<DOCUMENT>
<TYPE>EX-23.(A)
<SEQUENCE>15
<FILENAME>k91832exv23wxay.txt
<DESCRIPTION>CONSENT OF ERNST & YOUNG LLP FOR CMS ENERGY
<TEXT>
<PAGE>

                                                                 Exhibit (23)(a)

            Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the following Registration
Statements and in the related Prospectuses:

      (1)   Registration Statements (Form S-3 No. 333-51932, No. 333-52560, No.
            333-27849, No. 333-37241, No. 333-74958, No. 333-45556, No.
            333-119255, No. 333-119256) of CMS Energy Corporation;

      (2)   Registration Statement (Form S-4 No. 33-60007) of CMS Energy
            Corporation;

      (3)   Registration Statements (Form S-8 No. 333-32229 and No. 333-58686)
            pertaining to the CMS Energy Corporation Performance Incentive Stock
            Plan and Executive Stock Option Plan, respectively, and

      (4)   Registration Statement (Form S-8 No. 333-76347) pertaining to the
            Employee Savings and Incentive Plan of Consumers Energy Company;

of our reports dated March 7, 2005, with respect to the consolidated financial
statements and schedule of CMS Energy Corporation, CMS Energy Corporation
management's assessment of the effectiveness of internal control over financial
reporting, and the effectiveness of internal control over financial reporting of
CMS Energy Corporation, included in this Annual Report (Form 10-K) for the year
ended December 31, 2004.

                                               /s/ Ernst & Young LLP

Detroit, Michigan
March 7, 2005
</TEXT>
</DOCUMENT>
