Decision slashes on-peak hours, encourages electric vehicle adoption, and supports the economic development of rural and tribal communities

Arizona Corporation Commission slashes APS rates; Institutes new customer safeguards

November 3, 2021

Ellen Zuckerman, Southwest Energy Efficiency Project (SWEEP) |


[PHOENIX, AZ] – In a 3-2 decision Tuesday, utility regulators at the Arizona Corporation Commission (ACC) voted to slash rates for a vast majority of Arizona Public Service Company (APS) customers.

The $119 million cut to APS’s revenues came as commissioners denied cost recovery for the utility’s investments in the Four Corners coal plant and significantly reduced its return on equity. The decrease stood in stark contrast to the $184 million increase that the utility had originally sought.

As part of its decision, regulators also directed a number of changes to customer rate design championed by the Southwest Energy Efficiency Project (SWEEP) in partnership with Western Resource Advocates. The ACC reduced on-peak hours for residential time of use rates from 3-8pm to 4-7pm and directed the establishment of super off-peak charging rates for electric vehicle owners, while requiring educational programming for customers enrolling on residential demand rates.

The decision also directed $10 million to support communities economically devastated by the early closure of coal-fired power plants, with the opportunity for more funding support in the coming years.

“Utility regulators have taken important steps to reduce and fix the ways that APS customers are charged for electricity. These changes are long overdue,” said Ellen Zuckerman, Arizona Representative for SWEEP. “Thanks to improved education and more flexible rate options, APS customers will be better able to manage the cost of living in Arizona.”

“Preparing for the future means providing options for electric vehicle owners to charge their cars when there is less strain on the grid,” said Caryn Potter, Utility Program Manager for SWEEP. “The Arizona Corporation Commission’s decision does just that while also encouraging charging at times when solar energy is abundant.”

The Commission’s decision will take effect as early as December, with some rate design changes going into effect in approximately 10 months.

APS has also announced its intention to sue the ACC over the decision.


The Southwest Energy Efficiency Project (SWEEP) is a public interest organization promoting greater energy efficiency in Arizona, Colorado, Nevada, New Mexico, Utah, and Wyoming.