Slide 1: Q1 2026 Investor Deck
Q1 2026 INVESTOR DECK SOTTERTAIL W CORPORATION
Slide 2: Forward-Looking Statement
Forward-Looking Statement Except for historical information contained here, the statements in this presentation are forward-looking and made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. The words “anticipate,” “believe,” “can,” “confident,” “could,”
Slide 3: Otter Tail Corporation: Investment Thesis
Otter Tail Corporation Diversified, growing and delivering value Investment Thesis ELECTRIC MANUFACTURING Best in class utility: 01 EPS growth rate of 10% Founded in 1907 Owned and operated for over 20 years Serve approximately 134,000 customers in Diverse end-markets Strategic diversification: MN,
Slide 4: Vision & Mission
Vision & Mission Executing Our Vision Build top performing companies in a diversified organization with an electric utility as the foundation Mission Deliver value by building strong electric utility and manufacturing platforms 1 For our shareholders we deliver above average returns through commerci
Slide 5: Balanced Income and Growth Model
Balanced Income and Growth Model Strategic Diversification Electric platform has significant rate base growth plan, and our manufacturing platform generates incremental cash to help fund the plan To navigate long-term cycles and consistently achieve targeted 10-12% TSR ELECTRIC MANUFACTURING Deliver
Slide 6: Financial Performance Underpinned by Consistent, High-Performing Electric Utility
Financial Performance Underpinned by Consistent, High-Performing Electric Utility Electric Diluted Earnings Per Share 6% CAGR 7% CAGR $2.32 $2.16 Electric utility is our foundational $2.01 $1.91 business $1.73 $1.63 $1.48 Electric EPS growth rate is expected to $1.29 $1.36 $1.28 $1.24 approximate ra
Slide 7: Balanced Growth Driving Returns over Long-Term Cycles
Balanced Growth Driving Returns over Long-Term Cycles Our diversification has enabled us to produce a higher ROE than our utility peers over the long-term Since 1994, Otter Tail’s strategic diversification and capital efficiency has resulted in an ROE of 12.1%, greater than the broader Utility 19.3%
Slide 8: Attractive Long-Term TSR Algorithm
Attractive Long-Term TSR Algorithm Earnings drivers in Electric 7-9% long-term EPS growth1 and Manufacturing Sales growth ELECTRIC Incremental cash flow to fund growth 10-12% without the need for raising equity Rate base growth Load growth Operational, commercial and talent excellence TSR Efficiency
Slide 9: Otter Tail Power Company: Delivering Consistent Earnings Growth
Otter Tail Power Company: Delivering Consistent Earnings Growth 9
Slide 10: Otter Tail Power Company
Otter Tail Power Company Regulated and vertically integrated electric utility Constructive regulatory jurisdictions Low-cost generation resources Providing some of the lowest rates in the nation Serving approximately 134,000 customers across 70,000 square miles 5-year capital spending plan: $1.9B1 T
Slide 11: Rate Base Summary
Rate Base Summary Rate Base by Jurisdiction1 10% Jurisdiction Allowed ROE 8% Minnesota 9.48% 45% North Dakota 10.10% South Dakota 8.75% 37% FERC 10.48% Weighted Average 9.75% Minnesota North Dakota South Dakota FERC 1 The percentages are approximations as the jurisdictions have differing methodologi
Slide 12: Rate Base Growth
Rate Base Growth Long history of delivering… … and a clear path forward 10% Planned CAGR 2025-2030 $3.3B $3.4B $3.1B $2.8B $2.4B $2.1B $1.9B $1.7B $1.6B $1.6B $1.4B 2020 2021 2022 2023 2024 2025 2026(F) 2027(F) 2028(F) 2029(F) 2030(F) Otter Tail Power has proven track record of converting rate base
Slide 13: Renewable Generation and Storage Investments
Renewable Generation and Storage Investments Levers to support affordability as we transition: Solway Solar Abercrombie Solar Hoot Lake Battery Tax credits $80M capital investment $450M capital investment $120M capital investment Reducing energy costs Est completion date: Est completion date: Est co
Slide 14: Regional Transmission Investment
Regional Transmission Investment Projects intended to MISO1 LRTP2 MISO1 LRTP2 JTIQ3,4 enhance grid Tranche 1 Tranche 2.13 reliability Est. $475M Est. $800M - $1B Est. $450M - $500M capital investment Expect projects to have capital investment capital investment very limited impact on Otter Tail Powe
Slide 15: Balanced Energy Transition
Balanced Energy Transition Focus on reliability and affordability while transitioning to cleaner energy Energy Transition CO2 Reduction Target: Reduction in CO2 Generation Capacity 90% from Electric Generation by 2050 2005 534 11736 687 MW Electric Generation Scope 1 CO2 Emissions In millions of met
Slide 16: Load Growth Opportunities
Load Growth Opportunities Phases to Secure Large Load Existing Opportunity1 Well positioned to attract large loads • Locations identified with minimal delivery costs to site Letter of • Attractive service territory – low market energy prices 1 540 MW Intent and high renewable production Load growth
Slide 17: Constructive Regulatory Environment
Constructive Regulatory Environment Investment to support safe & reliable electric service Otter Tail Power’s jurisdictions are rated as Constructive or Neutral 1 MN Average/2 Track record Constructive ND Average/1 of timely regulatory SD Average/2 recovery jurisdictions We anticipate to recover ~ 9
Slide 18: Rate Case Activity
Rate Case Activity Minnesota South Dakota Docket 25-359 Docket EL25-022 Filed in October 2025 Filed in June 2025 • Last rate request filed in 2020 • Last rate request filed in 2018 • Requested: • Requested: • Net revenue increase of $44.8M (17.7% increase) • Net revenue increase of $5.7M (12.5% incr
Slide 19: Customer Rates and Affordability
Customer Rates and Affordability Proven Track Record Looking Ahead Our Electric Rates Compared to Regional and National Averages1 5-Year 2021 2022 2023 2024 2025 CAGR Rate Base Growth 10% Affordability enablers: -12% -14% -15% -16% MISO system-wide recovery 3 - 4% -19% -23% -23% Renewable energy tax
Slide 20: Driving Operational and Commercial Excellence in Electric
Strong Foundation: Vertical integration of generation, transmission and distribution: Driving Operational • • enables efficiency, cost control, and Commercial • compelling customer offering Excellence in Electric Levers for Excellence: Actions across the organization A strong foundation and • Prepar
Slide 21: Financial and Operational Targets
Financial and Operational Targets Electric platform Convert rate base Deliver attractive Achieved Delivering ROE to contribute growth to earnings rate base growth; customer 70% growth near a target affordability of consolidated 1:1 10% to approximate allowed ROE through balanced approach earnings ra
Slide 22: Electric Operations: Key takeaways
Electric Operations: Key takeaways Otter Tail Power Company positioned to deliver value to customers AND investors through long-term cycles 3 Proven track record of strong rate base growth (converting to earnings near a 1:1 ratio) and clear path to significant future rate base expansion 2 Strategica
Slide 23: Manufacturing Operations: Consistently Accretive Returns
Manufacturing Operations: Consistently Accretive Returns 23
Slide 24: Robust Manufacturing Platform
Robust Manufacturing Platform MANUFACTURING PLATFORM Manufacturing Segment Plastics Segment Providing metal Delivering Manufactures PVC pipe for municipal fabrication for custom thermoformed water, rural water, wastewater, storm machine parts and plastic products and drainage systems and other uses
Slide 25: Delivering Consistently Accretive Returns
Delivering Consistently Accretive Returns Manufacturing Platform ROE has been consistently Significant growth in sales and net income within accretive to the Otter Tail’s consolidated return the Manufacturing Platform since 2005 73% Sales Net Income 5.2% 12.1% 58% 61% 58% CAGR CAGR $737.3M $181.9M 5
Slide 26: Underpinned By Competitive Advantages Across Manufacturing Platform
Underpinned By Competitive Advantages Across Manufacturing Platform Manufacturing Segment Plastics Segment Serving diversified end markets High-quality customer service in highly-regulated industry With high value, custom products and solutions Responsive and reliable, with inventory management Prov
Slide 27: Serving Diversified Markets: Manufacturing Segment
Serving Diversified Markets: Manufacturing Segment Servicing wide array of customers 6% 8% 8% Other 15% Horticulture 12% Lawn & Garden Industrial 20% Agriculture Construction Rec. Vehicle 31% 2025 Located where our Expanding in Southeast US to Defensive positions growing with well established world-
Slide 28: Serving Diversified Markets: Plastics Segment
Serving Diversified Markets: Plastics Segment End markets served1: 90% Municipal 5% Residential / Commercial 5% Rural Water With over 200 distribution customers including 1 Reflects approximated long-term averages 28
Slide 29: Positive Long-Term Trajectory for Serviced Markets
Positive Long-Term Trajectory for Serviced Markets Manufacturing Segment Plastics Segment Reshoring of manufacturing Housing shortage Outsourcing trends by OEMs Infrastructure upgrade Housing shortage and replacement Power demand growth Water availability and transport Serving end markets with long-
Slide 30: Driving Organic Growth in Manufacturing
Efficiency gains through continuous improvement Driving Organic Growth in Manufacturing Growth with existing customers Strategic expansion projects 30
Slide 31: Delivering Growth at BTD Georgia
Delivering Growth at BTD Georgia Attractive opportunity within Southeast region unlocking up to $35M incremental sales opportunity and supporting long-term growth outlook FOCUSED ON: Facility expansion + implementing automation Expansion of BTD’s facility in Georgia creates new opportunities for BTD
Slide 32: Driving Growth in Plastics
Driving Growth in Plastics Multi-phased expansion project at Vinyltech in Phoenix, AZ PHASE 1 PHASE 2 Expanded facility Adding additional line Added large-diameter pipe Est. completion date: production capabilities early 2026 ON TIME ON BUDGET Delivering • Increasing Plastics segment nameplate produ
Slide 33: Historical and Estimated Long-Term Plastics Earnings Profile
Historical and Estimated Long-Term Plastics Earnings Profile Historical Average Sales Price of PVC Pipe1 Sales Price Decline Drives Earnings Normalization Dynamic market conditions $195M $201M contributed to significant $188M increase in PVC pipe prices $170M beginning in 2021 PVC pipe prices have $
Slide 34: Driving Operational and Commercial Excellence in Manufacturing
Driving Operational and Commercial Excellence in Manufacturing Engineering Agile Continuous & production operations improvement competency Excellence in Action Safety Reliability Project execution Efficiency 2025 total recordable incident rate Heavy focus placed on on-time BTD Georgia and Vinyltech
Slide 35: Manufacturing Financial and Operational Targets
Manufacturing Financial and Operational Targets Drive organic Manufacturing Free Consistently achieve Ongoing platform to cash flow accretive growth with efficiency contribute positive returns gains and 30% existing customers production reliability of consolidated earnings Maintain historical track
Slide 36: Manufacturing Operations: Key takeaways
Manufacturing Operations: Key takeaways Manufacturing set to continue driving ongoing accretive returns and incremental cash flow 3 Attractive growth opportunities across all business areas of Manufacturing 2 Defensive market positions – growing with well-established customers 1 Core competency in e
Slide 37: Financial Section
OTTERTAIL CORPORATION Financial Section 37
Slide 38: Attractive Long-Term TSR Algorithm
Attractive Long-Term TSR Algorithm Earnings drivers in Electric 7-9% long-term EPS growth1 and Manufacturing Sales growth ELECTRIC Incremental cash flow to fund growth 10-12% without the need for raising equity Rate base growth Load growth Operational, commercial and talent excellence TSR Efficiency
Slide 39: 2026 Outlook
2026 Outlook Actual 2026 Guidance Diluted EPS 2024 2025 Low High Electric $2.16 $2.32 $2.61 $2.69 Manufacturing 0.33 0.27 0.26 0.32 Plastics 4.77 4.05 2.49 2.71 Corporate (0.09) (0.09) (0.14) (0.10) Total $7.17 $6.55 $5.22 $5.62 Return on equity 19.3% 15.6% 11.5% 12.3% 39
Slide 40: Capital Allocation Priorities
Capital Allocation Priorities Focused on driving organic growth and consistent shareholder returns 01 02 03 04 Investment in Cash returns to Opportunistic Opportunistic returns the business shareholders M&A to shareholders $2.0B capex planned Target 50-60% long- Electric: focused on Via share repurc
Slide 41: Capital Expenditures
Capital Expenditures Customer-focused capital investment plan Capital Investments 2026 2027 2028 2029 2030 Total In millions Electric $750M Incremental investment Renewable Generation and Storage $ 251 $ 295 $ 89 $ 4 $ 6 $ 645 opportunity for Electric Disciplined Transmission 80 167 167 186 255 855
Slide 42: Dividend – A Key Part of Our TSR
Dividend – A Key Part of Our TSR Dividend Growth & Payout Ratio 8% CAGR $2.31 $2.10 $1.87 $1.75 $1.65 $1.56 $1.48 87 consecutive years of $1.34 $1.40 $1.25 $1.28 dividend payments Indicated dividend for 2026: Dividend payout ratio impacted by exceptional Plastics $2.31 (10.0% increase) segment finan
Slide 43: Balance Sheet Capable of Supporting Long-Term Strategy
Balance Sheet Capable of Supporting Long-Term Strategy Total available liquidity of 30.0% Consolidated Capital Structure and ROE 120.0% $706 million Strong 100.0% 2025 FFO/Debt 25.0% 22.1% balance Consolidated: ~ 55% 19.2% 25.6% 38.6% 37.8% 37.2% sheet: Otter Tail Power: ~ 18% 20.0% 46.3% 40.6% 80.0
Slide 44: Financing Plan
Financing Plan No external equity needs through at least 2030 Five-Year Financing Plan 5 Year $ in millions 2026 2027-30 Total LONG-TERM DEBT Financing plan Otter Tail Power Company supports utility Issuances $ 145 $ 620 $ 765 investments with Retirements - (162) (162) no external equity needs over
Slide 45: Well Balanced Debt Maturity Schedule
Well Balanced Debt Maturity Schedule Weighted average interest rate: 4.53% $100M $100M $90M $90M $80M $70M $64M $60M $60M $50M $50M $50M $50M $42M $40M $26M $15M $10M 2026 2027 2029 2030 2031 2034 2035 2037 2039 2040 2044 2048 2049 2050 2051 2052 2054 2055 Otter Tail Corporation Otter Tail Power 45
Slide 46: Investment Targets
Investment Targets Total Shareholder Return: 10-12% Key underlying assumptions Long-term EPS growth • Electric segment long-term EPS Dividend yield: ~ 3% growth rate approximates rate rate: 7-9% (2028 base year) base CAGR • Plastics segment earnings of Dividend Growth Rate: 6-8% $45M-$50M in 2028 Ta
Slide 47: Investor Relations Contacts
Investor Relations Contacts Beth Eiken Tyler Nelson Manager of Investor Relations Vice President of Finance and Treasurer beiken@ottertail.com tnelson@ottertail.com 47
Slide 48: Appendix
OTTERTAIL CORPORATION
Slide 49: Financial Performance
Financial Performance Annual Diluted EPS $7.17 $0.16 $(0.06) $- $6.55 $(0.72) 2024 Electric Manufacturing Plastics Corporate 2025 49
Slide 50: Otter Tail Power Regulatory Framework
Otter Tail Power Regulatory Framework Jurisdiction Minnesota North Dakota South Dakota Utility Commissioners Appointed Elected Elected Rate Case Test Year Future Future Historical1 Allowed Return on Equity 9.48% 10.10% 8.75% Earnings Sharing Mechanism No Yes2 Yes3 Rider Recovery for: Renewable Gener
Slide 51: Manufacturing Segment Products
Manufacturing Segment Products 51
Slide 52: Plastics Segment Products
Plastics Segment Products 52
Slide 53: Senior Management Team
Senior Management Team Chuck MacFarlane, President and CEO • Years in role: 11 • Years with the company: 24 Todd Wahlund, Vice President and CFO • Years in role: 2 • Years with the company: 33 Tim Rogelstad, Senior Vice President, Electric Platform • Years in role: 12 • Years with the company: 37 Jo
Slide 54: Board of Directors
Board of Directors Christopher Clark Jeanne Crain John Erickson Steven Fritze Dr. Kathryn Johnson Dr. Michael LeBeau Audit Committee; Corporate Audit Committee; Chair of Audit Committee; Compensation and Human Compensation and Human Capital Governance Committee Compensation and Human Corporate Capit