Modified · Reliable

Additional Currently, additional natural gas capacity is necessary to support reliable service and meet increasing energy needs. However, at this time existing natural gas pipelines into Arizona are currentlyfully committed. As a result, in July 2025, APS executed a gas transportation precedent agreement to secure a long-term supply of additional natural gas transportation. The new pipeline is expected to be operational by late 2029 and will be owned and operated by a third-partythird party. In July 2026, APS announced plans to convert two units at Cholla to natural gas, adding approximately 380 MW of gas-fired generation. The plan is subject to change pending the comparison to other generation sources that APS is considering in its evaluation of the 2025 ASRFP. The plan contemplates that construction on the gas conversion would begin in 2028 with a targeted in-service date in 2029. In addition to the planned Cholla gas conversion, APS plans to add up to 2,000 MW of flexible natural gas generation to its portfolio, designed to help meet the growing around-the-clock energy needs in Arizona. APS continues to explore additional development opportunities to meet Arizona’s growing needs.