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HomeMy WebLinkAbout20251216Post-Hearing Brief.pdf 04% -0IQAHO R® RECEIVED MEGAN GOICOECHEA ALLEN DECEMBER 16, 2025 Corporate Counsel IDAHO PUBLIC mqoicoecheaallen(a)idahopower.com UTILITIES COMMISSION December 16, 2025 Commission Secretary Idaho Public Utilities Commission 11331 W. Chinden Boulevard Building 8, Suite 201-A Boise, Idaho 83714 Re: Case No. IPC-E-24-44 Idaho Power Company's Application for Approval of a Special Contract and Tariff Schedule 28 to Provide Electric Service to Micron Idaho Semiconductor Manufacturing (Triton) LLC Dear Commission Secretary: Attached for electronic filing, please find Idaho Power Company's Post-Hearing Brief in the above-entitled matter. If you have any questions about the attached documents, please do not hesitate to contact me. Sincerely, n I I l Megan Goicoechea Allen MGA:cd Attachments 1221 W. Idaho St(83702) P.O. Box 70 Boise, ID 83707 MEGAN GOICOECHEA ALLEN (ISB No. 7623) DONOVAN E. WALKER (ISB No. 5921) Idaho Power Company 1221 West Idaho Street (83702) P.O. Box 70 Boise, Idaho 83707 Telephone: (208) 388-2664 Facsimile: (208) 388-6936 mgoicoecheaallen(a�,idahopower.com Dwalker(a)_idahopower.com Attorneys for Idaho Power Company BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION IN THE MATTER OF IDAHO POWER ) COMPANY'S APPLICATION FOR ) CASE NO. IPC-E-24-44 APPROVAL OF SPECIAL CONTRACT AND ) TARIFF SCHEDULE 28 TO PROVIDE ) IDAHO POWER COMPANY'S ELECTRIC SERVICE TO MICRON IDAHO ) POST-HEARING BRIEF SEMICONDUCTOR MANUFACTURING ) (TRITON) LLC. ) COMES NOW, Idaho Power Company ("Idaho Power" or the "Company"), and respectfully submits this Post-Hearing Brief pursuant to Idaho Public Utilities Commission ("Commission") Rule of Procedure 255 and the briefing schedule adopted by the Commission in Order No. 36853. I. INTRODUCTION Idaho Power appreciates the opportunity to offer this Post-Hearing Brief to help facilitate the Commission's final review and deliberations. Given the extensive record and number of complex issues presented, this brief will focus on certain issues discussed in the hearing record that the Company believes may benefit from clarification or further discussion. Thus, it is not intended to comprehensively address all of the potentially IDAHO POWER COMPANY'S POST-HEARING BRIEF - 1 disputed issues in this case, those that are not otherwise properly considered within the scope of this docket, or those that, in the Company's opinion, are adequately addressed in the hearing record. Thus, the Company's silence on a position or stance should not be construed as an endorsement of or agreement with any other party's position. Idaho Power respectfully submits this Post-Hearing Brief in support of approval of the energy services agreement ("ESA") for Micron Technology, Inc.'s ("Micron") new memory manufacturing fabrication complex ("Micron FAB") entered into by and between Idaho Power and Micron Idaho Semiconductor Manufacturing (Triton) LLC, a wholly- owned subsidiary of Micron, on November 21, 2024. At the outset, the Company believes it is important to clarify that the Micron FAB ESA does not result in favorable treatment for Micron; the Company agrees that existing customers should be protected from potential cost shifting caused by the Micron FAB, and other large loads, and this is exactly what the ESA helps to ensure. Based on the record developed in this case and as more fully explained below, the Company respectfully requests that the Commission approve the Micron FAB ESA as proposed and an updated Schedule 28. More specifically, the Company requests the Commission direct it to submit a compliance filing including a revised Schedule 28 to update: o The initial Energy Charge to $0.04084 per kilowatt ("kWh"), consistent with the revised workpaper reflecting the 2025 Marginal Cost Update — Single Run Method approved in Case No. IPC-25-17; and o The Contract Demand charge to $3.12 per kW and the Billing Demand charge to $20.25 per kW to reflect the 2025 General Rate Case ("GRC") Settlement Stipulation class cost-of-service study ("CCOS"). In the event that the Commission supports the recommendations of Commission Staff ("Staff") to modify the ESA contract terms related to the Marginal Cost-based Energy IDAHO POWER COMPANY'S POST-HEARING BRIEF - 2 Charges and the Minimum Monthly Billing Demand, the Company proposes that the Commission direct it to include an amendment to the Micron FAB ESA with its compliance filing revising: Section 5.5(b) "Minimum Monthly Billing Demand After Expansion" and Section 7.2 "Marginal Cost-Based Energy Charges" consistent with the amendments proposed by Micron at hearing in Micron Exhibits 304 and 305. Notably, the parties are largely aligned as to the way forward in the near-term on most of the Schedule 28 pricing components and those areas of disagreement that remain more appropriately addressed in other impending proceedings including the separate marginal cost docket agreed to as part of this case to address the concerns raised by the Idaho Irrigation Pumpers Association, Inc.'s ("IIPA"); the single-issue CCOS docket agreed to as part of the Settlement Stipulation submitted by the parties in the Company's 2025 GRC; and future GRCs that include Micron FAB in the test year. II. COURSE OF PROCEEDINGS On December 6, 2024, Idaho Power filed an Application with the Commission requesting an order approving the Micron FAB ESA and the rates proposed in tariff Schedule 28. The Commission issued a Notice of Application and Notice of Modified Procedure in Order No. 36446 on January 27, 2025, setting a 44-day comment deadline and a 14-day reply deadline. Petitions to intervene were filed by Micron, IIPA, Industrial Customers of Idaho Power ("ICIP"), and Clean Energy Opportunities ("CEO"). By various orders, the Commission granted these interventions.' On February 20, 2025, IIPA filed a Motion and Objection in this case pursuant to Rules 56, 203, 247, and 256, which was supported by ICIP in its Concurrence filed on ' Order Nos. 36460, 36479, 36483, and 36554. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 3 February 27, 2025, including two requests: (i) Objection to the use of modified procedure and demand for a technical hearing; and (ii) Motion to consolidate Case No. IPC-E-24-44 with the pending CPCN proceedings, Case Nos. IPC-E-24-45 and IPC-E-24-46. IIPA requested oral argument on the Motion. Responses to IIPA's motion were filed by Commission Staff on March 6 and Idaho Power and Micron on March 13, which all opposed the consolidation of cases and maintained that processing the case by modified procedure continued to be appropriate. After hearing oral arguments, on April 15, 2025, the Commission issued Order No. 36547 denying I IPA's request to consolidate cases but granting the request for a technical hearing. On July 28, 2025, the Commission issued a Notice of Schedule and Notice of Technical Hearing in Order No. 36689. Pursuant to the schedule set by the Commission, multiple rounds of testimony were exchanged: • Idaho Power: Direct Testimony (Connie G. Aschenbrenner, Grant T. Anderson, Jared L. Ellsworth) on April 30; Rebuttal Testimony (Anderson, Ellsworth) on July 30; Surrebuttal Testimony (Aschenbrenner, Anderson, Ellsworth) on August 29. • Commission Staff: Direct Testimony (Michael Eldred) on June 30; Surrebuttal Testimony (Eldred) on August 15. • Micron: Direct Rebuttal Testimony (Michael P. Gorman) on July 30;2 Surrebuttal Testimony (Gorman) on August 15. • IIPA: Direct Testimony (Lance D Kaufman, Ph.D., and Joint Written Testimony of 2 Micron filed Revised Direct Rebuttal Testimony of Michael P. Gorman on September 2, 2025. IDAHO POWER COMPANY'S POST-HEARING BRIEF -4 Representatives Stehanie Jo Mickelsen and Dan Garner) on June 30; Rebuttal Testimony (Kaufman) on July 30; Surrebuttal Testimony (Kaufman) on August 15. • CEO: Direct Testimony (Courtney White) on June 30; Rebuttal Testimony (Michael Heckler) on July 30; Surrebuttal Testimony (White and Heckler) on August 15. Throughout the proceeding, Staff and parties have also conducted extensive discovery on Idaho Power's filing. On October 28, 2025, the Commission held a technical hearing to receive evidence in this matter. On November 20, 2025, the Commission issued a Notice of Briefing Schedule and Notice of Deadline to Request Intervenor Funding in Order No. 36853. Closing briefs were filed by Staff, Micron, IIPA, and CEO on December 2. III. LEGAL STANDARD As a publicly regulated utility, Idaho Power is obligated under Idaho law to provide adequate, efficient, just, and reasonable service to all those that request it within its certificated service area and is prohibited from establishing preferential or discriminatory rates and from perpetuating unreasonable differences between customer classes.3 The Commission is specifically delegated broad authority to regulate and fix the charges assessed by a public utility for service and is charged with the responsibility of ensuring that such rates are just, reasonable, non-discriminatory, and non-preferential.4 The Idaho Supreme Court has long recognized that the Commission has broad discretion in pursuing its authority and appellate review of its decisions is limited.5 When the Commission's findings of fact are supported by substantial, competent evidence in the 3 Idaho Code §§ 61-301, 61-302, 61-315. 4 Idaho Code §§ 61-502, 61-503. 5 Idaho Code § 61-629; Building Contractors Association v. Idaho Pub. Utilities Comm'n and Boise Water Corp., 128 Idaho 534, 537, 916 P.2d 1259 (1996) ("Building Contractors"). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 5 record they are entitled to a presumption of correctness; in the face of conflicting evidence, the Court will not displace the Commission's findings of fact "even though the Court may justifiably arrive at a different conclusion if the matter were before it de novo.116 IV. ARGUMENT A. Idaho's Established Framework Ensures "Growth Pays for Growth" Unlike Emerging Mechanisms in Other Jurisdictions. Idaho Power has a statutory obligation to provide service to all customers, including large load service customers requesting new electric service greater than one megawatt ("MW").7 Generally, large load customers qualify to take service under Idaho Power's Schedule 19, Large Power Service ("Schedule 19"), which is available to and mandatory for customers who register a metered demand of 1 MW or more during three or more billing periods over a 12-month period, but whose aggregate power requirements on the same premises do not exceed 20 MW.8 If the large load customers' aggregate power needs are greater than 20 MW, they are ineligible for service under Schedule 19 and are required to make "special contract arrangements"with the Company.9 The special contract requirement allows for the unique characteristics of a customer of this size to be captured within the terms of a Commission- approved ESA and enables to the inclusion of provisions intended to provide protections to the Company and its other retail customers from the impacts that some large loads could impose because of sheer size and operating characteristics.10 For ratemaking purposes, each special contract customer is considered a separate class with different 6 See, e.g., Building Contractors, 128 Idaho at 537. Tr. at 314:11-13, 319:9-11 (IPC-Aschenbrenner Direct at 5, 9); Tr. at 380:5-7. 8 Tr. at 314:13-19 (IPC-Aschenbrenner Direct at 5). 9 Schedule 19; Tr. at 314:23-25 (IPC-Aschenbrenner Direct at 5). 10 Tr. at 315:5-14 (IPC-Aschenbrenner Direct at 6). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 6 conditions and contract terms affecting their rates, which allows for specific cost-of- service information for each ESA customer to be reviewed during rate proceedings.,, Because each special contract customer is its own class (i.e., a class of one), greater flexibility exists to mitigate the rate impacts of large loads without running afoul of the discrimination prohibitions found in Idaho law. Regardless of whether a large load customer will qualify to take service under Schedule 19 or will be required to negotiate a special contract, the Company evaluates whether there are existing facilities of adequate capacity and desired voltage available to meet the request.12 If there are not facilities of adequate capacity and voltage available, the Company will conduct a study to determine what facilities are necessary to interconnect.13 Idaho Power requires large load customers to cover the full cost of all distribution, substation, and transmission work that- but for the applicant's request-would not be constructed by Idaho Power through a Contribution in Aid of Construction ("CIAC") payment based on the total project cost.14 When determining rates for new special contract customers, Idaho Power must account for a number of factors15 including, but not limited to, each customer's unique needs, site-specific circumstances, infrastructure available at the time, and consideration of the potential impact of the load to the operation, safety, and reliability of Idaho Power's system.16 Special contract arrangements are highly customer and site-specific, and Idaho 11 Tr. at 315:5-9 (IPC-Aschenbrenner Direct at 6). 12 Tr. at 75:10-76:24 (IPC-Ellsworth Direct at 12-13); Tr. at 315:17-22, 317:1-318:18 (IPC-Aschenbrenner Direct at 6-8). 13 Tr. at 75:10-76:24 (IPC-Ellsworth Direct at 12-13); Tr. at 315:17-22, 317:1-318:18 (IPC-Aschenbrenner Direct at 6-8). 14 Tr. at 75:10-76:24 (IPC-Ellsworth Direct at 12-13); Tr. at 317:1-318:25 (IPC-Aschenbrenner Direct at 7- 8); Tr. at 812:23-813:22 (Staff-Eldred Direct at 4-5). 15 See, e.g., In the Matter of the Application of Idaho Power Company for Approval of a Special Contract with J.R. Simplot Company, Case No. IPC-E-13-23, Order No. 33038 at 11-12 (May 19, 2014). 16 Tr. at 314:25-315:14, 319:22-321:2 (IPC-Aschenbrenner Direct at 5-6, 9-10). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 7 Power determines rates for new special contract customers on a case-by-case basis. The special contract mechanism does not afford large load customers with preferential treatment. Rather, it is designed to ensure that large load service requests are carefully evaluated to enable the Company's ability to meet its obligation to all customers in its service area while protecting the Company and its many other retail customers from "unintended system impacts that large loads may impose because of their size and their time, nature, and pattern of use."17 The Commission has long recognized the value of this construct: We can see no reason to discontinue our policy of allowing special contracts for larger customers due to their size and the unusual characteristics of their respective loads. We are supportive of any type of pricing that is responsive to customer needs so long as the net revenues collected from those customers are fair and do not place an undue burden on other customers. Again, we encourage the utilities to be creative in this regard.18 While many other states are currently considering legislation and other solutions intended to protect existing customers from new large load consumers energy demands,19 the Company already has a solid framework in place to ensure that "growth pays for growth" and that other customers are not subsidizing large loads.20 As Idaho Power witness Ms. Aschenbrenner explained at hearing: [Idaho Power has] for decades now with any new large load, and frankly, any other load that comes on, really sought to assign costs that are solely attributable to those costs or that user to them. I believe that when you look at the history on our system over the last 10 years, I testified in my surrebuttal testimony to price increases that customers have experienced, 17 See, e.g., In the Matter of the Application of Idaho Power Company for Authority to Modify Special Contract Eligibility by Reducing the Upper Limit of Power Requirements for Large Load Customers, Case No. IPC-E-10-23, Order No. 32132 at 2 (Dec. 7, 2010). 18 In the Matter of the Commission's Investigation into Changes Occurring in the Electric Industry, Case No. GNR-E-91-1, Order No. 26555 at 8 (Aug. 16, 1996). 19 Tr. at 283-289 (IIPA-Mickelson, Garner Direct at 4-7); Tr. at 294:3-9; Tr. at 846:12-19 (Staff-Eldred Surrebuttal at 4). 20 Tr. at 159:24-160:13; Tr. at 171:16-172:1; Tr. at 178:13-20 (IPC-Anderson Direct at 5-6, 14-15, 20); Tr. at 209:2-22 (IPC-Anderson Surrebuttal at 5); Tr. at 342:3-13 (IPC-Aschenbrenner Surrebuttal at 8); Tr. at 384:13-19, 397-401. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 8 so over the 10-year period ending June of 2025, residential customers and the irrigators have experienced changes in prices of less than two percent. [Consumer Price Index] over that same time period was an average of three percent. That has been the result of careful mitigation of costs from Idaho Power Company, but I believe as well has been influenced by those growth pays for growth policies that we have implemented over time.21 Over the last several decades, supported by the Commission, the Company has developed and refined various methods and mechanisms to effectuate a "growth pays for growth" policy and protect other customers from adverse impacts due to new large loads;22 these approaches include requiring upfront contributions to capital expenditures associated with facilities necessitated by the large load customers as well as requiring the customer to take service under a special contract arrangement, which enables the Company to develop a pricing structure that addresses the current conditions on its system (i.e., resource constraints and increasing marginal cost of energy) and mitigates risk to other customers and allows for specific cost-of-service information as well as the unique operating characteristics of customers to be considered and captured within the terms of the contractual agreement.23 The suggestion that Idaho needs to consider putting a structure in place to address large load service requests because of what other jurisdictions are doing is misplaced and fails to appreciate the history and efficacy of the framework that already exists as testified to by Idaho Power witness Ms. Aschenbrenner: "I can tell you personally I have been contacted by other jurisdictions, my peers in other jurisdictions, asking how we are able to do this. We maintain rates that are 20 to 30 percent below the national average . . . We have been able to maintain that and I believe 21 Tr. at 397:25-398:14. 22 See, e.g., In the Matter of the Application of Idaho Power Company for Authority to Modify Special Contract Eligibility by Reducing the Upper Limit of Power Requirements for Large Load Customers, Case No. IPC-E-10-23, Order No. 32132 (Dec. 7, 2010). 23 Tr. at 315:1-14, 319:22-321:2 (IPC-Aschenbrenner Direct at 6, 9-10). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 9 in part because of the policies . . . that we have in place."24 B. The Micron FAB ESA Reflects "Growth Pays for Growth" Principle, Protects Existing Customers, and Aligns with Idaho Law and Commission Precedent. 1) Customer Protections Under the Micron FAB ESA. The Micron FAB ESA includes the strongest customer protections the Company has ever implemented for a special contract.25 Deliberate steps were taken to mitigate risk by incorporating robust customer safeguards into the special contract to protect other retail customers from the potential for cost shifting that could have otherwise resulted in the event Micron reduces its forecast after the Company has already made a commitment to invest in generation and transmission assets.26 The Micron FAB ESA contains several contractual provisions intended to protect Idaho Power and its other retail customers from the potential risk of financial harm in the event the load at the Micron FAB facility never fully materializes or is materially delayed including: Section 3, Termination Payment Provisions: Micron remains financially liable if its load fails to materialize, ensuring Idaho Power and its other customers are not exposed to undue financial risk. Section 5, Minimum Monthly Billing Demand and Contract Demand: Tied to forecasted load to ensure fair cost allocation and recovery of demand-related costs. Section 6, Facilities for Delivery to Micron FAB: Micron funds all necessary Interconnection Facilities through separate agreements. Section 10, Rigorous Credit Support Requirements: Stringent credit support 24 Tr. at 400:19-401:2. 25 Tr. at 176:15-17 (IPC-Anderson Direct at 19); Tr. at 329:9-16 (IPC-Aschenbrenner Direct at 16); Tr. at 835:2-836:2 (Staff-Eldred Direct at 21a-22). 26 Tr. at 176:17-24 (IPC-Anderson Direct at 19); Tr. at 329:9-330:2, 331:6-20 (IPC-Aschenbrenner Direct at 16-17, 18). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 10 requirements protect against default and reinforce contract reliability. 2) Pricing Structure Under the Micron FAB ESA. The Micron FAB ESA contains terms and conditions that are consistent with cost- based principles and methodology included in previously approved electric service agreements but tailored to fit the specific service requirements at the Micron FAB. Idaho Power evaluated Micron FAB's unique characteristics and other relevant circumstances to develop pricing that would reduce the potential for cost shifting and ensure that Micron fairly contributes to the incremental system costs necessary to serve its new load.27 The proposed pricing structure includes a methodology that does not rely exclusively on traditional frameworks but instead applies an approach informed by, though not bound to, past Commission-approved special contracts.28 Staff witness Eldred supports this structure and concluded that it adequately reflects cost-causation principles while providing meaningful protections for existing customer classes29. Under this framework, Micron's fixed, capacity-related costs are recovered through embedded cost-based demand charges, and its variable energy-related costs are recovered through a marginal cost-based energy charge.30 The demand component consists of a Contract Demand Charge, tied to Idaho Power's OATT rate,31 and a Billing Demand Charge that collects the remaining portion of Micron's allocated embedded generation and transmission capacity costs.32 These charges are consistent with established cost-of-service principles and Commission precedent.33 Because Micron's 27 Tr. at 158:10-159:3 (IPC-Anderson Direct at 4-5). 28 Tr. at 212:20-23 (IPC-Anderson Surrebuttal at 8). 29 Tr. at 814:12-815:2 (Staff-Eldred Direct at 6-7). 30 Tr. at 160:16-20 (I PC-Anderson Direct at 6) 31 Tr. at 163:14-16 (I PC-Anderson Direct at 8). 32 Tr. at 160:20-161:6 (IPC-Anderson Direct at 6-7). 33 Tr. at 161:1-9 (IPC-Anderson Direct at 7); Tr. at 199:22-25 (IPC-Anderson Rebuttal at 18). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 11 forecasted load will inform Idaho Power's long-term resource procurement decisions, the ESA includes provisions that lock in Contract Demand and Minimum Billing Demand levels when they are relied upon for planning, thereby protecting existing customers from potential cost shifting if Micron's actual usage later declines.34 The marginal-cost energy component is based on a detailed simulation of the hourly operation of Idaho Power's resource portfolio under expected system conditions.35 This refined approach, developed in consultation with Commission Staff and adjusted to address operational distortions associated with battery resources,36 ensures that Micron's energy charge reflects the incremental cost of serving its additional load. This marginal energy charge will be updated annually through the Company's filings in the Commission- approved marginal energy docket so that the rate remains aligned with changing fuel prices, market dynamics, hydro conditions, and resource operations.37 The embedded cost-based demand charges, the Contract Demand Charge and Billing Demand Charge, will be updated separately through future general rate cases or other Commission-approved rate proceedings.38 These updates will incorporate revised cost-of-service studies and reflect changes in both Micron's load characteristics and Idaho Power's overall system cost structure. Together, these update mechanisms ensure that the ESA's pricing remains equitable, transparent, and firmly aligned with cost causation over time, while maintaining appropriate safeguards against undue burdens on other customer classes. 34 Tr. at 159:24-160:13 (IPC-Anderson Direct at 5-6). 35 Tr. at 165:3-8 (IPC-Anderson Direct at 10). 36 Tr. at 165:15-167:7 (IPC-Anderson Direct at 10-12). 37 Tr. at 167:15-22 (IPC-Anderson Direct at 12). 38 Tr. at 163:22-25, 164:14-25 (IPC-Anderson Direct at 8, 9); Tr. at 183:1-185:2 (IPC-Anderson Rebuttal at 5-6). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 12 3) The Company's No-Harm Analysis Supports the Reasonableness of the Proposed Pricing Structure. a. Counterfactual No-Harm Analysis As part of the initial development of the pricing methodology for the Micron FAB ESA, the Company conducted a "no-harm" evaluation — a counterfactual analysis comparing scenarios from its 2023 IRP modeled with and without Micron's load.39 This analysis was conducted prior to execution of the proposed ESA and intended to help evaluate whether the proposed initial pricing structure could reasonably mitigate cost shifting.40 The no-harm analysis was not used to directly set prices or allocate costs but to quantify whether the Micron FAB was sufficiently allocated its share of both embedded and incremental system costs and to confirm that other customers are not subsidizing the Micron FAB load.41 Commission Staff agreed that the Company's input assumptions and evaluation of risk variables used in the no-harm analysis were reasonable based on the information known at the time the analysis was performed.42 While the analysis was intended to help in the initial assessment of the Company's proposed pricing structure, both the Company and Staff agree that it would not be appropriate to rely exclusively on the no-harm analysis in evaluating the reasonableness of the proposed pricing - it is one point among many that should be considered.43 b. Criticisms of the No-Harm Analysis and Alternative Analyses While both CEO and IIPA have been critical of the inputs relied on by the Company 39 Tr. at 171:16-173:3 (IPC-Anderson Direct at 12-16); Tr. at 224:7-14, 227:6-228:3 (IPC-Anderson Surrebuttal at 17, 20-21). 40 Tr. at 171:16-173:3 (IPC-Anderson Direct at 12-16); Tr. at 202:12-16 (IPC-Anderson Rebuttal at 21); Tr. at 224:7-14 (IPC-Anderson Surrebuttal at 17). 41 Tr. at 171:22-172:1 (IPC-Anderson Direct at 14-15); Tr. at 202:3-23 (IPC-Anderson Rebuttal at 21). 42 Tr. at 201:14-25 (IPC-Anderson Rebuttal at 20); Tr. at 832:8-24 (Staff-Eldred Direct at 19). 43 Tr. at 204:3-11 (IPC-Anderson Rebuttal at 23); Tr. at 832:8-24 (Staff-Eldred Direct at 19). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 13 in the original no-harm analysis, arguing for alternative assumptions or scenarios, their critique fails to appreciate that the nature of this type of counterfactual analysis is based on a particular point in time in order to confirm at the outset that the proposed pricing approach would not result in inappropriate cost-shifting to existing customers.44 These parties have also inflated the role of the Company's no-harm analysis, which was provided as a directional tool based on a defined set of assumptions and was not used to directly set prices or allocate costs.45 During the technical hearing, Dr. Kaufman presented multiple new exhibits,46 including, purportedly, several alternative no-harm analyses,47 for the first time in contravention of Commission Procedural Rule 267.03, which requires that exhibits be timely filed and "distributed or made available to all parties long enough before their introduction into evidence to allow the parties a reasonable opportunity to review them and to prepare to examine their substance, except exhibits that update exhibits previously timely filed may be filed if the other parties are afforded fair opportunity to examine the sponsoring witnesses." Confronted with numerous dense and voluminous hard copy exhibits live at the evidentiary hearing, neither Idaho Power or Micron were afforded appropriate opportunity to review the materials or to adequately question Dr. Kaufman regarding those exhibits or present responsive evidence on the record, and both parties objected to admission of IIPA Hearing Exhibits 211 through 218 on the record as a result.48 The Commission ultimately admitted the IIPA's new exhibits, noting it would give them 44 Tr. at 225:5-17, 227:5-228:3 (IPC-Anderson Surrebuttal at 18, 20-21). 45 Tr. at 171:16-173:3 (IPC-Anderson Direct at 12-16); Tr. at 202:3-23 (IPC-Anderson Rebuttal at 21); Tr. at 224:7-14, 227:6-25 (IPC-Anderson Surrebuttal at 17, 20). 46 IIPA Hearing Exhibits 211-224. 47 IIPA Closing Brief at 7-8; IIPA Hearing Exhibits 211, and 213-218. 48 Tr. at 478:21-480:16; Tr. at 606:9-12. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 14 "appropriate weight.1149 As a fact finding, quasi-legislative body, the Commission is not bound by the strict rules of evidence and may draw its own inferences from the record, aided by its own expertise.50 Pursuant to Commission Procedural Rule 261: "The Commission may use its expertise, technical competence and special knowledge when evaluating evidence." In considering the weight that should be afforded the exhibits proffered by IIPA at hearing, the Company believes that Idaho Rules of Evidence governing the admissibility of expert opinion testimony are instructive. In order for expert opinion testimony to be admissible, the party offering the evidence must show that the expert is a qualified expert in the field, that the evidence will be of assistance to the trier of fact, and that experts in the particular field would reasonably rely upon the same type of facts or data relied upon by the expert in forming his opinion.51 In its Closing Brief, IIPA claims that the exhibits submitted at the technical hearing presenting alternative no-harm analyses demonstrate that "harm exists."52 However, the opinions and exhibits offered by IIPA in this regard are not supported by competent evidence and lack sufficient indicia of reliability. As an initial matter, while IIPA's consultant has offered testimony on a broad range of topics, IIPA has failed to show how Dr. Kaufman, an economist, is qualified to offer opinions as proffered on specialized topics relating to, for example, transmission system planning, resource adequacy, or contract terms. No background information has been provided on the specific education, training, or other experience that Dr. Kaufman may have which could make his testimony 49 Tr. at 484:3-5. 50 Boise Water Corp. v. Idaho Pub. Utilities Comm'n, 97 Idaho 832, 838, 555 P.2d 163 (1976). 51 Ryan v. Beisner, 123 Idaho 42, 46-47, 844 P.2d 24 (Ct. App. 1992); I.R.E. 702 and 703. 52 IIPA Closing Brief at 8-9; Tr. at 472:4-476:15. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 15 helpful or reliable on these issues. These exhibits presented by IIPA at the technical hearing are fundamentally flawed and are not based on reliable or sound methodologies. For instance, Dr. Kaufman attempts to run alternate analyses by arbitrarily substituting individual generation resources without conducting a full portfolio re-optimization,53 ignoring resource interactions'54 system constraints, and portfolio cost dynamics. In addition, as more fully discussed below, he directly assigns transmission-related costs of system resources to Micron, which results in a distorted allocation of costs, and also introduces unexplained rate components, such as the incremental $0.02/kWh charge, without methodological justification or evidentiary support. Collectively, these flaws lead to IIPA understating Micron's cost responsibility, overstating costs to other customers, and materially inflating the incremental energy cost estimate. Moreover, many of the assumptions underlying IIPA's analyses are speculative, conclusory, or unsubstantiated by facts in the record, and at times directly refuted. For example, though the record in this case clearly demonstrates that the Gateway West transmission line and Mayfield substations are system resources needed to support broader system reliability and capacity regardless of Micron,55 IIPA contends, apparently based on geographic proximity, that some portion of incremental transmission costs for these resources should be directly assigned to Micron through an upfront CIAC and that the Company's no-harm analysis is therefore flawed for failing to account for these 53 Tr. at 252:18-24. 54 Tr. at 253:7-11. 55 Tr. at 89:3-11 (IPC-Ellsworth Rebuttal at 10); Tr. at 96:15-19 (IPC-Ellsworth Surrebuttal 4); Tr at 121:21-122:9. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 16 incremental transmission costs.56 In another instance, IIPA claims that the Company has embarked on a $5.6 billion capital spending plan for 2025 to 2029 to acquire necessary generation, transmission, and system upgrades, "primarily to serve Micron and other new large load customers . . ."57 In support of this assertion, IIPA does not rely on the record in this case but instead cites its own comments from the Company's 2025 Integrated Resource Plan docket.58 The opinions of IIPA's consultant appear to be largely based on his own authority and unsubstantiated personal beliefs, rather than a recognized and reliable scientific methodology or body of evidence. Though the Company was not provided the opportunity to present a response on the record or effectively cross-examine Dr. Kaufman on the exhibits, having now had the opportunity to review the information, it is clear that the methodology and analysis reflected in IIPA's alternative no-harm analyses set forth in Exhibit 211 through 218 is unsupported, unreliable, and would not be able to withstand expert scrutiny. The Company agrees that the Commission is capable of considering the information provided and, based on its expertise, determining how much weight, if any, to afford such dubious evidence. 4) Intervenor Claims of Harm and Proposed Alternatives Are Inconsistent with Idaho Law and Commission Precedent. a. The Micron FAB ESA Promotes "Growth Paying for Growth" The Micron FAB ESA is consistent with the "growth pays for growth" principle, protects existing customers, and aligns with Idaho law and Commission precedent. The record contains extensive evidence of the risk mitigation protections in the ESA that are 56 IIPA Closing Brief at 8-9; Tr. at 475:9-476:5; IIPA Exhibit 216. 57 IIPA Closing Brief at 3-4. 58 IIPA Closing Brief at 4, fn. 6 cites to IPC-E-25-23—IIPA's 2025 IRP Comments, at 6-9. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 17 supported by both Idaho Power and Staff. The ESA pricing structure and the risk mitigation measures protect Idaho Power's other customers from negative rate impacts associated with serving the Micron FAB and ensure that the costs of serving Micron are borne by Micron, not other customer classes. The Company recognizes that the Micron FAB represents a substantial and unique load and it therefore took great care to ensure it developed an approach that addressed the customer's unique characteristics.59 As Idaho Power witness Ms. Aschenbrenner explained: You know, when Micron approached us about this project, it is a significant load. It will be the largest load by far on our system. We didn't take that lightly. The negotiation with Micron for this ESA took nearly three years. Over that time, we assessed impacts on our system operationally to ensure that we would be able to provide service. We also took special care to look at the terms within the ESA to ensure that we put adequate protections in place to protect customers. We did that through the contract demand provisions. Micron has very limited ability to make adjustments to their contract demand during that ramp. In fact, at the time we executed the agreement, they're unable to make any changes to 2026 or 2027 contract demand amounts. They had until January 1 st of this year to make changes to 2028 levels, and then for 2029 and 2030, they have to notify Idaho Power by January 1st to make changes. We did that in part because we do procure resources and look out years in advance to ensure that we can serve customers and we wanted to ensure that we had mechanisms within the ESA that appropriately assigned the costs associated with those future resource procurements to Micron to protect other customers. In support of that, we also negotiated the credit provisions that we have in place, which did require that Micron provide a parent guarantee. We have replacement credit support. To the questions earlier about the adequacy of those, you know, from our internal credit team understand that to be commercially reasonable terms in an agreement like this to cover an obligation like that of Micron. We also have a termination clause within the agreement that either party 59 Tr. at 212:16-214:4 (IPC-Anderson Surrebuttal at 8-9). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 18 can terminate with notice. That extends to Idaho Power being able to terminate. If the agreement is terminated, Micron has to pay the remainder of those take-or-pay obligations at the time of termination, and so in looking holistically at the agreement, we do have an obligation to provide service to Micron. It is also extremely important to the Company that we maintain fair and reasonable rates for the rest of our customers and we believe that the agreement that we negotiated with Micron struck that balance.60 b. Micron is Not Receiving Preferential Treatment Throughout this proceeding the intervenors have made a number of conclusory claims regarding the Company's approach to large load service generally and the Micron FAB in particular that are unsupported by evidence and are either misleading or flat out incorrect. For example, representatives testifying on behalf of IIPA and CEO have suggested that Micron or other large load customers are receiving a bargain rate or preferential treatment at the expense of other customers, though they offer no evidence that this is actually occurring: • CEO states that the proposed ESA represents a "sweet deal" for both parties, based on the testimony of CEO Policy Director Heckler stating s0.61 • Similarly, testifying on behalf of IIPA, Representatives Mickelson and Garner, neither of whom are Idaho Power customers'62 have implied that Idaho Power is offering Micron and/or other large load service customers low rates that are subsidized by other customers, suggesting this may be driven by economic development:63 o "Utilities are prioritizing the energy demands of a small number of highly 60 Tr. at 398:15-400:8. 61 CEO Closing Brief at 11; Tr. at 802:20-803-4. 62 Tr. at 298:9-23. 63 Tr. at 294:13-296:19. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 19 energy-intensive consumers at the expense of their existing customers."64 o "We think it is despicable to subsidize Big Tech by socializing its costs through electricity prices charged to IPC's existing customers."65 o The Commission "should be more concerned about regulating the state sanctioned oligarchies that we created so that there is a fair and just rate to all and I don't think that is done by giving a rate decrease to a large user and socializing it across the board to the other users."66 The conclusory and unsupported contentions that misrepresent the intent or impact of the Micron FAB ESA should be disregarded by the Commission. c. Alternative Proposed Solutions are Misplaced and Misguided The intervenors in this docket have made various recommendations that are incompatible with Idaho law and Commission precedent. Both CEO and IIPA have suggested that some portion of incremental generation and/or transmission upgrade costs are not being adequately charged to Micron.67 In fact, the record makes clear that Micron is directly responsible for covering the full cost of all transmission and distribution upgrades required to serve the Micron FAB up-front through a CIAC,68 and Idaho Power witness Ms. Aschenbrenner testified that Micron has paid approximately $125 million in infrastructure that was necessary only to serve Micron.69 This up-front cost responsibility is intended to cover distribution, substation, and transmission work that - but for Micron's 64 Tr. at 289:17-20 (IIPA-Mickelson, Garner Direct at 7). 65 Tr. at 281:5-7 (IIPA-Mickelson, Garner Direct at 3). 66 Tr. at 293:23-294:3. 67 Tr. at 495:16-25, 501:3-7 (IIPA-Kaufman Direct at 3, 5); Tr at 617:22-25; IIPA Closing Brief at 6; Tr. at 742:20-744:8 (CEO-Heckler Rebuttal at 6); Tr. at 795:24-796:3 (CEO-Heckler Surrebuttal at 18); CEO Closing Brief at 3-6. 68 Tr. at 76:17-77:9 (IPC-Ellsworth Direct at 13-14); Tr at 90:1-91:13 (IPC-Ellsworth Rebuttal at 10-11); Tr. at 131:8-9. 69 Tr. at 371:9-16; Application for Approval of Special Contract and Tariff Schedule 28, Confidential Attachments 3 and 4 (describing the specific cost estimates). IDAHO POWER COMPANY'S POST-HEARING BRIEF -20 request - would not be constructed by Idaho Power.70 Additionally, the proposed pricing structure under the Micron FAB ESA, is intended to recover Micron FAB's proportional share of embedded system costs reflected in a respective test year revenue requirement in a general rate case.71 This includes a share of those generation resources in-service prior to the Micron FAB coming online as well as a share of those generation resources that come online in years 2026 and after.72 Because these are system resources that are used by all customers, it would not be appropriate to directly assign associated costs.73 Both CEO and IIPA, have suggested, however, that Micron should be directly assigned certain incremental generation and transmission resources.74 As Idaho Power witness Mr. Ellsworth explained, the planned transmission projects are not solely necessitated by Micron FAB;75 recognizing Micron FAB's system impact means Micron FAB will bear its allocated share, which also alleviates some of the burden from other customers.76 These are system resources—not facilities dedicated solely to Micron FAB.77 System generation and transmission are planned, procured, and operated to optimize service for all customers.78 Ms. Aschenbrenner reiterated at hearing: "Generation resources and transmission resources are utilized by all customers on our system. The way that we assign those costs, as I mentioned, is through the rate setting process. We 70 Tr. at 77:6-9 (IPC-Ellsworth Direct at 14); Tr. at 131:8-9; Tr. at 318:24-319:1 (IPC-Aschenbrenner Direct at 8-9). 71 Tr. at 210:6-13 (IPC-Anderson Surrebuttal at 6). 72 Tr. at 210:6-13 (IPC-Anderson Surrebuttal at 6). 73 Tr. at 210:19-20 (IPC-Anderson Surrebuttal at 6). 74 Tr. at 495:16-25, 501:3-7 (IIPA-Kaufman Direct at 3, 5); Tr at 617:22-25; IIPA Closing Brief at 6; Tr. at 742:20-744:8 (CEO-Heckler Rebuttal at 6); Tr. at 795:24-796:3 (CEO-Heckler Surrebuttal at 18); CEO Closing Brief at 3-6. 75 Tr. at 121:17-122:9; Tr. at 125:21-127:19. 76 Tr. at 211:8-13 (IPC-Anderson Surrebuttal at 7); Tr. at 245:12-246:1. 77 Tr. at 127:1-3; Tr. at 211:13-14 (IPC-Anderson Surrebuttal at 7). 78 Tr. at 211:14-16 (IPC-Anderson Surrebuttal at 7). IDAHO POWER COMPANY'S POST-HEARING BRIEF -21 don't have dedicated generation resources that serve customers."79 The proposal for Idaho Power to directly assign incremental generation directly to large load customers and for the Commission to distinguish between "new" and "existing" large load customers80 is inconsistent with Idaho law. An approach that assigns system- related costs to "new" customers would unlawfully discriminate against new customers; the Idaho Supreme Court has held that it is not appropriate to assess the investment costs of new plant to solely new customers, noting that each new customer that has come into the system at any time has contributed to the demand for new facilities and therefore recovering costs for new plant investment from new customers alone constitutes unlawful discrimination.81 The Company has explained that resource decisions are made for the system as a whole,82 and generation resources and transmission resources are utilized by all customers on its system.83 As such, it would be impossible to distinguish between new and old customers as to who is using a particular system resource and would therefore not be appropriate to impose a charge to only new customers based on the addition of new generational resources.84 Other proposals have suggested that if Micron were allowed to procure its energy on a competitive basis and not through Idaho Power's rate regulated entity, there would be no concern over cost shifting or contract risk.85 Micron's consultant Mr. Gorman 79 Tr. at 371:24-372:6. 80 IIPA Closing Brief at 7-8, 13-16. 81 Building Contractors, 128 Idaho at 538-39. 82 Tr. at 211:8-22 (IPC-Anderson Surrebuttal at 7). 83 Tr. at 372:2-3. 84 See Idaho State Homebuilders v. Washington Water Power, 107 Idaho 415, 421, 690 P.2d 350 (1984). 85 Tr. at 531:12-15 (IIPA-Kaufman Direct at 22); Tr. at 613:11-614:14; Tr. at 751:9-752:11 (CEO-Heckler Surrebuttal 9-10). IDAHO POWER COMPANY'S POST-HEARING BRIEF -22 explained the fallacy underpinning this suggestion: "[T]here is currently no competitive market option for Micron and no legal framework or regime in Idaho that would allow Micron to pursue direct retail access to electricity on a wholesale market."86 In other words this suggestion envisages a scenario that is incompatible with Idaho's chosen system of regulation. Idaho's system of electric regulation is based upon the notion that state regulation of a single service provider acting as a vertically integrated monopoly is in the public interest and better than, and preferrable to, an environment of competition and competitive service providers.87 Notably, Idaho's approach is not merely a remnant of the historical public utility tradition but the result of a reasoned and thoughtful reexamination of the traditional regulatory model within the modern context.88 While many states have been driven to implement deregulated or "retail choice" structures aimed at introducing competition into electricity markets ostensibly as a means to mitigate high electricity prices, customers of Idaho's regulated electric utilities are paying, on average, some of the lowest rates in the nation.89 The Commission has historically been wary of deregulation of Idaho's electric markets because it did not believe that approach would be in the best interests of all of Idaho's ratepayers and could erode the benefits historically 86 Tr. at 418:4-9 (Micron-Gorman Surrebuttal at 7). 87 See Idaho Power&Light Co. v. Blomquist et al., 26 Idaho 222, 141 P.1083 (1914). 88 In the Matter of the Commission's Investigation into Changes Occurring in the Electric Industry, Case No. GNR-E-96-1, Order No. 26555 at 4 (Aug. 16, 1996); Snake River Valley Elec. Assn v. PacifiCorp, 357 F.3d 1042, 1049 (9th Cir. 2004)("The state has made abundantly clear that it is advancing a policy that restricts competition in this regulated area. See, e.g., Idaho Code§ 61-332(2) (2004). By contrast, in the normal unregulated context, our general federal antitrust law policy favors open competition between competitors for consumers. We do not normally view the active efforts of one competitor to gain customers from another as "pirating"to be discouraged. Yet here, casting its legislative eye on the regulated markets for retail power supply, the Idaho legislature has set a specific policy aimed at restricting competition for customers, maintaining stability, and protecting existing suppliers. Id. The state has clearly articulated its policy to "stabilize"this regulated market for retail electrical suppliers."). 89 Tr. at 339:10-19 (IPC-Ashenbrenner Surrebuttal at 6); Tr. at 400:21-22. See also Case No. GNR-E-96- 1, Order No. 26555 at 3. IDAHO POWER COMPANY'S POST-HEARING BRIEF -23 enjoyed by Idaho's electric consumers, namely high-quality service at reasonable rates.90 Idaho's existing regulatory framework has proven to be remarkably resilient, adaptable, and dynamic— able to accommodate an ever-changing electric industry environment and capable of addressing a wide range of regulatory challenges and resolving both traditional and emerging issues. Thus, those intervenors suggesting that allowing Micron to procure energy on a competitive basis "fully resolves" the risk associated with the Micron FAB ESA91 are not only ignoring the operational realities92 but are presenting an overly simplistic view of the "solution" and overlooking the impacts such a resolution would have on the Company's other customers. As Idaho Power witness Ms. Aschenbrenner's testimony demonstrates, the introduction of competition in deregulated markets has not shown to be particularly beneficial for residential customers; a recent review of electric prices across jurisdictions shows that residential rates are much higher in states with deregulated or "retail choice" structures than in Idaho as reflected in Table 1.93 90 Case No. GNR-E-96-1, Order No. 26555 at 2-4. 91 Tr. at 531:12-15 (IIPA-Kaufman Direct at 22); Tr. at 613:11-614:14; Tr. at 751:9-752:11 (CEO-Heckler Surrebuttal 9-10). 92 See also Tr. at 418:14-20 (Micron-Gorman Surrebuttal at 7)(explaining that"the Micron Fab is in a market region where the competitive generation market is not fully developed and is not operated by a Regional Transmission Organization ("RTO")that ensures unfettered market access, which limits non load serving entities' access to market power supply.") 93 Tr. at 339:10-340:14 (IPC-Aschenbrenner Surrebuttal at 6-7). IDAHO POWER COMPANY'S POST-HEARING BRIEF -24 Table 1 EIA June 2025 - Residential Sector Residential Residential Rank State Rate (cents) Rank State Rate (cents) , 1 Nevada 11.42 26 West Virginia 15.82 Idaho 12.07 27 Missouri 15.84 3 Louisiana 12.64 28 Alabama 16.00 4 Washington 12.98 29 Georgia 16.00 5 Utah 13.12 30 Colorado 16.16 6 Nebraska 13.17 31 Indiana 16.60 7 Arkansas 13.33 32 Minnesota 17.14 8 North Carolina 13.33 33 Ohio 17.52 9 Kentucky 13.62 34 Delaware 18.15 10 Oklahoma 13.62 35 Illinois 18.33 11 North Dakota 13.68 36 Wisconsin 18.57 12 Mississippi 13.94 37 Maryland 19.33 13 Tennessee 13.98 38 Pennsylvania 19.70 14 South Dakota 14.23 39 Michigan 20.85 15 South Carolina 14.71 40 District of Columbia 22.70 16 New Mexico 14.77 41 Vermont 23.21 17 Montana 14.85 42 New Hampshire 23.51 18 Wyoming 14.89 43 New Jersey 24.88 19 Kansas 15.00 44 New York 26.53 20 Texas 15.23 45 Rhode Island 26.84 21 Arizona 15.28 46 Alaska 26.88 22 Florida 15.36 47 Connecticut 27.24 23 Iowa 15.39 48 Maine 28.14 24 Virginia 15.41 49 Massachusetts 30.37 25 Oregon 15.77 J 50 California 33.52 51 Hawaii 40.96 C. The Record Supports Approval of the Micron FAB ESA and Updated Schedule 28. Based on its comprehensive review of the Company's Application and the record developed in this case, Commission Staff, through Staff witness Mr. Michael Eldred, generally supports Idaho Power's proposed pricing structure and recommends the Commission approve the Micron FAB ESA contingent on Staff's proposed contract modifications related to the Marginal Cost-Based Energy Charges and the Minimum Monthly Billing Demand. Based on the record in this case and the Commission's experience in such matters and as set forth more fully below, the Company respectfully requests the Commission: IDAHO POWER COMPANY'S POST-HEARING BRIEF - 25 (i) Approve the Micron FAB ESA as filed, or in the alternative, if the Commission supports Staff's recommendation to modify certain contract provisions, the Commission should approve the ESA contingent on the Company implementing the two potential modifications proposed by Micron at hearing through an amendment to the ESA; and (ii) Approve the updated Schedule 28 Energy Charge and Demand Charges using the most current cost information available. 1) Staff's Recommended Contract Modifications. a. Marginal Cost-Based Energy Charges — ESA Section 7.2 Staff Recommendation: Staff supports the Company's proposed method and annual update process for determining the Marginal Energy Charges but recommends modifying Section 7.2 to clarify that the methodology may change in the future if a different method is adopted by the Commission and to ensure that any future pricing changes are subject to Commission approval prior to becoming effective.94 Idaho Power Position: Idaho Power does not oppose Staff's recommendation.95 However, the Company does not believe an amendment to Section 7.2 is necessary as it believes that the ESA already allows for future changes to the methodology to occur as approved by the Commission -- the method itself is not explicitly defined in the ESA.96 Moreover, the Company believes it is inherent in the structure of a Commission-approved special contract that any changes to pricing are subject to Commission approval prior to becoming effective.97 94 Tr. at 817:15-822:20 (Staff-Eldred Direct at 9-12). 95 Tr. at 192:6-7 (IPC-Anderson Rebuttal at 12). 96 Tr. at 192:7-15 (IPC-Anderson Rebuttal at 12). 97 Tr. at 192:15-18 (IPC-Anderson Rebuttal at 12). IDAHO POWER COMPANY'S POST-HEARING BRIEF -26 Notwithstanding, the Company does not oppose Staff's suggestion to be more explicit in the contract language if the Commission believes that to be appropriate,98 and Micron discussed a potential amendment to Section 7.2, presented in Micron Hearing Exhibit 305, to clarify the ESA to address Staff's recommendations if the Commission supports Staff's recommendation in this regard; Staff agreed that the proposed changes to Section 7.2 set forth in Micron Exhibit 305 implemented his recommendation to modify the contract terms regarding Marginal Energy Charges.99 Thus, while the Company believes the ESA as proposed adequately addresses the concern raised by Staff, if the Commission desires additional clarity the Company respectfully requests that the Commission direct the Company to submit an amendment revising Section 7.2 consistent with Micron Exhibit 305 in a subsequent compliance filing. b. Minimum Monthly Billing Demand — ESA Section 5.5(b) Staff Recommendation: Staff supports the proposed take-or-pay provisions encompassed by the Contract Demand and Minimum Monthly Billing Demand terms included in Section 5 of the ESA to mitigate potential risks to other customers100 but believed that additional protection was necessary after the scheduled ramp period to ensure Micron continues to pay for the incremental resources required to serve them.101 More specifically, Staff recommended that Section 5.5(b) be modified102 so that that the Minimum Monthly Billing Demand does not begin to reduce automatically after the scheduled load ramp but is instead revisited 5 years after the effective date of the 98 Tr. at 192:19-21 (IPC-Anderson Rebuttal at 12). 99 Tr. at 864:23-866:3; Micron Exhibit 304; Micron's Post-Hearing Brief at 24-25. 100 Tr. at 827:21-23 (Staff-Eldred Direct at 15). 101 Tr. at 828:4-8 (Staff-Eldred Direct at 16). 102 Tr. at 829:15-17 (Staff-Eldred Direct at 17). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 27 Embedded Contract Demand.103 If Micron showed stable loads and stability of revenue at that time, Staff acquiesced that it would be appropriate to begin reducing the Minimum Monthly Billing Demand based on the schedule proposed in Section 5.5(b).104 Idaho Power Position: Idaho Power believes that the ESA as proposed adequately mitigates risk to other customers. However, in the event that the Commission supports Staff's recommendation in this regard, Micron discussed a potential amendment to Section 5.5(b) at hearing, presented in Micron Hearing Exhibit 304, to address Staff's concerns with the language in the ESA that provided for automatic reductions to the Minimum Monthly Billing Demand to begin in 2030.105 Instead, the modified language proposed by Micron language provides that the Minimum Monthly Billing Demand will remain fixed unless either Idaho Power or Micron seek a reduction to the Minimum Monthly Billing Demand and the Commission determines that such reduction is in the public interest.106 Staff agreed that the proposed revisions to Section 5.5(b) set forth in Micron Exhibit 304 captured the goals of his recommendation to modify the contract terms provided for automatic reductions to the Minimum Monthly Billing Demand.101 Thus, while the Company believes the ESA as proposed adequately addresses the concern raised by Staff, if the Commission supports Staff's recommendation, the Company respectfully requests that it direct the Company to submit an amendment revising Section 5.5(b) consistent with Micron Exhibit 304 in a subsequent compliance filing. 103 Tr. at 829:21-830:2 (Staff-Eldred Direct at 17-17a). 104 Tr. at 831:1-5 (Staff-Eldred Direct at 18). 105 Tr. at 860:4-7, 861:8-862:19; Micron Exhibit 304; Micron's Post-Hearing Brief at 24-25. 106 Tr. at 861:19-862:2. 107 Tr. at 862:12:19. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 28 2) Staff's Recommended Compliance Update. a. Marginal Cost-Based Energy Charges Staff Recommendation: Staff recommends the Commission approve the Company's proposed method for determining the Marginal Cost-Based Energy Charge and direct the Company to submit a compliance filing to update the Energy Charge included in the proposed Schedule 28 tariff schedule, which was initially based on expectations from April 2024 through March 2025, to reflect a marginal energy rate based on expectations from April 2025 through March 2026 similar to the marginal energy rates approved in Case No. IPC-E-25-17.108 Idaho Power Position: Idaho Power agrees with Staff's recommendation for the Commission to approve the Company's proposed Energy Charge set forth in Schedule 28 adjusted to reflect the Commission-approved marginal cost-based pricing in Case No. IPC-E-25-17.109 To align the initial Energy Charge in Schedule 28 with the pricing approved in IPC-E-25-17, the Company proposes this charge be updated to $0.04084 per kWh, consistent with the revised workpaper reflecting the 2025 Marginal Cost Update — Single Run Method provided in IPC-25-17.110 b. Demand Charges Staff Recommendation: Staff recommends the Commission approve the Company's proposed method for determining the Demand Charges and order the Company to update the Demand Charges included in the proposed Schedule 28 tariff schedule through a compliance filing to reflect the aggregate Special Contract percentage 108 Tr. at 822:6-20 (Staff-Eldred Direct at 12); Commission Staff's Post-Hearing Brief at 2. 109 Tr. at 192:21-25, 205:4-6 (IPC-Anderson Rebuttal at 12, 24); Tr. at 230:8-11 (IPC-Anderson Surrebuttal at 23). 110 See Idaho Power Company's Application for its Annual Update to Marginal Pricing Used in Certain Schedules, Case No. IPC-E-25-17, Order No. 36619 (May 30, 2025). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 29 revenue increase authorized by the Commission in Case No. IPC-E-24-07.111 Idaho Power Position: In its initial filing, Idaho Power recommended the Commission approve the Billing Demand and Contract Demand charges contained in Attachment 2 to the Application, adjusted for the outcome of the Company's then pending limited issue rate case, IPC-E-24-07.112 At the time the ESA was executed, the most recent available Commission-reviewed CCOS study was the one relied on in the 2023 GRC settlement. Accordingly, Idaho Power relied on that as the foundation for the initially proposed charges, however, noted it would be reasonable for those rates to be adjusted consistent with the outcome of IPC-E-24-07. While the Company maintains its initial recommended pricing was reasonable given known information at the time the ESA was negotiated and executed, in recognition of concerns raised by intervenors in this matter as more fully discussed below, Idaho Power recommends that the Contract Demand and Billing Demand Charges set forth in Schedule 28, be adjusted to reflect the updated rates presented in Idaho Power Company's Response to IIPA's Fifth Production Request, which are reflective of the 2025 GRC Settlement Stipulation CCOS as follows: a Billing Demand charge of$20.25 per kW and a Contract Demand charge of $3.12 per kW.113 While this recommendation departs from Staff's suggested update mechanism and timing, the Company's approach achieves the same policy objective, which is to implement cost-based pricing while mitigating the risk of unintentionally setting initial rates too low, by anchoring initial Demand Charges to the updated pricing workpaper and 2025 111 Tr. at 825:4:10 (Staff-Eldred Direct at 14). 112 Application at 7. 113 Idaho Power Company's Response to IIPA's Fifth Production Request, Response to Request for Production No. IIPA 5-2. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 30 CCOS allocation foundation, which better reflects current embedded costs. 3) Other Staff Recommendations. a. PCA Accounting Treatment Staff recommends the Commission approve the Power Cost Adjustment ("PCA") accounting treatment proposed by the Company,114 which is to include the costs of supplying energy to the Micron FAB in the PCA and treat the energy related revenues under the ESA as a surplus sale and an offset to power supply costs.115 b. Future Considerations Staff recommends that the Company isolate the effect of new special contract customers when cost allocation and rates need to be set for these customers in future general rate cases and develop methods to ensure other customers are not harmed.116 The Company agrees that issues of class allocation are appropriately addressed in a future general rate case that includes the Micron FAB in the test year.'17 4) Other Party Recommendations and Company Response. a. Contract Modifications by IIPA and CEO IIPA recommends several additional ESA modifications, including clarifying that marginal cost pricing may include short-run or long-run marginal costs, adding explicit language that ESA "rates and methodologies" remain subject to Commission revision, and requiring a termination payment equal to a five-year average of demand and energy 14 Commission Staff's Post-Hearing Brief at 2; Tr. at 812:18-19, 837:10-24, 840:23-24 (Staff-Eldred Direct at 4, 23, 25). 115 Application at 9; Tr. at 331:24-332:8 (IPC-Aschenbrenner Direct at 18-19). 116 Tr. at 810:24-812:2, 817:6-10, 838:2-6 (Staff-Eldred Direct at 3-4, 9, 24); Commission Staff's Post Hearing Brief at 2. 117 Tr. at 230:16-19 (IPC-Anderson Surrebuttal at 22); Tr. at 362:21-363:9; Micron Post-Hearing Brief at 22 IDAHO POWER COMPANY'S POST-HEARING BRIEF - 31 charges.,18 CEO further proposes clarifying that additional transmission costs beyond traditional interconnection facilities should be recovered through upfront CIAC payments and allowing updates to the methods used to determine Energy and Demand charges.1' These changes are unnecessary and inconsistent with the ESA's purpose. Section 7.2 of the ESA already references Commission-approved marginal cost pricing and requires annual updates through compliance filings, leaving the methodology to Commission proceedings rather than embedding it in contract language.120 Adding short-run/long-run marginal cost language would duplicate existing authority and risk creating customer-specific rules that conflict with uniform ratemaking and/or could require future amendment to implement changes in methodology— seemingly in conflict with the prior recommendations to introduce language specifically allowing updates to the methods relied upon. In addition, Section 13.2 already subjects all ESA rates to the Commission's continuing jurisdiction and allows revisions upon a finding that changes are "just, fair, reasonable, sufficient, non-preferential, and nondiscriminatory." This clause preserves the Commission's ability to revise rates and methods without prescribing any methodology in the ESA, making IIPA's proposed language unnecessary.121 IIPA's proposed five-year termination payment is also unwarranted. Section 3.3 and Exhibit 2 already provide a structured methodology based on the net present value of then-current Commission-approved Contract Demand and Billing Demand charges, discounted using the Commission-approved cost of debt.122 This approach ensures 118 IIPA Closing Brief at 3. 119 CEO Closing Brief at 14-18. 120 Tr. at 192:12-25 (IPC-Anderson Rebuttal at 12). 121 Tr. at 336:5-338:5 (IPC-Aschenbrenner Surrebuttal at 4-5). 122 Micron FAB ESA at Section 3.3, Exhibit 2. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 32 termination payments reflect actual cost responsibility under current rates, rather than an arbitrary fixed average that could misalign with future Commission determinations. CEO's proposed changes to Section 6.1 are similarly unnecessary. The ESA already addresses additional interconnection and transmission facilities and expressly provides for separate construction agreements to ensure cost responsibility.123 Additionally, Micron is already required to install, own, and maintain all distribution facilities downstream from the point of delivery124 and fund the full cost of all upgrades through a CIAC.125 Further, upon project completion, Idaho Power will reconcile project costs and ensure Micron directly funds all incremental upgrades.126 Under the principles of cost causation, assigning these costs to Micron is just and reasonable because these upgrades are used exclusively by Micron.127 Adding language to prescribe a specific cost- recovery method, such as CIAC for bulk system facilities, would convert the ESA into a methodology document and risk conflict with Commission processes that govern system planning and cost recovery. b. Marginal Cost Issues IIPA makes a number of recommendations related to energy charges, and Idaho Power emphasizes that broader questions regarding the marginal energy pricing framework, such as whether to incorporate long-run marginal Costs,128 implement a true- 123 Tr. at 96:22-97:5 (IPC-Ellsworth Surrebuttal 4-5); Tr. at 813:13-22 (Staff-Eldred Direct at 5). 124 Tr. at 324:3-11 (IPC-Aschenbrenner Direct at 12). 125 Application for Approval of Special Contract and Tariff Schedule 28, Confidential Attachments 3 and 4 (describing the specific cost estimates). 126 Tr. at 76:17-77:9 (IPC-Ellsworth Direct at 13-14). 127 Tr. at 318:9-18 (IPC-Aschenbrenner Direct at 8). 128 Tr. at 503:7-11, 503:20-25 (IIPA-Kaufman Direct at 7); Tr. at 193:18-22, 195:5-13 (IPC-Anderson Rebuttal at 13-14); Tr. at 218:20-219:7 (IPC-Anderson Surrebuttal at 13-14). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 33 up mechanism'129 or address recovery of incremental Power Purchase Agreement (PPA) costs,130 are most appropriately considered in a subsequent marginal energy docket.131 IIPA is supportive of this approach,132 recognizing that a separate docket provides the necessary scope to address technical and policy considerations beyond the streamlined annual update process. Idaho Power believes this dedicated docket will allow for a comprehensive and transparent evaluation of the marginal cost-based pricing framework and ensure that any modifications are appropriately scoped and vetted.133 While IIPA continues to recommended a temporary marginal energy charge of $0.057 per kWh pending the outcome of the marginal energy docket,134 this proposed rate is an ad hoc construct unsupported by any Commission approved marginal cost methodology and therefore should be rejected by the Commission. Additionally, the support for the calculation of this temporary marginal energy rate was presented in the new exhibits presented by IIPA during the technical hearing'135 which as discussed above are fundamentally flawed and cannot serve as a reliable basis for ratemaking. CEO recommends that Schedule 28 be revised to implement time-of-use ("TOU") energy rates.136 While the Company's initial analysis concluded that a TOU pricing structure was not necessary for the Micron FAB ESA,137 the Company would not oppose 129 Tr. at 497:16-19, 521:4-8 (IIPA-Kaufman Direct at 4, 16); Tr. at 590:10-19 (IIPA-Kaufman Surrebuttal at 21); Tr. at 195:17-196:11 (IPC-Anderson Rebuttal at 14-15); Tr. at 218:8-219:7 (IPC-Anderson Surrebuttal at 13-14). 130 Tr. at 495:2-6, 503:14-506:4 (IIPA-Kaufman Direct at 3, 7-8); Tr. at 584:9-18 (IIPA-Kaufman Surrebuttal at 18); Tr. at 217:8-11 (IPC-Anderson Surrebuttal at 12). 131 Tr. at 218:20-219:7 (IPC-Anderson Surrebuttal at 13-14); Tr at 233:7-16; Tr at 237:15-19. 132 Tr. at 591:1-592:19 (IIPA-Kaufman Surrebuttal at 21-22); Tr. at 218: 8-17 (IPC-Anderson Surrebuttal at 13); IIPA Closing Brief at 3,10. 133 Tr. at 218:20-219:7 (IPC-Anderson Surrebuttal at 13-14). 134 IIPA Closing Brief at 2. 135 Tr. at 108:8-11; Tr. at 471:24—476:15. 136 Tr. at 692:2-7 (CEO-White Direct at 16); Tr. at 696:5-7, 719:16-720:21 (CEO-White Surrebuttal at 3, 15-15a); CEO Closing Brief at 17. 137 Tr. at 169:6-171:12 (IPC-Anderson Direct at 13-14). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 34 such an approach if the Commission determined it to be appropriate so long as the same underlying data relied upon for the proposed Energy Charge was used to calculate a weighted average by time period for the time periods which are consistent with all other industrial load pursuant to tariff Schedule 19.138 c. Demand Charges Addressing the Company's initial proposal to update the Contract Demand and Billing Demand Charges consistent with the composite rate change authorized for special contract customers in Case No. IPC-E-24-07, both IIPA and CEO raised concerns over the suitability of the data for determining initial rates. IIPA witness Dr. Kaufman emphasized that the starting rate should reflect expected incremental costs and be updated as costs become known.139 He warned of the "inertia" created if initial rates are set too low, noting that once established, low starting rates become difficult to correct in future rate cases due to negotiation dynamics such as caps, floors.140 CEO witnesses echoed similar concerns and urged the Commission to avoid deferring fixes to later proceedings.141 While the Company maintains its initial recommended pricing was reasonable given known information at the time the ESA was negotiated and executed, in recognition of intervenor concerns raised at hearing, the Company's revised its proposal as set forth in Section C, subsection (2)(b), above, to recommend the Commission adopt initial ESA pricing using the most current cost information available, consistent with the updated pricing workpaper submitted in Idaho Power Company's Response to IIPA's Fifth 138 Tr. at 196:14-25 (Anderson Rebuttal at 15); Tr. at 219:11-221:20 (Anderson Surrebuttal at 14-15). 139 Tr. at 570:18-571:5 (IIPA-Kaufman Surrebuttal at 11-12). 140 Tr. at 655:1-15. 141 Tr. at 728:22-25; Tr. 801:21-802:9. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 35 Production Request. In its Closing Brief, IIPA pointed to this discovery response and indicated "IIPA is comfortable accepting the revised contract and billing demand rates."142 d. Cost Allocation Issues Intervenors have also raised broader concerns regarding cost allocation for large load customers. IIPA states that applying traditional embedded cost allocation methods to unprecedented loads such as Micron will not ensure that "growth pays for growth" and cautions that these methods risk shifting costs to other customer classes.143 IIPA further recommends that incremental generation and transmission costs associated with Micron be identified and addressed in future cost allocation proceedings rather than embedded in the ESA.144 CEO characterizes the FAB load as "transformational" and argues that traditional cost allocation approaches are not adequate for customers of this size.145 CEO calls for guidance on how incremental infrastructure costs should be measured and allocated and notes that these issues cannot be fully resolved in this proceeding or a general rate case.146 Staff has acknowledged these concerns and agrees that cost allocation issues should be addressed in a dedicated forum.147 Staff witness Eldred testified that methodologies for assigning incremental growth-related costs and evaluating fairness in allocation should be explored in the cost allocation case.148 He further noted that a cost allocation case is "the proper place to review" incremental transmission impacts and 142 IIPA Closing Brief at 10. 143 IIPA Closing Brief at 2. 144 IIPA Closing Brief at 2. 145 Tr. at 800:22-23; CEO Closing Brief at 1,7. 146 CEO Closing Brief at 14-15. 147 Tr. at 870:4-13. 148 Tr. at 870:4-13. IDAHO POWER COMPANY'S POST-HEARING BRIEF - 36 related allocation factors.149 Consistent with these positions, Idaho Power emphasizes that the single-issue CCOS docket contemplated in the Settlement Stipulation pending approval in the 2025 GRC is the appropriate forum to explore these challenges. The Settlement Stipulation provides that this docket will examine alternatives to the Company's current CCOS methodology and will be initiated no later than the first quarter of 2026.150 The CCOS docket offers a structured process for parties and the Commission to evaluate whether adjustments to existing methodologies are warranted and to consider approaches that address the unique cost allocation issues presented by large load customers. V. CONCLUSION AND REQUEST FOR RELIEF There has been a long-standing policy at the Commission that to the extent feasible, costs should be assigned to the cost causer to mitigate upward pressure on rates that would otherwise exist,151 and Idaho Power, with support from the Commission, has a long history of applying a "growth pays for growth" policy to guide its cost assignment practices. The Micron FAB ESA was developed consistent with this principle and provides a timely and targeted framework for ensuring that Micron's costs are recovered fairly and consistently with cost causation principles, while protecting other customers from potential cost shifts as Micron's load grows overtime.152 While the parties have agreed to address certain issues related generally to marginal energy costs and cost allocation in follow-up proceedings, further regulatory process is not necessary for the Commission to issue a decision in this docket as to the Micron FAB ESA; it has the 149 Tr. at 871:14-22. 150 Case No. IPC-25-16, Direct Tatum at 12 (Oct. 24, 2025). 151 Tr. at 318:12-15 (IPC-Aschenbrenner Direct at 8); Tr. at 371:4-8. 152 Tr. at 205:18-21 (IPC-Anderson Rebuttal at 24). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 37 authority and procedural framework to do so and an extensive record to draw from based on several rounds of pre-filed testimony and the technical hearing.153 There is substantial, competent evidence in the records supporting the Commission's approval of the Micron FAB ESA subject to the modifications recommended by Commission Staff and an updated Schedule 28. More specifically, Idaho Power Company respectfully requests the Commission issue an order approving the Micron FAB ESA as proposed and an updated Schedule 28. More specifically, the Company requests the Commission direct it to submit a compliance filing including a revised Schedule 28 to update: o The initial Energy Charge to $0.04084 per kWh, consistent with the revised workpaper reflecting the 2025 Marginal Cost Update — Single Run Method approved in Case No. IPC-25-17; and o The Contract Demand charge to $3.12 per kW and the Billing Demand charge to $20.25 per kW to reflect the 2025 GRC Settlement Stipulation CCOS. In the event that the Commission supports the recommendations of Commission Staff to modify the ESA contract terms related to the Marginal Cost-based Energy Charges and the Minimum Monthly Billing Demand, the Company proposes that the Commission direct it to include an amendment to the Micron FAB ESA with its compliance filing revising: Section 5.5(b) "Minimum Monthly Billing Demand After Expansion" and Section 7.2 "Marginal Cost-Based Energy Charges" consistent with the amendments proposed by Micron at hearing in Micron Exhibits 304 and 305. Respectfully submitted this 16th day of December 2025. n IfAPCC�1.�c1 MEGAN GOICOECHEA ALLEN Attorney for Idaho Power Company 153 Tr. at 344:6-345:8 (IPC-Aschenbrenner Surrebuttal at 10-11). IDAHO POWER COMPANY'S POST-HEARING BRIEF - 38 CERTIFICATE OF SERVICE I HEREBY CERTIFY that on the 16th day of December 2025, 1 served a true and correct copy of Idaho Power Company's Post-Hearing Brief upon the following named parties by the method indicated below, and addressed to the following: Commission Staff Hand Delivered Chris Burdin U.S. Mail Deputy Attorney General Overnight Mail Idaho Public Utilities Commission FAX 11331 W. Chinden Blvd., Bldg No. 8 FTP Site Suite 201-A (83714) X Email PO Box 83720 Chris.Burdin(a-).puc.idaho.gov Boise, ID 83720-0074 Industrial Customers of Idaho Power Hand Delivered c/o Peter J. Richardson U.S. Mail Richardson Adams, PLLC Overnight Mail 515 N. 27th Street FAX Boise, Idaho 83702 FTP Site X Email peter _richardsonadams.com Dr. Don Reading Hand Delivered 280 S. Silverwood Way U.S. Mail Eagle, Idaho 83716 Overnight Mail FAX FTP Site X Email dread ingCc_mindspring.com Idaho Irrigation Pumpers Association, Hand Delivered Inc. U.S. Mail Eric L. Olsen Overnight Mail Echo Hawk & Olsen, PLLC FAX 505 Pershing Ave., Ste. 100 FTP Site P.O. Box 6119 X Email Pocatello, Idaho 83205 eloCa)_echohawk.com IDAHO POWER COMPANY'S POST-HEARING BRIEF - 39 Lance Kaufman, Ph.D. Hand Delivered 2623 NW Bluebell Place U.S. Mail Corvallis, OR 97330 Overnight Mail FAX FTP Site X Email lance(D_aegisinsight.com Micron Technology, Inc. Hand Delivered Austin Rueschhoff U.S. Mail Thorvald A. Nelson Overnight Mail Austin W. Jensen FAX Kristine A.K. Roach FTP Site Holland & Hart LLP X Email 555 17t" Street, Suite 3200 darueschhoff(c)_hollandhart.com Denver, CO 80202 tnelson hol land ha rt.corn awlensen(c)_hollandhart.com karoach(a),hol land hart.com aclee _hollandhart.corn Clean Energy Opportunities for Idaho Hand Delivered Kelsey Jae U.S. Mail Law for Conscious Leadership Overnight Mail 920 N. Clover Dr. FAX Boise, ID 83703 FTP Site X Email kelsey kelseylae.com Courtney White Hand Delivered Mike Heckler U.S. Mail 3778 Plantation River Drive, Suite 102 Overnight Mail Boise, ID 83703 FAX FTP Site X Email courtney(a�cleanenergyopportunities.com mike _cleanenergyopportunities.com 1 Christy Davenport Legal Administrative Assistant IDAHO POWER COMPANY'S POST-HEARING BRIEF -40