Report
January 23, 2020
An Assessment of APS’s New Bill Comparison Web Tool
Prepared for Arizona Public Service
Arizona Public Service (APS) intends to roll out a new web-based bill comparison tool (“web tool”) to customers this year. In preparation for that rollout, APS commissioned The Brattle Group (“Brattle”) to verify the accuracy of the web tool’s output (referred to as the “audit”). Specifically, using customer data and rates information provided by APS, we verified the accuracy of the tool’s recommendations regarding the rates that would have minimized customers’ historical bills by independently replicating the underlying calculations supporting those recommendations.