Public Service Company of Oklahoma (PSO), a unit of American Electric Power (NYSE: AEP), has discovered that its announcement of its Nov. 21 rate filing contained an incorrect estimate. The inaccuracy involved the calculation of a sample residential bill that was used to illustrate the impact of the proposed rate increase.
 
The correct estimated bill impact of PSO’s proposal, if approved, would result in an increase of approximately 8%, or around $6.50 per month, on the total bill of a residential customer using 1,000 kilowatt-hours per month.  PSO’s original announcement stated the estimated impact at approximately 3%, or around $2.25 per month.
 
“We deeply regret this mistake,” said Stuart Solomon, PSO president and chief operating officer. “This was a significant error, and we want to make sure our customers have the correct information about our rate filing and how it will affect them.”
 
The error in the sample residential bill occurred when PSO’s current winter prices were used in making the calculation, instead of the proposed, higher winter prices.  PSO discovered the error internally last night and notified the Oklahoma Corporation Commission (OCC) this morning.
 
This error only affects the calculation of the sample residential bill that was used in PSO’s public announcement of the rate filing.  PSO’s total rate increase request amount of $49.6 million is not affected by the error.
 
PSO, a unit of American Electric Power (NYSE: AEP), is an electric utility company serving approximately 514,000 customers in eastern and southwestern Oklahoma.  Based in Tulsa, PSO has more than 4,000 megawatts of generating capacity, and is the largest provider of wind energy in the state.