Phoenix, Ariz. —   The Arizona Corporation Commission’s Summer Preparedness Workshop is an important annual exercise, where state utility providers present their plans to the Commission regarding their capacity to meet peak demand during the extreme heat in the summer months.  The Commission also ensures that regulated utilities remain proactive in maintaining the power grid throughout the year and that the infrastructure remains safe and reliable.

Representatives from Arizona Public Service Company (APS), Tucson Electric Power Company (TEP) & UNS Electric (UNSE), Salt River Project (SRP), and Arizona Electric Power Cooperatives (AEPCO) delivered presentations outlining past, present, and future electricity peak load forecasts.  This year, Arizona utilities report they are forecasting another year of record-high electricity demand and informed the Commission that they are ready to produce a combined total of more than 24,000 MW of electricity to meet peak demand this summer.  Arizona utilities generate or procure power from diverse sources, including natural gas, coal, nuclear, solar, battery storage, wind, and hydroelectric, and storage facilities, as well as investing in short-term market purchases.

APS, the state’s largest electric utility, expects another record-breaking year for peak demand, forecasting it will need at least 8,491 MW to meet power demand this summer, and it plans to have 1,620 MW in reserves.  APS informed the Commission it is going to bring more than 1,550 MW of new solar and energy storage resources online this summer, all through purchase power agreements with third-party facilities. APS will also add 175 MW of new natural gas generation to its resource portfolio.

Similarly, SRP is also expecting to break records this summer, forecasting a peak demand high of 8,436 MW, and overall has forecasted a demand of 9,457 MW.   SRP added more than 1,100 MW of renewable resources last summer, bringing its total planned capacities to 9,810 MW.

TEP and Unisource serve approximately 738,000 customers in the Tucson metro area and in Northern Arizona. TEP projects its peak demand will increase to 2,434 MW and plans to have 400 MW in reserves. UNSE projects its peak demand will top out at 526 MW and plans to have 90 MW in reserves.  TEP’s Roadrunner Reserve project will add 200 MW of solar and 800 MW hours of energy storage to its portfolio this year. 

AEPCO, a not-for-profit electric generation and transmission cooperative that serves rural Arizona distribution cooperatives.  It is the only electric utility provider that is forecasting a lower peak demand load this year, compared to last year.  AEPCO informed the Commission it expects to reach 704 MW during peak demand in 2025, versus reaching a peak demand of 736 MW in 2024.  AEPCO explained the difference, saying its member distribution cooperatives own various solar and energy storage projects that are expected to go online this year.

“I am impressed with the level of planning and coordination all of our utilities go through to ensure that our Arizona energy grids are some of the top most reliable systems in the entire nation,” said Commissioner Rachel Walden. “That is a remarkable statement given our backdrop of some of the most extreme weather any state experiences.”

During the presentations, Chairman Kevin Thompson and Vice Chairman Nick Myers raised questions about two coal-fired power plants.  Earlier this month, President Donald Trump called for the coal-fired plant to remain open and operational.   The Cholla Power Plant (Cholla Plant) operated by APS ceased operations on March 17, 2025.   In its response, APS stated that the process of closing the plant began ten years ago because of new regulations from the U.S. Environmental Protection Agency (EPA), that would require new equipment for pollution control. Significant deferred capital and maintenance investments that would have to be made, the re-opening and continued operation of the Cholla plant would come at a significantly high cost for customers. APS further stated that it plans to preserve the infrastructure of the Cholla Power Plant and offered it as a potential site for future nuclear power generation or natural gas-fired power generation. 

TEP confirmed it is planning to retire Units 1 and 2 at their coal-fired Springerville Generating Station after the summer of 2027 and after the summer of 2032 respectively. TEP informed the Commission that the company plans to replace coal power with renewable energy and storage projects but is exploring whether it can repurpose the Springerville plant for additional nuclear or gas generation.  

The entire workshop can be accessed online at http://azcc.gov/live, and presentation materials can be viewed by going to https://edocket.azcc.gov/ and entering docket no AU-99999A-25-0004.

Next month, ACC Vice Chair Nick Myers is hosting a Special Meeting pertaining to Wildfire Mitigation in a Town Hall format to engage the community in a discussion on this critical issue. The event will be held on Thursday, May 15, 2025, in Payson, Arizona. For more details, go to https://azcc.gov/news/home/2025/04/10/vice-chair-myers-to-host-2nd-wildfire-mitigation-town-hall-in-payson.