Slide 1: Q4 2025 Investor Deck
Q4 2025 INVESTOR DECK SOTTERTAIL CORPORATION
Slide 2: Forward-Looking Statement
Forward-Looking Statement Except for historical information contained here, the statements in this release 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,” “est
Slide 3: Otter Tail Corporation: Diversified, growing and delivering value
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 Growth and Income Model
Balanced Growth and Income 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: 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 7: Track Record of Consistent Results
Track Record of Consistent Results Attractive ROE with defensive balance sheet EPS Growth Consolidated Capital Structure and ROE 30.0% 120.0% $7.00 $7.17 $6.78 22.6% 25.0% 22.1% 100.0% $6.47 25.6% Consolidated EPS 19.2% 36.3% (5YR CAGR) 20.0% 40.6% 38.6% 37.8% 80.0% 49.3% 46.3% 19.3% $4.23 15.0% 60.
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 without the need for raising equity Rate base growth Load growth Operational, commercial and talent excellence 10-12% Efficiency MAN
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 CANADA Regulated and vertically integrated electric utility Langdon Wind Energy Center MN Luverne Wind Farm Solway Constructive regulatory jurisdictions Coyote Station Ashtabula Wind Energy Center Combustion Turbine Low-cost generation resources Blue Jay Solar Blue Heron Sol
Slide 11: Rate Base Growth
Rate Base Growth Long history of delivering… … and a clear path forward 10% Planned CAGR 2025-2030 $3.4B $3.2B $3.0B $2.7B $2.4B $2.1B $1.9B $1.7B $1.6B $1.6B $1.4B $1.2B 2019 2020 2021 2022 2023 2024 2025(F) 2026(F) 2027(F) 2028(F) 2029(F) 2030(F) Otter Tail Power has proven track record of convert
Slide 12: Investing in Renewable Generation & Storage to Support a Clean Energy Future
Investing in Renewable Generation & Storage to Support a Clean Energy Future Levers to support affordability as we transition: Wind Repowering Integrated Resource Solar Development1 Plan Investments Tax credits $230M capital investment Est. $530M capital Up to 500 MW of new investment renewable gene
Slide 13: Changing Energy Mix Supports Reliability, Affordability and Significantly Lower Emissions
Changing Energy Mix Supports Reliability, Affordability and Significantly Lower Emissions Otter Tail Power Energy Resource Mix As a result of our changing energy mix, we are targeting reduced emissions 4% By 2030, We are Targeting 8% 3% 8% 23% 2% Of owned and contracted Reduction in carbon 9% 43% 55
Slide 14: Transmission Investment Priorities
Transmission Investment Priorities Projects intended to MISO1 LRTP2 MISO1 LRTP2 JTIQ3,4 help support grid Tranche 1 Tranche 2.13 reliability Est. $475M capital Est. $700M capital Est. $450M capital investment investment investment Expect projects to have very limited impact on Otter Tail Power custo
Slide 15: Load Growth Opportunities
Load Growth Opportunities Phases to Secure Large Load Well positioned to attract large loads Existing Opportunity • Approved tariffs in place • Locations identified with minimal delivery costs to Letter of site 1 540 MW Intent • Attractive service territory – low market energy prices and high renewa
Slide 16: Constructive Regulatory Environment
Constructive Regulatory Environment Investment to support safe & reliable electric service Otter Tail’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 ~ 90% of
Slide 17: Focus on Affordability During Growth
Focus on Affordability During Growth Investing to ensure: Ensuring affordability: Safe; Through • Renewable tax credits Reliable; Some of • MISO system wide recovery Efficient; and Increasingly clean electric Rate base growth + the lowest rates in the nation • Reduced energy costs • Technology enabl
Slide 18: Delivering Affordability for Customers
Delivering Affordability for Customers 20 Average Summer Residential Rate in Cents per kWh1 18 16.5 15.7 United States 16 14.6 13.6 13.8 14 13.1 13.1 Regional 12.7 12.4 11.7 12 11.6 11.3 11.2 10 10.5 10.2 8 2020 2021 2022 2023 2024 Otter Tail Power’s 16% below 30% below regional average national ave
Slide 19: Driving Operational and Commercial Excellence in Electric
Strong Foundation: Vertical integration of generation, transmission and distribution: • enables efficiency, Driving Operational • cost control, • compelling customer offering and Commercial Excellence in Electric Levers for Excellence: Actions across the organization A strong foundation and • Prepar
Slide 20: Financial and Operational Targets
Financial and Operational Targets Electric platform Convert rate base Deliver attractive Achieved Delivering to contribute growth to earnings rate base growth; customer growth near a target ROE 70% affordability of consolidated 1:1 10% to approximate allowed ROE through balanced investment and earni
Slide 21: Electric Operations: Key takeaways
Electric Operations: Key takeaways Otter Tail Power Company positioned to deliver value to customers AND investors through long-term cycles Proven track record of strong rate base growth 3 (converting to earnings at 1:1 ratio) and clear path to significant future rate base expansion 2 Strategically
Slide 22: Manufacturing Operations: Consistently Accretive Returns
Manufacturing Operations: Consistently Accretive Returns 22
Slide 23: Robust Manufacturing Platform
Robust Manufacturing Platform MANUFACTURING PLATFORM Manufacturing Segment Plastics Segment Providing metal Delivering custom Manufactures PVC pipe for municipal fabrication for custom thermoformed water, rural water, wastewater, storm machine parts and plastic products and drainage systems and othe
Slide 24: 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 group’s returns the Manufacturing Platform since 2005 73% Sales Net Income 6.0% 13.7% 58% 61% 58% $806.0M $214.4M CAGR CAGR 3.4% CA
Slide 25: 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 26: Serving Diversified Markets: Manufacturing Segment
Serving Diversified Markets: Manufacturing Segment Servicing wide array of customers 4% 7% 10% 13% Other Horticulture 15% Lawn & Garden Industrial 19% Agriculture Construction Rec. Vehicle 32% 2024 Located where our Expanding in Southeast US to Defensive positions growing with well established world
Slide 27: 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 27
Slide 28: 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 29: Driving Organic Growth in Manufacturing
Efficiency gains through continuous improvement Driving Organic Growth in Manufacturing Growth with existing customers Expansion projects in AZ and GA 29
Slide 30: 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 31: 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 production capa
Slide 32: Understanding the Normalization of Plastic Profits
Understanding the Normalization of Plastic Profits Historical Sales Price of PVC Pipe Sales Price Decline Drives Earnings Normalization Dynamic market conditions contributed to significant $195M $201M $188M increase in PVC pipe prices beginning in 2021 $167M PVC pipe prices have steadily declined $9
Slide 33: 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 2024 total recordable incident rate Heavy focus placed on on-time Expansion projects are pro
Slide 34: Manufacturing Financial and Operational Targets
Manufacturing Financial and Operational Targets Manufacturing Free Consistently achieve Ongoing Drive organic platform to cash flow contribute accretive growth with efficiency positive returns gains and 30% existing customers production reliability of consolidated earnings Maintain historical track
Slide 35: 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 36: Financial Section
OTTERTAIL CORPORATION Financial Section
Slide 37: 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 without the need for raising equity Rate base growth Load growth Operational, commercial and talent excellence 10-12% Efficiency MAN
Slide 38: 2025 Outlook
2025 Outlook Actual 2025 Guidance November 3, 2025 Diluted EPS 2023 2024 Low High Electric $2.01 $2.16 $2.31 $2.35 Manufacturing 0.51 0.33 0.22 0.26 Plastics 4.47 4.77 3.86 4.05 Corporate 0.01 (0.09) (0.07) (0.04) Total $7.00 $7.17 $6.32 $6.62 Return on equity 22.1% 19.3% 15.1% 15.7% 38
Slide 39: 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 40: Capital Expenditures
Capital Expenditures Customer-focused capital investment plan Capital Investments 2026 (F) 2027 (F) 2028 (F) 2029 (F) 2030 (F) Total In millions 2026 -2030 (F) $350M Electric Incremental investment Renewable Generation $ 169 $ 177 $ 154 $ 4 $ 6 $ 510 opportunity for Electric Disciplined Transmission
Slide 41: Dividend – A Key Part of Our TSR
Dividend – A Key Part of Our TSR Dividend Growth & Payout Ratio 7% CAGR $2.10 $1.87 $1.75 $1.65 $1.48 $1.56 86 consecutive years of $1.34 $1.40 dividend payments $1.25 $1.28 Indicated dividend for 2025: $2.10 (12.3% increase) Dividend payout ratio impacted by exceptional Plastics segment financial r
Slide 42: Strong Balance Sheet Supports Long-Term Strategy
Strong Balance Sheet Supports Long-Term Strategy Five-Year Financing Plan Equity ratio 64% 5 Year 2026 (F) 2027-30 (F) Strong ~ $325 million of cash and $ in millions Total LONG-TERM DEBT balance cash equivalents Otter Tail Power Company sheet: Parent company debt <10% of total debt Issuances $ 120
Slide 43: 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 43
Slide 44: 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 45: 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 45
Slide 46: Appendix
SOTTERTAIL CORPORATION
Slide 47: Financial Performance
Financial Performance YTD Diluted EPS $5.87 $0.04 $(0.13) $0.06 $5.32 $(0.52) 2024 Electric Manufacturing Plastics Corporate 2025 47
Slide 48: 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 49: Manufacturing Segment Products
Manufacturing Segment Products
Slide 50: Plastics Segment Products
Plastics Segment Products northern pipe products VINYLTECH MT! PVCePIPE OTTERTAIL CORPORATION
Slide 51: Senior Management Team
Senior Management Team Chuck MacFarlane Todd Wahlund Tim Rogelstad John Abbott Jennifer Smestad President and CEO Vice President and CFO Senior Vice President, Senior Vice President, Senior Vice President, Years in Role: 10 Years in Role: 1 Electric Platform Manufacturing Platform General Counsel an
Slide 52: Board of Directors
Board of Directors Jeanne Crain John Erickson Steven Fritze Dr. Kathryn Johnson Dr. Michael LeBeau Audit Committee; Chair of Audit Committee; Compensation and Human Compensation and Human Capital Compensation and Human Corporate Capital Management Management Committee; Capital Management Governance