Slide 1: Q4 2025 Earnings Conference Call
Q4 2025 Earnings Conference Call
Slide 2: Safe Harbor
Safe Harbor 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,” “
Slide 3: Company Overview
Company Overview Investment Thesis ELECTRIC MANUFACTURING Best in class utility: 1 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, ND, SD 2 Enhances consolidated ROE High utilizati
Slide 4: Key Highlights
Key Highlights Financial Results • Produced diluted EPS of $6.55, on upper end of guidance range • ROE of 16% on an equity layer of 63% Positioned for Future Growth • Interim rates went into effect in South Dakota • Obtained approval of interim rates in Minnesota • Phase 2 of Vinyltech expansion pro
Slide 5: Financial Summary
Financial Summary $ in millions, except per share data Quarter-to-Date Year-to-Date Net Income Diluted EPS Net Income Diluted EPS -5% -9% $54.8 $7.17 $51.8 $1.30 $1.23 $6.55 $301.7 $275.9 Q4 2024 Q4 2025 Q4 2024 Q4 2025 2024 2025 2024 2025 2026 EPS Guidance Midpoint: $5.42 5
Slide 6: Electric Platform
OTTERTAIL CORPORATION Electric Platform y Orenian POWER COMPANY
Slide 7: Minnesota Rate Case
Minnesota Rate Case Docket 25-359 • Last rate request filed in 2020 Request Filed with the Minnesota Public • Interim rate revenue of $28.6 million Utilities Commission went into effect January 1, 2026, October 2025 subject to refund • Procedural schedule: Net revenue ROE: Equity layer: increase: •
Slide 8: South Dakota Rate Case
South Dakota Rate Case Docket EL25-022 Request Filed with the South Dakota • Last rate request filed in 2018 Public Utilities Commission June 2025 • Interim rate revenue of $5.7 million went into effect December 1, 2025, Net revenue subject to refund ROE: Equity layer: increase: $5.7M 10.8% 53.54% •
Slide 9: Rate Base Investment Plan
Rate Base Investment Plan Significant Rate Base Growth $ in billions 10% CAGR $3.26 $3.42 1:1 $3.11 Conversion of rate base growth into Electric EPS growth $2.77 $2.40 ~ 90% $2.11 of our capital investment is expected to be recovered through riders and existing rates 2025 (A) 2026 (F) 2027 (F) 2028
Slide 10: Generation and Storage Project Updates
Generation and Storage Project Updates Wind Solway Abercrombie Hoot Lake Repowering Solar Solar Battery Est. investment: Est. investment: Est. investment: Est. investment: $230M $80M $450M $120M Est. completion date: Est. completion date: Est. completion date: Est. completion date: Substantially com
Slide 11: Transmission Project Updates
Transmission Project Updates MISO LRTP1 MISO LRTP Tranche 1 Tranche 2.1 JTIQ2 Est. investment: Est. investment: Est. investment: $475M $800M - $1B $450M - $500M Est. completion date: Est. completion date: Est. completion date: 2030 2034 2034 Recovery mechanism: Recovery mechanism: Recovery mechanism
Slide 12: Load Growth Opportunities
Load Growth Opportunities Phases to Secure Large Load Existing Opportunity Well positioned to attract large loads • Attractive service territory - low market energy prices Letter of and high renewable production 1 540 MW Intent • Locations identified with minimal delivery costs to site Load growth o
Slide 13: 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% (12)% Affordability enablers: (15)% (14)% (16)% MISO system-wide recovery 3 - 4% (19)% Renewable energy tax cred
Slide 14: Manufacturing Platform
OTTERTAIL CORPORATION Manufacturing Platform BTD TO. PLASTICS rorthernipe products 14
Slide 15: Industry Conditions: Manufacturing
Industry Conditions: Manufacturing BTD Manufacturing and T.O. Plastics Industries Served Industry Conditions Recreational Vehicle End market demand negatively impacted by: Lawn & Garden • Elevated levels of new and used Construction inventory at dealer level, specifically within lawn & garden and ag
Slide 16: Plastics Pricing and Volume Trends
Plastics Pricing and Volume Trends Northern Pipe Products and Vinyltech Corporation Historical Average Sales Price of PVC Pipe1 2025 Year-Over-Year Trends1 Q4 Full Year Average Sales Prices ↓ 20% ↓ 15% PVC pipe prices have steadily declined since late 2022 Sales Volumes ↑ 4% ↑ 8% Material Input Cost
Slide 17: Expansion Projects
Expansion Projects Positioned for Long-Term Growth Vinyltech Corporation • Completion dates: • Phase 1 - Q4 2024 • Phase 2 - early 2026 • Multi-phase expansion project, increasing nameplate production capacity (including large-diameter pipe) and resin and pipe storage • Plastics segment production c
Slide 18: Financial Results
CORPORATION OTTERTAIL
Slide 19: Annual Diluted EPS
Annual Diluted EPS $7.17 $0.16 $(0.06) $— $6.55 $(0.72) 2024 Electric Manufacturing Plastics Corporate 2025 19
Slide 20: Annual Diluted EPS: Electric and Manufacturing Detail
Annual Diluted EPS Segment Level Detail $0.12 $0.11 $0.14 $0.10 $2.32 $2.16 $(0.14) $(0.10) $(0.07) Electric 2024 Sales Weather Electric Rates O&M Depreciation Interest Other 2025 Volume & Rider Expense Expense Expense Revenue $0.33 $0.08 Manufacturing $0.27 $(0.03) $(0.04) $(0.02) $(0.04) $(0.01) 2
Slide 21: Annual Diluted EPS: Plastics and Corporate Detail
Annual Diluted EPS Segment Level Detail $0.42 $4.77 $0.35 $4.05 $(0.07) $(0.02) $(0.03) $(1.37) Plastics 2024 Sales Product Material Other SG&A Depreciation 2025 Volume Pricing Cost Manufacturing Expense Expense Costs Corporate $(0.09) $(0.04) $(0.09) $0.01 $0.03 2024 SG&A Investment Income Tax 2025
Slide 22: Balance Sheet
Balance Sheet $ in millions Capital Structure and ROE Line of Credit Availability Cash and Cash Equivalents with comparison to EEI Peers 1 37% 59% $149 15.6% Available $386 9.9% $170 Available $71 63% 41% Outstanding Otter Tail Corporation EEI Otter Tail Corporation Otter Tail Power 12/31/25 Equity
Slide 23: 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 % 23
Slide 24: Capital Expenditures
Capital Expenditures Customer-Focused Capital Investment Plan 2026 2027 2028 2029 2030 Total in millions $750M Electric Incremental investment opportunity for Electric Renewable Generation and Storage $ 251 $ 295 $ 89 $ 4 $ 6 $ 645 Disciplined Transmission capital 80 167 167 186 255 855 Driven by: d
Slide 25: Financing Plan
Financing Plan No external equity needs through at least 2030 $ in millions 2026 2027 - 2030 5YR Total Long-Term Debt Financing plan Otter Tail Power Company Disciplined supports utility Issuances $ 145 $ 620 $ 765 capital investments Retirements (162) (162) deployment without Otter Tail focused on:
Slide 26: Long-Term Plastics Earnings Profile
Long-Term Plastics Earnings Profile Northern Pipe Products and Vinyltech Corporation $ in millions $195 $201 $188 $170 $110 $98 $45$48 - $50 $24 2018 - 2020 2021 2022 2023 2024 2025 2026 (F) Continued Sales Inflationary 2028 (F) Average product volume increase price increase in input declines costs
Slide 27: 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 28: Appendix
OTTERTAIL CORPORATION Appendix
Slide 29: QTD Diluted EPS
QTD Diluted EPS $0.07 $0.12 $1.30 $1.23 $(0.20) $(0.06) Q4 2024 Electric Manufacturing Plastics Corporate Q4 2025 29
Slide 30: QTD Diluted EPS: Electric and Manufacturing Detail
QTD Diluted EPS Segment Level Detail $0.12 $0.06 $0.63 $0.03 $0.03 $(0.03) Electric $0.51 $(0.03) $(0.06) Q4 Sales Weather Electric Rates O&M Depreciation Interest Other Q4 2024 Volume & Rider Expense Expense Expense 2025 Revenue Manufacturing $0.06 $0.05 $0.01 $0.06 $(0.05) $(0.01) Q4 Sales Product
Slide 31: QTD Diluted EPS: Plastics and Corporate Detail
QTD Diluted EPS Segment Level Detail $0.92 $0.05 Plastics $0.11 $0.72 $(0.02) $(0.34) Q4 Sales Product Material Other Q4 2024 Volume Pricing Cost Manufacturing Costs 2025 Corporate $(0.09) $(0.18) $(0.12) $0.01 $0.02 Q4 SG&A Investment Income Tax Q4 2024 Expense Income Benefit & Other 2025 31
Slide 32: Dividend and Payout Ratio
Dividend and Payout Ratio 8% CAGR $2.31 $2.10 $1.87 $1.75 $1.56 $1.65 87 consecutive years of $1.40 $1.48 dividend payments $1.34 $1.25 $1.28 Indicated dividend for 2026: $2.31 (10.0% increase) Dividend payout ratio impacted by exceptional Plastics segment financial results driving a lower ratio 78%
Slide 33: Debt Maturity Schedule
Debt Maturity Schedule Weighted average interest rate: 4.53% $100 $100 $90 $90 $80 $70 $64 $60 $60 $50 $50 $50 $50 $42 $40 $26 $15 $10 2026 2027 // 2029 2030 2031 // 2034 2035 // 2037 // 2039 2040 // 2044 // 2048 2049 2050 2051 2052 // 2054 2055 Otter Tail Corporation Otter Tail Power 33
Slide 34: 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 Disciplined Rider Recovery for: cap