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                                                                    EXHIBIT 10.5

      This Twenty-Third Amendment to District Cooling System Use Agreement (the
"Twenty-Third Amendment"), dated as of November 1, 2005 (the "Effective Date")
by and between the City of Chicago, Illinois (the "City"), a home rule unit and
municipality under Article VII of the Constitution of the State of Illinois, and
Thermal Chicago Corporation, an Illinois corporation (the "Grantee").

                                  WITNESSETH:

      WHEREAS, the City and the Grantee have entered into that certain District
Cooling System Use Agreement dated as of October 1, 1994 (the "Original
Agreement"), as heretofore amended (the "Current Agreement"), which grants to
the Grantee (and its ' successors in interest) the non-exclusive right to use
certain public ways of the City to construct, operate and maintain a district
cooling system (the "System"); and

      WHEREAS, Exhibit 1 to the Current Agreement describes the "Current
Distribution Facilities" (as such term is defined in the Current Agreement) for
the Grantee's System; and

      WHEREAS, Exhibit 2 to the Current Agreement provides the Location Map of
the Grantee's System, including the Current Distribution Facilities; and

      WHEREAS, Grantee wishes to amend Exhibit 1 and Exhibit 2 to the Current
Agreement (the "Current Exhibit") to include in the Current Distribution
Facilities a portion of East Randolph Street

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from North Columbus Drive to a point approximately 340 feet east of the
right-of-way line of North Columbus Drive as described and depicted in amended
Exhibits 1 and 2, each as attached to this Twenty-Third Amendment (collectively,
the "Amended Exhibits"); and

      WHEREAS, the City Council of the City on October 6, 2005, adopted an
ordinance authorizing and approving execution of a Twenty-Third Amendment to the
Current Agreement in substantially the form of this Twenty-Third Amendment,
including the Amended Exhibits (the "Ordinance"); and

      WHEREAS, the City and the Grantee now desire to amend the Current
Agreement, including the Current Exhibits, subject to the terms and conditions
set forth below;

      NOW, THEREFORE,

      It is agreed by the parties hereto as follows:

      Section 1. The above recitals are expressly incorporated herein and made a
part of this Twenty-Third Amendment by reference as though fully set forth
herein. The capitalized terms not otherwise defined herein shall have the
meanings set forth in the Current Agreement.

      Section 2. As of the Effective Date of this Twenty-Third Amendment, the
current Exhibits are deemed superseded and replaced by the Amended Exhibits.

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      Section 3. The Grantee represents that, to the best of its knowledge, no
member of the governing body of the City and no other official, officer, agent
or employee of the City is employed by the Grantee or has a personal financial
or economic interest directly or indirectly in this Twenty-third Amendment or
any contract or subcontract resulting therefrom or in the privileges to be
granted hereunder except as may be permitted in writing by the Board of Ethics
established pursuant to (Chapter 2-156) of the Municipal Code of Chicago (the
"Code"). No payment, gratuity or offer of employment shall be made in connection
with this Nineteenth Amendment by or on behalf of any contractors to the Grantee
or higher tier subcontractors or anyone associated therewith, as an inducement
for the award of contracts, subcontracts or orders. Any agreement entered into,
negotiated or performed in violation of any of the provisions of said Chapter
2-156 shall be voidable as to the City.

      Section 4. Neither the Grantee nor its contractors shall be in violation
of the provisions of Section 2-92-320, Chapter 2-92 of the Code. In connection
herewith, the Grantee has executed the applicable Certification required under
the Illinois Criminal Code, 720 ILCS 5/33-11 (1994 State Bar Edition) and under
the Illinois Municipal Code, 65 ILCS 5/1-1 et seq. (1994 State Bar Edition).

      Section 5. It shall be the duty of the Grantee, all contractors, all
consultants, and all officers, directors, agents, partners, and employees of the
Grantee to cooperate with the Inspector General in any investigation or hearing
undertaken pursuant to Chapter 2-56 of the Code. The Grantee shall inform

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all its contractors of the provision and require understanding and compliance
herewith.

      Section 6. The Grantee has provided copies of its latest articles of
incorporation and bylaws and its certification of good standing from the Office
of the Secretary of State of Illinois. The Grantee has provided the City with
the Disclosure of Ownership Interest Affidavit for the Grantee and its direct
and indirect corporate parents.

      Section 7. If the Grantee conducts any business operations in Northern
Ireland, it is hereby required that the Grantee make all reasonable and good
faith efforts to conduct any such business operations in Northern Ireland in
accordance with the MacBride Principles for Northern Ireland as defined in
Illinois Public Act 85-1390 (1988 Ill. Laws 3220).

      Section 8. Pursuant to Section 2-156-030(b) of the Municipal Code of the
City of Chicago, it is illegal for any elected official of the city, or any
person acting at the direction of such official, to contact, either orally or in
writing, any other city official or employee with respect to any matter
involving any person with whom the elected official has a business relationship,
or to participate in any discussion in any city council committee hearing or in
any city council meeting or to vote in any discussion in any city council
meeting hearing or in any city council meeting or to vote on any matter
involving the person with whom an elected official has a business relationship.
Violation of Section 2-156-030(b) by any elected official with respect to this
Nineteenth Amendment shall be

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grounds for termination of the Current Agreement and this Nineteenth Amendment.
The term business relationship is defined as set forth in Section 2-156-080 of
the Code.

      Section 2-156-080 defines a "business relationship" as any contractual or
other private business dealing of an official, or his or her spouse, or of any
entity in which an official or his or her spouse has a financial interest, with
a person or entity which entitles an official to compensation or payment in the
amount of $2,500 or more in a calendar year; provided, however, a financial
interest shall not include: (i) any ownership through purchase at fair market
value or inheritance of less than one percent of the share of a corporation, or
any corporate subsidiary, parent of affiliate thereof, regardless of the value
of or dividends of such shares, if such shares are registered on a securities
exchange pursuant to the Securities Exchange Act of 1934, as amended; (ii) the
authorized compensation paid to an official or employee for his or employment;
(iii) any economic benefit provided equally to all residents of the city; (iv) a
time or demand deposit in a financial institution; or (v) an endowment or
insurance policy or annuity contract purchased from an insurance company. A
"contractual or other private business dealing" shall not include any employment
relationship of an official's spouse with an entity when such spouse has no
discretion concerning or input relating to the relationship between that entity
and the City.

      Section 9. Except as expressly modified in this Twenty-Third Amendment,
all other terms covenants and conditions in the Current Agreement (including
exhibits and attachments) remain

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unchanged and all affidavits, certificates and representations in the Current
Agreement (including exhibits and attachments) are deemed reaffirmed as if made
as of the date hereof.

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                                   EXHIBIT 1

                             TWENTY-THIRD AMENDMENT

      The Grantee's District Cooling System is anticipated to be constructed in
the Public Ways and at the approved plant locations set forth below. The exact
location of each component of Grantee's Distribution Facilities shall be
presented to and reviewed by the City as set forth in the Agreement on an
on-going basis prior to construction and installation in order to obtain permits
for construction and installation specifying the exact locations of the
Grantee's Distribution Facilities.

Production Plant #1:      Northeast corner of South State Street and East Adams
                          Street

Distribution Piping:      In LaSalle Street proceeding for 200 feet north, more
                          or less, from the intersection of West Adams Street.
                          In Dearborn Street from Adams Street to Lake Street
                          including the portions of the Dearborn Street/Madison
                          Street intersection. In Adams Street from LaSalle
                          Street to Michigan Avenue. In Madison Street, from
                          Dearborn Street to the north/south public alley which
                          lies 120 feet west of the west right-of-way line of
                          State Street and in said alley from Madison Street to
                          Monroe Street. In City property at the northwest
                          corner of Carroll Avenue and Dearborn Street. In West
                          Adams Street from Franklin Street to a point 100 feet
                          west of Lower Wacker Drive.

Production Plant #2:      Northwest corner of South Franklin Street and West
                          Congress Parkway

Distribution Piping:      In Van Buren Street, from Wacker Drive to Franklin
                          Street. In Franklin Street from Van Buren Street to
                          Lake Street. In Jackson Boulevard from Franklin Street
                          to 150 feet East of State Street.

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                          In the Jackson Boulevard/Dearborn Street intersection
                          and in Dearborn Street from such intersection to 100
                          feet south of such intersection. In LaSalle Street,
                          from West Wacker Drive to Van Buren Street. In
                          Washington Boulevard, from LaSalle Street to
                          approximately 300 feet west of Franklin Street. In the
                          Washington Street Trolley Tunnel from 300 feet west of
                          Franklin Street to North Water Street. On City
                          property consisting of viaducts and/or bridge
                          facilities located between Canal Street and the South
                          Branch of the Chicago River in the following
                          locations: West Washington Boulevard and West Monroe
                          Street. In Monroe Street, from Dearborn Street to
                          Clark Street.

Production Plant #3       Northeast corner of Randolph and Columbus Drive
                          (located in the Blue Cross/Blue Shield Building).

Distribution Piping:      In Columbus Drive, from Randolph Street to South Water
                          Street. In South Water Street, from Columbus Drive to
                          Garland Court. In Garland Court from Lake Street to
                          approximately 300 feet north of Wacker Drive. In Lake
                          Street, from Garland Court to LaSalle Street.

                          In LaSalle Street Trolley Tunnel, from Lake Street to
                          approximately 50 feet north of West Carroll Avenue. In
                          West Carroll Avenue, from the westerly right of way
                          line of Wells Street to Clark Street, and in addition,
                          the Clark Street/Carroll Avenue and Dearborn
                          Street/Carroll Avenue intersections. To the extent of
                          City property interests therein, in the lower Carroll
                          Avenue access driveway (but only to the extent
                          permitted by and consistent with City property
                          interest therein) extending from the south line of
                          West Kinzie Street beginning at a point 88 feet east
                          of North Dearborn Street for a distance of
                          approximately 98 feet south and

* Plant 4 is anticipated to be transferred to Northwind Chicago L.L.C. as an
  Affiliated Plant.

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                          thence generally in a southwesterly direction for
                          approximately 151 feet to the intersection of lower
                          Carroll Avenue and North Dearborn Street. In Kinzie
                          Street from 75 feet east of Dearborn Street to 75 feet
                          east of State Street. In LaSalle Street from West
                          Carroll Avenue to approximately 50 feet north of West
                          Carroll Avenue. Across and under Kinzie Street from
                          the Merchandise Mart to the building commonly known as
                          400 N. Franklin Street for piping with a maximum
                          trench-width of six (6) feet to be located west of the
                          Franklin Street/Kinzie Street intersection and east
                          of the Orleans Street/Kinzie Street intersection.
                          Across and under Orleans Street from the Merchandise
                          Mart to the Apparel Center for piping with a maximum
                          trench-width of six (6) feet to be located south of
                          the Kinzie Street/Orleans Street intersection and
                          north of the Chicago River.

                          In a portion of Kinzie Street from 75 feet east of
                          Dearborn to Dearborn Street. In Dearborn Street from
                          Kinzie Street to Ontario Street. In Ontario Street
                          from Dearborn Street to Wabash Avenue. In Wabash
                          Avenue from Grand Avenue to Huron Street. In Erie
                          Street from State Street to Rush Street. In Grand
                          Avenue from Wabash Avenue to a point approximately 150
                          feet east of St. Clair Street. In Rush Street from
                          Erie Street to Superior Street.

                          In Garland Court from Lake Street to Benton Place. In
                          Benton Place from Garland Court to Wabash Avenue. In
                          Randolph Street from a point 340 feet east of North
                          Columbus Drive to and including Michigan Avenue.

Production Plant #4:*     North Orleans Street on the west, North Wells Street
                          on the east, West Kinzie

* Plant 4 is anticipated to be transferred to Northwind Chicago L.L.C. as an
  Affiliated Plant.

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                          Street on the north, and the Chicago River on the
                          south (located in the Merchandise Mart building).

Distribution Piping:      In Washington Boulevard from Dearborn Street to State
                          Street. Under the Orleans Street viaduct from
                          Grantee's existing piping (north of the Chicago River)
                          to Kinzie Street. In Kinzie Street from the Kinzie
                          Street/Orleans Street intersection west to the north-
                          south public alley west of Orleans Street; north in
                          said north-south public alley to the east-west public
                          alley. In said east-west public alley west to a point
                          220.0 feet west of North Orleans Street. In the
                          north-south alley east of Kingsbury Street from
                          Hubbard Street to the existing piping in the east-west
                          alley south of Hubbard Street. In Hubbard Street from
                          Kingsbury Street to the north/south public alley
                          immediately east of Kingsbury Street. In Kingsbury
                          Street from Hubbard Street to Chicago Avenue up to and
                          including the intersection of Kingsbury Street and
                          Chicago Avenue. In Chicago Avenue from Kingsbury
                          Street to Larrabee Street. In State Street from Lake
                          Street to Randolph Street.

Production Plant #5:      Southeast corner of North State Street and East Kinzie
                          Street. (located in the IBM Building), 301 North State
                          Street.


Distribution Piping:      In Kinzie Street from 75 feet east of Dearborn Street
Plant #5                  to 75 feet east of State Street. In North State Street
                          from the intersection with West Kinzie Street to a
                          point approximately 200 feet south of such
                          intersection.

  This Exhibit is subject to amendment pursuant to the provisions of Section
7.1.2 of the Agreement (including City Council authorization and Departmental
approvals) to incorporate

* Plant 4 is anticipated to be transferred to Northwind Chicago L.L.C. as an
  Affiliated Plant.

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new Approved Plants and Additional Distribution Facilities and subject to
amendment pursuant to the provisions of Section 7.1.1 of the Agreement
(including Departmental approvals) to amend the locations of the Distribution
Facilities based on changes in construction conditions.

  All amendments requiring changes in location not based on construction
conditions shall require City Council authorization.

* Plant 4 is anticipated to be transferred to Northwind Chicago L.L.C. as an
  Affiliated Plant.

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      IN WITNESS WHEREOF, the City has caused this Twenty-Third Amendment to be
duly executed in its name and behalf as of the date first written by its
Commissioner of the Department of Environment, its Director of the Department of
Revenue and its Commissioner of the Department of Transportation and the Grantee
has signed and sealed the same on or as of the day and year first written.

(SEAL)

                                       CITY OF CHICAGO

/s/ [ILLEGIBLE]                        By: /s/ Sadhu Johnston
--------------------------                 -------------------------------------
Deputy City Clerk                      Title:  Commissioner of the
                                               Department of Environment

                                       By: /s/ [ILLEGIBLE]
                                           -------------------------------------
                                       Title: Director of the Department
                                              of Business Affairs and
                                              Licensing

                                       By: /s/ [ILLEGIBLE]
                                           -------------------------------------
                                       Title:  Commissioner of the
                                               Department of Transportation

Reviewed as to form
and legality:

/s/ Monica M. Monroe
------------------------------
Assistant Corporation Counsel
or Senior Counsel

ATTEST:                                THERMAL CHICAGO CORPORATION

/s/ James A. Pagnusel                  By: /s/ David A. Bump
--------------------------                 -------------------------------------
TITLE: SECRETARY                       Title: President

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