Common use of Optional Modifications Clause in Contracts

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its discretion and at its own or such Sublessee's cost and expense, modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, residual value, utility or remaining economic useful life of such Unit below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to such Modification, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicable. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of the return of such Unit pursuant to Section 6.1, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its discretion and at its own or such Sublessee's cost and expense, modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, utility, capacity, residual value, utility value or remaining economic useful life of such Unit below the fair market value, utility, capacity, residual value, utility value or remaining economic useful life thereof immediately prior to such Modification, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29Lease. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicable. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of the return of such Unit pursuant to Section 6.1, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.Section

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its discretion and at its own or such Sublessee's cost and expense, modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, utility, capacity, residual value, utility value or remaining economic useful life of such Unit below the fair market value, utility, capacity, residual value, utility value or remaining economic useful life thereof immediately prior to such Modification, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29Lease. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicable. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of the return of such Unit pursuant to Section 6.1, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.

Optional Modifications. The Lessee at any time may or may permit a Sublessee tomay, in its discretion and at its own or such Sublessee's cost and expense, modify, alter make or improve cause or permit to be made any Unit Modification to the Project as the Lessee considers necessary or desirable in a manner which the proper conduct of its business (any such Modification that is not required by Section 9.1 (a Required Modification being referred to as an "Optional Modification"); , provided that no the Lessee shall not make and shall prevent from being made any Optional Modification to the Project that would (i) shall diminish decrease by more than a de minimis amount the fair market value, current or residual value, utility or remaining economic useful life of such Unit the Project below the fair market value, current or residual value, utility or remaining economic useful life thereof of the Project immediately prior to such Modification, in more than a de minimis respect, Modification assuming such Unit the Project was then at least in the condition required to be maintained by the terms of this Project Lease or (ii) cause such Unit the Project to become "limited use limited-use" property" , within the meaning of Revenue Procedure Rev. Proc. 2001-28 or Revenue Procedure 28, 2001-29. Title to any Non-Severable 1 C.B. 1156, and no such Optional Modification shall be immediately vested in made unless (x) the Lessee provides to the Owner Lessor and, so long as the Lien of the Indenture shall not have been terminated and fully discharged, the Indenture Trustee a certification from the Geothermal Consultant that such Modification is not reasonably expected materially and adversely to affect the Owner Lessor. Title 's rights under the Sublease of Resource Sublease or otherwise materially reduce or impair the Geothermal Resource available to any Severable Modification the Lessee pursuant to the Resource Sublease Partial Assignment for the purpose of satisfying its obligations under the Power Purchase Agreement, (other than Required Modificationsy) shall remain with Lessee or the Sublessee as applicable. If Lessee shall at its cost cause such Severable Modifications have received all consents (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of the return of such Unit pursuant to Section 6.1including, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modificationsthe extent applicable, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting consents from the removal of Power Purchaser under the Power Purchase Agreement) and approvals from any Governmental Entity having jurisdiction and (z) such Severable Modifications in Modification could not reasonably be expected to have a manner consistent with Section 8.1; provided that such removal shall not Material Adverse Effect (i) diminish collectively, the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such returnImprovement Conditions").

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its discretion and at its own or such Sublessee's cost and expense, modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, utility, capacity, residual value, utility value or remaining economic useful life of such Unit below the fair market value, utility, capacity, residual value, utility value or remaining economic useful life thereof immediately prior to such Modification, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29Lease. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicable. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of the return of such Unit pursuant to Section 6.1, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as Lease Agreement (TRLI 2001-1B) provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its ---------------------- discretion and at its own or such Sublessee's cost and expense, expense modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, utility, capacity, residual value, utility value or remaining economic useful life of such Unit below the fair market value, utility, capacity, residual value, utility value or remaining economic useful life thereof immediately prior to such Modification, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29Lease. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicableLessee. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of the return of such Unit pursuant to Section 6.1, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its discretion and at its own or such Sublessee's cost and expense, modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, residual value, utility or remaining economic useful life of such Unit below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to such Modification, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicable. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of the return of such Unit pursuant to Section 6.1, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.or

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its ---------------------- discretion and at its own or such Sublessee's cost and expense, expense modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, residual valueutility, utility capacity, or remaining economic useful life of such Unit below the fair market value, utility, capacity, residual value, utility value or remaining economic useful life thereof immediately prior to such Modification, in more than a any non de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29Limited Use Property. Title to any Non-Non- Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicableLessee. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of the a return of such Unit other than pursuant to Section 6.115.6, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its ---------------------- discretion and at its own or such Sublessee's cost and expense, expense modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that ------------ no Modification (i) shall diminish the fair market value, residual valueutility, utility capacity, or remaining economic useful life of such Unit below the fair market value, residual valueutility, utility capacity, or remaining economic useful life thereof immediately prior to such Modification, in more than a any non de minimis minimus respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause Lease, provided -------- that Lessee shall not discriminate against such Unit to become "limited use property" within in making such modification, alteration or improvement as compared with other equipment of the meaning of Revenue Procedure 2001-28 same type as the Unit and which are owned or Revenue Procedure 2001-29leased by the Lessee. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicableLessee. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of a return other than pursuant to Section 15.6, prior to the return of such Unit pursuant to Section 6.1Lessor hereunder, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.

Optional Modifications. The Lessee at any time may or may permit a Sublessee to, in its discretion and at its own or such Sublessee's cost and expense, modify, alter alter, improve, replace or improve substitute any Unit in (an "Optional Modification"; and each of an Optional Modification and a manner which Required Modification is not required by Section 9.1 (a "Modification"); provided that no Optional Modification shall (i) shall diminish the fair market value, residual valueutility, utility or condition, remaining economic useful life life, or estimated residual value of such Unit below the fair market value, residual valueutility, utility or condition, remaining economic useful life life, or estimated residual value thereof immediately prior to such Modification, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or Lease, (ii) cause such any Unit to become "limited use property" within the meaning of Revenue Procedure 200176-28 30, (iii) otherwise result, in the opinion of Owner Participant's tax counsel, in adverse tax consequences to the Owner Participant or Revenue Procedure 2001-29the Lessor which are not subject to indemnification under the Tax Indemnity Agreement, or (iv) alter the essential function of such Unit from that for which it was designed and intended. Title to any Non-Severable Modification which is an Optional Modification shall be immediately vested in the Lessor. Title to any Severable Modification (other than which is not a Required Modifications) shall Modification shall, as between the Lessor and the Lessee, remain with the Lessee (subject to the rights, if any, of Bayer to such Severable Modification arising under the terms of the Facility Documents). During the Lease Term or at the Sublessee return of such Unit, and so long as applicableno Lease Default or Lease Event of Default shall have occurred and be continuing, the Lessee may remove and replace any Severable Modification which is not a Required Modification; provided, however, that the Lessee may remove in the ordinary course of the operation of the Units precious metal catalysts, commonly referred to as gauze changeouts (each, a "Gauze Changeout"), provided that each Gauze Changeout which is removed is simultaneously replaced with an operationally equivalent Gauze Changeout of equal or greater utility. If Lessee shall Upon the return of a Unit, if the Lessee, at its cost cost, shall cause such any Severable Modifications (other than which are not Required Modifications) Modifications to be made to any such Unit, and such Severable Modifications theretofore made have not been removed, the Lessor shall have the right, upon 90 days prior written notice in the case of the return of such Unit pursuant to Section 6.1, right to purchase any such Severable Modifications (other than Severable Modifications Modification consisting of proprietary or communications equipmentequipment of the Lessee) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition)fair market value. If the Lessor does not so elect to purchase such Severable Modifications, Lessee may remove Modifications or such Severable Modifications Modification consists of proprietary equipment of the Lessee and has not been removed, it shall have the right to cause, at the Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the upon return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such returnUnit.

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its discretion and at its own or such Sublessee's cost and expense, expense modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, utility, estimated residual value, utility value or remaining economic useful life of such Unit below the fair market value, utility, estimated residual value, utility value or remaining economic useful life thereof immediately prior to such Modification, other than in more than a de minimis respectmanner, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease Lease, or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29Limited Use Property. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicableunless it is a Required Modification, in which case title shall vest in Lessor pursuant to Section 9.1. If Lessee shall Lessee, at its cost and expense, shall cause such any Severable Modifications (other than which are not Required Modifications) to be made to any Unit, Lessee shall give written notice to Lessor briefly describing such Severable Modifications not less than 120 days prior to the return other than pursuant to Section 15.6 of such Unit to Lessor hereunder and Lessor shall have the right, upon 90 days prior written notice in the case of a return other than pursuant to Section 15.6, prior to the return of such Unit pursuant to Section 6.1Lessor hereunder, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expenseexpense and, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.

Optional Modifications. The Facility Lessee at any time may or may permit a Sublessee tomay, in its discretion and at its own or such Sublessee's cost and expense, modifysubject to the Owners Agreement, alter make or improve cause or permit to be made any Unit Modification to the Facility as the Facility Lessee considers desirable in a manner which is not required by Section 9.1 the proper conduct of its business (a any such non-Required Modification being referred to as an "Optional Modification"); provided that no the Facility Lessee shall exercise all rights, powers, elections and options available to it or any of its Affiliates under the Owners Agreement to prevent any Optional Modification (i) shall from being made to the Facility that would diminish the fair market value, residual value, utility or remaining economic useful life of such Unit below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to such Modification, in by more than a de minimis respectamount the current or residual value, remaining useful life or utility of the Facility below the current or residual value, remaining useful life or utility of the Facility immediately prior to such Optional Modification assuming such Unit the Facility was then at least in the condition required to be maintained by the terms of this Lease Facility Lease, or (ii) cause such Unit the Facility to become "limited use use" property" , within the meaning of Revenue Procedure 2001Rev. Proc. 75-28 28, 1975-1 C.B. 752 or Revenue Procedure 2001Rev. Proc. 76-2930, 1976-2 C.B. 647. Section 8.3 Title to Modifications. Title to any Non-Severable Modification an undivided interest equal to the Owner Lessor's Percentage in (a) all Required Modifications, (b) all Nonseverable Modifications and (c) all Modifications financed by the Owner Lessor by an Additional Equity Investment or a Supplemental Financing pursuant to Section 12.1 of the Participation Agreement shall (at no cost to the Owner Lessor and with no adjustment to the Purchase Price or, except as provided herein, Periodic Lease Rent, Renewal Lease Rent or Allocated Rent) immediately vest in the Owner Lessor, and such undivided interest shall immediately (i) become subject to this Facility Lease and, so long as the Lien of the Lease Indenture shall not have been terminated or discharged, the Lien of the Lease Indenture, and (ii) be immediately deemed part of the Facility Interest for all purposes of this Facility Lease. The Facility Lessee, at its own cost and expense, shall take such steps as the Owner Lessor and, so long as the Lien of the Lease Indenture shall not have been terminated or discharged, the Lease Indenture Trustee may reasonably require from time to time to confirm that title in such undivided interest has vested in Lessorthe Owner Lessor and that such undivided interest is subject to this Facility Lease and, so long as the Lien of the Lease Indenture shall not have been terminated or discharged, the Lien of the Lease Indenture. Title to No interest in any Optional Modification which is a Severable Modification (other than Required ModificationsSeverable Modifications which are financed by the Owner Lessor by an Additional Equity Investment or a Supplemental Financing pursuant to Section 12.1 of the Participation Agreement) shall remain with Lessee vest in the Owner Lessor or become subject to this Facility Lease or the Sublessee as applicable. If Lien of the Lease Indenture; provided, however, that if the Facility Lessee shall shall, at its cost and expense, cause such Optional Modifications which are Severable Modifications (other than Required Modifications) to be made to any Unitthe Facility, the Owner Lessor shall have the right, upon 90 days immediately prior written notice in the case of to the return of such Unit pursuant the Facility Interest to Section 6.1the Owner Lessor hereunder, to purchase an undivided interest equal to the Owner Lessor's Percentage in any such Optional Modifications which are Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their Modifications. The purchase price for such undivided interest shall be the then Fair Market Sales Value (taking into account their actual condition)of such undivided interest. If the Owner Lessor does not so elect to purchase such Optional Modifications which are Severable Modifications, the Facility Lessee may may, to the extent permitted by the Owners Agreement, remove such Severable Modifications at the end of the Facility Lease Term and the Facility Lessee shall repair any damage to the Facility and the Facility Site caused by such removal, all at the Facility Lessee's cost and expense; provided, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expensehowever, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life or utility of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in Facility by more than a de minimis respect, amount assuming such Unit was then the Facility would have been at least the time of removal in the condition required to be maintained by the terms of this Lease Facility Lease, or (ii) cause such Unit the Facility to become "limited use use" property" , within the meaning of Revenue Procedure 2001Rev. Proc. 75-28 28, 1975-1 C.B. 752 or Revenue Procedure 2001Rev. Proc. 76-2930, 1976-2 C.B. 647. If the Keystone Facility Lease 17 HOUOI:587609.2. Facility Lessee has not removed shall have failed to remove any Optional Modifications which are Severable Modification Modifications as above provided prior to the return of the related Unit as provided hereinFacility Interest to the Owner Lessor hereunder, title to an undivided interest equal to the Owner Lessor's Percentage in such Severable Modification Modifications shall pass (at no cost to Lessor the Owner Lessor) vest in the Owner Lessor. SECTION 9 NET LEASE This Facility Lease is a "net lease" and the Facility Lessee's obligation to make all Rent payments payable hereunder or other payments under the Operative Documents (and all amounts, including Termination Value, following termination of this Facility Lease) shall be absolute and unconditional under any and all circumstances, and shall not be terminated, extinguished, diminished, lost or otherwise impaired by any circumstance of any character, including by (i) any setoff, counterclaim, recoupment, defense or other right which the Facility Lessee may have against the Owner Lessor, the Owner Participant, the Equity Subsidiary, the Equity Investor, the Pass Through Trustee, the Lease Indenture Trustee or any other Person, including any claim as a result of any breach by any of said parties of any covenant or provision in this Facility Lease or any other Operative Document, (ii) any lack or invalidity of title or any defect in the title, condition, design, operation, merchantability or fitness for use of the date Facility or any Component thereof, or any eviction by paramount title or otherwise, or any unavailability of such returnthe Facility, the Facility Site, any Component thereof, any other portion of the Facility Interest, or any part thereof, (iii) any loss or destruction of, or damage to, the Facility or any Component thereof or interruption or cessation in the use or possession thereof or any part thereof by the Facility Lessee for any reason whatsoever and of whatever duration, (iv) the condemnation, requisitioning, expropriation, seizure or other taking of title to or use of the Facility Site, the Facility, any Component thereof, or any other portion of the Facility Interest by any Governmental Entity or otherwise, (v) the invalidity or unenforceability or lack of due authorization or other infirmity of this Facility Lease or any other Operative Document, (vi) the lack of right, power or authority of the Owner Lessor to enter into this Facility Lease or any other Operative Document, (vii) any ineligibility of the Facility or any Component thereof for any particular use, whether or not due to any failure of the Facility Lessee to comply with any Applicable Law, (viii) any event of"force majeure" or any frustration, (ix) any legal requirement similar or dissimilar to the foregoing, any present or future law to the contrary notwithstanding, (x) any insolvency, bankruptcy, reorganization or similar proceeding by or against the Facility Lessee or any other Person, (xi) any Lien of any Person with respect to the Facility Site, the Facility, any Component thereof, any other portion of the Facility Interest or any part thereof, or (xii) any other cause, whether similar or dissimilar to the foregoing, any present or future law notwithstanding, except as expressly set forth herein or in any other Operative Document, it being the intention of the parties hereto that all Rent (and all amounts, including Termination Value, following termination of this Facility Lease) payable by the Facility Lessee hereunder shall continue to be payable in all events in the manner and at times provided for herein. Such Rent (and all amounts, including Termination Value, following termination of this Facility Lease) shall not be subject to any abatement and the payments thereof shall not be subject to any setoff or reduction for any reason whatsoever, including any present or future claims of the Facility Lessee or any other Person against the Owner Lessor or any other Person under this Facility Lease or otherwise. To the extent permitted by Applicable Law, the Facility Lessee Keystone Facility Lease 18 HOU01:587609.2.

Optional Modifications. Lessee at any time may or may permit a Sublessee to, in its discretion and at its own or such Sublessee's cost and expense, expense modify, alter or improve any Unit in a manner which is not required by Section 9.1 (a "Modification"); provided that no Modification (i) shall diminish the fair market value, residual valueutility, utility capacity, or remaining economic useful life of such Unit below the fair market value, residual valueutility, utility capacity, or remaining economic useful life thereof immediately prior to such Modification, in more than a any non de minimis minimus respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause Lease, provided that Lessee shall not discriminate against such Unit to become "limited use property" within in making such modification, alteration or improvement as compared with other equipment of the meaning of Revenue Procedure 2001-28 same type as the Unit and which are owned or Revenue Procedure 2001-29leased by the Lessee. Title to any Non-Severable Modification shall be immediately vested in Lessor. Title to any Severable Modification (other than Required Modifications) shall remain with Lessee or the Sublessee as applicableLessee. If Lessee shall at its cost cause such Severable Modifications (other than Required Modifications) to be made to any Unit, Lessor shall have the right, upon 90 days prior written notice in the case of a return other than pursuant to Section 15.6, prior to the return of such Unit pursuant to Section 6.1Lessor hereunder, to purchase any such Severable Modifications (other than Severable Modifications consisting of proprietary or communications equipment) title to which is held by Lessee at their then Fair Market Sales Value (taking into account their actual condition). If Lessor does not so elect to purchase such Severable Modifications, Lessee may remove such Severable Modifications at Lessee's cost and expense, and if requested (which request shall be made by not less than 90 days prior written notice in the case of a return other than pursuant to Section 15.6) by Lessor will so remove such Severable Modifications at Lessee's cost and expense, and Lessee shall, at its expense, repair any damage resulting from the removal of any such Severable Modifications in a manner consistent with Section 8.1; provided that such removal shall not (i) diminish the fair market value, residual value, utility or remaining economic useful life of the Unit to which such Severable Modifications relate below the fair market value, residual value, utility or remaining economic useful life thereof immediately prior to the addition of such Severable Modifications, in more than a de minimis respect, assuming such Unit was then at least in the condition required to be maintained by the terms of this Lease or (ii) cause such Unit to become "limited use property" within the meaning of Revenue Procedure 2001-28 or Revenue Procedure 2001-29. If Lessee has not removed any Severable Modification prior to the return of the related Unit as provided herein, title to such Severable Modification shall pass to Lessor as of the date of such return.