CONFIDENTIAL TREATMENT REQUESTED. CONFIDENTIAL PORTIONS OF THIS DOCUMENT HAVE
BEEN REDACTED AND HAVE BEEN SEPARATELY FILED WITH THE COMMISSION.

                                                                 Exhibit 10.4.21


                                  Lease and Agreement
                                  Union Oil Company of California



                                 [COMPANY LOGO]

              THIS LEASE AND AGREEMENT, made and entered into as of this 13th
day of May, 1971, by and between MATHEW J. LA BRUCHERIE and JANE E. LA
BRUCHERIE, HUSBAND AND WIFE; and ROBERT T. O'DELL and PHYLLIS M. O'DELL, husband
and wife hereinafter referred to as "Lessor", whether one or more, and UNION OIL
COMPANY OF CALIFORNIA, a California corporation, hereinafter referred to as
"Lessee",

              WITNESSETH: That Lessor, for and in consideration of Ten Dollars
($10.00) in hand paid to Lessor by Lessee, the rentals provided for hereinafter,
and other good and valuable consideration, the receipt and adequacy of which are
hereby acknowledged and in consideration of the covenants and agreements
hereinafter contained by the Lessee to be kept and performed, Lessor has
granted, leased, let and demised and by these presents does grant, lease, let
and demise to Lessee, its grantees, successors and assigns, upon and subject to
the terms and conditions hereinafter set forth, all that certain land (herein
sometimes referred to as the "leased land") situate in the County of IMPERIAL,
State of CALIFORNIA, and more particularly described as follows, to-wit:

PARCEL 1:  Lot 29, subdivision of Tract 48, Township 16 South, Range 14 East,
--------   S.B.B. & M., 71.30 Acres, more or less, lying Southwesterly of
           Southern Pacific Railroad.

PARCEL 2:  Lot 28, subdivision of Tract 48, Township 16 South, Range 14 East,
--------   S.B.B. & M., 82.20 Acres, more or less, lying Northwesterly of
           Southern Pacific Railroad.




(deemed to contain, for the purposes hereof, 154 acres, whether there be more or
less) with the sole and exclusive right to Lessee to explore for (by such
methods as it may desire), drill for, produce, extract, take, remove and sell
hot water, steam and thermal energy and extractable minerals from, and to store,
utilize, process, convert and otherwise treat such hot water, steam and thermal
energy upon, said land, and to extract any extractable minerals during the term
hereof, and to inject or reinject in the leased land effluence from wells
located on the leased land or on lands in the vicinity thereof, with the right
of entry on the leased land and use and occupancy thereof at all times for said
purposes and the furtherance thereof, including the right to construct, use and
maintain thereon and to remove therefrom structures, facilities and

                                      -1-


installations, pipe lines, utility lines, power and transmission lines. Further,
the Lessee is hereby granted the use of roads and ponds on said land together
with such rights of way and easements across said land for the construction of
roads, ponds, pipe lines, power and telephone transmission lines as are
necessary or convenient for the exploration, operation and development of Leased
Substances on the leased land or in the vicinity thereof. In the event this
lease should terminate with respect to all other rights for any reason, the
rights herein granted with respect to such roads, ponds, rights of way and/or
easements as are being used at the time of such termination shall remain in
effect so long as such roads, ponds, rights of way and/or easements are being
used by the Lessee, its successors and assigns. Following such termination,
Lessee agrees to pay an annual rental during the period of use at the rate of
ten per cent (10%) of the then current value used in tax assessments of the land
occupied by such roads, ponds, rights of way and/or easements being used. The
possession by Lessee of the leased land shall be sole and exclusive for the
purposes hereof and for purposes incident or related thereto, excepting that
Lessor reserves the right to use and occupy said land, or to lease or otherwise
deal with the same, without unreasonable interference with Lessee's rights, for
mining or extraction and utilization of minerals lying on the surface of or in
vein deposits on or in said land, or for the extraction of oil, natural
hydrocarbon gas and other hydrocarbon substances, or for any and all uses other
than the use and rights permitted to Lessee hereunder. Lessee agrees to conduct
its activities in a manner which will not unreasonably interfere with the rights
reserved to Lessor. The leased land includes also any rights of Lessor,
presently owned or hereafter acquired, in and under roads, underlying ditches,
and rights of way traversing or adjacent to said land.

For the purposes hereof the following definitions shall apply:

(a) The terms "hot water", "steam" and "thermal energy" shall mean natural
geothermal water and/or steam, and shall also mean the natural heat of the earth
and the energy present in, resulting from or created by, or which may be
extracted from, the natural heat of the earth or the heat present below the
surface of the earth, in whatever form such heat or energy occurs;

(b) The term "extractable minerals" shall mean any minerals in solution in the
well effluence and all minerals and gases produced from or by means of any well
or wells on the leased land or by means of condensing steam or processing water
produced from or the effluence from any such well or wells; said term shall also
include any water so produced or obtained from condensation of steam; and
further provided that the term "gases" shall not include hydrocarbon gases that
can be produced separately from the hot water, steam and associated minerals;

(c) The term "Leased Substances" shall collectively refer to the matter,
substances and resources, defined in (a) and (b) above, that are the subject of
this lease;

(d) The term "power potential" as used herein with respect to any well or wells
shall mean the quantity, or units, of energy capable of being recovered from the
hot water, steam or thermal energy produced therefrom by means of any energy
conversion or utilization facility (including, but not limited to, electrical
generating facilities) or equipment designed for use thereof;

(e) The term "sufficient power potential" as used herein shall be deemed to mean
that power potential which, in the judgment of Lessee shaft be sufficient for
the commercial sale or

                                      -2-


utilization thereof, or shall warrant the construction of facilities for the
commercial sale or other utilization thereof, or shall justify additional
drilling or other operations on the leased land;

(f) The word "commercial" used in connection with various phrases herein shall
mean those quantities of Leased Substances produced, sold or used, the value of
which, after deducting Lessee's operating costs (or extraction costs in case of
extractable minerals), will provide to Lessee a net return over such costs
sufficient to cause Lessee to continue production thereof or to elect to proceed
with further development or exploratory operations on the leased land.

The terms and conditions of this Lease and Agreement are as follows, to-wit;

1. This lease shall be for a term of ten (10) years from and after the date
hereof (herein called "primary term") and so long thereafter as Leased
Substances, or any of them, be derived or produced in commercial quantities from
the leased land or lands pooled or combined therewith, and for so long, as well,
as Lessee is prevented from producing same, or the obligations of Lessee
hereunder are suspended, for the causes hereinafter set forth.

If at the expiration of the primary term Lessee has not completed one or more
wells on the leased land, or land pooled therewith, separately or collectively
producing or being capable of producing steam of sufficient power potential
and/or extractable minerals in commercial quantities but Lessee is then engaged
in operations for drilling or reworking of any well on the leased land or land
pooled therewith, this lease shall remain in force so long as drilling or
reworking operations are prosecuted (whether on the same or different wells)
with no cessation of more than six (6) months, and if they result in production
or the establishment to the satisfaction of the Lessee of the existence of
sufficient power potential and/or extractable minerals in commercial quantities,
such well or wells will be deemed to have been completed and such existence so
established during the primary term of this lease.

         2. It is understood and agreed that the initial consideration paid upon
the execution hereof covers not only the privileges granted to the date when a
rental is payable as hereinafter provided, but any and all other rights
conferred hereunder. If on or before one (1) year from the date hereof Lessee
has not drilled such well or wells on the leased land or land pooled therewith
as to indicate or establish to the satisfaction of Lessee the existence of
sufficient power potential and/or extractable minerals in commercial quantities,
then, but subject to Lessee's right of surrender, on or before said anniversary
date, Lessee shall pay or tender to Lessor an annual rental in the amount of
*** Dollars ($***), which shall constitute rental until the next anniversary
date hereof, and thereafter Lessee shall, on or before each succeeding
anniversary date during the primary term hereunder, pay or tender to Lessor an
annual rental in the aforesaid amount, this until such time as from the drilling
of well or wells on the leased land, or land pooled therewith, there has been
established to the satisfaction of the Lessee the existence of sufficient power
potential and/or extractable minerals in commercial quantities. Upon such
establishing as aforesaid, Lessee may nevertheless continue to pay or tender
annual rental payments on or before each anniversary date, this until Lessee has
commenced the actual sale of one or more Leased Substances, and so long as such
annual rental payments be so paid or tendered this lease shall remain in force
and effect, even though thereby extended past the primary term, and all payments
so paid or tendered after the expiration of said primary term shall be deemed
advance royalties, and so long as same are paid each well or wells

*** Confidential material redacted and filed separately with the Commission.

                                      -3-


shall be deemed to be actually producing one or more Leased Substances in
commercial quantities under the terms hereof; provided, however, that if within
five (5) years from the date of expiration of the primary term hereof Lessee
shall have failed to make, or make arrangements for by executed contract or
contracts, a bona fide commercial sale of one or more Leased Substances then
Lessor, at its option, may consider Lessee in default hereunder. Additionally,
should Lessee fail to make any annual payment herein provided for on or before a
particular anniversary date, Lessor may, at its option, consider Lessee in
default hereunder.

3. Lessee shall pay to Lessor as royalty *** percent (***%) of the gross
proceeds received by Lessee from the sale of hot water, steam or thermal energy,
as such, produced from the leased land at and as of the point of origin on the
leased land; royalty on steam may be computed and paid for on the basis of
pounds of steam produced, saved and sold by Lessee, or may be computed on the
basis of the number of kilowatt hours of electric power generated by the use of
such steam, but shall be computed and paid for on whatever basis which shall
properly reflect the royalty portion of the gross proceeds received by Lessee
from sale of hot water, steam and thermal energy, as such, produced from the
leased land at and as of the point of origin on the leased land. With respect to
extractable minerals, as royalty Lessee shall pay to Lessor Ten Percent (10%) of
the net proceeds received by Lessee from the sale of any gas (as herein defined)
and from the sale of effluence (containing minerals and/or minerals in solution)
produced and sold from any well or wells on the leased land, or, in the event
Lessee extracts from the effluence minerals and/or minerals in solution Ten
Percent (10%) of the proceeds received by Lessee from the sale of minerals
and/or minerals in solution contained in and extracted from the effluence
produced and sold from such well or wells less costs of transportation and
extraction. Lessor on or before the twenty-fifth day of the month next the
royalties accrued and payable for the preceding calendar month, or on or before
the twenty-fifth day of the month next following that in which Lessee receives
payment therefore from the purchaser thereof, whichever method shall apply, and
in making such royalty payments Lessee shall deliver to Lessor statements
setting forth the basis for computation and determination of such royalty.

              Lessee shall not be required to account to Lessor for or to pay
any royalty on hot water, steam, thermal energy or extractable minerals produced
by Lessee on the leased land which are not utilized, saved and sold, or which
are used by Lessee in its operations on or with respect to the leased land for
or in connection with the developing, recovering, producing, extracting and/or
processing of hot water, steam and/or minerals in solution or in facilities used
in connection therewith, including operations of facilities for the generation
of electric power, for its own consumption, or which are unavoidably lost.

              Lessee shall have the right, from time to time and at any time, to
commingle (for purposes of storing, transporting, utilizing, selling or
processing, or any of them) the or any of the Leased Substances produced or
extracted from production from the leased land or lands pooled therewith with
the Leased Substances, or any of them, produced from other lands or units in the
vicinity of the leased land, and in the event of such commingling Lessee shall
meter, gauge or measure the production from the leased land, or from the unit or
units including same or other units or lands, as the case may be, and compute
and pay Lessor's royalty payable under the provisions hereof on the basis of
such production so determined or allocated, as the case may be.

*** Confidential material redacted and filed separately with the Commission.

                                      -4-


              4. Lessee may, at any time or from time to time as a recurring
right, either before or after production but within twenty (20) years from the
date hereof, provided this lease is then in effect and Lessee is not in default,
for drilling, development, or operating purposes, pool, utilize or combine all
of the leased land into a unit with any other land or lands or leased or leases
(whether held by Lessee or others) adjacent , adjoining or in the immediate
vicinity of the leased land which Lessee desires to develop or operate as a
unit, provided that the total acreage to be embraced within any such drilling,
development, or operating unit shall not exceed one thousand nine-hundred twenty
(1,920) acres, plus an acreage tolerance of Ten Percent (10%). Such a unit shall
become in existence upon Lessee's filing in the office of the County Recorder in
the county in which the leased land is situated a notice of such unitization ,
describing said unit. Lessee shall also mail a copy of such notice to Lessor.
Any well (whether or not Lessee's well commenced, drilled, drilling and/or
producing or being capable of producing in any part of such unit shall for all
purposes of this lease be deemed a well commenced, drilled, drilling and/or
producing on the leased land, and Lessee shall have the same rights and
obligations with respect thereto and to drilling and producing operations upon
the lands from time to time include within any such unit as Lessee would have if
such lands constituted the leased land; provided, however, that notwithstanding
this or any other provision or provisions of this lease to the contrary:

              (1) production as to which royalty is payable from any such well
or wells drilled upon any such unit, whether located upon the leased land or
other lands, shall be allocated to the leased land in the proportion that the
surface acreage of the leased land in such unit bears to the total surface
acreage of such unit, and such allocated portion thereof shall for all purposes
of this lease be considered as having been produced from the leased land, and
the royalty payable under this lease with respect to the leased land included in
such unit shall be payable only upon that proportion of such production so
allocated thereto, and

              (2) if any taxes of any kind are levied or assessed (other than
taxes on the land and on Lessor's improvements), and a portion of which is
chargeable to Lessor under Paragraph 12 hereof, then the share of such taxes to
be borne by Lessor as provided in this lease, shall be in proportion to the
share of the production from such unit allocated to the leased land.

              Allocation as aforesaid of production from any such unit, whether
to the leased land or in like manner to other land therein, shall continue
notwithstanding any termination, either in whole or in part (by surrender,
forfeiture or otherwise), on this or any other lease covering lands in such unit
until such time as the owner of such lands so terminated shall enter into an
agreement to drill for or produce or shall drill for or produce or permit or
cause the drilling for or production from any part of such lands, whereupon all
such lands formerly included in such unit and as to which the lease covering the
same shall have terminated shall be excluded in determining the production to be
allocated to the respective lands in such unit; additionally, in the event of
the failure of Lessor's, or in any other owner's, title as to any portion of the
land included in any such unit, such portion of such land shall likewise be
excluded in allocating production from such unit; provided, however, Lessee
shall not be held to account for any production allocated to any lands excluded
from any such operating unit unless and until Lessee has actual knowledge of the
aforesaid circumstances requiring such exclusion. Any exclusion shall be deemed
effective the first day of the month next following the date upon which such
exclusion becomes finally established.

                                      -5-


              Lessee may, at its sole option, at any time when there is no
production in such unit of Leased Substances in quantities deemed paying by
Lessee, terminate such unit by a written declaration thereof, in the same manner
in which it was created.

              5. At such time as Lessee shall have drilled and completed such
well or wells on the leased land or land pooled therewith which shall indicate
to the satisfaction of Lessee a sufficient power potential, or the existence of
extractable minerals commercial quantities, Lessee may at any time thereafter
construct and install in the leased land facilities for the commercial sale or
use of hot water, steam or thermal energy produced from the leased land or lands
in the vicinity thereof or pooled therewith, or for the extraction of
extractable minerals, or for development of electric power from the use of steam
or thermal energy produced from the leased land or lands in the vicinity thereof
or pooled therewith.

              6. Lessee shall have the right to drill such well or wells on the
leased land as Lessee may deem desirable for the purposes hereof, including
wells for injection or re-injection purposes; provided, however, that Lessee
agrees to utilize for such purpose or purposes only so much of the leased land
as shall be reasonably necessary for Lessee's operations and activities thereon.
No well shall be drilled within one hundred (100) feet of any residence or barn
now on said land without Lessor's consent. Lessee shall have free use of water
from said land for all operations thereon or on land pooled therewith, provided
that such free use shall not interfere with Lessor's own use for domestic,
commercial, stock or agricultural purposes, nor interfere with any contractual
commitments of Lessor relating thereto and existing on the date hereof. Lessee
shall not be entitled to free use of any water which has been or is being
purchased by Lessor, Lessee shall not allow the fluid level of any effluence it
may inject or re-inject hereunder to be less than a depth of 200 feet below the
present surface of the leased land.

              Lessee agrees to fence all sump holes or other excavations, and
upon abandonment of any well on the leased land, the termination of the lease,
Lessee shall level and fill all sump holes and excavations, shall remove all
debris and shall leave the locations or premises used by Lessee in a clean and
sanitary condition. Abandonment of any well drilled by Lessee on the leased land
shall be accomplished in accordance with all applicable laws or regulation of
the governing municipality

              Lessee shall protect said land against liens of every character
arising from its operations thereon. Lessee, at its own expense, prior to
commencing operations on the leased land, shall obtain, and thereafter while
this lease is in effect shall maintain, adequate Workmen's Compensation
Insurance. Lessee shall protect Lessor against damages of every kind and
character arising out of the operations or working of Lessee or those under
Lessee's control upon the leased land, but Lessee shall not be liable hereunder
in the event of the negligence or willful misconduct of parties other than
Lessee. In the event any building or personal property be damaged or destroyed,
or grazing or agricultural lands be damaged or destroyed by Lessee's operations,
then Lessee shall be liable for, and to the extent of, the reasonable value
thereof.

              Lessee shall have the right at any time and from time to time to
remove from the leased land any and all casing, machinery, equipment,
structures, installations and property of every kind and character placed upon
said leased land by or pursuant to permission of Lessee,

                                      -6-


provided that if such removal should occur after termination hereof same shall
be completed within a reasonable time thereafter.

              7. Lessor, or its agents, at Lessor's sole risk, may at all times
examine said land and the workings, installations and structures thereon and
operations of Lessee thereon, and may at reasonable times inspect the books and
records of Lessee with respect [MISSING TEXT]

                  6-a     Any provision contained in Paragraph 6 hereof
                          notwithstanding, Lessee shall drill no well from the,
                          surface of the leased land except from drillsites
                          thereon to be designated by Lessor. Lessor agrees to
                          designate, with fifteen (15) days after receiving
                          Lessee's written request to do so, one (1) such
                          drillsite for every forty (40) acres or major fraction
                          thereof of the leased land together with adequate
                          rights of way from such drill site to a public
                          roadway. Such drillsites shall be, as near as
                          practicable in the form of a square containing five
                          (5) acres. In the event pipelines, utility lines,
                          power and/or transmission lines are deemed necessary,
                          Lessee agrees to secure Lessor's consent as to the
                          location of same.

                  6-b     Lessee agrees that upon entering upon the surface of
                          the leased land as provided in Paragraph 6-a hereof,
                          it shall pay Lessor a rental in an amount equal to
                          rentals paid for comparable lands in the area for
                          agricultural purposes but not to exceed *** Dollars
                          ($***) per acre per year. Such rentals shall be
                          payable annually in advance until Leased Substances
                          are produced from the leased land in commercial
                          quantities, until Lessee shall quitclaim its right to
                          enter upon the surface of said land or until this
                          lease shall terminate, whichever shall first occur.

              12. Lessee shall pay all taxes levied on Lessee's structures and
improvements placed on the leased land by Lessee. Lessee shall pay 90% and the
Lessor shall pay 10% of any taxes assessed against any Leased Substances stored
on the leased land. In the event any taxes are levied or assessed against the
right to produce Leased Substances from the leased land or in the event any
increase in the taxes levied or assessed against the leased land shall be based
upon the production from the leased land of Leased Substances, then in either
such event Lessee shall pay 90% of any such taxes or increase, as the case may
be, and Lessor shall pay 10% thereof. Lessor shall pay all taxes levied or
assessed against the leased land as such without reference to the production of
Leased Substances therefrom and shall pay all taxes levied and assessed against
any and all rights in or to or with respect to the leased land not covered by
this lease and shall pay all taxes levied and assessed against all structures
and improvements owned by Lessor or placed on the leased land by or pursuant to
permission of Lessor.

              13. The rights of either party hereunder may be assigned in whole
or in part, and the right and privilege so to do is hereby reserved by each
party, provided, however, that the Lessee shall not assign all or any part of
its interest except to a major oil or utility company, and the provisions hereof
shall extend to the heirs, successors and assigns of the parties hereto, but no
change or division in ownership of the land, rentals or royalties, however
accomplished, shall

*** Confidential material redacted and filed separately with the Commission.

                                      -7-


operate to enlarge the obligations or diminish the rights of Lessee, and Lessee
may continue to operate the leased land and to pay and settle rentals or
royalties as an entirety, and no such change in ownership shall be binding upon
Lessee until the expiration of thirty (30) days after Lessee is furnished with
satisfactory written evidence thereof. In the event of assignment of this lease
as to a segregated portion of said land, the rentals payable hereunder shall be
apportionable between the several leasehold owners ratably according to the
surface area of each, and default in rental payment by one shall not affect the
rights of other leasehold owners hereunder.

              14. The obligations of Lessee hereunder shall be suspended and the
term of this lease shall be extended, as the case may be, while Lessee is
prevented from complying therewith, in whole or in part, by strikes, lockouts,
riots, actions of the elements, accidents, delays in transportation, inability
to secure labor or materials in the open market, laws, rules or regulations of
any federal, state, municipal or other governmental agency, authority or
representative, or other matters or conditions beyond the reasonable control of
Lessee, whether or not similar to the conditions or matters herein specifically
enumerated.

              If any time after the expiration of fifteen (15) years from date
hereof the production of all Leased Substances ceases for any cause other than
one or more of the causes hereinabove enumerated, this lease shall nevertheless
remain in full force and effect for an additional period of one (1) year from
cessation and thereafter if, and so long as, Lessee commences and continues
diligently and in good faith the steps, operations or procedures to cause a
resumption of such production (either through the existing wells or the drilling
of new wells), until such production be resumed.

              15. All statements of production and royalty and all payments to
be made by Lessee to Lessor hereunder shall be sent to the persons hereinafter
set forth, respectively, at the addresses indicated and each such person shall
be entitled to receive that portion of the total rentals and royalty payable
hereunder as is hereinafter set froth after the name of such person:

Mathew J. LaBrucheri and Jane E. LaBrucherie    50%     Taxpayer's Indent
Robert T. O'Dell and Phyllis M. O'Dell          50%     No. 558 24 7862

P.O. Box 1420                                           Taxpayer's Indent
El Centro, California  92243                            No. ###-##-####

Lessee shall, upon notification of change of ownership in the lands or in
rentals or royalties hereunder, as provided in Paragraph 13 hereof, divide and
distribute the same to the new owners of such interests; provided, however, that
if at any time there are three or more persons entitled to rentals or royalties
hereunder, Lessee may at its option, withhold payment of such rentals or
royalties until a majority in interest of such persons designate in writing in a
recordable instrument delivered to Lessee, a bank, trust company or corporation,
as a common agent and depositary to, receive all payments due hereunder to such
persons. Such designation may be changed at any time in the same manner.
Delivery of all statements and payments hereunder may be made by depositing the
same in the United States mail duly addressed to Lessor at the above address or
addresses or to such agent and depositary which shall constitute full
performance of Lessee's obligation to make such delivery. In the event that the
amount payable under this lease shall result in a payment of less than Five
Dollars ($5.00) becoming due Lessor,

                                      -8-


Lessee may, at its option, withhold and accrue sufficient periodic payments
until the total due Lessor exceeds Five Dollars ($5.00).

              16. Any notice herein required or permitted to be given or
furnished by one party to the other shall be in writing, Delivery of such
written notice to Lessor shall be made by depositing the same in the United
States mail duly certified and addressed to Lessor at P.O. Box 1420 El Centro,
California, 92243 and delivery of such written notice to Lessee shall be made by
depositing the same in the United States mail duly certified and addressed to
Lessee at Union Oil Center, 461 South Boylston Street, Los Angeles, California
90017. Either party hereto may by written notice to the other party change its
address to any other location.

              17. In the event any part or portion or provision of this
instrument shall be found or declared to be null, void or unenforceable for any
reason whatsoever by any Court of competent jurisdiction or any governmental
agency having authority thereover, then and in such event only such part,
portion or provision shall be affected thereby, and such finding, ruling or
decision shall not in any way affect the remainder of this instrument or any of
the other terms or condition hereof, which said remaining terms and conditions
shall remain binding, valid and subsisting and in full force and effect between
the parties hereto, it being specifically understood and agreed that the
provisions hereof are severable for the purposes of the provisions of this
clause. In this connection, this lease shall not in any event extend beyond such
term as may be legally permissible under present applicable laws, and should any
such applicable law limit the term hereof to less than that herein provided,
then this lease shall not be void but shall be deemed to be in existence for
such term and no longer.

              18. If more than one person is named as a Lessor herein and one or
more of them fails to execute this lease, said lease shall nevertheless (when
accepted by Lessee) become effective as a lease from such of said named parties
Lessor as may have executed the same.

              19. This lease may be executed in any number of counterparts and
all such counterparts shall be deemed to constitute a single lease and the
execution of one counterpart by any party Lessor shall have the same force and
effect as if such party had signed all the other counterparts.

              20. This Lease and Agreement and all of the terms, covenants and
conditions hereof shall extend to the benefit of and be binding upon the
respective heirs, successors and assigns of the parties hereto.

                                      -9-


              IN WITNESS WHEREOF, the parties have caused this instrument to be
duly executed as of the date hereinabove first written.

/s/ Stanley Harris                             /s/ Matthew J. LaBrucherie
------------------------------------------     ------------------------------
Stanley Harris, Subscribing Witness to the     Matthew J. LaBrucherie
Signature of Mathew J. LaBrucherie


/s/ Stanley Harris                             /s/ Jane E. LaBrucherie
------------------------------------------     ------------------------------
Stanley Harris, Subscribing Witness to the     Jane E. LaBrucherie
Signature of Jane E. LaBrucherie

/s/ Stanley Harris                             /s/ Robert T. O'Dell
------------------------------------------     ------------------------------
Stanley Harris, Subscribing Witness to the     Robert T. O'Dell
Signature of Robert T. O'Dell

/s/ Stanley Harris                             /s/ Phyllis M. O'Dell
------------------------------------------     ------------------------------
Stanley Harris, Subscribing Witness to the     Phyllis M. O'Dell
Signature of Phyllis M. O'Dell
                                                          LESSOR

                                               UNION OIL COMPANY OF CALIFORNIA

                                               By:
                                                  ---------------------------
                                                           LESSEE

                                      -10-


                   AMENDMENT TO GEOTHERMAL LEASE AND AGREEMENT

         THIS AGREEMENT made and entered into as of this fifth day of April,
1976, by and between MATHEW J. LA BRUCHERIE and JANE E. LA BRUCHERIE, husband
and wife; and ROBERT T. O'DELL and PHYLLIS M. O'DELL, husband and wife,
hereinafter called "Lessor" and UNION OIL COMPANY OF CALIFORNIA, a California
corporation, hereinafter called "Lessee";

                              W I T N E S S E T H:

         THAT WHEREAS, Lessee presently holds all of the Lessee's right, title
and interest under that certain Geothermal Lease and Agreement dated May 13,
1971, entered into by and between Lessor and Lessee herein, covering 154.00
acres, more or less, situate in Imperial, more particularly described in said
lease; a Memorandum of which was recorded July 1, 1971 in Book 1311, at Page
996, Official Records of said County and State; and

         WHEREAS, it is the desire of the parties hereto to amend said lease by
modifying the primary term and rental clause thereof as hereinafter provided;

         NOW, THEREFORE, in consideration of Ten Dollars ($10.00) in hand paid
by Lessee to Lessor and other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, Lessor does hereby lease said land to
Lessee for the same purposes and upon all the same terms, provisions and
conditions, as contained in said lease of May 13, 1971, and the parties hereto
agree:

                  1.  That the first paragraph of the habendum clause which
                      appears on Page 2 of said lease is hereby deleted in its
                      entirety and the following is hereby substituted therefor:

                                      -11-


                      "This lease shall be for a term of ten (10) years from and
                      after the date hereof (herein called "primary term") and
                      so long thereafter as Leased Substances, or any of them,
                      be derived or produced in commercial quantities from the
                      leased land or lands pooled or combined therewith, and for
                      so long, as well, as Lessee is prevented from producing
                      same, or the obligations of Lessee hereunder are
                      suspended, for the causes hereinafter set forth or this
                      lease is continued in force by reason of any other
                      provision hereof."

                  2.  The words and numbers "***" appearing in the 6th and 7th
                      printed lines of Paragraph 2 are hereby deleted and the
                      words and numbers "***" are hereby substituted
                      therefor.

                  3.  The rental payments due hereunder have been paid by Lessee
                      and received by Lessor and operate to defer the
                      commencement of drilling operations until May 13, 1977.

         As hereby amended said lease shall be and remain in full force and
effect as to all its terms and provisions.

         This agreement shall be binding upon and shall inure to the benefit of
the heirs, personal representatives, successors and assigns of the parties
hereto.

         This agreement may be executed in any number of counterparts with the
same force and effect as though all parties signed the same document.

         IN WITNESS WHEREOF, the parties hereto have executed this instrument
the day and year first hereinabove written.

                                 /s/ Mathew J. La Brucherie
                                 ----------------------------------------------
                                 MATHEW J. LA BRUCHERIE

                                 /s/ Jane E. La Brucherie
                                 ----------------------------------------------
                                 JANE E. LA BRUCHERIE

*** Confidential material redacted and filed separately with the Commission.



                                      -12-




                                 /s/ Robert T. O'Dell
                                 ----------------------------------------------
                                 ROBERT T. O'DELL



                                 /s/ Phyllis M. O'Dell
                                 ----------------------------------------------
                                 PHYLLIS M. O'DELL


                                 ----------------------------------------------


                                 ----------------------------------------------

                                                    LESSOR

                                 UNION OIL COMPANY OF CALIFORNIA

                                 By:
                                    --------------------------------------------
                                                            Its Attorney in Fact

                                                     LESSEE



                                      -13-