Phoenix, Ariz. - Commissioners Kevin Thompson and Nick Myers successfully introduced an amendment requiring APS demonstrate it has acquired a sufficient mix of dependable and dispatchable capacity to ensure resource adequacy before it may exit Four Corners Power Plant (“Four Corners”). APS plans to exit Four Corners in 2031, which will result in the loss of an estimated 970 MWs of dependable generation capacity.

The amendment adopts a technology neutral approach while requiring the replacement capacity to be a mix of dependable and dispatchable resources. Dispatchable power sources can be deployed by grid operators on demand to match supply with electricity demand. Dispatchable resources are critical to meeting the peak demand period, when consumer demand for electricity is at its highest. They are also capable of being deployed regardless of weather conditions. 

“Arizona is experiencing tremendous growth and record-breaking demand for electricity, and along with that comes the need for new generation sources,” said Commissioner Kevin Thompson. “As long-standing and dependable coal plants continue to shut down in Arizona and across the country, it’s important to ensure Arizona’s grid remains reliable. We must deploy the most dependable generation sources in the most cost-effective manner. Our amendment holds APS accountable and helps ensure the lights and AC stay on for the foreseeable future."

“One of our highest priorities as Commissioners is to ensure Arizona’s electric grid remains safe and reliable into the future. Arizona cannot afford rolling brownouts and blackouts as other states have experienced, through their failed ideologically driven policies,” commented Commissioner Nick Myers, “This amendment ensures APS is properly planning for its exit from Four Corners in 2031 so that Arizona’s grid remains as reliable as ever.”   

The Commission adopted the amendment with a 4-1 vote at the ACC’s regular open meeting on October 8, 2024, with Commissioners Thompson, Myers, O’Connor, and Marquez Peterson supporting the amendment, and Commissioner Tovar opposing. The reliability provision was adopted as part the review of Integrated Resource Planning (“IRP”) proposals submitted by Arizona Public Service Company (APS), Tucson Electric Power Company (TEP), UNS Electric, Inc. (UNSE), and Arizona Electric Power Cooperative, Inc. (AEPCO). 

Commission review of these IRPs began on November 1, 2023. IRPs are a critical and regular planning process used by utilities to identify the most reliable and most cost-effective resources to meet Arizona’s growing customer demand for electricity. Arizona utilities set record-breaking peak demand for the second year in a row this summer. During the IRP presentations this year, long term APS load growth and demand projections demonstrated unprecedented growth coupled with massive capacity drops in replacement generation sources in the near future.

The amendment requires APS to demonstrate in annual reporting filings its progress towards ensuring resource adequacy and any factors that may impact their planned exit from Four Corners.

For more information, contact Ryan Anderson at randerson@azcc.gov or Amanda Hasty at Myers-Web@azcc.gov