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                                                                   EXHIBIT 10.26
                             BAYCORP HOLDINGS, LTD.

                        INCENTIVE STOCK OPTION AGREEMENT

     1.  GRANT OF OPTION. BayCorp Holdings, Ltd., a Delaware corporation (the
"Company"), hereby grants to Anthony Callendrello (the "Optionee"), an option,
pursuant to the Company's 1996 Stock Option Plan (the "Plan"), to purchase an
aggregate of 30,000 shares of Common Stock ("Common Stock") of the Company at a
price of $8.875 per share, purchasable as set forth in and subject to the terms
and conditions of this option and the Plan. Except where the context otherwise
requires, the term "Company" shall include the parent and all present and future
subsidiaries of the Company as defined in Sections 424(e) and 424(f) of the
Internal Revenue Code of 1986, as amended or replaced from time to time (the
"Code").

     2.  INCENTIVE STOCK OPTION. This option is intended to qualify as an
incentive stock option ("Incentive Stock Option") within the meaning of Section
422 of the Code.

     3.  EXERCISE OF OPTION AND PROVISIONS FOR TERMINATION.

          (a) VESTING SCHEDULE. Except as otherwise provided in this Agreement,
this option may be exercised prior to the seventh anniversary of the date of
grant (hereinafter the "Expiration Date") in installments as to not more than
the number of shares set forth in the table below during the respective
installment periods set forth in the table below.


                                                          NUMBER OF
                                                    SHARES AS TO WHICH
               EXERCISE PERIOD                     OPTION IS EXERCISABLE
               ---------------                     ---------------------

         On or after April 3, 2001                         10,000

         On or after April 3, 2002                         20,000

         On or after April 3, 2003                         30,000

The right of exercise shall be cumulative so that if the option is not exercised
to the maximum extent permissible during any exercise period, it shall be
exercisable, in whole or in part, with respect to all shares not so purchased at
any time prior to the Expiration Date or the earlier termination of this option.
This option may not be exercised at any time on or after the Expiration Date.

          (b) EXERCISE PROCEDURE. Subject to the conditions set forth in this
Agreement, this option shall be exercised by the Optionee's delivery of written
notice of exercise to the Treasurer of the Company, specifying the number of
shares to be purchased and the purchase price to be paid therefor and
accompanied by payment in full in accordance with Section 4. Such exercise shall
be effective upon receipt by the Treasurer of the Company of such written notice


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together with the required payment. The Optionee may purchase less than the
number of shares covered hereby, provided that no partial exercise of this
option may be for any fractional share or for fewer than ten whole shares.

          (c) CONTINUOUS EMPLOYMENT REQUIRED. Except as otherwise provided in
this Section 3, this option may not be exercised unless the Optionee, at the
time he or she exercises this option, is, and has been at all times since the
date of grant of this option, an employee of the Company. For all purposes of
this option, (i) "employment" shall be defined in accordance with the provisions
of Section 1.421-7(h) of the Income Tax Regulations or any successor
regulations, and (ii) if this option shall be assumed or a new option
substituted therefor in a transaction to which Section 424(a) of the Code
applies, employment by such assuming or substituting corporation (hereinafter
called the "Successor Corporation") shall be considered for all purposes of this
option to be employment by the Company.

          (d) EXERCISE PERIOD UPON TERMINATION OF EMPLOYMENT. If the Optionee
ceases to be employed by the Company for any reason, then, except as provided in
paragraphs (e) and (f) below, the right to exercise this option shall terminate
one year after such cessation (but in no event after the Expiration Date),
PROVIDED THAT this option shall be exercisable only to the extent that the
Optionee was entitled to exercise this option on the date of such cessation, and
PROVIDED, FURTHER, that if such exercise is subsequent to the period of three
months after such cessation, this option shall be treated as a non-statutory
option which does not meet the requirements of Section 422 of the Code. The
Company's obligation to deliver shares upon the exercise of this option shall be
subject to the satisfaction of all applicable federal, state and local income
and employment tax withholding requirements, arising by reason of this option
being treated as a non-statutory option or otherwise. Notwithstanding the
foregoing, if the Optionee, prior to the Expiration Date, materially violates
the non-competition or confidentiality provisions of any employment contract,
confidentiality and nondisclosure agreement or other agreement between the
Optionee and the Company, the right to exercise this option shall terminate
immediately upon written notice to the Optionee from the Company describing such
violation.

          (e) EXERCISE PERIOD UPON DEATH OR DISABILITY. If the Optionee dies or
becomes disabled (within the meaning of Section 22(e)(3) of the Code) prior to
the Expiration Date while he or she is an employee of the Company, or if the
Optionee dies within three months after the Optionee ceases to be an employee of
the Company (other than as the result of a discharge for "cause" as specified in
paragraph (f) below), this option shall be exercisable, within the period of one
year following the date of death or disability of the Optionee (but in no event
after the Expiration Date), by the Optionee or by the person to whom this option
is transferred by will or the laws of descent and distribution, PROVIDED THAT
this option shall be exercisable only to the extent that this option was
exercisable by the Optionee on the date of his or her death or disability.
Except as otherwise indicated by the context, the term "Optionee", as used in
this option, shall be deemed to include the estate of the Optionee or any person
who acquires the right to exercise this option by bequest or inheritance or
otherwise by reason of the death of the Optionee.

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          (f) DISCHARGE FOR CAUSE. If the Optionee, prior to the Expiration
Date, is discharged by the Company for "cause" (as defined below), the right to
exercise this option shall terminate immediately upon such cessation of
employment. "Cause" shall mean willful misconduct in connection with the
Optionee's employment or willful failure to perform his or her employment
responsibilities in the best interests of the Company (including, without
limitation, breach by the Optionee of any provision of any employment,
nondisclosure, non-competition or other similar agreement between the Optionee
and the Company), as determined by the Company, which determination shall be
conclusive. The Optionee shall be considered to have been discharged "for cause"
if the Company determines, within 30 days after the Optionee's resignation, that
discharge for cause was warranted.

     4. PAYMENT OF PURCHASE PRICE.

          (a) METHOD OF PAYMENT. Payment of the purchase price for shares
purchased upon exercise of this option shall be made (i) by delivery to the
Company of cash or a check to the order of the Company in an amount equal to the
purchase price of such shares, (ii) subject to the consent of the Company, by
delivery to the Company of shares of Common Stock of the Company then owned by
the Optionee having a fair market value equal in amount to the purchase price of
such shares, (iii) by any other means which the Board of Directors determines
are consistent with the purpose of the Plan and with applicable laws and
regulations (including, without limitation, the provisions of Rule 16b-3 under
the Securities Exchange Act of 1934 and Regulation T promulgated by the Federal
Reserve Board), or (iv) by any combination of such methods of payment.

          (b) VALUATION OF SHARES OR OTHER NON-CASH CONSIDERATION TENDERED IN
PAYMENT OF PURCHASE PRICE. For the purposes hereof, the fair market value of any
share of the Company's Common Stock or other non-cash consideration which may be
delivered to the Company in exercise of this option shall be determined in good
faith by the Board of Directors of the Company.

          (c) DELIVERY OF SHARES TENDERED IN PAYMENT OF PURCHASE PRICE. If the
Optionee exercises options by delivery of shares of Common Stock of the Company,
the certificate or certificates representing the shares of Common Stock of the
Company to be delivered shall be duly executed in blank by the Optionee or shall
be accompanied by a stock power duly executed in blank suitable for purposes of
transferring such shares to the Company. Fractional shares of Common Stock of
the Company will not be accepted in payment of the purchase price of shares
acquired upon exercise of this option.

          (d) RESTRICTIONS ON USE OF OPTION STOCK. Notwithstanding the
foregoing, no shares of Common Stock of the Company may be tendered in payment
of the purchase price of

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shares purchased upon exercise of this option if the shares to be so tendered
were acquired within twelve (12) months before the date of such tender, through
the exercise of an option granted under the Plan or any other stock option or
restricted stock plan of the Company.

     5.  DELIVERY OF SHARES; COMPLIANCE WITH SECURITIES LAWS, ETC.

          (a) GENERAL. The Company shall, upon payment of the option price for
the number of shares purchased and paid for, make prompt delivery of such shares
to the Optionee, PROVIDED THAT if any law or regulation requires the Company to
take any action with respect to such shares before the issuance thereof, then
the date of delivery of such shares shall be extended for the period necessary
to complete such action.

          (b) LISTING, QUALIFICATION, ETC. This option shall be subject to the
requirement that if, at any time, counsel to the Company shall determine that
the listing, registration or qualification of the shares subject hereto upon any
securities exchange or under any state or federal law, or the consent or
approval of any governmental or regulatory body, or that the disclosure of
non-public information or the satisfaction of any other condition is necessary
as a condition of, or in connection with, the issuance or purchase of shares
hereunder, this option may not be exercised, in whole or in part, unless such
listing, registration, qualification, consent or approval, disclosure or
satisfaction of such other condition shall have been effected or obtained on
terms acceptable to the Board of Directors. Nothing herein shall be deemed to
require the Company to apply for, effect or obtain such listing, registration,
qualification, or disclosure, or to satisfy such other condition.

     6.  NONTRANSFERABILITY OF OPTION. Except as provided in paragraph (e) of
Section 3, this option is personal and no rights granted hereunder may be
transferred, assigned, pledged or hypothecated in any way (whether by operation
of law or otherwise) nor shall any such rights be subject to execution,
attachment or similar process. Upon any attempt to transfer, assign, pledge,
hypothecate or otherwise dispose of this option or of such rights contrary to
the provisions hereof, or upon the levy of any attachment or similar process
upon this option or such rights, this option and such rights shall, at the
election of the Company, become null and void.

     7.  NO SPECIAL EMPLOYMENT RIGHTS. Nothing contained in the Plan or this
option shall be construed or deemed by any person under any circumstances to
bind the Company to continue the employment of the Optionee for the period
within which this option may be exercised.

     8.  RIGHTS AS A SHAREHOLDER. The Optionee shall have no rights as a
shareholder with respect to any shares which may be purchased by exercise of
this option (including, without limitation, any rights to receive dividends or
non-cash distributions with respect to such shares) unless and until a
certificate representing such shares is duly issued and delivered to the
Optionee. No adjustment shall be made for dividends or other rights for which
the record date is

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prior to the date such stock certificate is issued.

     9.  ADJUSTMENT PROVISIONS.

          (a) General If, through, or as a result of, any merger, consolidation,
sale of all or substantially all of the assets of the Company, reorganization,
recapitalization, reclassification, stock dividend, stock split, reverse stock
split or other similar transaction, (i) the outstanding shares of Common Stock
are increased or decreased or are exchanged for a different number or kind of
shares or other securities of the Company, or (ii) additional shares or new or
different shares or other securities of the Company or other non-cash assets are
distributed with respect to such shares of Common Stock or other securities, the
Optionee shall, with respect to this option or any unexercised portion hereof,
be entitled to the rights and benefits, and be subject to the limitations, set
forth in Section 15(a) of the Plan.

          (b) BOARD AUTHORITY TO MAKE ADJUSTMENTS. Any adjustments under this
Section 9 will be made by the Board of Directors, whose determination as to what
adjustments, if any, will be made and the extent thereof will be final, binding
and conclusive. No fractional shares will be issued pursuant to this option on
account of any such adjustments.

          (c) LIMITS ON ADJUSTMENTS. No adjustment shall be made under this
Section 9 which would, within the meaning of any applicable provision of the
Code, constitute a modification, extension or renewal of this option or a grant
of additional benefits to the Optionee.

     10.  MERGERS, CONSOLIDATION, DISTRIBUTIONS, LIQUIDATIONS ETC. In the event
of a consolidation or merger or sale of all or substantially all of the assets
of the Company in which outstanding shares of Common Stock are exchanged for
securities, cash or other property of any other corporation or business entity,
or in the event of a liquidation of the Company, prior to the Expiration Date or
termination of this option, the Optionee shall, with respect to this option or
any unexercised portion hereof, be entitled to the rights and benefits, and be
subject to the limitations, set forth in Section 16(a) of the Plan.

     11.  WITHHOLDING TAXES. The Company's obligation to deliver shares upon the
exercise of this option shall be subject to the Optionee's satisfaction of all
applicable federal, state and local income and employment tax withholding
requirements.

     12.  LIMITATIONS ON DISPOSITION OF INCENTIVE STOCK OPTION SHARES. It is
understood and intended that this option shall qualify as an "incentive stock
option" as defined in Section 422 of the Code. Accordingly, the Optionee
understands that in order to obtain the benefits of an incentive stock option
under Section 421 of the Code, no sale or other disposition may be made of any
shares acquired upon exercise of the option within one year after the day of the
transfer of such shares to him, nor within two years after the grant of the
option. If the Optionee intends to dispose, or does dispose (whether by sale,
exchange, gift, transfer or otherwise), of any such

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shares within said periods, he or she will notify the Company in writing within
ten days after such disposition.

     13.  INVESTMENT REPRESENTATIONS; LEGENDS.

          (a) REPRESENTATIONS. The Optionee represents, warrants and covenants
     that:

          (i) Any shares purchased upon exercise of this option shall be
     acquired for the Optionee's account for investment only and not with a view
     to, or for sale in connection with, any distribution of the shares in
     violation of the Securities Act of 1933 (the "Securities Act") or any rule
     or regulation under the Securities Act.

          (ii) The Optionee has had such opportunity as he or she has deemed
     adequate to obtain from representatives of the Company such information as
     is necessary to permit the Optionee to evaluate the merits and risks of his
     or her investment in the Company.

          (iii) The Optionee is able to bear the economic risk of holding shares
     acquired pursuant to the exercise of this option for an indefinite period.

          (iv) The Optionee understands that (A) the shares acquired pursuant to
     the exercise of this option will not be registered under the Securities Act
     and are "restricted securities" within the meaning of Rule 144 under the
     Securities Act; (B) such shares cannot be sold, transferred or otherwise
     disposed of unless they are subsequently registered under the Securities
     Act or an exemption from registration is then available; (C) in any event,
     an exemption from registration under Rule 144 or otherwise under the
     Securities Act may not be available for at least two years and even then
     will not be available unless a public market then exists for the Common
     Stock, adequate information concerning the Company is then available to the
     public and other terms and conditions of Rule 144 are complied with; and
     (D) there is now no registration statement on file with the Securities and
     Exchange Commission with respect to any stock of the Company and the
     Company has no obligation or current intention to register any shares
     acquired pursuant to the exercise of this option under the Securities Act.

          (v) The Optionee agrees that, if the Company offers for the first time
     any of its Common Stock for sale pursuant to a registration statement under
     the Securities Act, the Optionee will not, without the prior written
     consent of the Company, publicly offer, sell, contract to sell or otherwise
     dispose of, directly or indirectly, any shares purchased upon exercise of
     this option for a period of 90 days after the effective date of such
     registration statement.

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By making payment upon exercise of this option, the Optionee shall be deemed to
have reaffirmed, as of the date of such payment, the representations made in
this Section 13.

          (b) LEGENDS ON STOCK CERTIFICATES. All stock certificates representing
shares of Common Stock issued to the Optionee upon exercise of this option shall
have affixed thereto legends substantially in the following forms, in addition
to any other legends required by applicable state law:

          "The shares of stock represented by this certificate have not been
          registered under the Securities Act of 1933 and may not be
          transferred, sold or otherwise disposed of in the absence of an
          effective registration statement with respect to the shares evidenced
          by this certificate, filed and made effective under the Securities Act
          of 1933, or an opinion of counsel satisfactory to the Company to the
          effect that registration under such Act is not required."

          "The shares of stock represented by this certificate are subject to
          certain restrictions on transfer contained in an Option Agreement, a
          copy of which will be furnished upon request by the issuer."

     14.  MISCELLANEOUS.

          (a) Except as provided herein, this option may not be amended or
otherwise modified unless evidenced in writing and signed by the Company and the
Optionee.

          (b) All notices under this option shall be mailed or delivered by hand
to the parties at their respective addresses set forth beneath their names below
or at such other address as may be designated in writing by either of the
parties to one another.

          (c) This option shall be governed by and construed in accordance with
the laws of the State of Delaware.

Date of Grant:                         BAYCORP HOLDINGS, LTD.

May 25, 2000
                                       By: /s/ Frank W. Getman Jr.
                                           -------------------------------------
                                           Frank W. Getman Jr., President
                                           20 International Drive
                                           Suite 301
                                           Portsmouth, NH  03801-6809


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                              OPTIONEE'S ACCEPTANCE

     The undersigned hereby accepts the foregoing option and agrees to the terms
and conditions thereof. The undersigned hereby acknowledges receipt of a copy of
the Company's 1996 Stock Option Plan.


                                            OPTIONEE


                                            /s/ Anthony M. Callendrello
                                            ------------------------------------
                                            Anthony Callendrello
                                            63 Old Town Farm Road
                                            Exeter, NH 03833




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