Powering What’s NextBofA Power, Gas and Solar Leaders Conference

March 4, 2020

This presentation contains statements that may be considered forward looking statements, such as management’s expectations of financial objectives and projections, capital expenditures, earnings growth, plant retirements, rate base, and new generation plans. These statements speak of the Company’s plans, goals, beliefs, or expectations, refer to estimates or use similar terms. Actual results could differ materially, because the realization of those results is subject to many uncertainties including regulatory approvals and results, unanticipated construction costs or delays, economic conditions in our service territories, and other factors, some of which are discussed in more detail in the Company’s Form 10-K for the year ended December 31, 2019. All forward looking statements included in this presentation are based upon information presently available and the Company assumes no obligation to update any forward looking statements.

In addition, this presentation contains non-GAAP financial measures. The reconciliations between the non-GAAP and GAAP measures are provided in this presentation.

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Safe harbor

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5-7%EPS growth

through 2023(a)

~3%Dividend yield

with 5-7% CAGR(c)

~8-10%Total

Shareholder Return(b)

(a) Based on 2019 Non-GAAP temperature normalized EPS of $2.26(b) Total shareholder return proposition at a constant P/E ratio(c) Subject to approval by the Board of Directors

Constructive regulatory environments, customer-focused investments, virtually all earnings from regulated operations, strong balance sheet and liquidity

Investment considerations

Consistent performance

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Adjusted earnings per sharefrom continuing operations(non-GAAP temperature normalized)

Dividends per common share

(a) Annual common stock dividend target. Payment of the quarterly dividends is subject to the actual dividend declaration by the Board of Directors.

Regulated utility profile

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970,000Electric customers

420,000Gas customers

$9.4 B 13-month average 2019 rate base

$3.6 B 2019 operating revenues

3,600Employees

Interstate Power and Light (IPL)• 490,000 Electric customers• 225,000 Gas customers• $5.7 B Rate base 13-month avg.• $2.1 B Operating Revenues

Wisconsin Power and Light (WPL)• 480,000 Electric customers• 195,000 Gas customers• $3.7 B Rate base 13 month avg.• $1.5 B Operating Revenues

Iowa“IPL”

Wisconsin“WPL”

Our customer-focused strategyProvide affordableenergy solutions

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Make customer-focused investments

Grow customer demand

SUPPORTEconomic development by certifying development-ready sites

EXPANDRenewable energy

IMPROVECustomer experience

ENABLECustomer growth and distributed energy

INCREASEOperational efficiency and resiliency

See website www.alliantenergy.com/poweringwhatsnext

Our core values

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Act for tomorrowOur ESG profile

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30% of our energy mix will be from renewables

40% targeted reduction of CO2 from 2005 levels

75% targeted reduction of water supply needs from fossil-fueled generation

Eliminate coal from our energy mix

80% targeted reduction of CO2 from 2005 levels

By 2030: By 2050:Our clean energy vision

Additional information can be found in our Corporate Sustainability Report:alliantenergy.com/sustainability

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Our ESG profile: Environmental

-65% -75%

Water Supply Needs*

*preliminary estimate

• Permanently retired approximately 30% of our fossil-fueled generation capacity since 2005, including over 1,000 megawatts of retired coal-fired generation.

• Air quality control systems reduce emissions from our remaining coal-fired generation.

Achieved SO2, NOx and Hg reduction targets one year early

Great progress toward achieving 2030 reduction targets

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Our ESG profile: EnvironmentalTransitioning toward a cleaner energy mix

Gas34%

Nuclear-PPA12%

Other9%

Renewables18%

Coal27%

Balanced portfolio2019

730 MW of gas tocomplement renewablesin 2020

680 MW of wind investments in 2020

Up to 1,000 MW of solar investments by end of 2023

Additional renewables and gas2020-2023

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19%

YE 2018$8.3B

14%

Our ESG profile: EnvironmentalCoal is a declining percentage of our rate base (proxy for % of revenue from coal)

YE 2020$11.7B

Our ESG profile: SocialWorkforce Community

Economic Development• 16 Alliant Energy Growth Sites to

promote economic development in our communities

• 2,632 jobs created in 2019

• Renewable investments provide lease and tax payments to landowners and communities

Community Giving

• Community giving of over $7 million in 2019

• Drive Out Hunger initiative has raised funds for nearly 15 million meals

• Over 92,000 annual employee volunteer hours in 2019

Safety

• Severity rate much lower than EEI benchmark

• Targeted injury reduction plans in 2020 to reduce injuries

• Board oversight of safety program

• “Good catches” and “near misses” program are leading indicators

• Community natural gas and electric public safety presentations

Cyber and Physical Security

• Board oversight of programs

• Annual employee awareness training, company wide on-going phishing training and testing

• Protocols drilled routinely

• 54% of employees covered under collective bargaining in 2019

• Perfect score on Corporate Equality Index 2017, 2018, and 2019

• Health and wellness program for employees and their families

• 6 active employee resource groups

• Support re-deployment of workforce thru apprenticeship, job shadowing and career days

• On-site, online and webinar-based training, and tuition reimbursement

• College internship program

• Pre-apprenticeship and apprenticeship programs

• Business Roundtable and CEO Action for Diversity and Inclusion commitment

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Board of Directors • Lead independent director with clearly defined

and robust responsibilities

• Executive sessions of independent directors held at each board meeting

• Annual board and committee self-assessments

• Average age = 58; Average tenure = 7.4

Women40%

20%Under 55, 20%

55‐59, 40%

60‐65, 20%

Over 65, 20%

Over 7 years, 40%

7 years or less, 60%

Tenure diversity

70%

15%

7.5%7.5%

Earnings per Share

Customer experience

2020 Performance pay

Environmental

Diversity

Annualmetrics

Ethnic diversity Age diversityGender diversity

Executive Compensation• Strong linkage of compensation to achievement

of financial, customer focused and ESG-related goals

• Substantial portion of performance-based at-risk compensation

Our ESG profile: Governance

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Generation and distribution transformation drives growth

Transitioning to cleaner energy resources

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Based on approximate capacity in megawatts As of December 2019

**Does not include Wisconsin Clean Energy Blueprint solar of 1,000 MW to be in-service by end of 2023

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Wind Solar Hydro Total

Owned MW in-service 1,410(a) 11 41 1,462

Owned MW under construction 480 5 -- 485

Purchased power agreements MW (b) 1,060 4 18 1,082

Owned MW under development -- 1,000 -- 1,000

Total MW 2,950 1,020 59 4,029(a) Includes both utility and non-utility owned wind(b) Purchased power agreements in place for 2020

A growing portfolio of renewable assets

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Project* Owner Size (MW) NCF ** In-service

Cedar Ridge WPL 68 MW 30% 2008

Forward Energy WPL 59 MW (of 129) 27% 2008

Whispering Willow East IPL 299 MW 34%

2009

Franklin County 2012

Bent Tree WPL 201 MW 29% 2011

Upland Prairie IPL 300 MW 38%*** 2019

English Farms IPL 170 MW 36%*** 2019

Whispering Willow Expansion IPL 201 MW 47% - 49% 2020

Golden Plains IPL ~200 MW 46% - 48% 2020

Richland IPL ~130 MW 44% - 46% 2020

Kossuth WPL ~150 MW 45% - 47% 2020

* All projects have received regulatory approval**NCF = Net Capacity Factor for 2019 for developed sites***Partial year, placed in service end of Q1 2019

2008 2009 2011 2012 2018 2019 2020

Over 1,700 MW

Growing wind generation investments

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Accelerating solar generation investmentsProject* Owner Size (MW DC) CAP** In-service

Wisconsin Clean Energy Blueprint WPL Up to 1,000 MW 2021-2023

South Fond du Lac Community Solar WPL ~1.0 MW 2020

West Riverside WPL ~4.0 MW 2020

Marshalltown IPL 2.6 MW 2020

Downtown DubuqueIPL 6.1 MW ~15%

2017

West Dubuque 2017

Indian Creek Nature Center IPL 0.1 MW ~13% 2016

Rock River PPA 2.2 MW ~16% 2016

Madison G.O. demonstration project WPL 0.3 ~13% 2016

**CAP = Annual CAP Factor for 2019

Wisconsin Clean Energy BlueprintRegulatory Approval – Plan to file first certificate of authority(CA) in the first half of 2020Investment Tax Credits (ITC): 2019 investment to qualify a portion for 30% ITC, rely on qualifying equipment acquisition to qualify the entire planPartnership: Maximize customer benefits from investment tax creditsInvestments in Capital Expenditure Plan: ~$780 millionSiting: 200 MW self-developed sites; ~500 MW under exclusivity agreements with developers, actively working to secure the remaining sites for the plan

• Supports capacity need resulting from planned coal and gas retirements

• Cost-effective source of energy with low natural gas prices and highly efficient heat rate

• 50% less CO2 emissions and 75% less water used than retiring coal plants

• Ramp rate 80 MW per minute

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Utilities and electric cooperatives Purchase option amount

Option timing

Adams-Columbia Electric CooperativeRock Energy CooperativeCentral Wisconsin Electric Cooperative

~60 megawattsOptions

exercised January 2018

Wisconsin Public Service Corporation up to 200 megawatts 2020 – 2024Madison Gas and Electric Company up to 50 megawatts 2020 - 2025

WPL’s West Riverside Energy Center

Size: 730 MW combined-cycle natural gas facilityContractor: AECOM selected as EPC contractorMajor equipment: GE Frame 7FA.05 combustion turbinesEfficiency: Heat rate is expected to be just under 6,500 btu/kwhCost: WPL’s share of estimated cost is $600 million for facility, excluding transmission network upgrades and AFUDCConstruction timing: Expected to be placed into service in Q2 2020

Joint owners: Book-value purchase for partial ownership of the facility

Gas generation complements renewables

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Advancing a clean energy future25 kV – Design standard

Undergrounding – Resiliency improvements

Smart devices –

• AMI - meter reading, remote connect/disconnect

• Fault detection

• Self healing

Communications – Fiber

Battery storage – 650kW self-contained installation

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Economic Development• WPL is developing a project to expand natural gas

capacity by 20% in its western Wisconsin corridor

Reliability and Affordability• Automating meter reading• Increasing remote monitoring • Remote connect/disconnect• Fault detection without rolling trucks

Safety• Modifying existing pipes for enhanced inspection and verification requirements• Replacing and modifying aging gas transmission lines• Replacing distribution line made of certain material through the Integrity Management program

Gas distribution for economic growth

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(In b

illion

s)

Other

Gasdistribution

Electricdistribution

Othergeneration

Renewableprojects

Customer-focused investments drive rate base growth

2020 2021 2022 2023

$1.4

$1.2(b)Future annual capital expenditures forecasted to be between $1.2 billion and $1.4 billion.(a)

(a) Balancing customer affordability with customer focused investment opportunities.(b) Includes $1.1 billion capital expenditures and $0.1 billion for impacts of DAEC PPA termination

$1.3 $1.4

Our economic development efforts

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Hydroponic tomato growing facilityMason City, IA

Expand bean product lineFort Madison, IA

Probiotic solutions facilityDe Forest, WI

Beaver Dam Commerce Park520 contiguous acresOne of the largest available business properties in WI

Big Cedar Industrial Center1,391 contiguous acresFirst certified Mega Site in IA

In 2019…

16Growth Sites

44New industrial, warehouse

and office projects

$1.2 BCorporate facility investment

2,632Jobs Created

CWPCo - Consolidated Water Power Company new WPL customer starting in 2021

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Financing and Regulatory matters

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2020 Financing plansLong-Term Debt

IPL WPL AEF

(in millions) Amount Coupon Amount Coupon Amount Coupon

Issuances up to $300 up to $350 up to $300Maturities ($200) 3.65% ($150) 4.60% ($300) ~2.20%

Common Equity

Issuance Methodup to $225 Forward Sale Agreements of 4.3 million shares initially priced at $52.235 per share

~$25 Shareowner Direct Plan

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Key regulatory initiativesInterstate Power and Light Company Estimated dates

Iowa Utilities Board• Decision regarding IPL Retail Base Rate Review (historical test year 2018 for electric and a future forecasted 2020 test

period for electric (RPU-2019-0001) and gas (RPU-2019-0002))

Federal Energy Regulatory Commission (FERC)• Rehearing request decision regarding authorized return on equity (ROE) amounts for MISO transmission owners (ITC) H2 2020

Wisconsin Power and Light Company Estimated datesPublic Service Commission of Wisconsin

• Decision regarding 2020 WPL retail electric fuel only rate review

• File certificate of authority request for solar generation H1 2020

• File retail electric and gas 2021-2022 Test Period Rate Review Q2 2020

• Decision regarding construction authority for Western WI Pipeline (6680-CG-168) H1 2020

FERC• Rehearing request decision regarding authorized ROE amounts for MISO transmission owners (ATC) H2 2020

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Appendix

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Reconciliation between GAAP and non-GAAP EPS2015 2016 2017 2018 2019

GAAP EPS from continuing operations $1.69 $1.65 $1.99 $2.19 $2.33

• Temperature impacts 0.04 0.06 (0.06) (0.05)

Non-GAAP Adjustments:

• Losses from sales of Minnesota distribution assets 0.04

• Voluntary employee separation charges 0.02

• Valuation charge related to the Franklin County Wind Farm 0.23

• Tax reform (0.08) (0.02)

• Net write-down of regulatory assets due to IPL electric rate review settlement 0.02

• American Transmission Company Holdings return on equity reserve adjustment (0.02)

Non-GAAP temperature normalized EPS from continuing operations $1.79 $1.88 $1.99 $2.11 $2.26