EXHIBIT 24.8 POWER OF ATTORNEY The undersigned, as President and Chief Executive Officer of Public Service Company of Oklahoma (the "Company"), hereby makes, constitutes and appoints R. Russell Davis his true and lawful attorneys-in-fact and agents, with full power and authority to execute in the name and on behalf of the undersigned, in any and all capacities, the Company's Annual Report on Form 10-K for 1995 and any and all amendments thereto, to be filed under the Securities Exchange Act of 1934, as amended, and any other documents and instruments incidental thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the Securities and Exchange Commission, hereby granting to such attorney-in-fact, and agents, full power and authority of substitution and revocation in the premises and full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully for all intents and purposes as the undersigned might or could do in person and hereby ratifying and confirming all that such attorneys-in-fact and agents, may do or cause to be done by virtue of this Power of Attorney. IN WITNESS WHEREOF, I have hereunto executed this Power of Attorney this 16th day of January, 1996. Robert L. Zemanek Subscribed and sworn to before me this 16th day of January, 1996 by Robert L. Zemanek. Lina P. Holm Notary Public My Commission Expires: January 28, 1999