Exhibit 23(c)

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Amendment No. 1 to Registration Statement No. 333-141416 on Form S-3 of our report dated February 22, 2007, (which report expresses an unqualified opinion and includes an explanatory paragraph relating to the adoption of Statement of Financial Accounting Standards No. 158, “Employers’ Accounting for Defined Benefit Pension and Other Postretirement Plans”) relating to the consolidated financial statements and financial statement schedule of Public Service Company of Colorado, appearing in the Annual Report on Form 10-K of Public Service Company of Colorado for the year ended December 31, 2006, and to the reference to us under the heading “Experts” in the Prospectus, which is part of such Registration Statement.

/s/ DELOITTE & TOUCHE LLP

Minneapolis, Minnesota

April 25, 2007