EXHIBIT 15.1

AWARENESS LETTER OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

MidAmerican Energy Holdings Company

Des Moines, Iowa

We have reviewed, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the unaudited consolidated interim financial information of MidAmerican Energy Holdings Company and subsidiaries for the three-month and six-month periods ended June 30, 2007 and 2006, and have issued our report dated July 31, 2007. As indicated in such report, because we did not perform an audit, we expressed no opinion on that information.

We are aware that our report referred to above, which was included in your Quarterly Report on Form 10-Q for the quarter ended June 30, 2007, is being used in this Registration Statement.

We also are aware that the aforementioned report, pursuant to Rule 436(c) under the Securities Act of 1933, is not considered a part of the Registration Statement prepared or certified by an accountant or a report prepared or certified by an accountant within the meaning of Sections 7 and 11 of that Act.

/s/ Deloitte & Touche LLP

DELOITTE & TOUCHE LLP

Des Moines, Iowa

September 14, 2007