NorthWestern Energy : Wells Fargo Energy and Power Symposium 2025 – marketscreener.com

8-K Date: December 09, 2025 Lone Peak – Big Sky, Montana

NorthWestern Energy

NorthWestern Energy Group, Inc.

dba: NorthWestern Energy Ticker: NWE (Nasdaq)

3 https://www.northwesternenergy.com

Corporate Support Office 3010 West 69th Street Sioux Falls, SD 57108 (605) 978-2900

Director – Corporate Development & Investor Relations Officer

Travis Meyer 605-978-2967

travis.meyer@northwestern.com

Recent Highlights

• Received Montana PSC approval of our 2025 Wildfire Mitigation Plan
  

• Year-to-Date September GAAP diluted EPS of $2.22 vs. $2.34 prior
  

• 
  Affirming 2025 earnings guidance range of $3.53 – $3.652
• 
  Integrated Energy West natural gas assets, customers, and employees
  

• Announced Agreement with Black Hills Corporation for an all-stock Merger of Equals
  

  • Filed joint applications for transaction approval with regulatory commissions in Montana, Nebraska, and South Dakota

• Filed a tariff waiver request with MPSC for recovery of operating costs
  

  associated with the Avista Colstrip interest3

• 
  Submitted 131 MW natural gas generation project in the Southwest Power Pool (SPP) expedited resource adequacy study
  

• Dividend Declared: $0.66 per share payable December 31, 2025 to
  

shareholders of record as of December 15, 2025

4

1. See “Year-to-Date 2025 Non-GAAP Earnings” slide in Appendix for additional details.

2. See “2025 Earnings Bridge” slide that follows for additional details and major assumptions included in guidance.

3. See “Colstrip Transaction Overview” slide that follows for additional details.

Thank you

Overview

5

Pure Electric & Gas Utility

Solid Utility

Foundation

Earnings & Cash Flow

Attractive Future Growth Prospects

Financial Goals & Metrics

Best Practices Corporate Governance

NWE – An Investment for the Long Term

• 100% pure electric and natural gas utility with over 100 years of operating history

• Solid economic indicators in service territory

• Diverse electric supply portfolio ~58% hydro, wind, & solar

• Residential electric and gas rates below national average

• Solid system reliability

• Low leaks per 100 miles of pipe

• Solid JD Power Overall Customer Satisfaction scores

• Recent and ongoing rate reviews in all jurisdictions aid earnings, cash flow, and balance sheet strength

• NOLs and tax credits expected to mitigate future cash tax obligations into 2028

• History of consistent annual dividend growth

• Disciplined maintenance capital investment program focused on reliability, capacity, asset life, and compliance

• Further opportunity for energy supply investment to meet significant capacity shortfalls

• Target 4%-6% EPS growth plus dividend yield to provide competitive total return

• Target dividend long-term payout ratio of 60%-70%

• Target debt to capitalization ratio of 50%-55% with liquidity of $100 million or greater

6

5th Best Governance Score

About NorthWestern

South Dakota Operations

Electric

65,300 customers

3,735 miles – transmission & distribution lines 420 MW nameplate owned power generation

Natural Gas

50,500 customers

1,851 miles of transmission and distribution pipeline

Montana Operations

Electric

413,400 customers

25,390 miles – transmission & distribution lines

1,065 MW maximum capacity owned power generation

Natural Gas

214,500 customers

7,354 miles of transmission and distribution pipeline

17.85 Bcf of gas storage capacity

Own 28.2 Bcf of proven natural gas reserves

Energy West Natural Gas Acquired July 2025 and adds an incremental 33,000 customers and 640 miles of distribution pipeline

Nebraska Operations

Natural Gas

43,300 customers

830 miles of distribution pipeline

7 Data as of 12/31/2024

The NorthWestern Value Proposition

+

Approximately 4% to 5% Dividend Yield

+

Base Capital Plan:

4% to 6% EPS Growth

Incremental Opportunities:

> 6% EPS Growth

8

2025-2029 Capital Investment

($ Millions)

=

8% to 11% Total Return

• 
  Data centers & new large-
  

  $2.74 billion

  of highly executable and low-risk capital investment forecasted over the next five years.

  This investment is expected to drive annualized earnings and rate base growth of approximately 4% – 6%.

  See “Strong Growth Outlook” slide that

  follows for additional information.

load opportunities

• FERC Regional Transmission
  

• Incremental generating
  

capacity

(subject to successful resource procurement bids)

=

>11% Total Return

A Diversified Electric and Gas Utility

9

Data as reported in our 2024 10-K

Highly Carbon-Free Supply Portfolio

NWE

MT

Contracted energy from Colstrip Energy Limited Partners (CELP), Yellowstone Energy Limited Partners (YELP) as well as a majority of the contracted wind, hydro and solar are federally mandated Qualifying Facilities, as defined under the Public Utility Regulatory Policies Act of 1978 (PURPA).

NorthWestern does not own all the renewable energy certificates (RECs) generated by contracted resources and periodically sells its own RECs

with proceeds benefiting retail customers. Accordingly, we cannot represent that 100% of carbon-free energy in the portfolio was delivered to our customers.

SD

Based upon 2024 MWh’s of owned and long-term contracted resources.

Approximately 58% of our total company owned and contracted supply is

10 carbon-free – better than the national average of ~42% in 2024. (eia.gov table 7.2b)

Source: marketscreener.com