20250313Staff 23-27 to INT.pdf

RECIVED
CHRIS BURDIN MARCH 3E 025
DEPUTY ATTORNEY GENERAL IDAHO PUBLIC
IDAHO PUBLIC UTILITIES COMMISSION UTILITIES COMMISSION
PO BOX 83720
BOISE, IDAHO 83720-0074
[phone]
IDAHO BAR NO. 9810
Street Address for Express Mail:
11331 W CHINDEN BLVD, BLDG 8, SUITE 201-A
BOISE, ID 83714
Attorney for the Commission Staff
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF INTERMOUNTAIN )
GAS COMPANY'S APPLICATION FOR ) CASE NO. INT-G-24-05
DETERMINATION OF 2023 ENERGY )
EFFICIENCY EXPENSES AS PRUDENTLY )
INCURRED ) FOURTH PRODUCTION
REQUEST OF THE
COMMISSION STAFF
TO INTERMOUNTAIN GAS
COMPANY
Staff of the Idaho Public Utilities Commission, by and through its attorney of record,
Chris Burdin, Deputy Attorney General, requests that Intermountain Gas Company("Company")
provide the following documents and information as soon as possible, but no later than
THURSDAY,APRIL 3, 2025.
This Production Request is to be considered as continuing, and the Company is requested
to provide,by way of supplementary responses, additional documents that it, or any person
acting on its behalf, may later obtain that will augment the documents or information produced.
Please provide answers to each question, supporting workpapers that provide detail or are
the source of information used in calculations, and the name,job title, and telephone number of
the person preparing the documents. Please also identify the name,job title, location, and
telephone number of the record holder.
FOURTH PRODUCTION REQUEST
TO INTERMOUNTAIN GAS COMPANY 1 MARCH 13, 2025

In addition to the written copies provided as response to the requests,please provide all
Excel spreadsheets and electronic files with formulas intact and enabled.
REQUEST NO. 23: The Evaluation on page 9 states that the modeling analysis used for
the Whole Home program"aligns with the IPMVP Option D". The International Performance
Measurement and Verification Protocol ("IPMVP") Option D: Calibrated Simulation calls for
calibration of energy models using consumption data; however, the evaluation does not reference
calibration of its energy model. Please explain how the evaluator calibrated its Ekotrope model
as part of the modeling analysis. Additionally,please provide the following for any calibrations
conducted:
a. Please explain what time period and data set was used to calibrate the model;
b. Please explain how this data set is consistent with step 2 of IPMVP Table 9;
c. Please explain how this data set is representative of the actual operations of a
participant home;
d. Please provide a list of model input parameter adjustments made as a result of the
calibration process for each of the rebates sampled;
e. Please provide any communications between the Company and the evaluator
supporting the calibration practices of the evaluation;
f. Please provide model calibration requirements of the Evaluation, Measure
&Verification("EM&V")plan; and
g. Please explain how a model calibrated with billing data avoids or retains the biases of
a billing analysis identified by the evaluator.
REQUEST NO. 24: The Evaluation on page 31 highlights the Regional Technical
Forum ("RTF")'s New Homes protocol "because this document provides further support for the
validity of energy modeling for residential new construction homes because the RTF has
provided guidance for such programs to be evaluated using this method, in line with the results
provided in Section 4.1.5." However, Section 9 of the New Homes Protocol recommends
program evaluations to validate ex-post program savings due to uncertainty in the REM/Rate
model estimates for heating energy savings. Please reconcile these conflicting statements. In the
response, please clearly differentiate the terminology used to refer to the use of energy model
FOURTH PRODUCTION REQUEST
TO INTERMOUNTAIN GAS COMPANY 2 MARCH 13, 2025

estimates for program planning from the use of energy modeling analysis for program
evaluations.
REQUEST NO. 25: In response to Production Request No. 9, the Company states that
"Because the billing analysis results were relatively close to the Unit Energy Savings ("UES")
values, the Company chose to use the RTF values for the 95 and 97% efficient furnaces in a
weighted rebate based on actual participation data from the EM&V study."
a. Please provide workpapers clearly showing how the proposed Technical Reference
Manual ("TRM")UES value is calculated in Excel format with equations intact and
enabled.
b. Please provide supporting documentation demonstrating how close the results of the
billing analysis are to the UES values.
REQUEST NO. 26: The Evaluation recommends for each measure (except for the
Whole Home rebate)that the Company"utilize the residential TRM developed using the RTF
savings values to estimate expected measure savings for the program moving forward. This
methodology is in line with the evaluation method other utilities in Idaho use to evaluate their
space heating measures." Separately, the Evaluation recommends that the Company evaluate its
energy efficiency rebates using the relevant RTF workbook. Please clarify the Evaluation's
recommendations with respect to program planning and for program evaluation. In the response,
please clearly differentiate the terminology used in recommendations for program planning and
recommendations for program evaluation.
REQUEST NO. 27: Please provide the forecasted General Overhead Costs, Residential
Overhead Costs, and Commercial Overhead Costs for the Energy Efficiency Program for 2024,
2025, and 2026 in Excel format.
FOURTH PRODUCTION REQUEST
TO INTERMOUNTAIN GAS COMPANY 3 MARCH 13, 2025

DATED at Boise, Idaho, this 131h day of March 2025.
Chris Burdin
Deputy Attorney General
1:\Utility\UMISC\PRDREQ\INT-G-24-05 PR#4.docx
FOURTH PRODUCTION REQUEST
TO INTERMOUNTAIN GAS COMPANY 4 MARCH 13, 2025

CERTIFICATE OF SERVICE
4 -
I HEREBY CERTIFY THAT I HAVE THIS 0 DAY OF MARCH 2O25,
SERVED THE FOREGOING FOURTH PRODUCTION REQUEST OF THE
COMMISSION STAFF TO INTERMOUNTAIN GAS COMPANY , IN CASE NO.
INT-G-24-05, BY E-MAILING A COPY THEREOF, TO THE FOLLOWING:
LORI BLATTNER PRESTON N CARTER
DIR—REGULATORY AFFAIRS GIVENS PURSLEY LLP
INTERMOUNTAIN GAS CO 601 W BANNOCK ST
PO BOX 7608 BOISE ID 83702
BOISE ID 83707 E-MAIL: Rrestoncarterggivenspursley.com
E-MAIL: lori blattnergint ag s.com morgangoodinggivenspursley.com
igcregulato!ygintgas.com stephaniewg ig venspursley.com
Ed Jewell, Deputy City Attorney Katie O'Neil, Energy Program Manager
Jessica Harrison, Deputy City Attorney Boise City Dept. of Public Works
Boise City Attorney's Office P.O. Box 500
P.O. Box 500 Boise, ID 83701-0500
Boise, ID 83701-0500 EMAIL: koneilgcityofboise.org
EMAIL: eiewell(c-cilyofboise.org
jharrisonga cityofboise.org
boisecityattorneygcityofboise.or —J
PATRICIA JORDAN, S CRETARY
CERTIFICATE OF SERVICE