Exhibit 23(d)

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement on Form S-3 of our report dated February 20, 2008 (which report expresses an unqualified opinion and includes an explanatory paragraph relating to the adoption of Financial Accounting Standards Board (FASB) Interpretation No. 48, “Accounting for Uncertainty in Income Taxes — an interpretation of FASB Statement No. 109”), relating to the consolidated financial statements and financial statement schedule of Public Service Company of Colorado and subsidiaries, appearing in the Annual Report on Form 10-K of Public Service Company of Colorado and subsidiaries for the year ended December 31, 2007, and to the reference to us under the heading “Experts” in the Prospectus, which is part of this Registration Statement.

/s/ DELOITTE & TOUCHE LLP

Minneapolis, Minnesota

February 6, 2009