Exhibit 10.3(a)
                                                                 ---------------

                                    SERIES C
                                    --------

                                PROMISSORY NOTE
                                ---------------


$7,920,000                                              Tehachapi, California
                                                        December 23, 1985


          FOR VALUE RECEIVED,  ZOND WINDSYSTEM  PARTNERS,  LTD.,  SERIES 85-C, a
California Limited Partnership (the "Partnership") hereby promises to pay to the
order of ZOND CONSTRUCTION CORPORATION IV, a California corporation ("ZCC IV"),
at 112 South Curry Street, Tehachapi, California 93561, or
at such other address as may be designated by ZCC IV from time to time in
writing, in lawful money of the United States of America, the principal sum of
SEVEN MILLION NINE HUNDRED TWENTY THOUSAND DOLLARS ($7,920,000), together with
interest thereon as provided for below and, upon demand, all costs (including
without limitation reasonable attorney's fees) properly incurred in connection
with the enforcement of, and the collection of all amounts due under, this
Series C Promissory Note (this "Promissory Note").

          Simple interest shall accrue on the outstanding principal balance of
this Promissory Note from and after December 23, 1985 at a rate of 10.75% per
annum, computed on the basis of the actual number of days elapsed over a 360-day
year.

          The partnership promises to pay the principal amount of this
Promissory Note, together with simple interest accrued at a rate set forth above
on the outstanding balance of such principal amount, in thirty-two equal,
semiannual, installments, each in the amount of FIVE HUNDRED TWENTY-THREE
THOUSAND SEVEN HUNDRED SEVENTY AND 46/100 DOLLARS ($523,770.46), consisting of
principal and accrued interest. The first such installment shall be paid on the
six month anniversary date of the date set forth in the immediately preceding
paragraph, the second such installment shall be paid on the twelve month
anniversary date of the date set forth in the immediately preceding paragraph
and thereafter one installment each shall be paid at six month intervals on the
dates in each year commencing from the year 1987 and continuing through the year
2001 which correspond to the six month and twelfth month anniversary date of the
date set forth in the immediately preceding paragraph.

          This Note has been issued and is secured pursuant to a Purchase Note
and Security Agreement (Series C) [the "Agreement"] dated as of December 2, 1985


                                      -1-



between the Partnership and ZCC IV and is further secured by a Series C Deed of
Trust and Assignment of Rents dated as of December 2, 1985 (the "Deed of Trust")
made by the Partnership in favor of ZCC IV. Upon the occurrence of an Event of
Default (as defined in the Agreement) or an event of default as provided for in
Section 4.01 of the Deed of Trust, the same not having been cured during any
applicable cure period provided for in the Agreement or Deed of Trust, ZCC IV
may, at its election, declare all unpaid principal of, and all unpaid interest
accrued under, this Promissory Note to be immediately due and payable, and, in
the event such amounts are not immediately paid upon demand therefor, ZCC IV may
exercise its rights as a secured party under the Agreement and/or as the
beneficiary under the Deed of Trust, to foreclose on the security interests
granted to ZCC IV under the Agreement and/or the Deed of Trust. This Promissory
Note shall be without recourse to the Partnership, and in the event of any
failure by the Partnership to pay any amount when due or payable (at the stated
time of maturity or upon acceleration or otherwise) under this Promissory Note,
ZCC IV's sole recourse shall be to the security provided for with respect to
this Promissory Note in the Agreement and the Deed of Trust and the Partnership
shall in no event be personally liable under this Promissory Note.

          This Promissory Note is subject to mandatory prepayment in accordance
with the provisions of the Agreement. Any optional prepayment shall be applied
against payments due under the Promissory Note in reverse order of maturity.

          All payment to be made under this Promissory Note shall be
unconditional, and shall not be subject to offset, defense or counterclaim until
all amounts payable under this Promissory Note have been paid in full.

          The Partnership hereby waives presentment, demand, protest or notice
of any kind in connection with this Promissory Note, except to the extent such
waiver is not permitted by law.



                                      -2-





          The Promissory Note shall be construed in accordance with and governed
by the laws of the State of California.


                                     ZOND WINDSYSTEM PARTNERS, LTD.
                                     SERIES 85-C
                                     a California Limited Partnership
                                     112 South Curry Street
                                     Tehachapi, California  93561

                                     By its authorized General Partner:

                                          ZOND WINDSYSTEMS MANAGEMENT
                                          CORPORATION V,
                                          a California Corporation



                                          By:  /s/ Kenneth C. Karas
                                             ----------------------------------
                                             Kenneth C. Karas
                                             Senior Vice President
                                             Chief Financial Officer


          This Note is a replacement for that certain Series C Promissory Note
dated December 23, 1985 in the original principal amount of $7,920,000 payable
to Zond Construction Corporation IV which was lost by the pledgee thereof, First
Interstate Bank of California, as Trustee, as evidenced by the attached
Affidavit of Loss.



                                      -3-





                                    ALLONGE


          Pay to the order of ZOND SYSTEMS, INC., a California corporation, that
certain Series C Promissory Note dated December 27, 1985, in the original
principal amount of $7,920,000, made by Zond Windsystem Partners, Ltd. Series
85-C, a California limited partnership, in favor of Zond Construction
Corporation IV, a California corporation, and subsequently amended by that
certain Modification Agreement dated as of July 1, 1986, the original
replacement of which Promissory Note is attached hereto. In addition, the
undersigned hereby conveys, transfers and assigns to ZOND SYSTEMS, INC., a
California corporation, all the rights and benefits given to the undersigned
pursuant to that certain Affidavit of Lost, Destroyed or Stolen Promissory Notes
(The "Notes"), dated August 20, 1992 and executed by First Interstate Bank of
California Trustee, a copy of which is attached hereto.


Dated:  May 14, 1997                      ZOND WINDSYSTEMS HOLDING
        ------------                      COMPANY, a California corporation



                                          By:  /s/Adam S. Umanoff
                                             ----------------------------------

                                          Title:  Sr Vice Pres.
                                                -------------------------------





The following should be typed on the last page of the copy of the Promissory
Note:

          This Series C Promissory Note has been endorsed to Zond Systems, Inc.,
a California corporation, on May 14, 1997, pursuant to the Allonge attached
                             ------
hereto.



DATE PRINTED 17-DEC-85                                                    PAGE 1

ZOND SYSTEMS, INC.

LOAN AMORTIZATION SCHEDULE: SEMI-ANNUAL   SERIES 85-C PURCHASE NOTE - 1st
                                          100 TURBINES

FILE NAME: [ILLEGIBLE]


                                                                            
  PRINCIPAL AMOUNT        )    7,920,000         EQUAL AMORTIZATION               )           1
  TERM IN YEARS           )           16         EQUAL PRINCIPAL                  )           2
  INTEREST RATE (ANNUAL)  )       10.750%        SEMI-ANNUAL EQUAL AMORTIZATION   )  523,770.46
  LOAN AMORTIZATION       )            1         SEMI-ANNUAL EQUAL PRINCIPAL      )  247,500.00




                                                            SEMI-ANNUAL
                              SEMI-ANNUAL    SEMI-ANNUAL    TOTAL          REMAINING
SEMI-ANNUAL    BEGINNING      PRINCIPAL      INTEREST       PAYMENT        PRINCIPAL
PERIOD         PRINCIPAL      PAID           PAID           BALANCE        BALANCE
- ------------   ------------   ------------   ------------   ------------   ---------------
                                                              
           1   7,920,000.00      98,070.46     425,700.00     523,770.46      7,821,929.54
           2   7,821,929.54     103,341.74     420,428.71     523,770.46      7,718,587.80
           3   7,718,587.80     108,896.36     414,874.09     523,770.46      7,609,691.44
           4   7,609,691.44     114,749.54     409,020.91     523,770.46      7,494,941.90
           5   7,494,941.90     120,917.33     402,853.13     523,770.46      7,374,024.57
           6   7,374,024.57     127,416.64     396,353.82     523,770.46      7,246,607.94
           7   7,246,607.94     134,265.28     389,505.18     523,770.46      7,112,342.66
           8   7,112,342.66     141,482.04     382,288.42     523,770.46      6,970,860.62
           9   6,970,860.62     149,086.70     374,683.76     523,770.46      6,821,773.92
          10   6,821,773.92     157,100.11     366,670.35     523,770.46      6,664,673.81
          11   6,664,673.81     165,544.24     358,226.22     523,770.46      6,499,129.58
          12   6,499,129.58     174,442.24     349,328.21     523,770.46      6,324,687.33
          13   6,324,687.33     183,818.51     339,951.94     523,770.46      6,140,868.82
          14   6,140,868.82     193,698.76     330,071.70     523,770.46      5,947,170.07
          15   5,947,170.07     204,110.06     319,660.39     523,770.46      5,743,060.00
          16   5,743,060.00     215,080.98     308,689.48     523,770.46      5,527,979.02
          17   5,527,979.02     226,641.58     297,128.87     523,770.46      5,301,337.44
          18   5,301,337.44     238,823.57     284,946.89     523,770.46      5,062,513.87
          19   5,062,513.87     251,660.34     272,110.12     523,770.46      4,810,853.53
          20   4,810,853.53     265,187.08     258,583.38     523,770.46      4,545,666.46
          21   4,545,666.46     279,440.88     244,329.57     523,770.46      4,266,225.57
          22   4,266,225.57     294,460.83     229,309.62     523,770.46      3,971,764.74
          23   3,971,764.74     310,288.10     213,482.35     523,770.46      3,661,476.64
          24   3,661,476.64     326,966.09     196,804.37     523,770.46      3,334,510.55
          25   3,334,510.55     344,540.51     179,229.94     523,770.46      2,989,970.04
          26   2,989,970.04     363,059.57     160,710.89     523,770.46      2,626,910.48
          27   2,626,910.48     382,574.02     141,196.44     523,770.46      2,244,336.46
          28   2,244,336.46     403,137.37     120,633.06     523,770.46      1,841,199.09
          29   1,841,199.09     424,806.00      96,964.45     523,770.46      1,416,393.08
          30   1,416,393.08     447,639.33      76,131.13     523,770.46        968,753.75
          31     968,753.75     471,699.94      52,070.51     523,770.46        497,053.81
          32     497,053.81     497,053.81      26,716.64     523,770.46               .00