EXHIBIT 15.1

AWARENESS LETTER OF INDEPENDENT REGISTERED

PUBLIC ACCOUNTING FIRM

MidAmerican Energy Company

Des Moines, Iowa

We have reviewed, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the unaudited interim financial information of MidAmerican Energy Company and subsidiary for the three-month periods ended March 31, 2007 and 2006, and have issued our report dated May 4, 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 March 31, 2007, is being incorporated by reference in this Registration Statement and in Post-Effective Amendment No. 1 to Registration Statement No. 333-134163 on Form S-3.

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.

Des Moines, Iowa

May 7, 2007