On Aquila, Inc. Letterhead]

Exhibit 10.1.4

[On Aquila, Inc. Letterhead]

       August 31, 2007

Xxxxxx Xxxxxxx, Esq.	Xxxx Xxxxxxx, Esq.
Black Hills Corporation	Great Plains Energy Incorporated
000 Xxxxx Xxxxxx	0000 Xxxxxx
Rapid City, SD 57709	Kansas City, MO 64106

Re: Partnership Interests Purchase Agreement and Asset Purchase Agreement (collectively, the "Agreements") by and among Aquila, Inc. ("Aquila"), Black Hills Corporation ("Black Hills"), Great Plains Energy Incorporated ("Great Plains") and Xxxxxxx Acquisition Corp. ("Xxxxxxx")

Dear Xxxxx and Xxxx:

Under the terms of the Agreements, as modified by that certain letter dated as of June 29, 2007, Black Hills and Great Plains are to attach schedules setting forth Retained Agreements and Shared Agreements prior to September 1, 2007. We recognize that this deadline may be implausible and therefore propose extending the date set forth under section 2.2(1) and 8.5(d) of the Agreements to October 1, 2007. Of course we will work to assist you in the identification process.

If you are in agreement, please sign below on the attached signature page where indicated and return a copy of this letter to me by fax or e-mail.

Very truly yours,

AQUILA, INC.

By:           /s/ Xxxxxxxxxxx X. Xxxxx

Name:  Xxxxxxxxxxx X. Xxxxx

Title:                      General Counse

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Signature Page to August 31, 2007 Letter Agreement

ACKNOWLEDGED, CONSENTED TO, AND ACCEPTED BY:

BLACK HILLS CORPORATION

By:           /s/ Xxxxxx X. Xxxxxxx

Name:      Xxxxxx X. Xxxxxxx

Title:        General Counsel

GREAT PLAINS ENERGY INCORPORATED

By:           /s/ Xxxxx Xxxxxxx

Name:     Xxxxx Xxxxxxx

Title:      Executive Vice President – Finance and Strategic Development and CFO

XXXXXXX ACQUISITION CORP.

By:           /s/ Xxxx X. Xxxxxxx

Name:     Xxxx X. Xxxxxxx

Title:       Secretary and Treasurer

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