Slides
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Alliant Energy Corporation October 30, 2026 Q3 2026 Earnings Call
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2 2026 Q3 Earnings Call Forward-looking Statements The information regarding earnings per share guidance, earnings per share growth, load growth opportunities and timing, projected demand, estimated effective income tax rates, forecasted and estimated capital expenditures, capex opportunities, forecasted rate base and construction work in progress, dividend targets, financing plans and sources of funding, and regulatory plans contain forward-looking statements. Statements containing words such as “projected,” “anticipate,” “estimated,” “plan,” or words of similar import, or that include future years are also forward-looking statements. Actual results could differ materially because the realization of those results is subject to many uncertainties, including: ability to obtain all regulatory approvals, local approvals, and other approvals and permits in a timely manner; the ability and cost to attract large load growth customers and to provide sufficient generation and the ability of ITC and ATC to provide sufficient transmission capacity for potential load growth timely; the ability of potential large load growth customers to timely construct new facilities, due to local or state regulatory actions, zoning, siting, or permitting actions, public or community opposition or other factors, as well as the resulting higher system load demand by expected levels and timeframe; the state of the economy in the service territories of IPL and WPL; state and federal legislation; weather; and other factors discussed in more detail in Alliant Energy Corporation’s earnings release dated October 29, 2026, and in Alliant Energy’s SEC filings. Alliant Energy cannot provide any assurance that the assumptions used in the forward-looking statements or otherwise are accurate or will prove to be correct. All forward-looking statements included in this presentation are based upon information presently available, and Alliant Energy assumes no obligation to update any forward-looking statements. Non-GAAP Financial Measures This presentation contains references to ongoing earnings, which is a non-GAAP financial measure. The reconciliations between ongoing earnings and the GAAP measure are provided in this presentation. Ongoing earnings refers to non-GAAP diluted earnings per share. Cautionary Statements
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3 2026 Q3 Earnings Call >60% ~3.4 GW increase in projected data center demand through 2031(1) THE ADVANTAGETM Solutions-oriented approach Unlocking the potential of our customers and communities Driving affordability Retail electric rates below national averages; Iowa electric rate stability plan extends to 2030 Resource plan flexibility Adding to robust, diverse, and reliable energy resources Regulatory frameworks aligned for growth Regulatory tools enabling disciplined, customer-driven growth ALLIANT ENERGY Powering a future you want to own +1 year Extend IPL electric base rate stability plan through 2030 while earning authorized ROE $15.9 B 2027-2030 capital plan with robust upside 19% growth over prior $13.4 B ‘26-’29 plan 8%+ 2027-2030 ongoing EPS growth Long-term outlook raised to 6-8%+ $1.2 B Estimated customer savings from U.S. DOE guaranteed loan program(2) ~40% 2027-2030 equity needs covered by forwards executed under ATM 13% Investment CAGR(3) 2025-2030 (1) Based on contracted max demand compared to 2025 base of ~5.5GW max demand (2) Estimated customer savings when compared to traditional debt financing over the life of the U.S. DOE guaranteed loans if full y funded (3) Rate base + construction work in progress compound annual growth rate
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4 2026 Q3 Earnings Call Data Center Progress ICR = Individual Customer Rate (1) Approved with conditions. Modified ESA and ICR tariff may be found under Docket No. 6680 -TE-115. Filed ICR for Google 2 data center with the Iowa Utilities Commission Customer / Location Construction / Progress Load Ramp Timeline ICR Status QTS 1 Cedar Rapids, IA Under construction 2026 – 2029 Approved Google 1 Cedar Rapids, IA Under construction 2026 – 2027 Approved Meta Beaver Dam, WI Under construction 2026 – 2027 Approved(1) QTS 2 Clinton, IA Community ordinances under review 2028 – 2031 To be filed Google 2 Cedar Rapids, IA Planning 2029 – 2030 Filed 3.4 GW Large Data Center Load Growth (generation to serve load included in investment plan) ~12% Retail Electric Sales Growth CAGR 2025-2031
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2026 Q3 Earnings Call Solving for Affordability – Iowa Iowa electric base rate stability while earning authorized ROE IPL retail electric base rates held flat through 2030 2025 2026 2027 2028 2029 2030 Base rates stable through at least 2029 (prior plan) +1 year extensionHow it works Tax credits Retention of tax benefits until investments are in base rates; ITCs recognized as needed to earn authorized ROE, PTCs recognized as earned Energy margins Energy margins and capacity retained until investments are in base rates Shared benefits Earnings sharing mechanism shares benefits of load growth and operational efficiencies with customers and shareowners $800M Estimated customer savings from U.S. DOE guaranteed loan program(1) • $3.5B U.S. Department of Energy loan program • Lower-cost financing for a portion of estimated IPL debt issuances • Supports generation buildout to serve customer growth 5 (1) Estimated customer savings when compared to traditional debt financing over the life of the U.S. DOE guaranteed loans if full y funded
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2026 Q3 Earnings Call Supporting customers and communities • Data centers provide meaningful benefits to communities they serve with tens of millions of dollars investments • Large load tariff ensures proper cost allocation among new and existing customers Lower operating costs ~$235M WI customer 2027 fuel savings from solar generation, battery energy storage, and the continued operation of Columbia and Edgewater ~$50M Awarded DOE grants offset costs for WI energy storage and dry bottom ash projects Enhancing customer value • Capacity enhancements to existing fleet • Leased underground conduit for fiber use for data center customer • Renewables keep fuel cost low; ~37% of 2025 retail sales coming from renewable energy • Safe-harboring planned renewable and energy storage projects – enabling cost-effective energy solutions 6 Solving for Affordability – Wisconsin $400M Estimated customer savings from U.S. DOE guaranteed loan program(1) • ~$1.6B U.S. Department of Energy loan program • Lower-cost financing for a portion of estimated WPL debt issuances • Supports generation buildout to serve customer growth (1) Estimated customer savings when compared to traditional debt financing over the life of the U.S. DOE guaranteed loans if full y funded
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2026 Q3 Earnings Call Building Stronger Communities – Converting prospects to projects 1 Growing interest Increased interest in locating new large-load projects in Iowa and Wisconsin 2 Active site discussions Robust pipeline of opportunities across ~10 sites within Iowa and Wisconsin 1 Higher bar for adding new large load into our plans ✓ Land control ✓ Transmission studies underway or complete ✓ Planned generation to serve load at pace of customer ✓ Executed Electric Supply Agreement (ESA) ✓ Local permitting Land control Transmission studies Executed ESA Planned Generation Growth in the plan Local permitting 7 In advanced discussions of 2-4 GW large load prospects: Anticipate conversion of approx. 1 GW within next ~6 months Local engagement Large-load customers are increasing engagement with local communities
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8 2026 Q3 Earnings Call Three months ended September 30, 2025 ongoing earnings per share $1.12 Timing of income tax expense 0.18 Revenue requirements from capital investments at IPL and WPL 0.17 Higher equity earnings from corporate venture investments 0.07 Higher other operation and maintenance expenses (0.07) Higher financing expense (0.07) Allowance for funds used during construction 0.04 Higher depreciation expense (0.03) Estimated temperature impacts on retail electric sales 0.02 Other (including higher temperature-normalized retail electric sales) 0.09 Three months ended September 30, 2026 earnings per share $1.52 Financial Results Q3 2026 Q3 2025 GAAP net income (in millions) $398 $281 GAAP earnings per share (EPS) $1.52 $1.09 Ongoing EPS(2) $1.52 $1.12 ALLIANT ENERGY Q3 2026 Highlights NARROWED 2026 ONGOING EARNINGS GUIDANCE Strong results support expectations within the upper half of original guidance range DEPT of ENERGY LOAN PROGRAM BRINGS GREATER VALUE TO CUSTOMERS ~$5 billion loan program lowers costs for customers and supports generation buildout ADVANCING CUSTOMER GROWTH ICR filing for Google 2 data center expansion in Cedar Rapids, IA Narrowed 2026 ongoing EPS guidance(1)(2) $3.41 - $3.46 (1) Initial 2026 ongoing earnings guidance range $3.36 - $3.46 (2) Ongoing earnings per share is a non-GAAP financial measure. References to ongoing earnings exclude material charges or income that are not normally associated with ongoing operations.
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2026 Q3 Earnings Call Initiated Projected Earnings and Dividend Growth in 2027 2027 ongoing EPS Guidance: $3.63 – $3.73 $3.41 $3.68 2026 Original Midpoint 2027 EPS Guidance Midpoint 8% increaseKey Drivers: • Higher earnings from capital investments, incl. AFUDC • Higher depreciation expense • Higher financing costs • Higher operation and maintenance expense due to higher labor and inflation 2027 Dividend Target: $2.25 per share • 5% increase over 2026 target • Target dividend payout ratio of 60-70% of ongoing earnings 9 Payment of the 2027 quarterly dividend is subject to the actual dividend declaration by the Board of Directors each quarter, which is expected in January 2027 for the first quarter dividend.
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2026 Q3 Earnings Call 2026E 2027E 2028E 2029E 2030E 6-8%+ long-term annual ongoing EPS growth target; 8%+ ongoing EPS growth target for 2027-2030 Proven Strong Execution Fueling Near-Term Growth Outlook $3.41 – $3.46 $3.63 – $3.73 Drivers of estimated 2027 – 2030 EPS growth: • Growth in rate base • Expected load ramp of large load customers, including data centers • Ability to earn our authorized return on equity through constructive regulatory outcomes - Including Iowa electric base rate stabilization plan through 2030 NEAR -TERM GROWTH OUTLOOK 8%+ 10
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2026 Q3 Earnings Call +19% increase in CapEx supports 13% investment CAGR thru 2030 with minimal regulatory lag Increasing Investments to Support Economic Development and Growth $5.1 $6.8 $2.3 $0.6 $1.1 Energy Storage & Renewables Thermal Generation & LNG Electric Distribution Gas Distribution Other (including American Transmission Company) $15.9 billion 13-month average(1) ($ in billions) $16.9 $31.5 2025 2030 PROJECTED RATE BASE + CONSTRUCTION WORK IN PROGRESS UPDATED CAPEX 2027 -2030 ($ in billions) 13% CAGR 11 19% vs. prior $13.4B plan (2026-2029) (1) Average of 13-monthly balances from December to December
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2026 Q3 Earnings Call12 ~$2.5B increase in 4-year estimated capital expenditures with robust additional capex opportunities Thermal Generation & LNG $6.8B (+$2.2B) 2,800 MW New generation 280 MW Increased capacity at existing units 2 BCF LNG and gas lateral investments Natural gas generation in-service: 2027 – 2031 Energy Storage & Renewables $5.1B (+$0.1B) 1,200 MW Energy storage 1,300 MW New renewables Safe harboring 100% complete for energy storage and wind resources Energy storage in-service: 2027-2030 Renewables in-service: 2029 Distribution, Technology & Other $4.0B (+$0.2B) $2.3B Electric distribution investments $0.6B Gas distribution investments $0.8B Technology, facilities, fleet, etc. $0.3B Equity investment in American Transmission Company Expanding Diversified and Sustainable Energy Resources $15.9B 2027-2030 Capex plan Capex Opportunities 2027-2030 • Generation capacity resources for anticipated large load opportunities • Wind repowering or refurbishments of vintage 2019-2020 wind assets • Renewable and energy storage for individual customers as solutions for achieving sustainability goals Approximate figures for $ and MW
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2026 Q3 Earnings Call 1. Cash from operations less common dividends 2. Reflects common shares to be issued under the DRIP plan and future equity issuances 3. New debt reflects debt issuances, net of repayments Balanced funding approach for capital investment program 13 Cash from Operations 26% Tax Credit Monetization 13% New Debt, incl. Hybrids 44% Equity 17% $15.9B Capital Expenditures 2027-2030 1 2 3 SOURCES OF FUNDING 2027 -2030 Financial strength and a balanced flexible funding plan position us to execute on growth Financing Expectations • Financing capex investments with a balance of new debt, utilization of hybrids and new common equity • Change in equity financing attributed to ~40% equity financing of incremental capex growth through 2030 • Utilization of ~$5 billion U.S. Department of Energy loan program lowers cost for customers • Maintain a target dividend payout ratio of 60-70% of ongoing earnings • Committed to maintaining current investment grade credit ratings with S&P and Moody’s Total Equity 27-30 Forwards Executed under ATM DRIP Program 27-30 Remaining to be Addressed EQUITY ISSUANCES ($ in billions) $2.7B $1.5B $1.1B $0.1B Settlements throughout 2027-2028
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2026 Q3 Earnings Call14 2026 and 2027 Debt Financing Plans • Approximately $310M and $470M in tax credits are anticipated to be transferred in 2026 and 2027, respectively • Expect to utilize U.S. Department of Energy guaranteed loan program for a portion of 2026 and 2027 estimated IPL and WPL debt issuances to lower cost for customers • Executed a $300M interest rate swap to fix the SOFR rate at 3.10% for the anticipated AEC variable rate term loan borrowings through March 2028 • Financing plans are subject to change, depending on capital expenditures, regulatory outcomes, changes in tax credit transferability assumptions, changes in legislation or tax policies, financing structure and timing, including the refinancing of short-term or interim financings with longer-term debt, or other factors Estimated Remaining Debt Issuances 2026 Completed Financing Activity 2026 2027 Issuance Date Rate Maturity Date Amount Type AE Finance/Parent — Up to $1.0B March 2026 Variable March 2027 $400 Term Loan IPL Up to $200M Up to $1.3B August 2026 5.10% September 2031 $500 Senior Debenture WPL Up to $300M Up to $500M Financing plans support growth in capex and upcoming 2027 maturities ($ in millions) Maturities Type Amount Rate Maturity Date AEC/AE Finance Term Loan $400 Variable March 2027 Senior Notes $375 5.40% June 2027 WPL Debentures $300 3.05% October 2027
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2026 Q3 Earnings Call Approved Docket Increase Energy Storage by 125 MW in Franklin County, Iowa GCU-2025-0006 15 Advancing Iowa Regulatory Initiatives Pending Approval Docket Anticipated Decision Date 175 MW Marshall County BESS Project GCU-2026-0009 Q4 2026 720 MW Morgan Valley Energy Center Natural Gas Project GCU-2026-0002 Q1 2027 170 MW English Farms BESS Project GCU-2026-0010 Q1 2027 ICR Filing for Google 2 data center TF-2026-0089 Q1 2027 ~1,200 MW Riverhawk Energy Center Natural Gas Project GCU-2026-0005 Q2 2027 What to watch… • Announcement of new economic development projects – including additional data centers • Filings for additional renewable and flexible, dispatchable resources • Filing of QTS Clinton ICR data center contract in Iowa • FERC policy decision on allowing interconnection customers to potentially self-fund network upgrades (EL24-80-000)
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2026 Q3 Earnings Call Advancing Wisconsin Regulatory Initiatives Pending Approval Docket Anticipated Decision Date 277 MW Columbia Wind Project 9836-CE-100 & 6680-BS-102 Q1 2027 Large Load Tariff 6680-TE-119 Q2 2027 Riverside Capacity and Efficiency Project 6680-CE-192 Q2 2027 Approved Docket Rock County LNG 6680-CG-171 16 What to watch… • Announcement of new economic development projects – including additional data centers • Filings for additional renewable and flexible, dispatchable resources • Filing of WPL retail electric and gas rate review for test periods 2028 and 2029 in Q1 2027 • FERC policy decision on allowing interconnection customers to potentially self-fund network upgrades (EL24-80-000)
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APPENDIX 17
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2026 Q3 Earnings Call 2026 Guidance Assumptions • Higher earnings on growing capital investments, including AFUDC • Forecasted 2026 capital expenditures of ~$3 billion weighted toward the second half of the year, with average construction work in progress balances of ~$2 billion • ~2-3% retail electric sales growth, including data center construction & commissioning sales • Normal temperatures in utility service territory • ~5% higher operating and maintenance expense, weighted toward the first half of the year • Higher depreciation and amortization expenses due to new energy resources • Higher financing costs, including common equity dilution • Utilization of tax credits in Iowa utility to earn up to its authorized retail electric ROE • Estimated effective tax rate of ~(28%) 18 2026 ongoing earnings guidance based on the following assumptions (as compared to 2025 levels) Tax Benefit Timing Q1 Actual Q2 Actual Q3 Actual Q4 Estimated Total Year 2026 EPS timing impact $0.01 $(0.12) $0.29 $(0.18) $-- 2025 EPS timing impact 0.02 (0.07) 0.11 (0.06) -- Estimated EPS Variance ($0.01) $(0.05) $0.18 $(0.12) $-- Ongoing earnings per share is a non-GAAP financial measure. References to ongoing earnings exclude material charges or income that are not normally associated with ongoing operations.
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2026 Q3 Earnings Call GAAP to Ongoing Earnings Reconciliation GAAP EPS Adjustments Ongoing EPS 2026 2025 2026 2025 2026 2025 IPL $0.96 $0.64 $— — $0.96 $0.64 WPL 0.60 0.48 — — 0.60 0.48 Corporate Services 0.02 0.01 — — 0.02 0.01 Subtotal for Utilities and Corporate Services 1.58 1.13 — — 1.58 1.13 ATC Holdings 0.05 0.04 — — 0.05 0.04 Non-Utility and Parent (0.11) (0.08) — 0.03 (0.11) (0.05) Alliant Energy Consolidated $1.52 $1.09 $— $0.03 $1.52 $1.12 The following table provides a summary of Alliant Energy’s results for the three months ended September 30: Non-utility and Parent: Non-GAAP EPS Adjustments 2026 2025 State income tax apportionment charge -- $0.03 Ongoing, or non-GAAP, earnings for the three months ended September 30 do not include the following items that were included in the reported GAAP earnings: 19