December Investor Meetings December 2023

Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking statements are often identified by words such as “estimate,” “predict,” “may,” “believe,” “plan,” “expect,” “require,” “intend,” “assume,” “project,” "anticipate," "goal," "seek," "strategy," "likely," "should," "will," "could," and similar words. Because actual results may differ materially from expectations, we caution you not to place undue reliance on these statements. A number of factors could cause future results to differ materially from historical results, or from outcomes currently expected or sought by Pinnacle West or APS. These factors include, but are not limited to: the current economic environment and its effects, such as lower economic growth, a tight labor market, inflation, supply chain delays, increased expenses, volatile capital markets, or other unpredictable effects; our ability to manage capital expenditures and operations and maintenance costs while maintaining reliability and customer service levels; variations in demand for electricity, including those due to weather, seasonality (including large increases in ambient temperatures), the general economy or social conditions, customer, and sales growth (or decline), the effects of energy conservation measures and distributed generation, and technological advancements; the potential effects of climate change on our electric system, including as a result of weather extremes such as prolonged drought and high temperature variations in the area where APS conducts its business; power plant and transmission system performance and outages; competition in retail and wholesale power markets; regulatory and judicial decisions, developments, and proceedings; new legislation, ballot initiatives and regulation or interpretations of existing legislation or regulations, including those relating to environmental requirements, regulatory and energy policy, nuclear plant operations and potential deregulation of retail electric markets; fuel and water supply availability; our ability to achieve timely and adequate rate recovery of our costs through our rates and adjustor recovery mechanisms, including returns on and of debt and equity capital investment; our ability to meet renewable energy and energy efficiency mandates and recover related costs; the ability of APS to achieve its clean energy goals (including a goal by 2050 of 100% clean, carbon-free electricity) and, if these goals are achieved, the impact of such achievement on APS, its customers, and its business, financial condition, and results of operations; risks inherent in the operation of nuclear facilities, including spent fuel disposal uncertainty; current and future economic conditions in Arizona; the direct or indirect effect on our facilities or business from cybersecurity threats or intrusions, data security breaches, terrorist attack, physical attack, severe storms, or other catastrophic events, such as fires, explosions, pandemic health events or similar occurrences; the development of new technologies which may affect electric sales or delivery, including as a result of delays in the development and application of new technologies; the cost of debt, including increased cost as a result of rising interest rates, and equity capital and the ability to access capital markets when required; environmental, economic, and other concerns surrounding coal-fired generation, including regulation of GHG emissions; volatile fuel and purchased power costs; the investment performance of the assets of our nuclear decommissioning trust, pension, and other postretirement benefit plans and the resulting impact on future funding requirements; the liquidity of wholesale power markets and the use of derivative contracts in our business; potential shortfalls in insurance coverage; new accounting requirements or new interpretations of existing requirements; generation, transmission and distribution facility and system conditions and operating costs; the ability to meet the anticipated future need for additional generation and associated transmission facilities in our region; the willingness or ability of our counterparties, power plant participants and power plant landowners to meet contractual or other obligations or extend the rights for continued power plant operations; and restrictions on dividends or other provisions in our credit agreements and ACC orders. These and other factors are discussed in the most recent Pinnacle West/APS Form 10-K and 10-Q along with other public filings with the Securities and Exchange Commission, which you should review carefully before placing any reliance on our financial statements, disclosures or earnings outlook. Neither Pinnacle West nor APS assumes any obligation to update these statements, even if our internal estimates change, except as required by law. In this presentation, references to net income and earnings per share (EPS) refer to amounts attributable to common shareholders.

T H E P I N N A C L E W E S T S T O R Y Navigating Short-Term Challenges. Longer-Term, A Powerful Growth Story 3 1 Company Profile - Solid Foundation 2 Growth Outlook Remains Strong 3 Customer Initiatives and ESG Leadership 4 Financial Outlook & 2022 Rate Case

A T A G L A N C E Arizona’s Largest Electric Company 4 $22.7BConsolidated assets $4.3BRevenues ~$8.6B Market cap ~6.3 GW Generating capacity owned or leased – year end 1.3MCustomers ~51%Current % from clean energy LargestNuclear plant in U.S. Service Territory1 Key Facts as of Dec. 31, 2022 1 As of December 31, 2022. Arizona

Attractive Customer Mix and Shifting Generation Profile 5 Residential 48% Commercial & Industrial 52% Other >1% Demand Side Management 15% 1 As of December 31, 2022. Gas 25% Renewable 12% Purchased 4% Coal 20% Nuclear 24% Retail Sales Mix1 Energy Mix – Will Shift Going Forward1

T H E P I N N A C L E W E S T S T O R Y Navigating Short-Term Challenges. Longer-Term, A Powerful Growth Story 6 1 Company Profile - Solid Foundation 2 Growth Outlook Remains Strong 3 Customer Initiatives and ESG Leadership 4 Financial Outlook & 2022 Rate Case

2023 EPS guidance 7 Key Factors and Assumptions as of November 2, 2023 2023 Adjusted gross margin (operating revenues, net of fuel and purchased power expenses, x/RES,DSM,CCT)1 $2.72 – $2.77 billion • Retail customer growth of 1.5%-2.5% • Weather-normalized retail electricity sales growth of 1.0%-3.0% • Includes 1.0%-2.0% contribution to sales growth of new large manufacturing facilities and several large data centers • Assumes normal weather for balance of year forecast Adjusted operating and maintenance expense (O&M x/RES,DSM,CCT)1 $915 – $935 million Other operating expenses (depreciation and amortization, and taxes other than income taxes) $1.02 – $1.03 billion Other income (pension and other post-retirement non-service credits, other income and other expense) $43 – $48 million Interest expense, net of allowance for borrowed and equity funds used during construction (Total AFUDC ~$96 million) $265 – $285 million Net income attributable to noncontrolling interests $17 million Effective tax rate 12.8% – 13.3% Average diluted common shares outstanding 113.7 million EPS Guidance $4.10 – $4.30 1 Excludes costs and offsetting operating revenues associated with renewable energy and demand side management programs. For reconciliation, see slide 30.

Key drivers for EPS guidance1 1 Retail customer growth of 1.5%-2.5% Weather-normalized retail electricity sales growth of 1.0%-3.0% Transmission revenues LFCR 2019 Rate Case Appeal Outcome 8 2023 EPS guidance of $4.10-$4.30 key drivers1,2 • Long-term EPS growth target of 5%-7%3 • Retail customer growth of 1.5%-2.5%4 • Weather-normalized retail electricity sales growth of 4.5%-6.5%4 1 Arrows represent expected comparative year-over-year impact of each driver on earnings. 2 As of November 2, 2023. Long-term guidance and key drivers  Depreciation, amortization and property taxes due to higher plant in service  Operations and maintenance expense  Interest expense  Pension and OPEB 3 Long-term EPS growth target based on the Company’s current weather-normalized 5-year compound annual growth rate projections from 2022-2026. 4 Forecasted guidance range through 2025.

Arizona remains among the fastest growing states in the U.S. 9 Consistent Residential Growth Past Five Years Strong 2.5% Sales CAGR Past Three Years 0.6% 0.8% 4.2% 2.4% 1.0%-3.0% 0% 1% 2% 3% 4% 5% 6% '19 '20 '21 '22 '23E Total Sales Growth2,3 2Weather-normalized 32019-2021 as reported in PNW Statistical Reports 1.9% 2.1% 2.3% 2.4% 2.2% 1.5%-2.5% 0% 1% 2% 3% '18 '19 '20 '21 '22 '23E APS Residential Growth Natn'l Avg. - Residential Residential Customer Growth1 1National average from 2022 Itron Annual Energy Survey Report

Best-in-class service territory supports high tech growth and economic development 10 Our Approach: Focus on Four Main Areas Supports Influx of Manufacturing and Distribution – Examples • Business attraction and expansion • Community development • Entrepreneurial support • Infrastructure support • Taiwan Semiconductor Increased investment from $12B to $40B factory • Proctor & Gamble $500M capital investment in manufacturing facility • Jacuzzi $30M investment in 143k sq ft facility • Rehrig Pacific Company $80M investment in manufacturing facility • Air Products & Chemicals $160M investment in manufacturing facility • KORE Power $850M DOE loan to fund 1.3M sq ft facility

A clear plan for clean energy transition 11 Progress Towards Meeting Clean Energy Commitment Pathway 2005 2019 2030 2050 Since 2020, have contracted over 4,500 MW of clean energy and storage to be in service for APS customers by end of 2025 Successfully installed 201 MW of APS owned batteries at our AZ Sun sites and 150 MW of solar at the Agave Solar Facility Charted course for healthy mix of APS-owned and third party- owned assets, to be continued through future planned RFPs 24% 50% 65% 100%

We Will Pursue Improvements in the Regulatory Environment 12 ✓ Filed a new rate case to reduce regulatory lag and improve the ROE ✓ Working with stakeholders on common issues including reducing regulatory lag and improving customer experience ✓ Continue to find alignment with the regulators ✓ Focus on customer affordability ✓ Successfully appealed last rate case to clarify the prudency standard in Arizona

We Have Embraced a Customer-Centric Strategy 13 Deliver exceptional customer service Ensure superior reliability and operating performance, anchored in safety Make intelligent and clean investments to support a growing Arizona Preserve strong financial health while sustaining customer affordability Customer Focused