20231228Exhibit 1.pdf

Intermountain Gas Company
IGRAC Invite and Meeting Materials
2023 – 2028
Exhibit No. 1
INTEGRATED RESOURCE PLAN
MAY 2, 2023 INTERMOUNTAIN GAS RESOURCE ADVISORY COMMITTEE (IGRAC)
WELCOME
Introductions
Name
Organization you are representing
BENEFITS OF AN IRP
Blueprint to meet the Company’s firm customer demands over a five-year forecast period based on various assumptions
Provides frequent updates to the projected growth on the Company’s system
Considers all available resources to meet the needs of the Company’s customers on a consistent and comparable basis
Solicits input from Stakeholders during the modeling process
Helps to ensure Intermountain Gas Company will continue to provide reliable
energy service while minimizing costs
INTERMOUNTAIN GAS COMPANY
Integrated Resource Plan Process
Demand Supply & Delivery Resources
Economic Overview
Residential & Commercial Customer Growth
Load Demand Curves
Industrial Demand
Design
WeatherResidential & Commercial Usage Per Customer
Optimization Modeling
Transportation Capacity & Storage Distribution System Overview
Demand Supply & Deliverability
Energy Efficiency:
Residential & Commercial
Natural Gas Supplies
Non-Traditional Resources
System Enhancements
Demand Supply
Economic Overview
Residential & Commercial
Customer Growth
Design Weather
Industrial Demand
AGENDA
Welcome & Introductions –Brian Robertson
Safety Moment & Feedback Process –Brian Robertson
IRP Recommendations – Brian Robertson
System Overview –Brian Robertson
Economic Forecast–Brian Robertson
Residential & Commercial Customer Growth –Brian
Robertson
Design Heating Degree Days –Min Park
Industrial Customer Forecasts – Nicole Gyllenskog & Dave Swenson
Load Demand Curves– Brian Robertson
Questions/Discussion
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SAFETY MOMENT FEEDBACK SUBMISSIONS
[e-mail]
Please provide comments and feedback within 10 days
2021 IRP ACKNOWLEDGEMENTAND IRP RECOMMENDATIONS
Final Order No. 35438 – Commission Acknowledged Intermountain’s 2021 IRP Filing
Commission Recommendations for Intermountain’s IRP Process:
Staff recommends that the Company quantify the effects of new building codes and the Company's energy efficiency programs and incorporate estimates into its per customer usage models.
Staff recommends that the Company provide Staff capacity and cost information as enhancement projects are completed and brought online.
Staff recommends the Company vet future CPA results for accuracy to ensure the savings estimates and assumptions are reasonable and achievable.
Staff appreciates the Company incorporating model validation into this IRP and encourages the Company to continue to enhance this validation process as more AMI data becomes available.
Staff believes the Company can continue to enhance public participation by continuing to increase members of the IGRAC, providing materials to members prior to meetings, and making IRP information available on its website.
SYSTEM OVERVIEW
BRIAN ROBERTSON
SUPERVISOR, RESOURCE PLANNING
INTERMOUNTAIN GAS COMPANY
Intermountain Gas Company is a natural gas local
distribution company, founded in 1950 and served its
first customer in 1956
Provides service to 76 communities across southern
Idaho
402,300+ customers
THROUGHPUT BY CUSTOMER CLASS
Residential34%
Commercial17%
Large Volume49%
Residential Commercial Large Volume
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INTERMOUNTAIN GAS COMPANY DISTRIBUTION SYSTEM AREAS OF INTEREST (AOI)
Distribution System Segments:
Canyon County
Central Ada County Lateral
North of State Street Lateral
Sun Valley Lateral
Idaho Falls Lateral
All Other Customers
REGIONAL PIPELINES
ECONOMIC FORECAST
BRIAN ROBERTSON
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
WOODS & POOLE ECONOMICS, INC. Regional Projections
The methods used by Woods & Poole to generate the county projections proceed in four stages.
• First, forecasts to 2050 of total United States personal
income, earnings by industry, employment by industry, population, inflation, and other variables are made.
• Second, the country is divided into 179 Economic Areas (EAs) as defined by the U.S. Department of Commerce, Bureau of Economic Analysis (BEA). The EAs are aggregates of contiguous counties that attempt to measure cohesive economic regions in the United States.
• The third stage is to project population by age, sex, and race for each EA on the basis of projected net migration rates. For stages two and three, the U.S. projection is the control total for the EA projections.
• The fourth stage replicates stages two and three except that it is performed at the county level, using the EAs as the control total for the county projections.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
Idaho Economic Forecast
for the State of Idaho and the Counties in Idaho
Future household growth, which is the key driver for future residential customer growth is modeled as a function of total population (less those individuals in group quarters), and general economic conditions in the state.
In brief: good or improving economic conditions will speed up the rate of household growth, however worsening or declining economic conditions will slow the rate of household formation and, in turn, slow the rate of household growth.
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INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
Idaho Economic Forecast
The Great Recession of 2008 brought about a significant decline in Idaho's nonagricultural employment. From year-end 2007 through 2010 Idaho
nonagricultural employment decreased by 7.9%, a loss of 51,500 jobs. The effects of 2008 – 2010 recession were relatively long lasting. Total nonagricultural employment in the state attained an annual average of
654,700 in 2007. It took 7 years, until the year 2014, for nonagricultural employment in the state reach prerecession levels.
Since 2014 Idaho’s economy has regained its economic footing. Total nonagricultural employment in the state surged upward gaining nearly 105,000 jobs in five years – an annual average pace of 3.0% per year.
During those five years Idaho was consistently ranked among the 5 fastest growing states in the nation.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
Idaho Economic Forecast
The COVID-19 Pandemic & Idaho’s Economic & Population Growth:
In 2020 the COVID-19 pandemic brought Idaho’s economic growth to a
halt. From February 2020 to April 2020 nonagricultural in Idaho declined by
9.8% - a decrease of 74,300 jobs in a period of two months. This was a much sharper and steeper economic decline than that experienced in the
2008 Great Recession.
Initial expectations were that an economic recovery could be a long and tedious process. However, the latest economic statistics seem to indicate
that that may not be the case in Idaho. The growth in Idaho’s population
was a driving force in Idaho’s economic growth prior to the pandemic and continues today. Population growth in the state has brought new jobs to
the state and spurred on construction and trade employment in the state.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
Idaho Economic Forecast
The COVID-19 Pandemic & Idaho’s Economic & Population Growth:
Some statistics:
While Idaho’s non-ag employment declined by nearly 74,000 in two months, construction employment in the state continued to grow – up 5.2%
(about 1,800 jobs) at year-end 2020 when compared to year-earlier levels. Non-ag employment has since rebounded to expected levels beginning
mid-2021.
Total population in Idaho has increased at a robust pace since 2010. Through 2019 the US Census Bureau estimates that Idaho’s population increased by 219,500 (14.0% - a annual average increase of 2.0% per
year over the 2010 to 2019 period). These increases are overwhelmingly due to a robust in-migration to Idaho. A 2.0% annual average rate of
population growth, minus a natural population growth rate of 0.42% per
year, leaves an annual average population increase of 1.58% per year (about 28,000 persons per year) due to in-migration.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
Idaho Economics Winter 2020 Economic Forecast
The COVID-19 Pandemic & Idaho’s Economic & Population Growth:
The COVID – 19 pandemic has not yet slowed Idaho’s population growth.
Per the US Census Bureau, Idaho was ranked as the fastest growing state in the nation during 2020. This has only continued into 2021 and
2022, as Idaho’s population grew 2.98% and 1.82%, respectively. Idaho was the fastest growing state in 2020 and 2021, and the second fastest growing state in 2022.
What is origin of Idaho’s population in-migration? Statistics indicate that California is the major source of Idaho’s current population growth. The pandemic has accelerated that pace of out-migration. The latest US
Census Bureau estimates California’s 2022 population decreased nearly
114,000 last year. Over the last 2 years the Census Bureau has estimated that approximately 236,000 persons per year have left California.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
And Then There is Idaho’s Population Growth
The Base Case Economic Forecast assumes a normal amount of economic fluctuation and normal business cycles it is the “best estimate” of future
economic activity in the State and it’s forty four counties.
The High Growth Scenario assumes a more rapidly growing economy --
similar to the growth that Idaho experienced in the 1990s.
The Low Growth Scenario assumes a period of slower economic growth for
the State of Idaho with fewer employment opportunities in the future. In turn,
slower economic growth will slow the rate of population growth in the state by decreasing population in-migration (or causing a population out-migration) and
slowing the rate of future household growth in the state.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
The Economic Forecast
In the 2023 - 2030 Forecast Period Idaho’s Economy will experience:
An annual average increase in Nonagricultural employment of 2.5% per year,
adding nearly 709,500 jobs to the State’s payrolls.
Population growth averaging 1.13% per year over the 2023 - 2030 forecast period with, by the year 2030, the State’s population nearing 2,020,700. Ada
and Canyon counties are projected to attain a total population of 844,000 in
the year 2030.
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INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLANThe Economic Forecast
Nonagricultural employment in Idaho is expected to increase by nearly
120,000 over the 2023 to 2030 forecast period. But some industries will fare better than others:
Agriculture is projected to remain steady with only gaining a modest 600
additional statewide jobs by 2030.
Similarly, the Mining industry is expected to gain only an 300 jobs statewide by the year 2030.
Manufacturing employment in Idaho is predicted to increase at an annual
average rate of 0.53%per year over the 2023 - 2030 period for an absolute gain of nearly 3,000 jobs from the 2022 employment levels.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
The Economic Forecast
The Transportation, Wholesale and Retail Trade, and the Utilities industries are expected to post annual average employment gains of 0.94% per year over the 2023 to 2030 period producing an absolute gain of close to 12,700
new jobs in the State.
Employment in the Finance, Insurance, and Real Estate Industries is expected to increase by 19,000 over the 2023 - 2030 period -- an annual average increase of 2.3% per year.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
The Economic Forecast
The Service Industries in Idaho are expected to be the fastest growing in terms of employment growth over the 2023 to 2030 period –
Employment in the Professional and Technical Services category is
forecasted to increase by 10,600 over the 2023 - 2030 period -- an annual average increase of 1.9% per year.
Education and Health Services employment in the State is forecasted to increase by 31,360 over the 2023 - 2030 period -- an annual average
increase of 2.8% per year.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
The Economic Forecast
Idaho employment in the Leisure and Hospitality Industries is forecasted to
increase by nearly 16,700 over the 2023 - 2030 period -- an annual average increase of 2.0% per year. Lastly, employment in the category of Other Services is projected to increase by 6,200 over the 2023 - 2030 period -- an
annual average increase of 1.5% per year.
In total, Idaho Service Industry Employment is projected to increase by 22,900 over the 2023 to 2030 period – 60.6% of the overall increase in Non-Ag employment in the State over the forecast period.
Government employment is predicted to increase at an annual average rate
of 0.8% per year over the 2023 - 2030 period with a net gain of nearly 7,000 jobs statewide.
INTERMOUNTAIN GAS COMPANYINTEGRATED RESOURCE PLAN
The Economic Forecast
QUESTIONS ?
10 MINUTE BREAK
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RESIDENTIAL & COMMERCIAL
CUSTOMER GROWTH
BRIAN ROBERTSON
SUPERVISOR, RESOURCE PLANNING
AOI
GROWTH
RATE
FORECAST INPUTS
Residential 2015 2015 2015 2015 2015 2016 20168 9 10 11 12 1 2Ada 135420 135729 136271 136864 137502 137814 138092Bannock 20637 20660 20767 20911 21057 21112 21148Bear Lake 1157 1160 1159 1165 1170 1171 1170Bingham 7160 7169 7206 7251 7330 7349 7364Blaine 9783 9793 9805 9851 9876 9885 9898
Year County Population Employment2023 ADA 511.806 375.9032023 BANNOCK 89.713 50.5712023 BEAR LAKE 6.093 3.5452023 BINGHAM 47.651 23.782023 BLAINE 23.738 22.917
Woods and Poole Data
Historic Actual Customer Counts 
FORECASTING COMPONENTS
Economic Forecast – State of Idaho
CCG,Class= α0+ α1PopCG+ α2EmpCG+ Fourier(k) + ARIMA(p,d,q)
Model Notes:
C = Customers; CG = County; Class = Residential, Commercial, Industrial, or Interruptible;ARIMA(p,d,q) = Indicates that the model has p autoregressive terms, d difference terms, and q moving average terms; Pop = Population; Emp = Employment; Fourier(k) = Captures seasonality of k number of seasons.
Start with Linear Model
Some are Naïve models
Tests for any collinearity
‘Boots-on-the-Ground’ Observations/Feedback
2021 IRP COMMERCIAL FORECAST VS ACTUALS
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ADA COUNTY CUSTOMER FORECAST OWYHEE COUNTY CUSTOMER FORECAST
FORECASTING GROWTH-AREAS OF INTEREST (AOI)
CANYON COUNTY CUSTOMER FORECAST
SUN VALLEY CUSTOMER FORECAST IDAHO FALLS CUSTOMER FORECAST
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N. OF STATE & CENTRAL ADA
AREAS OF INTEREST
GIS Shape File of AOI’s
N of State Street & Central Ada
N STATE ST CUSTOMER FORECAST
CENTRAL ADA CUSTOMER FORECAST ALL OTHER CUSTOMER FORECAST
TOTAL SYSTEM CUSTOMER FORECAST
QUESTIONS?QUESTIONS?
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HEATING DEGREE DAYS & DESIGN WEATHER
MIN PARK
REGULATORY ANALYST
WEATHER
Weather is a Key Residential & Commercial Demand Driver
Heating Degree Days are Used to Capture Weather Effects
Two Primary Weather Scenarios are Used in the IRP:
Normal HDD
Design HDD
HEATING DEGREE DAY(HDD)
What is a Heating Degree Day?
Industry-Wide Standard Measuring Degrees Below a Set Base Temperature
Base of 65 Degrees is Most Common
March 2nd, 2023 - Boise Example:
Daily High: 39 Degrees °F
Daily Low: 23 Degrees °F
Mean: 31 Degrees °F
65 Degrees – 31 Degrees = 34 HDD
NORMAL HEATING DEGREE DAYS
Benchmark for the IRP
Used for Routine Planning and Represent the Typical or “Normal”
Weather Expected on a Given Day
30-Year Rolling Average of Daily Mean Temperatures
Normal for the IRP is the 30-Years Ended December 2022
NORMAL HEATING DEGREE DAYS DESIGN DEGREE DAYS
Design Degree Days Model the Coldest Temperatures that Could
Feasibly Occur on Intermountain's System
Created by Modeling Design Peak Day, then Modeling the
SurroundingWeek, Month, and Year
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DESIGN PEAK DAY
Design Peak Day is the Absolute Coldest Day Planned for in the Design Year
Engaged Idaho State Climatologist, Dr. Russell Qualls, to Conduct a Peak Day
Study
Study Produced a Range of Peak Days for Various Probability Assumptions
50-Year Peak-Day Event was Selected (78 HDD)
Peak Day is Modeled to Occur on Jan 15th of the Design Year
PEAK 5-DAY DESIGN
The Days Surrounding the Peak Day are Modeled After the Coldest
Recorded Consecutive 5-Days in a 50 Year Period.
Peak Day is Assumed to be the Second Day in the 5-Day Period.
PEAK 5-DAY
DESIGN
PEAK MONTH
DESIGN
The Days Surrounding the Peak 5-Day Period are Modeled After the Coldest Calendar
Month in the last 50 Years
The Current Peak Month is
December 1985
This Month Forms the Basis
for January Design Weather
DESIGNING THE REST OF THE YEAR
The Rest of the Year is Modeled After the Coldest Heating Year in a 50 Year Record
Oct 1984 – Sep 1985 Continues to be the Coldest
This Period Also Included the Coldest Critical Three Month Heating Period (Dec-
Feb)
DEGREE DAY GRAPH
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AOI DEGREE DAYS
Intermountain’s service area is climatologically diverse
Idaho Falls or Sun Valley vs. Boise
Intermountain has developed unique Degree Days for each AOI
Methods used to calculate AOI Degree Days mirror the Total Company
approach
AOI DEGREE DAYS
Weather Stations West
to East:•KBOI•KEUL
•KTWF•KSUN
•KPIH
•KIDA•KRXE
QUESTIONS?QUESTIONS?
2023 IRP
LARGE VOLUME CUSTOMER FORECAST
NICOLE GYLLENSKOG & DAVE SWENSON
MANAGERS, INDUSTRIAL SERVICES
WHAT IS A LARGE VOLUME CUSTOMER?
149 largest customers; approximately 46% of 2022 sales
Mix of “Industrial” and “Commercial” types
As a group exhibit fairly high load factor
Provide thousands of Idaho jobs; huge impact on economy
SENDOUT STATISTICS
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SENDOUT STATISTICS
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Intermountain Gas Company -Annual Therm Sales
Total Company Large Volume LV % of Total
REQUIREMENTS OF A LARGE VOLUME CUSTOMER
Minimum 200,000 Therms per contract-year requirement
Must elect 1 of 3 tariffs:
LV-1 bundled sales
T-3 interruptible transporation or T-4 firm transportation
Minimum one-year contract; the contract sets the term and Maximum Daily Firm Quantity (MDFQ) for firm peak day use
Contracts are site specific; can combine meters on contiguous property
CLASSIFICATION OF CURRENT 149 LV CUSTOMERS
Percent of Total
By Rate Class:# of # of Therms
LV-1 Sales – 36 24% 4%
T-3 Interruptible Transport – 9 6% 11%
T-4 Firm Transport – 104 70% 85%
Total – 149 100% 100%
SEGMENTATION OF 149 LARGE VOLUME CUSTOMERS
By Market “Segment”# %Therms%
Potato Processors – 18 12% 27%
Other Food Processors – 18 12% 32%
Meat & Dairy – 23 15% 13%
Ag & Feed – 8 5% 1%
Chemical/Fertilizer – 3 3% 9%
Manufacturing – 33 22% 7%
Institutional – 33 22% 6%
Other – 13 9% 5%
Total – 149 100% 100%
LOCATION OF 149 LARGE VOLUME CUSTOMERS (BC)
By AOI:# % Therms%
IFL – 28 19% 18%
SVL – 4 3% 1%
Central Ada – 2 1% 1%
State Street – 3 2% 1%
Canyon County – 21 14% 14%
All Other – 91 61% 65%
Total – 149 100% 100%
OVERVIEW OF FORECASTTECHNIQUE
Most not as weather sensitive as the Core Market
Small population (not as many customers)
Not as homogenous as Core (size, weather sensitivity)
Don’t use statistics/regression techniques
Use an “adjusted” historical usage approach
Forecast both Therm use and CD (MDFQ/MDQ)
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APPLICATION OF FORECAST TECHNIQUE
Adjusted historical data with customer information and other
data (e.g. EDO's) to develop three forecasts
Base Case
High Growth
Low Growth
Assumed growth by specific customers
Used recent trends to validate results
SENDOUT STATISTICS
BASE CASE SCENARIO ASSUMPTIONS
Starts with historical actuals
Adjust for customer information and trends
Natural gas prices competitive with other energy sources
Economy dealing with inflation and supply chain issues
Includes 5 new customers
Mix of segments; 4 T-4 and1 LV-1; 3 are "All Other" in Magic Valley and 2 are in Canyon.
Compounded annual growth rate of 1.01%
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Potato Other Food Dairy and Ag Chem/Fertlzr Manufact Institutional Other
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IRP Large Volume Base Case Forecast by Segment (Therms)
2023 2024 2025 2026 2027 2028
HIGH GROWTH SCENARIO ASSUMPTIONS
Starts with Base Case Forecast
Natural gas prices remain comparatively low
Economy comes out of the inflation with continued growth
Assumes 10 new customers totaling 5.5 million Therms by 2028
Additions mostlyT-4 (9); 4 Meat & Dairy and 5 various segments; most growth in All Other
Compounded annual growth rate of 2.37%
SENDOUT STATISTICS
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IRP Large Volume High Growth Forecast by Segment (Therms)
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LOW GROWTH SCENARIO ASSUMPTIONS
Starts with Base Case Forecast
Assume gas prices are less competitive
Economy slows; recession or inflation causes slowing in growth
Removed any customer having difficulty staying above the
200,000 Therm annual minimum
Two new T-4 customers; 2 in the “Other,” segment
Compounded annual growth rate of -.07%
SENDOUT STATISTICS
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IRP Large Volume Low Growth Forecast by Segment (Therms)
2023 2024 2025 2026 2027 2028
SENDOUT STATISTICS
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IRP Large Volume Annual Therms
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SENDOUT STATISTICS
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IRP Total Large Volume Annual Therms
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OPTIMIZATION MODELING -
MDFQ VS THERM FORECAST
Use MDFQ not therm forecast in optimization model
Contract includes Maximum Daily Firm Quantity (MDFQ)
Intermountain provides MDFQ 365 day/year; gas supply
MDFQ trends therm projections
Only firm customers in design peak; no interruptible
Includes new customer additions
Compounded annual growth rate of .08%
SENDOUT STATISTICS
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Potato Other Food Chemical/Fertillzer Manufacturing Meat&Dairy Institutional Other Ag&Feed
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Base Case MDFQ by Segment
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QUESTIONS?QUESTIONS?
LOAD DEMAND CURVES
Incorporates several inputs
Res & Com Customer Forecast, Normal and Design Weather, Use Per Customer, Demand Side Management, and Large Volume Forecast.
LDC = (Customer Forecast * HDD * User Per Customer) – DSM + LV Forecast
Load Demand Curve Utilization
Identifies potential upstream pipeline and distribution system constraints
Resource Optimization
Storage Management
Remedies for Any Constraints Will be Identified Later
Note: Load Demand Curves for upstream pipeline modeling will differ from distribution system modeling
AREAS OF INTEREST
Idaho Falls Lateral
Sun Valley Lateral
Canyon County Lateral
North of State Street Lateral
Central Ada County
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QUESTIONS?QUESTIONS?
ADDITIONAL MEETINGS
Thursday, June 8, 2023 via Microsoft Teams
Usage Per Customer
Energy Efficiency
Supply Side Resources
Distribution System Modeling
Wednesday, August 2, 2023 via Microsoft Teams
Potential Capacity Enhancements
Resource Optimization
Planning Results
FEEDBACK SUBMISSIONS
[e-mail]
Please provide comments and feedback within 10 days
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Page 1 of 2

IGRAC #1
Date & time: 5/2/2023, 9:00 AM to 11:00 PM MT
Location: Microsoft Teams Meeting
Presenters: Brian Robertson, Min Park, Nicole Gyllenskog,
In attendance: Bruce Folsom, Kevin Keyt, Brian Robertson, Kathleen Campbell, Nicole Gyllenskog, Mark Sellers-Vaughn, Lori Blattner, Brenna Garro, Matthew Hunter, Min Park, Michael Parvinen, Teresa McKnight, Eric Wood, Susan Davidson, Zachary Sowards, Russ Nishikawa, Dave Swenson, Jennifer DeBoer, Robyn Sellers

Introduction
Brian Robertson, Supervisor of Resource Planning, opened the meeting by welcoming and thanking stakeholders for participating in Intermountain’s IRP Process. Brian then proceeded with introductions, the agenda, a safety moment, and a reminder of the stakeholder engagement goals.

Presentation #1 – 2021 IRP Acknowledgement and IRP Recommendations (Brian Robertson)
• Recommendations o Quantify effects of new building code changes
o Provide capacity and cost information o Ensure accuracy of savings estimates and assumptions from CPA
o Enhance validation as more AMI data becomes available o Make IRP info available on website Comment: Kathleen Campbell ensures they have more AMI data and will be using it Presentation #2 – System Overview (Brian Robertson)
• Large Volume 47% Residential 34% Commercial 17%
• Areas of Interest o Canyon County o Central Ada County Lateral o North of State Street Lateral o Sun Valley Lateral o Idaho Falls Lateral o All Other Customers Question: “Are there multiple lines from Pocatello to Idaho Falls?” Answer: “The Idaho Falls lateral runs from Pocatello to St. Anthony. Along the lateral there is a couple sections that have looped to reinforce the lateral. The Idaho Falls lateral has seen significant growth over the last couple of IRP’s” – Kathleen Campbell Presentation #3 – Economic Forecast (Brian Robertson)
• Nonagricultural employment decreased by 7.9% in Recession of ‘08
• April 2020 saw 9.8% decline due to pandemic
• Since 2010 Idaho’s population increased 14%
Page 2 of 2

• Fastest growing state in 2020, 2021, and second fastest in 2022
• 1.13% population growth/year projected 2023-2030
Presentation #4 – Residential & Commercial Growth (Brian Robertson)
• Forecast inputs o Woods and Poole population and employment
o Historical customer count
• ARIMA model with Fourier term Question: “How are you defining customer?” Answer: “Based on meter count and unique ID” – Lori Blattner, Kathleen Campbell, Brian Robertson Question: “Does Sun Valley account for snow melt in customer count seasonality?” Answer: “No we don’t include snow melt because those are interruptible customers” – Kathleen Campbell Presentation #5 – Heating Degree Days & Design Weather (Min Park)
• Heating Degree Day based off 65 degrees
• 30-day rolling average of daily mean temperatures
• Design Degree Days model coldest temperature from Design Peak Day
• Peak Day modeled to occur Jan 15
Presentation #6 – Large Volume Customer Forecast (Nicole Gyllenskog)
• 149 large volume customers make up 47% of sales
• Minimum of 200,000 therms per contract year to be LVC
• Start with historic trends and add customer trends Question: “At what point are you restrained by capacity on NWP?” Answer: “We will have a discussion about this IGRAC 3” – Brian Robertson Answer: “For T3, T4 contracts (most LVCs) the gas supply purchasing, and transportation is the customer or gas marketers’ responsibility” – Dave Swenson Answer: “NWP is Bi-directional and has fewer constraints in Intermountain territory than over in Cascade territories” – Kathleen Campbell Answer: “Gas storage has increased to serve Intermountain customers and pipeline constraints in Intermountain’s service territory has not been a concern yet.” – Mark Sellers-Vaughn Presentation #7 – Load Demand Curves (Brian Robertson)
• Load Demand Curve = (Customer Forecast * HDD *Use Per Customer) – DSM + LV Forecast Comment: “Analyst to analyst questions and discussion is important, and should be done frequently” – Bruce Folsom The Meeting was Adjourned – IGRAC #2 will be held on June 8, 2023 @ 9 AM MT
INTEGRATED RESOURCE PLAN
JUNE 8, 2023 INTERMOUNTAIN GAS RESOURCE ADVISORY COMMITTEE (IGRAC)
WELCOME
Introductions
Feedback Process
Agenda
2
FEEDBACK SUBMISSIONS
[e-mail]
Please provide comments and feedback within 10 days
3
AGENDA
Welcome & Introductions – Mark Sellers-Vaughn (Manager, Supply Resource Planning)
Safety Moment – Jenny De Boer (Resource Planning Economist I)
Distribution System Modeling –Kathleen Campbell (Senior Engineer)
Avoided Cost Methodology –Min Park (Regulatory Analyst I)
Energy Efficiency – Kathy Wold (Manager, Energy Efficiency)
Supply Resources and Transportation & Storage Resources–Eric Wood (Supervisor, Gas Supply), Devin McGreal (Sr. Resource Planning Economist)
Questions/Discussion
4
Demand Supply & Delivery Resources
Economic Overview
Residential & Commercial Customer Growth
Load Demand Curves
Industrial Demand
Design
WeatherResidential & Commercial Usage Per Customer
Optimization Modeling
Transportation Capacity & Storage Distribution System Overview
Demand Supply & Deliverability
Energy Efficiency:
Residential & Commercial
Natural Gas Supplies
Non-Traditional Resources
System Enhancements
Demand Supply 5
SAFETY MOMENT
6
1 2
3 4
5 6
AREAS OF INTEREST (AOI)
Distribution System Segments:
Canyon County
Central Ada County Lateral
“North of State Street” Lateral
Sun Valley Lateral
Idaho Falls Lateral
All Other Customers
7
DISTRIBUTION
SYSTEM PLANNING
KATHLEEN CAMPBELL, PE – SENIOR ENGINEER
ZACHARY SOWARDS – ENGINEER III
IDAHO
JUNE 8TH, 2023
SYSTEM DYNAMICS:
Piping:
•Diameter – ½” to 16”
•Material – Polyethylene and Steel
•Operating Pressure – 60 psi to 850 psi
•Idaho – approx. 7,155 miles of distribution &
284 miles of transmission
9
SYSTEM DYNAMIC'S CONT.
Facilities:
•Regulator stations – Over 600
•Other equipment such as LNG, odorizer and compressors
10
SYSTEM DESIGN
11
SYNERGI GAS MODELING
To evaluate our systems for growth and potential future deficits we use our gas modeling software, Synergi Gas
Distributed and supported by DNV
Models incorporates:
Total customer loads
Existing pipe and system configurations
Hydraulic modeling software that allows us to predict flows and pressures on our system based on gas demands predicted during a peak weather event.
Models are updated every three years and maintained between rebuilds
12
7 8
9 10
11 12
SYNERGI MODEL EXAMPLE
13
MODEL BUILDING PROCESS
Synergi models are completely rebuilt every three years and maintained/updated between rebuilds
When models are rebuilt
•We export current GIS data to build spatial model
•We export 5 years of CC&B billing data to CMM to create an updated demands file
•We validation and calibrate each district model to a recent low-pressure event using existing data (ERXs/pressure charts/SCADA/metertek/LV usage)
•We create a design day model based on the updated heating degree day determined by gas supply (determined by trending historical weather events)
IGC models were rebuilt in Fall of 2021
14
DATA GATHERING
CC&B (Customer Billing Data)
15
DATA GATHERING
SCADA Data
Real time and historical flow characteristics at specific locations in the
system
16
DATA GATHERING
Peak Heating Degree Day (HDD) modeled
by IGC based on historical weather data
Peak HDD = 65 –Average Daily TempTown HDD Avg Daily Temperature (⁰F)
Boise 75 -10
Nampa 68 -3
Pocatello 82 -17
Idaho Falls 88 -23
Twin Falls 77 -12
Ketchum 82 -17
17
CUSTOMER MANAGEMENT MODULE (CMM)
Brings CC&B customer data into Synergi as demands file
Demand file applies load spatially in the
model.
18
13 14
15 16
17 18
IDAHO FIXED NETWORK UPDATE
•IGC has a goal of reading 90% of customer meters though Fixed Network
Devices
•Device installation has been ongoing with 61% coverage completed though
Q1 2023
•90% coverage expected by end of year 2023
19
FIXED NETWORK TO MODELING COMPARISON
Fixed Network VS
CMM
2021 2023
Number of Data
Points Compared
100 892
% Difference 12% 2%
2021 Data was collected from a single service territory
2023 Data was collected from all IGC service territories containing fixed network devices
20
CALIBRATED VS PEAK DEGREE DAY
y = 0.0152x + 0.1118
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 10 20 30 40 50 60
MCF
H
DEGREEDAY
LOAD VSTEMPERATURE
HEAT
40 DD = 0.72 MCFH
58 DD = 0.99 MCFH
PEAKDD
CALIBRATEDDD
BASE
21
IDENTIFICATION OF SYSTEM
DEFICITS/CONSTRAINTS
SYNERGI MODELING CAPABILITIES:
•Review Large Volume Customer requests
•Model RNG
•Supports design/sizing of pipe and pipeline components (regulator stations, compressors)
•Future planning
•Model IRP predicted growth
•Identify deficiencies
•Determine system reliability
•Optimize distribution enhancement options
•Cold Weather Action Plans and Modeling Curtailments/Interruptible Customers 23
WHAT IS A CAPACITY DEFICIT?
A deficit is defined as a critical system that is at or limiting capacity.
Critical system examples include:
•Pipeline bottlenecks
•Minimum inlet pressure to a regulator station or HP system
•Minimum inlet pressure to compressor (suction)
•Component limiting capacity
24
19 20
21 22
23 24
DISTRIBUTION SYSTEM MODELING PROCESS TO ENSURE WE CAN
MEET IRP GROWTH PREDICTIONS
As part of the IRP process, we complete a comprehensive review of all of our
distribution system models every two years to ensure that we can maintain reliable
service to our customers during peak low temperature events.
With our capital budget cycle, we also complete system reviews on an annual basis.
If a deficit is predicted the system is evaluated and a reinforcement/enhancement is
proposed and selected based on alternative analysis considerations and placed into
the capital budget based on timing needs of the predicted deficit.
25
DISTRIBUTION
ENHANCEMENT/REINFORCEMENT
OPTIONS TO ADDRESS DEFICITS
ENHANCEMENT OPTIONS
Pipeline: •Replacements •Reinforcements•Loops & Back feeds•Pressure Increases•UpratesFacility UpgradesAdditional Regulator Stations feeding the distribution systemNew Strategically placed Gate StationsCompressor Stations
27
DISTRIBUTION ENHANCEMENT EXAMPLE
Theoretical low-
pressure scenario
28
DISTRIBUTION ENHANCEMENT OPTIONS
Low pressure scenario
•Compressor station infeasible
•Other Solutions?
REGS?
PIPE?
29
DISTRIBUTION ENHANCEMENT OPTIONS
Reinforcement option #1
30
25 26
27 28
29 30
DISTRIBUTION ENHANCEMENT OPTIONS
Reinforcement option #2
31
ENHANCEMENTS CONSIDERATIONS
Scope
Cost
Capacity Increase
Timing
System Benefits
Alternative Analysis
Feasibility
32
ENHANCEMENT REVIEW AND
SELECTION PROCESS TO CAPITAL BUDGET
ENHANCEMENT SELECTION GUIDELINES:
Shortest segment of pipe that addresses deficiency
Segment of pipe with the most favorable construction conditions
Segment of pipe that minimizes environmental concerns and impacts to the
community
Segment of pipe that provides opportunity to add additional customers
Total construction cost including restoration
34
ENHANCEMENT SELECTION PROCESS:
Info & Data
Project & Schedules
35
ITERATIVE PROCESS OF IRP
2023 20242023 IRP
2025 IRP
2027 IRP
2025 2026 2027
20292028202520262027
2027 2028 2029 2030 2031
36
31 32
33 34
35 36
QUESTIONS?QUESTIONS?AVOIDED COST METHODOLOGY
MIN PARK
REGULATORY ANALYST
A BRIEF HISTORY
INT-G-19-04, Order No. 34536 directed the Company to review its avoided cost calculations.
In early 2020, Intermountain invited interested members of the Energy Efficiency Stakeholder Committee (EESC)
to join an Avoided Cost Subcommittee.
Met three times between February and June 2020
The Subcommittee came to an understanding on the general Avoided Cost methodology
Avoided cost subcommittee met in March of 2022
Could not agree on distribution cost (still set at 0)
39
AVOIDED COST OVERVIEW
The Avoided Cost is used to put a dollar value to energy savings.
This allows utilities to spot opportunities where energy efficiency is more cost effective than a supply-side option.
“A Penny Saved is a Penny Earned.”
40
Commodity
Costs
Transportation
Costs
Distribution
Costs
41
FORMULA
𝐴𝐶=𝐶𝐶+𝑇𝐶+𝑉𝐷𝐶
𝐴𝐶= Nominal Avoided Cost Per Therm
𝐶𝐶 = Commodity Cost
𝑇𝐶= Transportation Cost
𝑉𝐷𝐶= Variable Distribution Cost
42
37 38
39 40
41 42
COMMODITY COST CALCULATION
The price of a molecule of gas depends on the basin, the time of year, and even the day of the week.
Calculation starts with internal 30-year price forecasts for three primary basins.
Basins prices are weighted based on company Day Gas purchase data.
Normal Heating Degree Days (HDD65) are used to shape monthly prices.
43
TRANSPORTATION COST CALCULATION
Includes the cost of reserving additional capacity on the Northwest Pipeline.
Based on costs & volumes listed in latest tariffs for RS and GS-1 customers.
Also contains variable costs associated with transporting gas to city gate.
44
DISTRIBUTION COST CALCULATION
Energy efficiency can lead to delaying or even avoiding costly pipeline capacity expansions.
Large expansions occur irregularly, making it difficult to quantify this type of saving.
Currently, the calculation contains a placeholder value of $0.00 for this cost component.
As part of this IRP Process, Intermountain will work with stakeholders to try to develop a distribution system cost.
45
2023 IRP UPDATES
Updated Basin price forecast.
Updated HDD Shaping to use 2022 Normal weather.
Added new year of Day Gas purchase data.
Updated transportation cost with latest PGA tariff.
Inflation Rate updated from 2% to 3.15 %.
46
QUESTIONS?QUESTIONS?
ENERGY EFFICIENCY RESULTS
KATHY WOLD
MANAGER, ENERGY EFFICIENCY
43 44
45 46
47 48
Demand Side Management (DSM) refers to
resources acquired through the reduction of
natural gas consumption due to increases in
efficiency of energy use.
49
Option A:Purchase MMBtu from Supplier A
$$$$
Option B:
Energy Efficiency ProgramTherm savings (MMbtu)$$
DSM: Resources acquired through the reduction of consumption due to energy efficiency
50
www.intgas.com/saveenergy 51 www.intgas.com/saveenergy 52
www.intgas.com/saveenergy
53
Commercial Energy Efficiency
54
49 50
51 52
53 54
May 25, 2023
INTERMOUNTAIN GAS
COMPANY
2023 CONSERVATION
POTENTIAL ASSESSMENT
EESC PRESENTATION
FINAL RESULTS
GUIDEHOUSE TEAM
Robin Maslowski
Project Director
Guidehouse
Brian Chang
Measure Lead
Guidehouse
Neil Podkowsky
Project Manager
Guidehouse
Raniel Chan
Modeling Lead
Guidehouse
Aneesha Aggarwal
Deputy Project Manager
Guidehouse
Jon Starr
Professional Director
Guidehouse
56
WHAT ARE THE OBJECTIVES FOR THIS CONSERVATION
POTENTIAL ASSESSMENT (CPA)?
• Rationally and transparently estimate achievable natural gas energy efficiency (EE) potential within IGC service territory
• Forecast net impacts from 2024-2044
Assess Achievable Energy Savings Potential
• Inform IGC’s EE goals, portfolio planning, and budget setting• Contribute to IGC’s Integrated Resource Planning process (IRP)
• Identify new EE savings opportunities
Apply Results
57
2023 CPA METHODOLOGY
WHAT IS A CONSERVATION POTENTIAL ASSESSMENT?
Technical PotentialTotal energy savings available by end-use and sector, relevant to current population forecast
Economic Potential
Utility Cost Test (UCT) cost-effectivenessscreen
Achievable PotentialEE expected to be adopted by programs
Establishes Goals & Scenarios for Forecast
• Avoided Costs• Measure Costs
• Historical Program Achievements• Program Budget• Customer Adoption Characteristics
• Measure Energy Savings• Measure Life• Technology Density and Saturation
59
The EE savings that could be expected in response to specific levels of program incentives and assumptions about existing policies, market influences, and barriers.
Estimated by:
o Calculating the market share, or penetration of
measures based on customer awareness of the measure and customer willingness to adopt the measure
o Willingness is determined by comparing payback time associated with efficient measure against competing measures
o Calibrating forecast using historic program data
ACHIEVABLE POTENTIAL FOR REBATE PROGRAMS
Technical Potential
Total energy savings available by end-
use and sector, relevant to current population forecast
Economic Potential
Cost-effectiveness Screen
Achievable
Potential
EE expected to be adopted by
programs
60
55 56
57 58
59 60
DETAILED RESULTS
NATURAL GAS ENERGY (MMTHERMS/YEAR) CUMULATIVE NET ACHIEVABLE POTENTIAL BY SECTOR
0
5
10
15
20
25
30
35
Sa
v
i
n
g
s

P
o
t
e
n
t
i
a
l

(
M
M
T
h
e
r
m
s
/
y
e
a
r
)
Commercial Residential
62
TOTAL NATURAL GAS CUMULATIVE NET ACHIEVABLE POTENTIAL AS A % OF FORECAST NATURAL GAS SALES
0%
1%
2%
3%
4%
5%
6%
7%
8%
Po
t
e
n
t
i
a
l

a
s

%

o
f

S
a
l
e
s
Commercial Residential
63
CUMULATIVE NET NATURAL GAS ACHIEVABLE POTENTIAL BY RESIDENTIAL SECTOR END USE (MMTHERMS/YEAR)(BUSINESS AS USUAL)
0
5
10
15
20
25
30
35
Sav
i
n
g
s

P
o
t
e
n
t
i
a
l

(
M
M
T
h
e
r
m
s
/
y
e
a
r
)
HVAC
Hot Water
Envelope
Appliance
64
CUMULATIVE NET NATURAL GAS ACHIEVABLE POTENTIAL BY COMMERCIAL CUSTOMER SEGMENT (MMTHERMS/YEAR)(BUSINESS AS USUAL)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044
Sa
v
i
n
g
s

P
o
t
e
n
t
i
a
l

(
M
M
T
h
e
r
m
s
/
y
e
a
r
)
Com-Retail
Com-Other
Com-Office
Com-Manufacturing/Industrial
Com-Lodging
Com-Light/Converted
Com-Healthcare
Com-Food Service
Com-Education
65
SCENARIOS
•Increasein adoption parameters for customer awareness and willingness to adopt EE technologies.
• Incentives at 50%incremental
cost.
Unconstrained Historical
Budget
• Assumes a ramp up of customer adoption through 2029 driven by increased IGC program activity
•Without constraining program spending to historical levels.
• Incentives at 50%incremental cost.
Medium Adoption High Adoption,
High Incentive
•Further increased adoption
parameters for customer awareness and willingness to adopt to highest levels based on Guidehouse’s experience and rules of thumb.
• Incentives at 65% incremental cost.
66
61 62
63 64
65 66
TOTAL NATURAL GAS ENERGY (MMTHERMS/YEAR) CUMULATIVE NET ACHIEVABLE POTENTIAL BY SCENARIO
0
20
40
60
80
100
120
Sa
v
i
n
g
s

P
o
t
e
n
t
i
a
l

(
M
M
T
h
e
r
m
s
/
y
e
a
r
)
Business as Usual Unconstrained Historic Budget Medium Adoption High Adoption, High Incentive
67
CUMULATIVE NET NATURAL GAS ENERGY ACHIEVABLE SAVINGS BY SCENARIO
0
50
100
150
200
250
300
350
Sa
v
i
n
g
s

P
o
t
e
n
t
i
a
l

(
M
M
T
h
e
r
m
s
/
y
e
a
r
)
Technical Economic Business as Usual
Unconstrained Historic Budget Medium Adoption High Adoption, High Incentive
68
QUESTIONS?QUESTIONS?
69
BREAKBREAK
70
SUPPLY & DELIVERY RESOURCES
ERIC WOOD
SUPERVISOR, GAS SUPPLY
What’s the goal? To meet the energy needs and expectations of our customers:
Reliability (365 days per year)
Security (delivery on the coldest day)
Competitive and stable prices through a mix is fixed priced hedges
Efficiently meet future growth
Frequently evaluate the portfolio
GAS SUPPLY PLANNING
72
67 68
69 70
71 72
NATURAL GAS SUPPLIES
What are Traditional Supply Resources?
Natural gas supply; the molecules or “commodity”
Interstate pipeline capacity
Storage facility capacity
Energy Efficiency
What are Non-Traditional
Supply Resources?
Renewable Natural Gas
Hydrogen
73
NATURAL GAS SUPPLIES
Where Does "Our" Gas Come From?
Canadian gas supply (~90%)
British Columbia
Alberta
Rockies’ gas supply (~10%)
Wyoming, Colorado, Utah etc.
Access to supply somewhat dependent upon available transport capacity
74
North
American
gas plays
75
Gas Supply Forecast - Observations
Robust increase in shale gas production
Mature basins (WCSB, gulf on & offshore)
Today: ample supply vs demand
NATURAL GAS SUPPLIES
76
NATURAL GAS PRODUCTION BY PLAY 2007-2023
Source: EIA 77
U.S. NATURAL GAS CONSUMPTION BY SECTOR
Bc
f

p
e
r

d
a
y
Source: EIA AEO2021
78
73 74
75 76
77 78
Gas Supply - Pricing
Natural gas is a commodity and market is liquid
Price follows supply and demand fundamentals
Price history & forecast
NATURAL GAS SUPPLIES
79
HISTORIC GAS PRICES
80
Enbridge Explosion
RECENT HISTORIC GAS PRICES
Winter 2023 Low Storage/Pipeline Constraints
$-
$10.0000
$20.0000
$30.0000
$40.0000
$50.0000
Historic Pricing
SUMAS ROCKIES NYMEX AECO (US$)
81
Intermountain's IRP Price Forecast
Intermountain’s long-term planning price forecast is based on a blend of current market pricing along with long-term fundamental price forecasts.
The fundamental forecasts include sources such as Wood Mackenzie, EIA, the Northwest Power and Conservation Council (NWPCC), Bentek and the Financial Forecast Center’s long-term price forecasts.
Used weighted prices from the sources based on historical performance, beginning in year two of the forecast.
While not a guarantee of where the market will ultimately finish, Henry Hub NYMEX is 100% of the forecast for the first year as it is the most current information that provides some direction as to future market prices.
Intermountain is gathering Renewable Natural Gas information and plans to model RNG as a potential resource in the upstream optimization process.
NATURAL GAS PRICE FORECAST
82
Preliminary Weights:Sumas – 10%Rockies – 10%AECO – 80%
INTERMOUNTAIN'S IRP PRICE FORECAST
83
INTERMOUNTAIN GAS COMPANY
2023-28 INTEGRATED RESOURCE PLAN
INTERSTATE TRANSPORTATION AND STORAGE RESOURCES
79 80
81 82
83 84
Intermountain holds firm, long-term contracts for interstate capacity on four (4) pipelines - two U.S. and two Canadian
All gas directly delivered to Intermountain comes through the Williams Northwest system
Firm capacity on Northwest is determined at both receipt and delivery points
INTERSTATE TRANSPORTATION AND STORAGE RESOURCES
85
Interstate Transportation Capacity – cont.
Delivery to Intermountain Service Territory
Firm Capacity Held Directly by Intermountain
City Gate Delivery Direct from Suppliers
Capacity Segmentation
Capacity Release and Mitigation for Intermountain
Market forces drive new capacity projects
INTERSTATE TRANSPORTATION AND STORAGE RESOURCES
86
NORTHWEST PIPELINE,
GTN, NOVA AND
FOOTHILLS
87
CAPACITY RESOURCES
2021 2022 2023 2024 2025 2026
Sumas (3k is winter only)0 0 0 0 0 0
Stanfield 221,565 221,565 221,565 221,565 221,565 221,565
Rockies 106,478 106,478 106,478 59,328 59,328 59,328
Citygate 10,000 10,000 10,000 - - -
Total Capacity 338,043 338,043 338,043 280,893 280,893 280,893
Storage Withdrawals with Bundled Capacity 185,512 185,512 185,512 155,175 155,175 155,175
Maximum Deliverability 523,555 523,555 523,555 436,068 436,068 436,068
Northwest Daily Maximum Transportation Capacity (MMBtu)
88
What is storage?
Natural or man-made structures where natural gas can be injected and stored for later retrieval
Gas is normally injected during periods of lower demand and lower prices
Gas is usually withdrawn during periods of higher demand
and higher prices
STORAGE RESOURCES
89
Why do we need storage?
Demand curve is not linear
Annual supply curve somewhat linear
Transport capacity is very linear
Not feasible to meet peak demand with only interstate capacity and must-take gas purchases alone
Storage enhances winter/peak delivery capability and minimizes costs by balancing flat supply with seasonal demands
STORAGE RESOURCES
90
85 86
87 88
89 90
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
1 25 49 73 97 121 145 169 193 217 241 265 289 313 337 361
MM
B
t
u

(
0
0
0
'
s
)
Example Load Duration CurveWith Only Storage and Gas Supply
Transport CapacityStorage W ithdrawals
Storage Injections
91
Uses
“Needle” peaking
Winter baseload
Day-to-day load balancing
Natural gas price hedge
System integrity/emergency issues
Types
Liquefied Storage (LNG)
Underground
STORAGE RESOURCES
92
Liquefied Storage Characteristics
Natural gas is liquefied @ minus 260°F
Liquid occupies 1/600 volume of vapor
Nearly pure methane, non-corrosive, non-toxic and yes, SAFE
High regasification/withdrawal capability
Ideal for needle peaking, system balancing and system integrity issues
STORAGE RESOURCES
93
Liquefied Storage Characteristics
Liquefaction is slow which limits ability to cycle
inventory
Liquefaction is energy intensive high cycling and inventory cost
Generally stored in above-ground tanks
No methane is released into the atmosphere
STORAGE RESOURCES
94
PLYMOUTH LNG FACILITY
95
Underground Storage Characteristics
Gas is injected under pressure into developed salt domes, depleted well structures, underground aquifers or other porous geological formations
Maximum daily withdrawal less than liquid storage; operating capability is dependent upon inventory level and pressure
Injections comparatively faster and cycling costs are lower than liquid storage; multiple inventory cycles can enhance cost effectiveness
STORAGE RESOURCES
96
91 92
93 94
95 96
Location & Type of Storage used by Intermountain
Nampa, ID LNG – liquid (Intermountain)
Plymouth, WA LNG – (Northwest Pipeline)
Rexburg, ID Satellite LNG (Intermountain)
Jackson Prairie - underground aquifer in western WA (Northwest Pipeline)
Clay Basin - underground depleted well reservoir in NE Utah (Questar Pipeline)
STORAGE RESOURCES
97
STORAGE RESOURCES - LOCATIONS
98
STORAGE RESOURCES
Daily Withdrawal Daily Injection
Facility SeasonalCapacity % ofNov-Mar Maximum% of Peak Max Vol # of DaysRedeliveryCapacity
Nampa 600,000 1%60,000 16%3,500 166 None
Plymouth*1,475,135 4%155,175 43%12,500 213 TF-2
Jackson Prairie 1,092,099 3%30,337 8%30,337 36 TF-2
Clay Basin 8,413,500 20% 70,114 19% 70,114 120 TF-1
Grand Total 11,580,734 28%315,626 86%116,451
Intermountain’s 2023/24 Storage Statistics (MMBtu)
99
0
50
100
150
200
250
300
350
400
450
1 15 29 43 57 71 85 99 113 127 141 155 169 183 197 211 225 239 253 267 281 295 309 323 337 351 365
MM
B
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Days
Sample LDC with Efficient Mix of All Supply Resources
Storage Not Needing Interstate Citygate Delivered
Storage & Winter Gas Needing Interstate
Year round Gas
Transport Capacity
Storage Injections
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QUESTIONS?QUESTIONS?
FEEDBACK SUBMISSIONS
[e-mail]
Please provide comments and feedback within 10
days
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THIRD MEETING
August 2, 2023, 9:00 a.m. - Noon
Potential Capacity Enhancements
Resource Optimization
Planning Results
Remaining IRP Process
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IGRAC #2
Date & time: 6/8/2023, 9:00 AM to 12:00 PM MT
Location: Microsoft Teams Meeting
Presenters: Mark Sellers-Vaughn, Jenny De Boer, Kathleen Campbell, Zachary Sowards, Min Park, Kathy Wold, Eric Wood
In attendance: Mark Sellers-Vaughn, Jenny De Boer, Kathleen Campbell, Zachary Sowards, Min Park, Kathy Wold, Eric Wood, Bruce Folsom, Kevin Connell, Mathew Hunter, Michael Parvinen, Nicole Gyllenskog, Rick Keller, Kevin Keyt, Teresa McKnight, Jason Barnes, Jason Talford, Taylor Thomas, Jett Hawk, Kristen Sreda, Devin McGreal

Introduction
Mark Sellers-Vaughn opened the meeting by welcoming and thanking stakeholders for participating in Intermountain’s IRP Process. Mark then proceeded with introductions, the agenda, and a reminder of the
stakeholder engagement goals. Jenny De Boer presented a safety moment.

Presentation #1 – Distribution System Modeling (Kathleen Campbell, Zachary Sowards)
• System Dynamics
o Pipeline diameter ½” to 16” o Operating pressure 60psi to 850psi
• Model System in Synergi
• Peak Heating Degree Day o Peak HDD = 65 – Average Daily Temp
• Fixed Network
o Can read meters on ongoing basis rather than manual monthly reads o IGC has a goal of reading 90% of meters through Fixed Network by the end of 2023
o Currently 61% of meters are read through Fixed Network
• System Deficits o Pipeline bottleneck
o Minimum inlet pressure to compressor o Component limiting capacity
Question: “What is the compressor station for?” Answer: “Compressors will boost pressure on a lateral. Instead of running another pipeline, a compressor can be used to solve pressure issues for long laterals
such as the Sun Valley Lateral.” -Kathleen Campbell Question: “What level of granularity is used in the model?” Answer: “They run at a higher level as to not inundate the model with too much data, I will get into this later on in the presentation” -Kathleen Campbell Question: “Do you look at gas quality and BTU to make sure you are getting what you are paying for?” Answer: “We check Williams and have our own BTU zones to ensure proper billing.” – Kathleen Campbell Question: “Are you able to increase pressure on 60psi pipes?” Answer: “Every pipeline has an MAOP (max allowable operating pressure) and anything
over that would be subject to an upgrade.” – Kathleen Campbell Question: “How do you determine which pipeline size you upgrade to on expansions?”
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Answer: “We look at a 5-year snapshot to make sure we don’t over-project the need. There are certain areas with exceptions such as Boise and Nampa which have had incredibly high growth in the last couple years.” – Kathleen Campbell Presentation #2 – Avoided Cost Methodology (Min Park)
• Nominal Avoided Cost per Therm = Commodity Cost + Transportation Cost + Variable Distribution Cost o Commodity Cost Calc
 Calc starts with internal 30-year price forecasts for three primary basins
(weighted on day gas purchase data)
 Heating Degree Day used to shape monthly prices, based off 65 degrees o Transportation Cost Calc
 Cost of reserving additional capacity on Northwest Pipeline o Distribution Cost Calc
 Energy efficiency can lead to delaying or even avoiding costly pipeline expansions Question: “Is the inflation rate commonly used in the calculation?” Was it used in years past?” Answer: “In previous years, we also used inflation rate but it increased this year as it is based on a five-year average.” – Min Park Question: “Previous years’ costs all seem relatively even but for updated costs there is a lot of variability, can you explain what is driving this change?” Answer: “The numbers are based off gas prices by year, they are weighted based off HDD shaping. Inflation caused a change in gas prices.” – Min Park Question: “Gas prices are always up and down and previous years don’t reflect this volatility, is there a change in HDD shaping methodology?” Answer: “I don’t think there was a big difference in shaping I think it was due to the pricing we saw earlier this year and inflation.” – Min Park Answer: “We can look into this and provide more explanation as to why we saw this in the current IRP, but the pricing volatility from this winter certainly has had an effect.” – Mark Sellers-Vaughn Question: “What stakeholders are you working with?” Answer: “I am not sure, I was just told stakeholders.” – Min Park Answer: “I think it would be Intermountain walking through the methodology and soliciting feedback through the process.” – Mark Sellers-Vaughn Question: “Specifically what committee would the distribution costs be discussed in of the four stakeholder meetings?” Answer: “I believe it would be the Avoided Cost Sub-Committee.” – Kathy Wold Comment: “Please cover how the inflation rate has been included in this calculation in the past during the sub-committee meeting. Also please address it in the next IGRAC.” Presentation #3 – Energy Efficiency (Kathy Wold)
• Demand Side Management
o Option A: purchase MMbtu from supplier o Option B: purchase energy efficiency programs through customers
• Incentives can stack on top of each other
• Conservation Potential Assessment o Assess achievable energy savings potential o Apply results
• What is CPA? o Technical Potential
 Total energy savings available relevant to population
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o Economic Potential
 Cost effectiveness
o Achievable Potential
 EE expected to be adopted by programs Question: “What is a HERS rating?” Answer: “Home Energy Rating System is a third party who rates new builds by energy efficiency. They perform tests and give an energy efficiency score. This measures items that are important to energy savings.” – Kathy Wold Question: “The whole home incentives stacked with the smart thermostat incentives may
have some overlap, do you have any insight on how these can be disentangled?” Answer: “I am unsure about the specifics of that, but I will check and follow up.” – Kathy
Wold Question: “For the modeling in the Base case of the IRP which model are you looking to use?” Answer: “The conservative scenario would be using business as usual, but we will be
working with the IRP team to decide which scenario to use.” – Kathy Wold Question: “What is considered a lot versus a little therm savings when looking at DSM
commercial savings?” Answer: “All savings are good savings; in terms of our commercial program it is new in development and small in comparison to the residential program.” – Kathy Wold Question: “What avoided cost are we using, the one from the previous slides?” Answer: “We are using the avoided cost calculation that comes from the Resource Planning Team which Min was referencing in the previous slides.” – Kathy Wold
Presentation #4 – Supply Resources and Transportation & Storage Resources (Eric Wood, Jenny
De Boer)
• Gas Supply Planning o Reliability o Security o Competitive and stable prices o Efficiently meet future growth o Frequently evaluate portfolio
• Traditional Supply Resources o Natural Gas Supply
o Pipeline Capacity o Storage Capacity
o Energy Efficiency
• Non-Traditional Supply Resources o Renewable Natural Gas
o Hydrogen
• Storage Resources o Use
 Needle peaking
 Winter baseload
 Day-to-day load balancing
 Gas price hedge
 Emergency issues o Types
 Liquefied Storage
 Underground Question: “What is “lease and plant other” on the graph?” Answer: “I am unsure, this is from EIA so I will have to look into that.” – Eric Wood
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Question: “What is the arrangement pertaining to ownership of JP and Clay Basin storage facilities?” Answer: “We don’t own capacity, we lease it from them.” – Eric Wood Question: “How does needle peaking work with capacity on the pipeline?” Answer: “Usually we use LNG for needle peaking because we can draw greater amounts more quickly, it is a little different than normal capacity on the pipeline. We use a
separate contract only for storage to get the gas to the distribution system. Nampa and Rexburg are located behind the citygate so don’t require excess upstream pipeline capacity.” – Eric Wood Question: “In the past when market price was more predictable, after the end of the heating
season gas was cheap and we used that to fill storage. Now that doesn’t seem to be the case. It seems as if storage doesn’t seem to work as a hedge anymore, is
that accurate?” Answer: “Last summer we had delayed summer injections due to higher prices, but we still found times to buy cheaper fill gas. This continues into the current year as hydropower kicks up in May and June and allows us to capitalize on cheaper gas
than we tend to see in late summer.” – Eric Wood Question: “Can you explain your hedging portfolio a bit?” Answer: “The hedging portfolio is mostly handled by our marketer IGI. It is a three-year portfolio under constant evaluation. We provide them with a forecast for the year, the front of every month, and the daily forecast so IGI can plan to buy for storage or day gas for demand.” – Eric Wood Quesiton: “Was Intermountain exposed to volatile pricing this winter? How much was hedging able to help?” Answer: “Intermountain was shielded a bit, as they buy less from sumas. Intermountain was positioned well this last winter, they were exposed to some day gas pricing
but tried to rely more on long term contracts and gas from storage.” – Eric Wood The Meeting was Adjourned Action Items:
1. Look in the work papers to see how inflation has been included in Avoided Cost calculations
in this past IRP cycle and previous cycles to determine how the methodology has changed. 2. Follow up on how the overlap of stacking entire-system and smart thermostat energy
efficiency programs contributes to double counting or how it is disentangled.
INTEGRATED RESOURCE PLAN
AUGUST 2, 2023
INTERMOUNTAIN GAS RESOURCE ADVISORY COMMITTEE (IGRAC)
WELCOME
Introductions
Feedback Process
Agenda
FEEDBACK SUBMISSIONS
[e-mail]
Please provide comments and feedback within 10 days
AGENDA
Welcome & Introductions – Brian Robertson (Supervisor, Resource Planning)
Safety Moment – Devin McGreal (Sr, Resource Planning Economist)
Load Demand Curves –Brian Robertson (Supervisor, Resource Planning)
Potential Capacity Enhancements – Kathleen Campbell (Engineer III, Engineering Services)
Resource Optimization –Jenny De Boer (Resource Planning Economist I), Brian Robertson (Supervisor, Resource Planning)
Questions/Discussion
Demand Supply & Delivery Resources
Economic Overview
Residential & Commercial Customer Growth
Load Demand Curves
Industrial Demand
Design
WeatherResidential & Commercial Usage Per Customer
Optimization Modeling
Transportation Capacity & Storage Distribution System Overview
Demand Supply & Deliverability
Energy Efficiency:
Residential & Commercial
Natural Gas Supplies
Non-Traditional Resources
System Enhancements
Demand Supply
SAFETY MOMENT
DEVIN MCGREAL
SR. RESOURCE PLANNING ECONOMIST
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LOAD DEMAND CURVES
BRIAN ROBERTSON
SUPERVISOR, RESOURCE PLANNING
LOAD DEMAND CURVE KEY VARIABLES
Based on Design Weather Conditions
Low, Base and High Growth Core Market Customer Projections
Customer Usage Per Degree Day
MDFQ for Large Volume Customers
PEAK SEASON CORE MARKET LOAD DEMAND CURVE
METHODOLOGY
Usage/Customer per Degree Day Forecasted Core Customers
Total Daily Usage
Large Volume MDFQ
Total Daily Usage
Demand Side Management
HDD
LOAD DEMAND CURVE
Load Demand Curve: A forecast of Daily Gas Demand Using ‘Design’ Temperatures, and Predetermined ‘Usage Per Customer’
Designed to Measure Distribution Capacity at Our 5 Areas of Interest (AOIs)
To Measure Total Company for Upstream Capacity
Based on Current Resources or Resources Scheduled to be Available During the IRP Period
Remedies for Any Constraints Will be Identified Later
Storage Management
CAPACITY RESOURCES
2023 2024 2025 2026 2027 2028
Sumas (3k is winter only) 3,000 0 0 0 0 0
Stanfield 221,565 221,565 221,565 221,565 221,565 221,565
Rockies 106,478 106,478 106,478 59,328 59,328 59,328
Citygate 10,000 10,000 10,000 - - -
Total Capacity 341,043 338,043 338,043 280,893 280,893 280,893
Storage Withdrawals with Bundled Capacity 185,512 185,512 185,512 155,175 155,175 155,175
Maximum Deliverability 526,555 523,555 523,555 436,068 436,068 436,068
Northwest Daily Maximum Transportation Capacity (MMBtu)
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•Intermountain has segmented
capacity from Sumas to IGC at Stanfield. Intermountain owns Stanfield to IGC.
•Stanfield Capacity is dependent on GTN, including GTN
Xpress which is expected to be online in 2023.•Intermountain is receiving approximately 21,000 dth/day capacity on NOVA, Foothills, and GTN on April 1, 2024.
•On-System Storage is 65,000 dth/day.
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DESIGN
CAPACITY OF
DISTRIBUTION
SYSTEM
Idaho Falls Lateral
Sun Valley Lateral
Canyon County Lateral
State Street Lateral
Central Ada County
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QUESTIONS?QUESTIONS?
KATHLEEN CAMPBELL, P.E. - SENIOR ENGINEER - ENGINEERING SERVICES
ZACHARY SOWARDS - ENGINEER III – ENGINEERING SERVICES
IGRAC #2 COVERED:
System dynamics
Synergi model process
Identification of system deficits/constraints
Distribution enhancement/reinforcement options to address deficit
Enhancement considerations and selection process into 5-year budget
THIS PRESENTATION WILL COVER:
Project needs to support core growth for each AOI
Alternative Analysis to resolve deficit (if it has not already been covered in a previous IRP)
Timing, Cost and capacity gained for each project/alternative.
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OTHER AOI
Reinforcements required to meet 2028 growth predictions
Payette Gate Upgrade
2024 - $3.49M
New Plymouth Gate Upgrade
2024 - $2.67M
CANYON COUNTY AOI
Requires reinforcements by 2023 to meet IRP growth predictions
AOI capacity limiter: 6-inch, 8-inch and 10-inch HP bottleneck on Ustick Rd
Alternatives considered were discussed in 2021 IRP
Ustick Phase III was selected in 2021 IRP
Ustick Phase III has been designed and permitted and will begin construction in August 2023
Ustick Phase III is estimated to cost $12.8M
CANYON COUNTY - BOTTLENECK CANYON COUNTY : USTICK PHASE III
STATE STREET LATERAL AOI
Requires reinforcements by 2025 & 2026 to meet IRP growth predictions
AOI Capacity Limiter: 12-inch HP bottleneck on State Street and 4 in HP bottleneck on Linder Rd & State Penn
(Boise #2) Gate Capacity
Alternatives considered for 12-inch HP & 4- HP bottleneck were discussed in 2021 IRP
State Street Phase II Uprate was selected in 2021 IRP
State Street Phase II is budgeted for 2024
State Street Phase II is estimated to cost $902K
State Penn Gate Upgrade is budgeted for 2025 Design and 2026 Construction
State Penn Gate Upgrade is estimated to cost $2.73M
STATE STREET AOI - BOTTLENECK
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STATE STREET PHASE II UPRATE CENTRAL ADA COUNTY AOI
Requires reinforcements by 2023 to meet IRP growth predictions
AOI Capacity Limiter: 10-inch and 8-inch HP bottleneck on Meridian Rd and Victory Rd
Alternatives considered were discussed in 2021 IRP
12-inch South Boise Loop was selected in 2021 IRP
12-inch South Boise Loop will be online in Fall of 2023
12-inch South Boise Loop is estimated to cost $17.9M
CENTRAL ADA COUNTY AOI - BOTTLENECK 12-INCH SOUTH BOISE LOOP
SUN VALLEY LATERAL AOI
Requires reinforcements by 2023 to meet IRP growth predictions.
AOI Capacity Limiter: End of line pressure to Ketchum area
Alternatives considered were discussed in the 2019 IRP
Shoshone Compressor Station was selected in 2019 IRP
Shoshone Compressor Station is scheduled for commissioning in August
Shoshone Compressor Station is estimated to cost $6.7M
SUN VALLEY LATERAL AOI - BOTTLENECK
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SHOSHONE COMPRESSOR STATION IDAHO FALLS LATERAL AOI
Requires reinforcements by 2024 to meet IRP growth predictions.
AOI Capacity Limiter: End of line pressure to St. Anthony’s
Alternatives considered were discussed in the 2021 IRP
Blackfoot Compressor Station was selected in 2021 IRP
Blackfoot Compressor Station has been ordered and will be installed in 2024
Blackfoot Compressor Station is estimated to cost $20M
IDAHO FALLS AOI - BOTTLENECK BLACKFOOT COMPRESSOR STATION
AOI CAPACITY SUMMARY AND TIMING NEEDS:
Year Ada County AOI Capacity (th/day)
Ada County AOI Reinforcement Required
State Street Lateral AOI Capacity (th/day)
State Street Lateral AOI Reinforcement Required
Canyon County AOI Capacity (th/day)
Canyon County AOI Reinforcement Required
Sun Valley Lateral AOI Capacity (th/day)
Sun Valley AOI Reinforcement Required
Idaho Falls Lateral AOI Capacity (th/day)
Idaho Falls AOI Reinforcement Required
2023 870,000 12-inch S Boise Loop 820,000 None 1,390,000.00 12-inch Ustick Phase III 247,500Shoshone Compressor Station 904,000.00 None
2024 870,000 None 820,000 None 1,390,000.00 None 247,500None 1,093,000.00 IFL Compressor Station
2025 870,000 None 950,000 State Street Uprate 1,390,000.00 None 247,500None 1,093,000.00 None
2026 870,000 None 950,000 State Penn Gate Upgrade 1,390,000.00 None 247,500None 1,093,000.00 None
2027 870,000 None 950,000 None 1,390,000.00 None 247,500None 1,093,000.00 None
2028 870,000 None 950,000 None 1,390,000.00 None 247,500None 1,093,000.00 None
QUESTION OR COMMENTS ON:
QUESTIONS?
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IRP OPTIMIZATION MODEL
JENNY DE BOER; RESOURCE PLANNING ECONOMIST I
BRIAN ROBERTSON; SUPERVISOR, RESOURCE PLANNING
Draft Design Base Results
Demand Supply & Delivery Resources
Economic Overview
Residential & Commercial Customer GrowthIndustrial Demand
Design Weather
Design Residential &
Commercial Usage
Transportation, Capacity & Storage Distribution System Overview
Supply & Deliverability
Energy Efficiency –
R&C
Natural Gas Supplies
Non-Traditional
Resources
Demand Supply
Load Demand Curves
Optimization Modeling
Demand
System Enhancements
IRP OPTIMIZATION MODELING
IGC IRP Model “Integrates”/Coordinates all the main functional elements of IGC operation:
Gas Demand/Load, how much & where is gas consumed, “Load Duration Curve” (LDC) by area of interest.
Gas Supply, from where, how much, and what price is gas supplied to meet demand (LDC).
Gas Transport, how does gas move from supply to demand area given pipeline size and prices.
Demand Side Management (DSM), cost effective energy efficiency is used to reduce demand
Local Gas Distribution, local lateral sizing is explicitly modeled to meet demand & ensure reliability
The IRP model utilizes PLEXOS®, a linear optimization model, to determine the least cost manner to have loads served by supply, transport, DSM & laterals.
All results presented here are draft subject to further IGC review.
WHAT IS OPTIMIZATION?
Utilizes a standard mathematical technique called “linear programming” …to optimize over all possible combinations.
The model knows the exact load and price for every day of the planning period based on the analyst’s input and can therefore minimize costs in a way that would not
be possible in the real world.
Therefore, it is important to recognize that linear programming analysis provides
helpful but not perfect information to guide decisions.
Selects from a mix of resources over planning horizon to meet forecasted loads.
MODEL ELEMENTS
Functional components:
Demand forecast (Area’s of Interest)
Traditional supply resources
Existing and potential gas supplies by basin
Storage resources
Transportation capacity resources
Price forecast
Non-traditional supply e.g., new distribution capacity, RNG, DSM etc.
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MODEL
STRUCTURE
Transport, Storage, Supply, & Demand Areas to Idaho (IGC))
MODEL
STRUCTURE
Transport
•Transportation contracts are the means of how Intermountain gets the gas from
the supplier to the end user.
•Transportation has an MDQ, a
Reservation Charge (D1 rate), a Flow Charge (transportation rate), and a fuel loss percentage.
•A maximum delivery quantity (MDQ) which is the maximum amount of gas Intermountain can move on the pipeline on a single day.•A D1 rate which is the reservation rate to have the ability to move the MDQ amount on the pipeline.•A transportation rate which is the rate per dekatherm that is actually moved on the pipeline.•The fuel loss percentage is the statutory percent of gas based on the tariff from the pipeline that is lost and unaccounted for from the point of where the gas was purchased to the citygate.
MODEL
STRUCTURE
Storage
•Intermountain has storage at 5 locations: Jackson Prairie (JP), Plymouth
(Ply), Clay Basin, Nampa, and Rexburg.•Storage injections targets are set at 35% by the end of June, 80% by the end
of August, and 100% by the end of September to emulate cycling storage
for non-needle peaking storage.
•Intermountain can withdrawal approximately 30,377 dth per day from JP, 155,175 dth per day from Plymouth, and 70,144 dth per day from Clay Basin for a total of approximately 255,626
dth per day of off-system storage.
•Intermountain can withdrawal approximately 60,000 dth per day from
Nampa and 5,500 dth per day from Rexburg for a total of approximately 65,500 dth per day of on-system
storage.
MODEL
STRUCTURE
Supply
•Intermountain can purchase gas at three markets; AECO, SUMAS, and OPAL.
•At each market Intermountain can purchase gas at different
locations along the pipeline.•For each year, Intermountain uses Base, Winter base,
Summer and Winter day gas, and Peak day incremental supplies as inputs.
•Over the planning horizon, the contracts are renewed in November and April.
MODEL
STRUCTURE
Supply
MODEL
STRUCTURE
Demand Area
•Demand is forecasted at the five areas of interest, as well as all other customers.
•Demand is determined by the load demand curves.
•Each area of interest has DSM, which decrements demand at the avoided cost price.
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MODEL
STRUCTURE
Transport, Storage, Supply, & Demand Areas to Idaho (IGC))
DRAFT MODEL
RESULTS -
LATERALS
Lateral Capacity Summary By Year
2023Base Year (Dth)Area of Interest Core Peak Day Deliverability % of Deliverability Total Peak Day Capacity % of CapacityIDAHO FALLS 66,430 65,434 102% 86,121 90,400 95%SUN VALLEY 18,074 17,803 102% 19,784 20,000 99%CANYON COUNTY 77,739 76,572 102% 101,399 103,200 98%
STATE STREET 74,536 73,418 102% 75,346 82,000 92%
CENTRAL ADA 72,896 71,803 102% 72,996 74,500 98%ALL OTHER 179,722 177,025 102% 276,942
2024Year 2 (Dth)Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 68,118 68,022 100% 86,609 90,400 96%SUN VALLEY 18,330 18,304 100% 20,040 20,000 100%CANYON COUNTY 80,650 80,536 100% 104,310 103,200 101%STATE STREET 76,141 76,034 100% 76,951 82,000 94%CENTRAL ADA 74,488 74,383 100% 74,588 74,500 100%
ALL OTHER 183,036 182,777 100% 280,656
2025Year 3 (Dth)Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 69,832 68,195 102% 88,423 90,400 98%SUN VALLEY 18,586 18,150 102% 20,296 20,000 101%CANYON COUNTY 83,549 81,591 102% 107,409 103,200 104%STATE STREET 77,743 75,920 102% 78,553 82,000 96%CENTRAL ADA 76,077 74,294 102% 76,177 74,500 102%ALL OTHER 186,272 181,905 102% 283,892
DRAFT
MODEL
RESULTS -LATERALS
2026Year 4 (Dth)
Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 71,533 57,738 124% 90,124 90,400 100%SUN VALLEY 18,838 15,205 124% 20,548 20,000 103%CANYON COUNTY 86,620 69,916 124% 110,480 103,200 107%
STATE STREET 79,343 64,042 124% 80,153 82,000 98%
CENTRAL ADA 77,664 62,687 124% 77,764 74,500 104%ALL OTHER 189,530 152,980 124% 287,570
2027Year 5 (Dth)
Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 73,239 57,862 127% 91,870 90,400 102%SUN VALLEY 19,093 15,084 127% 20,803 20,000 104%CANYON COUNTY 89,520 70,725 127% 113,380 103,200 110%STATE STREET 80,942 63,948 127% 81,752 82,000 100%
CENTRAL ADA 79,251 62,612 127% 79,351 74,500 107%ALL OTHER 192,821 152,337 127% 291,461
2028Year 6 (Dth)
Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 74,943 57,977 129% 93,574 90,400 104%SUN VALLEY 19,348 14,968 129% 21,058 20,000 105%CANYON COUNTY 92,441 71,513 129% 116,301 103,200 113%STATE STREET 82,542 63,856 129% 83,352 82,000 102%
CENTRAL ADA 80,838 62,537 129% 80,938 74,500 109%ALL OTHER 196,116 151,718 129% 294,806
DISTRIBUTION SYSTEM SHORTFALL SOLVES
ADA County – Bend 12-inch S Boise Loop
State Street – State Street Uprate and State Penn Gate Upgrade
Canyon County – 12-inch Ustick Phase III
Sun Valley Lateral – Shoshone Compressor Station
Idaho Falls – IFL Compressor Station
TRANSPORTATION SHORTFALL SOLVES
Contract Renewals
GTN Xpress
Alternative Transportation Uptake
Renewable Natural Gas
Others?
DRAFT MODEL
RESULTS -
LATERALS
Lateral Capacity Summary By Year
2023Base Year (Dth)Area of Interest Core Peak Day Deliverability % of Deliverability Total Peak Day Capacity % of CapacityIDAHO FALLS 66,430 76,156 87% 86,120 90,400 95%SUN VALLEY 18,070 20,716 87% 19,780 24,750 80%CANYON COUNTY 77,740 89,122 87% 101,400 139,000 73%STATE STREET 74,540 85,454 87% 75,350 82,000 92%CENTRAL ADA 72,900 83,574 87% 73,000 87,000 84%ALL OTHER 179,720 206,034 87% 276,940
2024Year 2 (Dth)Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 68,060 78,775 86% 86,550 109,300 79%SUN VALLEY 18,320 21,204 86% 20,030 24,750 81%CANYON COUNTY 80,560 93,243 86% 104,220 139,000 75%STATE STREET 76,040 88,012 86% 76,850 82,000 94%CENTRAL ADA 74,390 86,102 86% 74,490 87,000 86%ALL OTHER 182,920 211,719 86% 280,540
2025Year 3 (Dth)Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 69,720 78,982 88% 88,310 109,300 81%SUN VALLEY 18,570 21,037 88% 20,280 24,750 82%CANYON COUNTY 83,380 94,457 88% 107,240 139,000 77%STATE STREET 77,550 87,852 88% 78,360 95,000 82%CENTRAL ADA 75,880 85,960 88% 75,980 87,000 87%ALL OTHER 186,050 210,766 88% 283,670
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DRAFT MODEL RESULTS -LATERALS
2026Year 4 (Dth)
Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 71,350 75,440 95% 89,940 109,300 82%SUN VALLEY 18,810 19,888 95% 20,520 24,750 83%CANYON COUNTY 86,380 91,332 95% 110,240 139,000 79%
STATE STREET 79,060 83,592 95% 79,870 95,000 84%
CENTRAL ADA 77,380 81,816 95% 77,480 87,000 89%ALL OTHER 189,200 200,046 95% 287,240
2027Year 5 (Dth)Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 72,980 75,587 97% 91,610 109,300 84%SUN VALLEY 19,050 19,731 97% 20,760 24,750 84%CANYON COUNTY 89,210 92,397 97% 113,070 139,000 81%STATE STREET 80,570 83,449 97% 81,380 95,000 86%
CENTRAL ADA 78,870 81,688 97% 78,970 87,000 91%
ALL OTHER 192,390 199,264 97% 291,030
2028Year 6 (Dth)Area of Interest Core Peak Day Transport % of Transport Total Peak Day Capacity % of CapacityIDAHO FALLS 74,600 75,714 99% 93,230 109,300 85%SUN VALLEY 19,290 19,578 99% 21,000 24,750 85%CANYON COUNTY 92,070 93,445 99% 115,930 139,000 83%STATE STREET 82,080 83,306 99% 82,890 95,000 87%CENTRAL ADA 80,370 81,570 99% 80,470 87,000 92%ALL OTHER 195,580 198,501 99% 294,270
DRAFT MODEL RESULT GENERAL SUPPLY BALANCE
SUMMARY
Supply Area Oct-23 Nov-23 Dec-23 Jan-24 Feb-24 Mar-24 Apr-24 May-24 Jun-24 Jul-24 Aug-24 Sep-24
AECO 4,574,030 5,911,230 7,178,870 7,178,870 6,715,720 6,641,870 3,437,110 2,328,310 1,331,320 1,266,320 1,402,300 2,804,780 Sumas 310,000 - - - - 90,000 300,000 744,440 300,000 310,000 310,000 300,000
Rockies 310,000 - - - - - 300,000 310,000 300,000 310,000 310,000 300,000 ALL OTHER 3,540 3,430 3,540 3,540 3,320 3,540 3,430 3,540 3,430 3,540 3,540 3,430
CENTRAL ADA 3,070 2,970 3,070 3,070 2,870 3,070 2,970 3,070 2,970 3,070 3,070 2,970 CYN CNTY 2,750 2,660 2,750 2,750 2,570 2,750 2,660 2,750 2,660 2,750 2,750 2,660 ID FALLS 1,660 1,600 1,660 1,660 1,550 1,660 1,600 1,660 1,600 1,660 1,660 1,600 N STATE ST 3,040 2,940 3,040 3,040 2,840 3,040 2,940 3,040 2,940 3,040 3,040 2,940 SUN VLLY 180 180 180 180 170 180 180 180 180 180 180 180
Storage 0 - 1,874,520 4,408,850 1,610,840 121,550 0 0 0 0 0 0
DRAFT MODEL RESULT GENERAL SUPPLY BALANCE
SUMMARY
Year 6
Supply Area Oct-27 Nov-27 Dec-27 Jan-28 Feb-28 Mar-28 Apr-28 May-28 Jun-28 Jul-28 Aug-28 Sep-28AECO 2,556,690 3,104,670 6,277,900 6,160,670 5,843,340 4,014,720 1,544,050 1,423,950 1,233,110 1,274,210 1,284,210 1,508,470
Sumas 1,224,890 887,000 916,570 916,570 857,440 916,570 1,187,000 1,026,270 887,000 916,570 919,940 1,057,150 Rockies 1,232,980 1,193,210 1,232,980 1,232,980 1,153,430 1,232,980 1,493,210 1,232,980 1,193,210 1,232,980 1,232,980 1,193,210 ALL OTHER 16,640 16,100 16,640 16,640 15,570 16,640 16,100 16,640 16,100 16,640 16,640 16,100 CENTRAL ADA 14,430 13,960 14,430 14,430 13,500 14,430 13,960 14,430 13,960 14,430 14,430 13,960 CYN CNTY 11,630 11,250 11,630 11,630 10,880 11,630 11,250 11,630 11,250 11,630 11,630 11,250 ID FALLS 10,640 10,300 10,640 10,640 9,960 10,640 10,300 10,640 10,300 10,640 10,640 10,300 N STATE ST 14,260 13,800 14,260 14,260 13,340 14,260 13,800 14,260 13,800 14,260 14,260 13,800 SUN VLLY 1,830 1,770 1,830 1,830 1,710 1,830 1,770 1,830 1,770 1,830 1,830 1,770 Storage 0 1,199,150 1,385,180 4,270,210 1,164,770 1,239,120 0 0 0 0 0 0
DRAFT MODEL RESULT GENERAL SUPPLY BALANCE
SUMMARY
SUMMARY
Employs Utility Standard Practice Method To Optimize System
Models DSM & Storage
Handles storage withdrawal and injection across seasons
Provides a check on need for lateral expansion.
Provides a check on transport and supply capacity
QUESTIONS?QUESTIONS?
67 68
69 70
71 72
FEEDBACK SUBMISSIONS
[e-mail]
Please provide comments and feedback within 10 days
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IGRAC #3
Date & time: 8/2/2023, 9:00 AM to 12:00 PM MT
Location: Microsoft Teams Meeting
Presenters: Brian Robertson, Devin McGreal, Kathleen Campbell, Zachary Sowards, Jenny De Boer
In attendance: Mark Sellers-Vaughn, Brian Robertson, Devin McGreal, Kathleen Campbell, Zachary Sowards, Jenny De Boer, Nicole Gyllenskog, Eric Wood, Kevin Keyt, Rick Keller, Michael Parvinen, Min Park, Susan Davidson, Bruce Folsom, Teresa McKnight

Introduction
Brian Robertson opened the meeting by welcoming and thanking stakeholders for participating in Intermountain’s IRP Process. Brian then proceeded with introductions, the agenda, and a reminder of the stakeholder engagement goals. Devin McGreal presented a safety moment.

Presentation #1 – Load Demand Curves (Brian Robertson)
• Based on Design Weather Conditions
• Low, Base, and High Growth Core Market Customer Projections
• Customer usage per Degree Day
• MDFQ for Large Volume Customers
• Customer per Degree Day * HDD * Forecasted Core Customers = Total Daily Usage
• Total Daily Usage – Demand Side Management + Large Volume MDFQ = Total Daily Usage Question: “When you look at the total daily usage does that include DSM? It looks like DSM is double counted.” Answer: “The first total daily usage in the equation is through historic use and then forecasted future DSM is added in as well” – Brian Robertson Question: “Demand does not include interruptible, correct? Answer: “This is purely firm contract demand, no interruptible.” – Brian Robertson Presentation #2 – Potential Capacity Enhancements (Kathleen Campbell, Zachary Sowards)
• Reinforcements required to meet 2028 growth predictions o Payette Gate Upgrade, 2024
o New Plymouth Gate Upgrade, 2024
• Canyon County AOI o Requires enforcements by 2023 to meet IRP growth predictions
o Bottleneck on Ustick road
• State Street Lateral AOI o Requires enforcements by 2025 & 2026 to meet IRP growth predictions o Bottleneck on State Street and on Linder Road
• Central Ada AOI
o Requires reinforcements by 2023 to meet IRP growth predictions o Bottleneck on Meridian Road and Victory Road
• Sun Valley Lateral AOI o Requires enforcements by 2023 to meet IRP growth predictions
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o End of line pressure to Ketchum
• Idaho Falls Lateral AOI o Requires reinforcements by 2024 to meet IRP growth predictions Question: “If projects were accepted in a previous IRP, are they looked at again for each IRP cycle?” Answer: “Yes, they are looked over again to ensure they are necessary” – Kathleen
Campbell Question: “Doesn’t Payette include its own direct natural gas connection?” Answer: “I can check and follow up with that” – Kathleen Campbell Answer: “I can address that, nothing out there currently is being added to the Intermountain system” – Eric Wood Question: “Looking at phase III is that a reconstruction of an existing line?” Answer: “We had already done phase I and phase II, and the cost was prohibitive to run a new line, so we continued with the planned upgrade.” – Kathleen Campbell Question: “Could you give some insight on what it takes to upgrade?” Answer: “We have to go through pressure tests, apply for permits, physically do a leak survey, etc.” – Kathleen Campbell Question: “What type of compressors do you use are they natural gas fired or electric (Shoshone compressor)?” Answer: “It is natural gas fired.” – Zachary Sowards Question: “What is the discharge vs suction pressure (Blackfoot compressor station)?” Answer: “I will double check before writing the narrative, but discharge is 700 pounds and suction is 500 pounds.” – Zachary Sowards Comment: “It would be nice to see your upgrade summary include 2019/2021 IRP costs to see how much costs have increased.” Answer: “Yes, with inflation things have changed. I have provided current costs, but I can also provide previous costs. One of the cost drivers is the cost of land, especially in the Idaho Falls Lateral.” – Kathleen Campbell Question: “Do you do a full life cycle analysis of compressors when you evaluate type of compressors you use for these projects? Answer: “We did include Net Present Value calculations for these upgrades.” – Brian Robertson Question: “Does that include NPV for all compressor options?” Answer: “Yes, we did that for the compressor options including maintenance over a 20-year period.” – Kathleen Campbell Presentation #3 – Resource Optimization (Jenny De Boer, Brian Robertson)
• Transportation Shortfall Solves
o Contract Renewals o GTN Xpress
o Alternative Transportation Uptake o Renewable Natural Gas Question: “When did you start using PLEXOS?” Answer: “In the beginning of 2022” – Brian Robertson Question: “What is your time intervals associated with your model? Is it daily?” Answer: “Yes, it is daily.” – Brian Robertson Question: “Is PLEXOS used just for demand or is it also used for dispatch?” Answer: “We have only used PLEXOS for planning purposes so far.” – Brian Robertson Question: “Is your load looking into system constraints to meet the load?” Answer: “Yes, for our core customers” – Brian Robertson Question: “What is the measurement being used, dekatherms?” Answer: “Yes, dekatherms.” – Brian Robertson
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The Meeting was Adjourned Action Items: 1. Consider adding in 2019/2021 costs of the upgrade summary into the IRP narrative for
comparison with current price.