EXHIBIT 24. Power of Attorney

     Each  director of  Southwestern  Public  Service  Company  whose  signature
appears herein hereby appoints Bill D. Helton and Doyle R. Bunch II, and each of
them severally,  as his or her  attorney-in-fact  to sign in his or her name and
behalf, in any and all capacities stated herein, and to file with Securities and
Exchange Commission, any and all amendments to this Annual Report on Form 10-K.


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