   Events of Default.  The occurrence and continuance of any of the
               -----------------
following events ("Events of Default") whatever the reason for such Event of
                   -----------------
Default and whether it shall be voluntary or involuntary or be effected by
operation of law or pursuant to any judgment, decree or order of any court or
any order, rule or regulation of any administrative or governmental body, shall
constitute an Event of Default hereunder and shall entitle Collateral Agent
(subject to the Indenture) to exercise any and all of its rights and remedies
hereunder or at law:

          (a)  the occurrence (whether as a result of acts or omissions by any
Guarantor or any other Person) of an Event of Default under the Indenture; or

          (b)  the failure on the part of any Pledgor to observe or perform any
covenant, condition or agreement on its part to be observed or performed, or the
breach of any representation or warranty of a Pledgor contained in this
Agreement or the Partnership Agreement and such failure continues uncured for 30
or more days from the date a Responsible Officer of such Pledgor receives notice
thereof from the Collateral Agent;  provided that if such Pledgor commences and
diligently pursues efforts to cure such default within such 30-day period, such
Pledgor may continue to effect such cure of the default and such default will
not be deemed an Event of Default for an additional 60 days so long as such
Pledgor is diligently pursuing such cure.

          5.   Remedies.
               --------

          (a)  If any Event of Default has occurred and is continuing,
Collateral Agent shall have the right, at its election, but not the obligation,
to do any of the following, with respect to such Pledgor: (i) subject to Section
5(e) below and applicable law, vote or exercise any and all of such Pledgor's
rights or powers under the Partnership Agreement, including any rights or powers
to manage or control CLC; (ii) subject to Section 5(e) and applicable law
demand, sue for, collect or receive any money or property at any time payable to
or receivable by such Pledgor on account of or in exchange for all or any part
of the Collateral; (iii) institute and prosecute any action at law or suit in
equity or other proceeding to collect or enforce any Obligations or rights
hereunder or in the Collateral, including specific enforcement of any covenant
or agreement contained herein or in the Partnership Agreement, or to foreclose
or enforce the security interest in all or any part of the Collateral granted
herein, or to enforce any other legal or equitable right vested in it by this
Agreement or by law; (iv) sell or otherwise dispose of any or all of the
Collateral or cause all or any part of the Collateral to be sold or otherwise
disposed of in one or more sales or transactions, at such prices as Collateral
Agent may deem commercially

                                       5


reasonable, and for cash or on credit or for future delivery, without assumption
of any credit risk, at any broker's board or at public or private sale, without
demand of performance or notice of intention to sell or of time or place of sale
(except such notice which under applicable law cannot be waived), and any Holder
of the Senior Secured Notes, any Permitted Additional Senior Lender, or any
other Person may be the purchaser of any or all of the Collateral so sold and
thereafter hold the same absolutely free from any claim or right of whatsoever
kind, including any equity of redemption, of such Pledgor or CLC, any such
demand, notice or right and equity being hereby expressly waived and released
(to the extent permitted by applicable law); (v) incur expenses, including
reasonable attorneys' fees, consultants' fees, and other costs appropriate to
the exercise of any right or power under this Agreement; (vi) perform any
obligation of such Pledgor hereunder or under the Partnership Agreement; (vii)
secure the appointment of a receiver for such Pledgor (to the extent and in the
manner permitted by applicable law); or (viii) exercise any other or additional
rights or remedies granted to a secured party under the UCC. If, pursuant to
applicable law, prior notice of any such action is required to be given to such
Pledgor or CLC, such Pledgor and CLC hereby acknowledge and agree that the
minimum time required by such applicable law, or if no minimum is specified, ten
(10) Business Days, shall be deemed a reasonable notice period.

          (b)  In addition to the foregoing remedies, Collateral Agent (subject
to Section 3(c)) may, but shall not be obligated to, cure any Event of Default
and incur reasonable fees, costs and expenses in doing so, in which event CLC or
the relevant Pledgor shall immediately reimburse Collateral Agent on demand for
all such fees, costs and expenses, together with interest on the total amount at
a rate equal to the "Prime Rate" of Bankers Trust Company, as such rate is
announced from time to time, plus one percent (1%) (the "Default Rate"). Subject
to the such Pledgor's rights described in paragraph (c) below to contest certain
claims, taxes, assessments, charges, liens and encumbrances, Collateral Agent
shall be the sole judge of the validity of any adverse claims, taxes,
assessments, charges, liens or encumbrances pertaining to the Collateral, and
the amount to be paid in satisfaction thereof, and of the necessity therefor,
provided Collateral Agent shall be under no obligation to do any such acts or to
make any such payments.

          (c)  Each Pledgor may contest in good faith any taxes, assessments and
other governmental charges in connection with the Collateral and, in such event,
may permit the taxes, assessments or other charges so contested to remain unpaid
during any period, including appeals, when such Pledgor is in good faith
contesting the same, so long as (i) reserves have been established in an amount
sufficient to pay any such taxes, assessments or other charges, accrued interest
thereon and potential penalties or other costs relating thereto, or other
adequate provision for the payment thereof shall have been made, (ii)
enforcement of the contested tax, assessment or other charge is effectively
stayed for the entire duration of such contest, and (iii) any tax, assessment or
other charge determined to be due, together with any interest or penalties
thereon,

                                       6


is immediately paid after resolution of such contest. Additionally, each Pledgor
may contest in good faith Liens for any tax, assessment or other governmental
charge, by appropriate proceedings, so long as (i) such proceedings shall not
involve any substantial danger of the sale, forfeiture or loss of the
Collateral, title thereto or any interest therein, or (ii) in connection with
such proceedings a bond or other security has been posted or provided in such
manner and amount as to provide that any taxes, assessments or other charges
determined to be due will be promptly paid in full when such contest is
determined.

          (d)  All reasonable costs and expenses (including without limitation
agents' and reasonable attorneys' fees and expenses) incurred by Collateral
Agent, Trustee, any Holder of the Senior Secured Notes or Permitted Additional
Senior Lender in connection with exercising any remedy provided for herein or at
law, curing any Event of Default or performing any of a Pledgor's agreements
contained herein or in the Partnership Agreement or in respect of any part of
the Collateral, together with interest thereon computed at the Default Rate from
the date on which such costs or expenses are incurred to the date of payment
thereof, shall constitute indebtedness secured by this Agreement and shall be
paid by such Pledgor or CLC to Collateral Agent, Trustee such Holder of the
Senior Secured Notes or such Permitted Additional Senior Lender, as the case may
be, on demand.

          (e)  So long as no Event of Default has occurred and is continuing,
each Pledgor reserves the right to exercise all of its rights under the
Partnership Agreement (except as limited by the Indenture) and to receive all
income and other distributions and payments from CLC in respect of the
Collateral.  Notwithstanding any other term or provision of this Agreement, each
Pledgor shall be entitled to receive and retain for its own benefit and use all
distributions and other payments paid by CLC to such Pledgor in respect of the
Collateral prior to the occurrence of an Event of Default.

          (f)  The net proceeds of any foreclosure, collection, recovery,
receipt, appropriation, realization or sale of the Collateral shall be applied
in the order of priority specified in Section 5.10 of the Indenture.  If all
Obligations and any other amounts due under this Agreement have been
indefeasibly paid, satisfied and discharged in full, any surplus then remaining
shall be paid to Pledgors, if they are lawfully entitled to receive the same, or
shall be paid to whomsoever a court of competent jurisdiction may direct.

          (g)  The Collateral Agent shall not be deemed to make any
representations as to the value or condition of the Collateral and shall incur
no liability in respect thereof.

          6.   Remedies Cumulative; Delay Not Waiver.  No right, power or remedy
               -------------------------------------
herein conferred upon or reserved to Collateral Agent, Trustee, the Holders of
the Senior Secured Notes or the Permitted Additional Senior Lenders, if any, is
intended to be exclusive of

                                       7


any other right, power or remedy, and every such right, power and remedy shall,
to the extent permitted by law, be cumulative and in addition to every other
right, power and remedy given hereunder or now or hereafter existing at law or
in equity or otherwise. The assertion or employment of any right or remedy
hereunder shall not prevent the concurrent assertion or employment of any other
appropriate right or remedy. No delay or omission of Collateral Agent to
exercise any right or power accruing upon the occurrence and during the
continuance of any Event of Default as aforesaid shall impair any such right or
power or shall be construed to be a waiver of any such Event of Default or an
acquiescence therein. Every power and remedy given by this Agreement may be
exercised from time to time, and as often as shall be deemed expedient, by
Collateral Agent.

          7.   Covenants and Representations of Pledgors.  Each Pledgor
               -----------------------------------------
covenants, agrees and represents, solely with respect to itself, as follows:

          (a)  Pledgor will perform and comply, in all material respects, with
all obligations and conditions on its part to be performed hereunder, under the
Partnership Agreement or with respect to the Collateral.

          (b)  Pledgor (i) is, respectively, (A) a limited liability company
duly organized, validly existing and in good standing under the laws of the
State of Delaware, in the case of CAC, and (B) a limited partnership duly
organized, validly existing and in good standing under the laws of  the State of
Delaware, in the case of CAG, and in each case such Pledgor has all requisite
power and authority under the laws of its state of organization to enter into
the Partnership Agreement and to perform its obligations thereunder and to
consummate the transactions contemplated thereby, (ii) is duly qualified,
authorized to do business and in good standing in each jurisdiction where the
character of its properties or the nature of its activities makes such
qualification necessary, (iii) has all requisite power and authority (W) to
carry on its business as now being conducted and as proposed to be conducted by
it, (X) to execute, deliver and perform this Agreement and the Partnership
Agreement to which it is a party, in its individual capacity, (Y) to take all
action as may be necessary to consummate the transactions contemplated
thereunder and (Z) to grant liens and security interest provided for in this
Agreement, and (iv) has all requisite power and authority under the Partnership
Agreement to execute and deliver, on behalf of CLC, each Financing Document to
which CLC is a party.

          (c)  Pledgor has (i) taken all necessary action to authorize the
execution, delivery and performance of the Partnership Agreement and this
Agreement and each Financing Document to which it is a party; and (ii) duly
executed and delivered the Partnership Agreement and this Agreement and each
Financing Document to which it is a party.  Neither any Pledgor's execution and
delivery of this Agreement and the other Financing Documents to which it is a
party nor its consummation of the transactions contemplated thereby nor its
compliance with the

                                       8


terms thereof (i) does or will contravene the Partnership Agreement, the
articles of incorporation or formation documents of such Pledgor or any other
requirements of law applicable to or binding on such Pledgor or any of its
properties, (ii) does or will contravene or result in any breach of or
constitute any default under, or result in or require the creation of any Lien
(other than Permitted Liens) upon any of its property under, any agreement or
instrument to which it is a party or by which it or any of its properties may be
bound or affected or (iii) does or will require the consent or approval of any
Person which has not already been obtained.

          (d)  The Partnership Agreement has been duly authorized, executed and
delivered by such Pledgor, has not been amended or otherwise modified, and is in
full force and effect and is binding upon and enforceable against such Pledgor
in accordance with its terms.  There exists no default under the Partnership
Agreement by such Pledgor.

          (e)  This Agreement is the legal, valid and binding obligation of such
Pledgor, enforceable against such Pledgor in accordance with its terms, except
to the extent the enforceability may be limited by applicable bankruptcy,
insolvency, moratorium, reorganization or other similar laws affecting the
enforcement of creditors' rights and subject to general equitable principles.

          (f)  Pledgor has not executed and is not aware of any effective
financing statement, security agreement or other instrument similar in effect
covering all or any part of the Collateral on file in any recording office,
except such as may have been filed pursuant to this Agreement or the other
Financing Documents or pursuant to the documents evidencing Permitted Liens.

          (g)  Pledgor is the lawful owner of and has full right, title and
interest in and to, the Collateral, subject to no mortgages, liens, charges, or
encumbrances of any kind other than as granted pursuant to the Partnership
Agreement, and has full power and lawful authority to pledge, assign and grant a
security interest in the Collateral granted by it  hereunder. Pledgor will, so
long as any Obligations shall be outstanding, warrant and defend its title to
the Collateral against any claims and demands which may affect to a material
extent its title to, or the Collateral Agent's right or interest in, such
Collateral.

          (h)  Pledgor will not directly or indirectly create, incur, assume or
suffer to exist any Liens on or with respect to any part of the Collateral other
than the rights and interests of the Collateral Agent, the Trustee, the Holders
of the Senior Secured Notes and the Permitted Additional Senior Lenders, if any,
hereunder, Permitted Liens and rights of Pledgors under the Partnership
Agreement. Pledgor will at its own cost and expense promptly take such action
as may be necessary to discharge any such liens not so permitted.

                                       9


          (i)  Pledgor has not assigned any of its rights under the Partnership
Agreement or any of the Collateral except as provided in this Agreement.

          (j)  Any action or proceeding to enforce the rights granted or to
protect or preserve the Collateral under this Agreement may be taken by
Collateral Agent either in Pledgor's name or in Collateral Agent's name, as
Collateral Agent may deem necessary.

          (k)  Without the prior written consent of Collateral Agent, or as
otherwise permitted by the Indenture, Pledgor shall not (i) terminate or make
any material modification or amendment of the Partnership Agreement (unless
required, in the opinion of Pledgor, to maintain the Project as a "qualifying
facility"), (ii) fail to deliver to Collateral Agent a copy of each demand or
notice received or given by it relating to the Partnership Agreement and which
could reasonably be expected to have a material adverse effect upon the
Collateral or Collateral Agent's rights therein, or (iii) sell, contract to
sell, assign, transfer or dispose of any of the Collateral.

          (l)  Without the prior written consent of Collateral Agent, or as
otherwise permitted by the Indenture, each Pledgor covenants that it shall not
(i) permit CLC to directly or indirectly create, incur, assume or suffer to
exist any Liens on or with respect to any asset of CLC other than the rights and
interests of the Collateral Agent, the Trustee, the Holders of the Senior
Secured Notes and the Permitted Additional Senior Lenders, if any, hereunder,
Permitted Liens and rights of Pledgors under the Partnership Agreement, (ii)
permit CLC to directly or indirectly incur, assume or guarantee any debt.

          (m)  Pledgor shall give to Collateral Agent prompt written notice of
any material default, event of default or event which with the giving of notice
or the passage of time or both might become an event of default (however
"default" or "event of default" may be defined) under the Partnership Agreement,
whether by CLC, such Pledgor, or any other Person, of which such Pledgor has
actual knowledge or has received notice.

          (n)  If a Pledgor in its capacity as a partner receives any income or
distribution of money or property of any kind in respect of the Collateral from
CLC while an Event of Default has occurred and is continuing, such Pledgor shall
hold such income or distribution of money or property as trustee for and shall
deliver the same to Collateral Agent.

          (o)  Pledgor will, at all times, keep accurate and complete records of
the Collateral. Pledgor shall, at all times on three (3) Business Days' notice,
permit representatives of Collateral Agent at any time during normal business
hours of such Pledgor to inspect and make abstracts from such Pledgor's books
and records pertaining to the Collateral. Upon the occurrence and continuance of
any Event of Default, at Collateral Agent's request, Pledgor shall promptly
deliver any and all such records to Collateral Agent.

                                       10


          (p)  Pledgor will give prompt notice in writing to Collateral Agent of
any change in the location of the place of business where correspondence,
notices or proceeds in connection with the Collateral are received or located or
of any change in the location of the place of business where records concerning
Collateral are kept.

          (q)  Pledgor is not, and will not,  be or become, or cause CLC to be
or become or to be deemed by any Governmental Authority to be, solely as a
result of the construction, ownership, leasing or operation of the Project, the
sale of electricity therefrom or the entering into of any Financing Document or
any transaction contemplated thereby, a "utility" or subject to or not exempt
from regulation under the FPA (other than such regulation contemplated under 18
C.F.R. (S) 292.601(e)) or the PUHCA (other than Section 9(a)(2) of PUHCA) or
under state laws and regulations respecting the rates or the financial or
organizational regulation of public or electric utilities except as a Qualifying
Facility under PURPA.

          (r)  Pledgor will not do anything or cause, suffer or permit anything
to be done, including without limitation sale or other transfer of a Pledgor's
partnership interest in CLC or of any stock, partnership interest or other
ownership interest in any Pledgor (other than the exercise by others of remedies
under the Financing Documents), which may cause the Project to lose its status
as a Qualifying Facility.

          (s)  Pledgor shall not register any other secured party as a
"registered owner" (as defined in Section 8-301 of the New York UCC) of any
partnership interest in CLC.

          8.   Certain Consents and Waivers.
               ----------------------------

          (a)  Each Pledgor hereby consents to the other Pledgor entering into
this Agreement in favor of Collateral Agent for the benefit of the Trustee, the
Holders of the Senior Secured Notes and the Permitted Additional Senior Lenders,
if any. Each Pledgor specifically agrees that such action may, among other
things, assign or delegate to Collateral Agent rights to cure defaults under the
Partnership Agreement, to exercise voting rights and other rights to manage or
control CLC, and to act as such other Pledgor's attorney-in-fact in a manner
similar to the assignment and delegation of such rights provided herein. Each
Pledgor (to the extent permitted by applicable law) agrees that it will
recognize and accept such assignment and delegation and the exercise of such
rights by Collateral Agent in connection with this Agreement and agrees that any
option or rights of any Pledgor to acquire any of the Collateral from any other
Pledgor pursuant to the Partnership Agreement shall be subordinate to any right
of the Trustee in the Collateral created hereunder.

                                       11


          (b)  Each Pledgor hereby waives, to the maximum extent permitted by
law (i) all rights under any law limiting remedies, including recovery of a
deficiency, under an obligation secured by a deed of trust on real property if
the real property is sold under a power of sale contained in the mortgage, and
all defenses based on any loss whether as a result of any such sale or
otherwise, of Pledgor's right to recover any amount from CLC, whether by right
of subrogation or otherwise; (ii) all rights under any law to require Collateral
Agent to pursue CLC or any other Person, any security which Collateral Agent may
hold, or any other remedy before proceeding against Pledgor; (iii) all rights of
reimbursement or subrogation, all rights to enforce any remedy that Collateral
Agent, the Trustee, the Holders of the Senior Secured Notes or the Permitted
Additional Senior Lenders, if any, may have against CLC, and all rights to
participate in any security held by Collateral Agent until the Obligations have
been paid and the covenants of the Indenture have been performed in full; (iv)
all rights to require Collateral Agent to give any notices of any kind,
including without limitation notices of nonpayment, nonperformance, protest,
dishonor, default, delinquency or acceleration, or to make any presentments,
demands or protests, except as expressly provided herein and in the Indenture;
(v) all rights to assert the bankruptcy or insolvency of CLC as a defense
hereunder or as the basis for rescission hereof; (vi) all rights under any law
purporting to reduce Pledgors' Obligations hereunder if Pledgors' Obligations
are reduced; (vii) all defenses based on the disability or lack of authority of
Pledgor or any Person, the repudiation of the Guarantees or any related
Financing Documents by Pledgor or any Person, the failure by Collateral Agent,
the Trustee, the Holders of the Senior Secured Notes or any Permitted Additional
Senior Lender, if any, to enforce any claim against Pledgor, or the
unenforceability in whole or in part of any Financing Document; (viii) all
suretyship and guarantor's defenses generally; (ix) all rights to insist upon,
plead or in any manner whatever claim or take the benefit or advantage of, any
appraisal, valuation, stay, extension, marshaling of assets, redemption or
similar law, or exemption, whether now or at any time hereafter in force, which
may delay, prevent or otherwise affect the performance by Pledgor or its
obligations under, or the enforcement by Collateral Agent of, this Agreement;
(x) any requirement on the part of Collateral Agent, Trustee, the Holders of the
Senior Secured Notes or any Permitted Additional Senior Lender, if any, to
mitigate the damages resulting from any default; and (xi) except as otherwise
specifically set forth herein, all rights of notice and hearing of any kind
prior to the exercise of rights by Collateral Agent upon the occurrence and
during the continuation of an Event of Default to repossess with judicial
process or to replevy, attach or levy upon the Collateral. To the extent
permitted by applicable law, each Pledgor waives the posting of any bond
otherwise required of Collateral Agent in connection with any judicial process
or proceeding to obtain possession of, replevy, attach, or levy upon the
Collateral, to enforce any judgment or other security for the Obligations, to
enforce any judgment or other court order entered in favor of Collateral Agent,
or to enforce by specific performance, temporary restraining order, preliminary
or permanent injunction, this Agreement or any other agreement or document
between any Pledgor, Collateral Agent, Trustee, the Holders of the Senior
Secured Notes or any Permitted Additional Senior Lender, if any. Each Pledgor
further agrees that upon the occurrence

                                       12


and continuance of an Event of Default, Collateral Agent may elect to
nonjudicially or judicially foreclose against any real or personal property
security it holds for the Obligations or any part thereof, or to exercise any
other remedy against Pledgor, any security or any guarantor, even if the effect
of that action is to deprive a Pledgor of the right to collect reimbursement
from CLC for any sums paid by such Pledgor to Collateral Agent, Trustee or any
Holder of the Senior Secured Notes or any Permitted Additional Senior Lender, if
any.

          (c)  If Collateral Agent may, under applicable law, proceed to realize
its benefits under any of the Financing Documents giving Collateral Agent a Lien
upon any Collateral, whether owned by Pledgor or by any other Person, either by
judicial foreclosure or by nonjudicial sale or enforcement, Collateral Agent
may, at its sole option, determine which of its remedies or rights it may pursue
without affecting any of the rights and remedies of Collateral Agent under this
Agreement. In the event Collateral Agent shall bid at any foreclosure or
trustee's sale or at any private sale permitted by law or the Financing
Documents, Collateral Agent may bid all or less than the amount of Obligations.
To the extent permitted by applicable law, the amount of the successful bid at
any such sale, whether Collateral Agent or any other party is the successful
bidder, shall be conclusively deemed to be the fair market value of the
Collateral and the difference between such bid amount and the remaining balance
of the Obligations shall be conclusively deemed  to be the amount of the
Obligations.

          9.   CLC's Consent and Covenants.  CLC hereby consents to the
               ---------------------------
assignment of and grant of a security interest in the Collateral to Collateral
Agent and to the exercise by Collateral Agent of all rights and powers assigned
or delegated to Collateral Agent by each Pledgor hereunder, including without
limitation the rights upon and during an Event of Default to exercise such
Pledgor's voting rights and other rights under the Partnership Agreement to
manage or control CLC, subject to the notice and other requirements of
applicable law.  CLC further agrees to perform all covenants and obligations
herein which, by their express or implied terms, are to be performed by CLC.

          10.  Attorney-in-Fact.  Each Pledgor hereby irrevocably constitutes
               ----------------
and appoints Collateral Agent its true and lawful attorney-in-fact to enforce
all rights of such Pledgor with respect to the Collateral, including without
limitation, the right to vote, demand, receive and enforce such Pledgor's rights
with respect to the Collateral, and to give appropriate receipts, releases and
satisfactions for and on behalf of and in the name of such Pledgor or, at the
option of Collateral Agent, in the name of Collateral Agent, with the same force
and effect as such Pledgor could do if this Agreement had not been made;
provided, however, Collateral Agent shall not exercise such rights except upon
- --------  -------
the occurrence and during the continuation of an Event of Default. This power
of attorney is a power coupled with an interest and shall be irrevocable.

          11.  Place of Business; Location of Records.
               --------------------------------------

                                       13


          (a)  Unless Collateral Agent is otherwise notified, the place of
business and chief executive office of each respective Pledgor is and all
records of each respective Pledgor concerning the Collateral are and will be
located at the following addresses:


          CAITHNESS ACQUISITION COMPANY, LLC,
          c/o Caithness Energy, L.L.C.
          1114 Avenue of the Americas, 41st Street
          New York, New York  10036

          CAITHNESS GEOTHERMAL 1980 LTD., L.P.,
          c/o Caithness Energy, L.L.C.
          1114 Avenue of the Americas, 41st Street
          New York, New York  10036

          (b)  All notices required or permitted under the terms and provisions
hereof shall be in writing and any such notice shall be effective if given in
accordance with the provisions of Section 10.02 of the Indenture.  Notices to
each Pledgor may be given at the address of CLC set forth in such Section 10.02
above. Notices to Collateral Agent shall be given to Collateral Agent c/o
Trustee at its address set forth in such Section 10.02.

          12.  Perfection; Further Assurances.
               ------------------------------

          (a)  Each Pledgor agrees that from time to time, it will promptly
execute and deliver all instruments and documents as required by Section 3(a)
hereof. Without limiting the generality of the foregoing, each Pledgor will (i)
deliver the Collateral or any part thereof to Collateral Agent, as Collateral
Agent may request, accompanied by such duly executed instruments of transfer or
assignment as Collateral Agent may request, and (ii) execute and file such
financing or continuation statements, or amendments thereto, and such other
instruments, endorsements or notices, as may be reasonably necessary in order to
perfect and preserve the assignments and security interests granted or purported
to be granted hereby.

          (b)  Each Pledgor shall pay all filing, registration and recording
fees and all refiling, re-registration and re-recording fees, and all reasonable
expenses incident to the execution and acknowledgment of this Agreement, any
instruments of further assurance, and (except as otherwise provided in the
Indenture) all federal, state, county and municipal stamp taxes and other taxes,
duties, imports, assessments and charges arising out of or in connection with
the execution and delivery of this Agreement, any agreement supplemental hereto,
any financing statements, and any instruments of further assurance.

                                       14


          (c)  Each Pledgor shall give Collateral Agent at least forty-five (45)
days prior written notice before it changes the location of its place of
business and chief executive office and shall, at the expense of each Pledgor,
execute and deliver such instruments and documents as may be required by
Collateral Agent to maintain a prior perfected security interest in the
Collateral.

          13.  Continuing Assignment and Security Interest; Transfer of Loans.
               --------------------------------------------------------------
This Agreement shall create a continuing pledge and assignment of and security
interest in the Collateral and shall (i) remain in full force and effect until
payment in full of the Obligations, (ii) be binding upon CLC, Pledgors, and
their respective successors and assigns, and (iii) inure, together with the
rights and remedies provided herein, to the benefit of Collateral Agent, the
Holders of the Senior Secured Notes, the Permitted Additional Senior Lenders, if
any, and their respective successors, transferees and assigns. Without limiting
the generality of the foregoing, but subject to Section 2.06 of the Indenture,
any of the Holders of the Senior Secured Notes and the Permitted Additional
Senior Lenders, if any, may assign or otherwise transfer all or any part of or
interest in their Senior Secured Notes to any other Person to the extent
permitted by and in accordance with the Indenture, and such other Person shall
thereupon become vested with all or an appropriate part of the benefits in
respect thereof granted to the Holders of the Senior Secured Notes herein or
otherwise. The release of the security interest in any or all of the Collateral,
the taking or acceptance of additional security, or the resort by Collateral
Agent to any security it may have in any order it may deem appropriate, shall
not affect the liability of any person on the Obligations. Upon the payment and
performance in full of the Obligations, the security interest granted hereby
shall terminate and all rights to the Collateral shall revert to Pledgors. Upon
any such termination, Collateral Agent shall, at Pledgors' expense, execute and
deliver to Pledgors such documents as CLC or Pledgors shall reasonably request
to evidence such termination. If this Agreement shall be terminated or revoked
by operation of law, Pledgors will indemnify and save Collateral Agent, the
Trustee, the Holders of the Senior Secured Notes and the Permitted Additional
Senior Lenders, if any, harmless from any loss which may be suffered or incurred
by Collateral Agent, Trustee, the Holders of the Senior Secured Notes and the
Permitted Additional Senior Lenders, if any, in acting hereunder prior to the
receipt by Collateral Agent, its successors, transferees or assigns of written
notice of such termination or revocation.

          14.  Liability.  The obligations hereunder are subject to the
               ---------
limitations set forth in Section 6.11 of the Credit Agreement, the provisions of
which are hereby incorporated by reference.

          15.  Attorneys' Fees.  In the event any legal action or proceeding
               ---------------
(including without limitation any of the remedies provided for herein or at law)
is commenced to enforce or interpret this Agreement or any provision thereof,
the prevailing party shall be entitled to recover

                                       15


its reasonable attorneys' fees and other reasonable costs and expenses incurred
therein from the losing party, and, if a judgment or award is entered in any
such action or proceeding, such attorneys' fees and other costs and expenses may
be made a part of such judgment or award.

          16.  Severability.  Any provision of this Agreement which is
               ------------
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof, and any such prohibition or
unenforceability in any jurisdiction shall not invalidate or render
unenforceable such provision in any other jurisdiction.

          17.  Successors and Assigns.  All covenants and agreements contained
               ----------------------
herein shall be binding upon, and inure to the benefit of, the parties and their
respective successors and assigns. Pledgor and CLC shall cause any assignee to
pledge the assigned Collateral to the Collateral Agent.

          18.  Headings.  The headings of the various sections herein are for
               --------
convenience of reference only and shall not define or limit any of the terms or
provisions hereof.

          19.  Governing Law.  This Agreement, including all matters of
               -------------
construction, validity, performance and the creation, validity, enforcement or
priority of the lien of, and security interests created by, this Agreement in or
upon the Collateral shall be governed by the laws of the State of New York,
without reference to conflicts of law (other than Section 5-1401 of the New York
General Obligations Law), except as required by mandatory provisions of law and
except to the extent that the validity or perfection of the lien and security
interest hereunder, or remedies hereunder, in respect of any particular
Collateral are governed by the laws of a jurisdiction other than the State of
New York.

          20.  Time.  Time is of the essence of this Agreement.
               ----

          21.  References to Other Documents.  All defined terms used in this
               -----------------------------
Agreement which refer to other documents shall be deemed to refer to such other
documents as they may be amended, supplemented or replaced from time to time,
provided such documents were not amended in breach of a covenant contained in
any agreement to which any Pledgor, CLC, Collateral Agent or Trustee is a party.

          22.  Reinstatement.  This Agreement shall continue to be effective or
               -------------
be reinstated, as the case may be, if at any time any amount received by
Collateral Agent in respect of the Obligations is rescinded or must otherwise be
restored or returned by Collateral Agent upon the insolvency, bankruptcy,
reorganization, liquidation of any Pledgor or CLC or upon the dissolution of, or
appointment of any intervenor or conservator of, or trustee or similar official

                                       16


for any Pledgor or CLC or any substantial part of any Pledgor's or CLC's assets,
or otherwise, all as though such payments had not been made.

          23.  Statute of Limitations.  Each Pledgor hereby waives the right to
               ----------------------
plead any statute of limitations as a defense to any indebtedness or obligation
hereunder or secured hereby to the full extent permitted by law.

          24.  Entire Agreement.  This Agreement, together with any other
               ----------------
agreement executed in connection herewith, is intended by the parties as a final
expression of their agreement and is intended as a complete and exclusive
statement of the terms and condition thereof.

          25.  Counterparts.  This Agreement may be executed in one or more
               ------------
counterparts, each of which shall be deemed an original but all of which shall
together constitute one and the same agreement.

          26.  Waiver of Jury Trial.  EACH PLEDGOR, CLC AND COLLATERAL AGENT
               --------------------
HEREBY KNOWINGLY, VOLUNTARILY, AND INTENTIONALLY WAIVE ANY RIGHTS THEY MAY HAVE
TO A TRIAL BY JURY IN RESPECT OF ANY LITIGATION BASED HEREON, OR ARISING OUT OF,
UNDER, OR IN CONNECTION WITH, THIS AGREEMENT OR ANY OTHER COLLATERAL DOCUMENTS
OR FINANCING DOCUMENT, OR ANY COURSE OF CONDUCT, COURSE OF DEALING, STATEMENTS
(WHETHER VERBAL OR WRITTEN), OR ACTIONS OF THE COLLATERAL AGENT, CLC OR ANY
PLEDGOR.  THIS PROVISION IS A MATERIAL INDUCEMENT FOR THE COLLATERAL AGENT TO
ENTER INTO THIS AGREEMENT.

          27.  Regarding the Collateral Agent.   The Collateral Agent shall be
               ------------------------------
afforded all of the rights, powers, protections, immunities and indemnities set
forth in that certain Security Agreement dated as of the date hereof between
Pledgors and Collateral Agent as if the same were specifically set forth herein.

                 [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                                       17


          IN WITNESS WHEREOF, Pledgors, CLC Collateral Agent have caused this
Partnership Interest Pledge Agreement to be duly executed by their partners and
officers thereunto duly authorized, as of the day and year first above written.


                    Caithness Acquisition Company, LLC,
                    a Delaware limited liability company,

                         By:  /s/ Christopher T. McCallion
                              ----------------------------
                              Christopher T. McCallion
                              Executive Vice President

                    Caithness Geothermal 1980 Ltd., L.P.,
                    a Delaware limited partnership,
                    its General Partner

                         By:  Caithness Power, L.L.C.,
                              a Delaware limited liability company
                              its: General Partner

                              By:  /s/ Christopher T. McCallion
                                   ----------------------------
                                   Christopher T. McCallion
                                   Executive Vice President




                    U.S. BANK TRUST NATIONAL ASSOCIATION,
                    as Collateral Agent

                    By:  /s/ Judy P. Manansala
                         ---------------------
                    Name:  Judy P. Manansala
                           -----------------
                    Title: Trust Officer
                           -------------

                                       18


                    ACCEPTED AND AGREED
                    -------------------

                    COSO LAND COMPANY,
                    a California general partnership

                    By:  Caithness Acquisition Company, LLC,
                         a Delaware limited liability company,

                         By:  /s/ Christopher T. McCallion
                              ----------------------------
                              Christopher T. McCallion
                              Executive Vice President

                    By:  Caithness Geothermal 1980 Ltd., L.P.,
                         a Delaware limited partnership,
                         its General Partner

                         By:  Caithness Power, L.L.C.,
                              a Delaware limited liability company
                              its: General Partner

                              By:  /s/ Christopher T. McCallion
                                   ----------------------------
                                   Christopher T. McCallion
                                   Executive Vice President

                                       19