The ACC grilled APS President Jeff Guldner for over 6 hours* on Wednesday.  Guldner apologized and the company took complete responsibility for erroneous advice caused by the company's Rate Comparison Tool website.  

The company identified the source of the problem as a programming error introduced in a February 4th update.  That error shifted the Time of Use Rate period by one hour on the Comparison Tool.  The actual billing is on a separate system and was never compromised.  

However, customers that used a lot of power just prior to the start of the real time of use rates--for example, those that pre-cooled their house--were advised to switch off of Time of Use because the website recorded their pre-cooling as On Peak.

Approximately 10,000 customers accessed the website and then switched to more expansive plans APS is issuing automatic refunds plus an additional $25 credit to those customers.

(*I met with Jeff briefly at APS the following day and he said that the meeting was so long that no one won the pool.)