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Home My WebLink About20240326INT to Staff 21_23-25.pdfINTERMOUNTAIN GAS COMPANY’S RESPONSES TO STAFF’S SECOND PRODUCTION REQUEST PAGE 1 OF 2 18274371.1) Preston N. Carter, ISB No. 8462 Morgan D. Goodin, ISB No. 11184 Givens Pursley LLP 601 W. Bannock St. Boise, ID 83702 Telephone: (208) 388-1200 Facsimile: (208) 388-1300 prestoncarter@givenspursley.com morgangoodin@givenspursley.com Attorneys for Intermountain Gas Company BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION IN THE MATTER OF INTERMOUNTAIN GAS COMPANY’S 2023 INTEGRATED RESOURCE PLAN Case No. INT-G-23-07 INTERMOUNTAIN GAS COMPANY’S RESPONSES TO THE SECOND PRODUCTION REQUEST OF THE COMMISSION STAFF Intermountain Gas Company (“Intermountain” or “Company”), in response to the Second Production Request of the Commission Staff to Intermountain Gas Company dated February 26, 2024, submits the following responses. Responsive documents are available for download using the link provided in the accompanying email. Confidential responses and documents are subject to the protective agreement in this case, and are available for download using a password- protected link that will be provided separately by email. The password will be provided in a third email. DATED: March 25, 2024. By:_____________________________ Preston N. Carter Givens Pursley LLP Attorneys for Intermountain Gas Company RECEIVED Monday, March 25, 2024 4:47PM IDAHO PUBLIC UTILITIES COMMISSION INTERMOUNTAIN GAS COMPANY’S RESPONSES TO STAFF’S SECOND PRODUCTION REQUEST PAGE 2 OF 2 18274371.1) CERTIFICATE OF SERVICE I HEREBY CERTIFY THAT on March 25, 2024, I caused a true and correct copy of the foregoing to be served upon the following parties as indicated below: Monica Barrios-Sanchez Commission Secretary Idaho Public Utilities Commission P.O. Box 83720 Boise, Idaho 83720-0074 monica.barriossanchez@puc.idaho.gov Email U.S. Mail Fax Hand Delivery Preston N. Carter INTERMOUNTAIN GAS COMPANY CASE INT-G-23-07 SECOND PRODUCTION REQUEST OF THE COMMISSION STAFF Preparer/Sponsoring Witness: Brian Robertson/ Brian Robertson REQUEST NO. 21: Please explain how the impact of existing DSM programs is reflected in the Company's load forecasts. Please clearly indicate the basis used to estimate this impact (i.e., annual report, previous Conservation Potential Assessment ("CPA"), Evaluation Verification, and Measurement ("EM& V"), etc.). RESPONSE NO. 21: Intermountain utilizes actual use per customer data through the CMM model and builds linear regression models to build a relationship between use per customer and HDDs. Since these linear regression models utilize actual use per customer data, and the actual use per customer data incorporates usage from customers who have participated in existing DSM programs, the linear regression models are the best method to reflect the impact of existing DSM programs on the Company’s load forecast. INT-G-23-07 IPUC Staff PR 21 Page 1 of 1 INTERMOUNTAIN GAS COMPANY CASE INT-G-23-07 SECOND PRODUCTION REQUEST OF THE COMMISSION STAFF Preparer/Sponsoring Witness: Kathy Wold/ Brian Robertson REQUEST NO. 23: Please explain the assumptions that the Guidehouse CPA used for gas heat pumps. Please explain how these assumptions account for the impact to the Company's efforts to develop, prepare, and transform the residential HVAC market. RESPONSE NO. 23: Guidehouse characterized gas heat pump using the savings and cost algorithms in the Iowa TRM (measure 2.4.21, gas-fired heat pumps). The algorithm calculates savings based on the assumed AFUE efficiency of baseline heating equipment and the gas heat pump (130% AFUE). The Iowa TRM also provides an incremental cost assumption of $115 per kBTUh for gas heat pumps, which is 5-7x higher than the incremental costs for the high-efficiency furnace or boiler measures which are in competition with gas heat pumps, but not surprising given the emerging nature of gas heat pump technology. The primary objective of the CPA was to develop an estimate of the potential for gas energy efficiency over a 20-year time horizon, and with the anticipated near-term market introduction of gas heat pumps, this measure was included in the study. The therm saving information provided by the Iowa TRM will be helpful in designing a future gas heat pump incentive for Intermountain’s traditional resource acquisition program. In a more tangential way, this information will signal to the market (contractors, installers, designers, builders), the savings that can be achieved with gas heat pumps, but will not directly impact the Company’s efforts to develop, prepare, and transform the residential HVAC market. Regardless of the identified savings, market acceptance of gas heat pumps will rely on availability, contractor awareness, and INT-G-23-07 IPUC Staff PR 23 Page 1 of 2 installation education for installers, which are all efforts of market transformation. The focus of market transformation is to accelerate the adoption of gas heat pump technologies in North America. INT-G-23-07 IPUC Staff PR 23 Page 2 of 2 INTERMOUNTAIN GAS COMPANY CASE INT-G-23-07 SECOND PRODUCTION REQUEST OF THE COMMISSION STAFF Preparer/Sponsoring Witness: Kathy Wold/ Brian Robertson REQUEST NO. 24: Please explain in detail what specific inputs Guidehouse used from the 2020 Impact EM&V to calibrate its model to historical performance. Please clearly specify the analysis type that informed annual unit therm savings values (i.e., control group billing analysis, pre-post billing analysis, simulation analysis). RESPONSE NO. 24: Guidehouse used Company EM&V results to calibrate residential furnace unit savings values (therm per furnace/household). Guidehouse ultimately used the unit therm savings values from the Company's 2021 internal EM&V furnace impact evaluation, which was a pre-post billing analysis of 819 program participants from the 2017-2018, 2019, 2020, and 2021 program years. The evaluation found an average savings of 81 therms per furnace for a 95 AFUE furnace relative to an 80 AFUE baseline. This is the value which Guidehouse used to calibrate furnace savings. This per-unit therm savings value was also multiplied with the number of furnaces installed in each historic program year to yield annual historical savings targets which were used in the model calibration. Using a consistent unit therm savings value in each year for the historical calibration targets was necessary for consistency with the overall modeling approach which assumes a constant unit therm savings over time. INT-G-23-07 IPUC Staff PR 24 Page 1 of 1 INTERMOUNTAIN GAS COMPANY CASE INT-G-23-07 SECOND PRODUCTION REQUEST OF THE COMMISSION STAFF Preparer/Sponsoring Witness: Kathy Wold/ Brian Robertson REQUEST NO. 25: In the Energy Efficiency Potential section of the IRP on page 77, the Company describes that "for measures with no historical data the model was calibrated so these measures would have very little achievable potential compared to measures with historical data." Please explain the rationale used to support this assumption and explain how the Company determined the appropriate adjustment amount for these measures. RESPONSE NO. 25: In potential modeling cases where there is no existing data to calibrate measures or end uses, general best practice is to either base calibration parameters on similar end uses or measures as a proxy, or exclude measures if the program or market is highly mature and developed. In this case, Guidehouse chose to calibrate using payback adders from similar measures on an end use basis to avoid excluding measures solely because they have not yet been offered in the Company's relatively new programs. This approach makes use of what data does exist that can inform adoption trajectories in order to assess the potential from measures that could be offered in the future. INT-G-23-07 IPUC Staff PR 25 Page 1 of 1