APS

APS SHARES TIPS FOR STAYING SAFE THIS MEMORIAL DAY WEEKEND Keep outdoor celebrations fun and stress-free with these simple precautions PHOENIX – As Memorial Day weekend approaches, it’s a time to remember those who gave their lives in military service. As many families and friends gather outside for the holiday at barbecues and pool parties, Arizona Public Service (APS) is encouraging safety. Taking a few simple precautions around outdoor summer celebrations can help prevent electrical accidents and keep loved ones safe. Tips to stay safe around electricity outdoors: • Pool days and playlists are a perfect pair - water and electricity are not. Keep speakers, chargers and other electronics far from the splash zone and never handle electrical devices with wet hands. When cleaning pools, be aware of overhead power lines, especially when using longhandled tools. • Keep outdoor lighting away from water. Ensure a safe vertical clearance over a pool’s water surface for popular backyard décor like string lights. Know where pool equipment breakers and shutoffs are located, in case of emergency. • Avoid overloading outlets and cords. This can lead to electric shock and severe injury. Use only weather-resistant, heavy-gauge extension cords specifically designed for outdoors. • Secure items like umbrellas, trampolines, pool floats and patio furniture. Arizona winds can quickly blow items into power lines, causing outages and a dangerous end to a fun celebration. Similarly, avoid flying drones, kites or other aerial toys near power lines. • Practice balloon safety. Mylar balloons and power lines are a party foul. The metallic coating on Mylar balloons can damage power lines and knock out power to homes and businesses. Keep balloons secured, then deflate and properly dispose of them. • Stay away from downed power lines. Keep a distance of at least 100 feet, call 911 and then contact APS. For more ways to stay safe around electricity, visit aps.com/safety. APS customers can plan their summer celebrations with savings in mind. Customers on time-of-use rate plans can enjoy lower-priced rates the full 24 hours of the day on off-peak holidays – including Memorial Day, Juneteenth and Fourth of July. Learn more about your rate plan options and holiday off-peak benefits at aps.com/plans. APS serves 1.5 million homes and businesses in 11 of Arizona’s 15 counties and is a leader in safely delivering reliable, affordable electricity in the Southwest. APS maintains a diverse range of energy resources, including nuclear from the Palo Verde Generating Station, natural gas, coal, solar, wind and energy storage – a mix that’s about 58% clean. With 140 years of experience serving Arizona, APS is the main subsidiary of Pinnacle West Capital Corp. (NYSE: PNW). APS Shares Tips For Staying Safe this Memorial Day Weekend

Our rate case hearing is beginning, and you might have questions. To learn how rates help deliver the reliable energy you count on, what we're doing to protect residential and small business customers from data center costs, and more, visit aps.com/ratecase.

APS RATE CASE HEARING BEGINS; FINAL DECISION TO COME LATER THIS YEAR No impacts to monthly bills until winter Today marks the start of the evidentiary hearing in the Arizona Public Service (APS) rate case before the Arizona Corporation Commission (ACC). This hearing is the latest step in a lengthy open and transparent rate review process that started in June 2025 and will likely continue through the end of 2026. Why is APS requesting a rate increase? Current APS rates are based on costs from five years ago. Inflation and rising expenses mean those rates no longer cover what it takes to operate and strengthen the electric grid today. By updating rates to reflect current costs, APS can continue to provide customers with the top-tier reliability they need and expect, especially during Arizona’s long, hot summers. As a regulated utility, APS must look backward to adjust its rates based on the actual costs it paid to serve customers in 2024 and 2025. This ensures rates more accurately match the true costs of providing electric service to customers. For context, over the past five years, APS has experienced rapidly rising costs of equipment needed to deliver power to customers. One example is transformer costs which are, on average, 49-90% higher now than when our rates were last set. (See graphic below.) How does the rate proposal protect affordability and reliability for APS customers? In addition to ensuring a reliable energy grid and upgrading equipment, the rate case introduces measures to further support customers. Amid rising costs for infrastructure, equipment and materials, APS is anticipating unprecedented growth within its service territory. To protect residential and small business customers, APS is making sure new large energy users, like data centers, continue to pay their full cost of service. The plan proposes a rate increase of more than 45% increase for data centers and updated cost allocation for system investments, like power plants, so growth-related costs are assigned to the customer classes driving expansion. APS’s application also outlines a formula rate, under which future costs (e.g., infrastructure, fuel, etc.) are reviewed annually and allocated to the customer group responsible for those costs, such as data centers. What comes next? During the hearing, which is expected to last just over a month, APS and other parties (known as intervenors), will present evidence, answer questions and provide on-the-record testimony about energy grid investments APS made in 2024 and 2025 to enable top-tier reliability for its customers. No rate adjustments will occur until the rate case process is complete. In the months after the hearing concludes: The ACC’s Administrative Law Judge will consider the evidence presented and issue a Recommended Opinion and Order (ROO) for the Commission’s consideration. APS and intervenors will have an opportunity to file exceptions or responses to the ROO. The ACC will publicly review and vote on the case. A final decision is expected toward the end of the year. If approved, a rate adjustment would follow. What about summer electric bills? With the arrival of hotter weather, most customers will naturally use more energy as air conditioners work harder to keep homes cool. That higher energy usage in the summer drives higher bills for most customers. APS’s rate proposal will have zero impact on customer bills this summer. It’s important for customers to know they have options to manage their bills and lower their costs. For example, customers can compare rate plans by using APS’s rate comparison tool at aps.com/compare. Customers can visit aps.com/save for tips to save energy. Customer Support and Resources APS helps connect customers facing financial hardship to programs and resources that can make a difference. The Crisis Bill Assistance program provides up to $1,000 for those in need. Eligible customers can also receive monthly discounts of up to 25% or 60% through the APS Energy Support program. Learn more at aps.com/assistance or by calling the 24/7 Customer Care Center. APS advisors are available in English and Spanish at 602-371-7171 or 800-253-9405. tr.ee/86XTY4

We continue to monitor and work closely with fire departments to support firefighter safety and emergency response efforts near electrical equipment.

Our crews maintain more than 38,000 miles of power lines and manage vegetation year-round. As drought and bark beetles impact Arizona forests, we're identifying and removing hazard trees to reduce wildfire risk. Take a behind-the-scenes look. tr.ee/YrZ305D

Thank you @GovernorHobbs for taking the time to see firsthand how Palo Verde Generating Station helps keep the lights on for Arizona families and businesses.

Double the volunteer service in @PinalCounty! Celebrating 140 years of @apsFYI serving Arizona with service projects statewide as the single biggest day of volunteerism in company history. Volunteers planted 25 trees in @TownofFlorence & cleaned up a mile in @CityOfCG

Since that first gas lamp was lit in 1886 at Central and Washington, one thing has remained constant, supporting the people and communities who call Arizona home. Over the past 140 years, life has changed but we’re proud to grow with the state, helping take care of the energy that powers Arizona, today and into the future. 💡💙

Since 1886, supporting Arizona communities has stayed at the heart of our mission. This Wednesday, we’re marking 140 years of service by giving back with our largest day of service yet and a $1.4M investment in the communities we all live, work and play. tr.ee/Hfo7tT

Service has been safely restored as of April 22 at 6:45 p.m. Crews actively patrolled powerlines serving approximately 5,600 customers, using trucks, drones and UTVs to assess miles of line in rugged terrain. While we know it's difficult to be without power, these temporary outages help reduce the risk of wildfires during extreme weather conditions. We thank you for your patience.

@xrepoman We will have ongoing assessments and forecasting using innovated fire modeling software and our APS meteorologist. Thank you for sharing your concerns and appreciate your patience.

@xrepoman We understand how frustrating and stressful power interruptions can be. Once the fire risk conditions have diminished, field crews will inspect the lines that were shut off. If there is no damage, electricity will be restored during daylight hours. Thank you.

Turn the power back on please.

Temporary ice distribution locations can be found on the outage map at aps.com/outagemap.

Public Safety Power Shutoff began at 9:00AM this morning in the impacted areas of Doney Park, Timberline, Fernwood, Mormon Lake, Cosnino, Sunset Crater, Walnut Canyon, Valle, and some locations in and around Grand Canyon National Park, excluding Bright Angel Lodge, El Tovar and the railway station. Temporary ice distribution locations can be found on the outage map at aps.com/outagemap. Residential customers affected by the outage can be reimbursed for the purchase of up to 40 pounds of bagged ice or 20 pounds of dry ice to help preserve food. Complete the form here: aps.com/icereimburseme… Inspections and restoration will begin as soon as weather conditions permit.  Visit aps.com/psps or aps.com/outagemap for updates.

We have directly notified approximately 5,800 potentially impacted customers in advance of a Public Safety Power Shutoff. To ensure customers receive alerts, we encourage them to sign in to their aps.com account to make sure contact information is up to date.

Tiny feet on the run! 👣 When a little one makes a break for it near our downtown Phoenix service center, our team didn't hesitate. APS Supervisor Kort Meyer and Troubleman Robert Butler jump into action to stop the child from reaching the busy street. tr.ee/C0fWJr

By staying connected, customers can be better prepared and informed during potential power shutoffs and other emergency situations. Learn more about our wildfire mitigation efforts at aps.com/wildfires or more about PSPS at aps.com/psps. 12/12

To register for @yavapaicounty emergency alerts, visit: yavapaiready.gov. 11/12

As summer approaches and dry conditions persist, wildfire preparedness is our daily priority. For more than 10 years, we have invested in efforts reduce wildfire risk as part of comprehensive wildfire mitigation program. 🧵1/12 👇