APS KEEPS POWER FLOWING DURING RECORD ENERGY DEMAND Investments in the grid, year-round maintenance, and careful planning help APS deliver the reliable service customers count on when they need it most. PHOENIX – As sustained high summer temperatures pushed energy use to a new high late last week, Arizona Public Service (APS) customers counted on reliable power to keep homes, businesses and air conditioners running. And APS delivered, as customers set a new all-time peak energy demand record on Friday, July 24, 2026, using 9,053 megawatts (MW) between 5:00 and 6:00 p.m., according to preliminary figures. The previous record was set Aug. 7, 2025, when APS customers’ energy use hit a peak of 8,648 MW. One MW of energy is enough to serve about 160 Arizona homes. As high temperatures impact many parts of the country, the U.S. Department of Energy issued an emergency order on July 26 directing the deployment of backup generation resources in a number of states to ensure grid reliability. The order does not apply to Arizona Public Service and does not impact APS customers. APS has sufficient generation and reserves to serve our customers throughout the state. APS provides top-tier reliable service to customers throughout the year, supported by investments, years of planning and year-round preparation to keep the lights on and air conditioners running during Arizona’s hottest days. Ensuring this level of reliability requires proactive infrastructure maintenance, grid upgrades, resource planning and power plant readiness that strengthen the reliability and resiliency of the electrical system. APS crews, supported by a team of meteorologists and other experts, regularly inspect, maintain and upgrade critical infrastructure, prepare equipment and generating resources for periods of high demand, and train year-round for storms and emergencies. Together, these efforts ensure customers have safe, reliable power when they need it most. Peak demand is the period of time when customer energy use is at its highest. This is the fourth consecutive year APS customers have set a peak energy use record, reflecting continued growth across Arizona as more people move here, new businesses open and the economy expands. This growth requires APS to invest more than $2.5 billion a year in upgrades, operations and maintenance of the electrical system to provide customers with top-tier reliability. APS is strengthening Arizona's energy future with a balanced mix of resources designed to support reliability while meeting growing energy demand. Flexible natural gas generation helps APS integrate more solar, wind and energy storage on the grid, ensuring energy is available when customers need it most, especially during Arizona's hottest days. Nuclear energy also remains a critical component of APS's portfolio, supported by ongoing investments in Palo Verde Generating Station and the continued evaluation of future nuclear generation opportunities.

From Legacy to Future: APS Plans to Convert Cholla Power Plant to Natural Gas PHOENIX – Arizona Public Service (APS) announced today it plans to convert two units at its Cholla Power Plant in Joseph City, Navajo County, Arizona to natural gas. The repurposed resource, with operations beginning in 2029, will help meet the state’s growing energy demand while maintaining reliable, affordable electric service for customers. Originally commissioned in 1962, the Cholla Power Plant played a vital role in powering Arizona for decades, providing a critical power supply to the state. Beginning in the last decade, federal environmental mandates forced the phased retirement of the plant’s coal units, completed in March 2025. APS plans to convert two units at the site to natural gas, preserving its legacy in the state while leveraging existing transmission lines and infrastructure to support Arizona’s energy future. “Cholla has been an important part of the communities of Joseph City, Holbrook, Navajo County and northeastern Arizona for decades and has been foundational to Arizona’s energy grid,” said Johnny Penrod, APS Vice President of Generation. “Repurposing the Cholla Power Plant for natural gas allows us to build on that legacy – supporting reliable, affordable energy for our customers while continuing to invest in the communities who have long supported this plant.” Navajo County Supervisor Jason Whiting, who frequently met with APS leadership to advocate for Cholla to be converted to natural gas, expressed his appreciation for the company's decision. "I could not be more excited by this announcement," Whiting stated. "APS's decision to convert Cholla into a natural gas plant will strengthen our local economy, create jobs and support our schools. Even more importantly, it will help power our state with reliable, affordable energy." Supporting Arizona’s growth with a diverse energy mix Arizona is one of the fastest-growing states in the country, and its energy needs are projected to rise significantly in the coming years. Transitioning the Cholla Power Plant to natural gas could: Add approximately 380 megawatts (MW) of energy. Provide enough power to serve about 61,000 homes across Arizona. By repurposing an existing site, APS can provide customers with a cost-effective solution while strengthening reliability. Natural gas plays a key role by: Its ability to provide around-the-clock power to meet customer needs at any time of the day. Responding quickly to changes in customer peak energy demand. Complementing renewable energy resources like solar and wind power and battery energy storage. The facility would further support APS’s diverse energy mix – which includes nuclear from the Palo Verde Generating Station, natural gas, coal, solar, wind and battery energy storage – ensuring top-tier, reliable service as Arizona continues to grow. Renewed economic impact and community benefits Repowering the Cholla site with natural gas is expected to provide meaningful economic benefits for Joseph City, Holbrook and surrounding communities by reinvigorating the plant’s presence in the region. The project will support hundreds of jobs during construction and, once in operation, is expected to provide several dozen permanent jobs to help run the facility. The plant will also provide meaningful tax revenue to the area and help stimulate new economic activity. Looking ahead Construction on the gas conversion is expected to begin in 2028 with a targeted in-service date in 2029. This project will need to go through formal permitting and planning processes and will include ongoing community outreach through open houses, newsletters and aps.com/chollaconversion.