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Lesson 4 of 9 · about 18 minutes

Ratepayer Protections at the Utility Commission

You'll be able to

  • Describe how a case moves through the Idaho PUC and where the public can take part
  • Sort data center costs into dedicated facilities, shared transmission and generation, and say who usually pays each
  • Compute what a minimum bill collects when a data center uses less than it contracted for
  • Describe where the Idaho Power large-load cases stand as of October 2026

A county commission can't set electric rates. Neither can a city council, a planning commission or a development agreement. In Idaho, the rates and service terms of investor-owned utilities belong to the Idaho Public Utilities Commission, three commissioners appointed by the governor. If residents want protection from paying for a data center's power, the PUC case is where that protection gets written or doesn't.

The grid and who pays lesson covered the national picture: Ohio's 85 percent minimum, Virginia's new GS-5 class, Texas Senate Bill 6. This lesson goes inside the Idaho process and the arithmetic of the protections.

How a case moves

Applicationfiled, case no. Notice andintervention Discovery,testimony Staff, publiccomments Hearing ororder Modified procedure: written comments only, no hearing. Technical hearing: sworn witnesses, cross-examination, then an order. Public comments can be filed online at any stage before the deadline. Every filing is posted under the case number unless marked confidential.
The usual path of an Idaho PUC case. Big contracts often take more than a year.

A utility files an application, and the commission assigns a case number like IPC-E-26-07 (Idaho Power, electric, filed in 2026, case 07). The commission issues a notice setting an intervention deadline. Groups that want formal party status petition to intervene. Then comes discovery, where parties send each other written questions, and testimony. The case proceeds either by modified procedure, meaning written comments only, or by technical hearing with sworn witnesses. Commission staff file their own analysis. Members of the public can file comments without intervening. Then the commission issues an order.

Staff comments and the final order often matter more than the application. Staff comments or decision memos often put a number on the risk to other customers that the utility's filing glosses over. And the final order tells you what was actually approved, which may differ from what was asked.

Sorting the costs into buckets

When a utility serves a 300 MW customer, the new costs sort into the buckets below, and each one is fenced off differently.

BucketExamplesWho usually paysProtection toolHow well it works
Dedicated facilitiesSubstation at the site, a radial line serving only the campusThe customer, up front or through a facilities chargeContribution in aid of construction; direct assignmentWell, if the contract says so
Shared transmissionNew high-voltage lines and upgrades that also carry power for othersDivided among customer classesCost-of-service allocation; tariff rules assigning upgradesContested; depends on the study method
Generation and power supplyNew gas plants, solar and storage, market purchasesAll customers through rates, unless a special arrangement appliesMinimum bills, long terms, exit fees, dedicated resourcesPartial; hardest to fence off

Ari Peskoe and Eliza Martin of the Harvard Environmental and Energy Law Program, in a March 2025 review of nearly 50 proceedings, argued that special contracts often let data center costs spill into the second and third buckets. Utilities and the industry respond that newer large-load tariffs exist to stop that. The way to test either claim in a given case is to find each bucket in the filing and see who pays.

The Idaho record, as of October 2026

Idaho now has a large-load statute. House Bill 911 passed the House 65-3 and the Senate 34-1, was signed April 10, 2026 (Session Law Chapter 335) and took effect July 1, 2026. It adds Idaho Code 61-335, "New Large Load and Ratepayer Protection": large new loads served under contracts signed on or after that date need a commission-approved contract, and the utility must show other customers are not harmed. Other bills failed: SB 1368 in 2026, which would have required commission approval before serving a customer adding 30 MW or more, according to the Idaho Conservation League tracker; and H0395 in 2025, which passed the House and died in a Senate committee. (House Bill 609 in 2026, a bill to revise the data center sales and property tax exemptions, also stalled after committee referral.) Read the statute and the commission cases together: the cases still set the terms for each customer.

IPC-E-21-42, Brisbie LLC. The application, dated December 22, 2021, sought approval of a special contract for an enterprise data center. In Final Order No. 35777 on May 11, 2023, the commission approved it with modifications. The order describes Brisbie as becoming Idaho Power's largest customer with a 90 percent expected load factor, served under a new Schedule 33 in which Idaho Power buys renewable resources to cover its energy. Staff found that transmission construction and operating costs up to the delivery point would not fall on other ratepayers, and recommended parent guarantees for the life of the purchase agreements. Idaho Power's no-harm analysis projected a $17.8 million benefit to other customers over 10 years. Staff called it insufficient because it rested on a single set of assumptions. The commission added protections: an 85 percent adjustment on credits for excess energy, a backstop at hourly market prices, no capacity payments until the system actually needs capacity, and commission review of future purchase agreements tied to the contract.

IPC-E-24-44, Micron. A special contract and new Schedule 28 for a memory chip plant, filed December 6, 2024, approved with modifications in Order No. 37039 on May 8, 2026, with the compliance filing approved in Order No. 37092 on July 8, 2026. A chip fab is not a data center, but this is the most recent template for a very large load on Idaho Power's system.

IPC-E-26-07, cost of service for new large loads. Filed March 31, 2026. Idaho Power asks the commission to evaluate its class cost-of-service method, consider alternatives, and decide how costs should be assigned to new large-load customers. This is the second and third bucket fight. Intervenors are the Idaho Irrigation Pumpers Association, Micron, the Industrial Customers of Idaho Power, the City of Boise, the Northwest Energy Coalition, Clean Energy Opportunities for Idaho, the Federal Executive Agencies and Bayer (through its affiliate Ruveon LLC). The irrigators moved for a technical hearing in June. The commission issued a notice of schedule in Order No. 37170 on September 16, and Idaho Power filed direct testimony with allocation models on September 23, 2026. The order sets staff and intervenor testimony for November 25, a public comment deadline of December 14, 2026, and a technical hearing starting January 19, 2027. No decision as of the docket's October 7 update.

What a minimum bill does and doesn't cover

Example: the 300 MW customer that shows up at 120

An invented utility signs a contract with Project Tamarack for 300 MW, with a minimum demand of 85 percent, like Ohio's tariff. Assume a demand charge of $12 per kW-month (an invented round number; real charges are in the tariff).

  • Minimum billed demand: 300 MW x 0.85 = 255 MW = 255,000 kW.
  • Minimum monthly demand bill: 255,000 x $12 = $3,060,000.
  • Actual use after two years: 120 MW. Bill at actual use: 120,000 x $12 = $1,440,000.
  • Extra collected by the minimum: $3,060,000 minus $1,440,000 = $1,620,000 a month, or $19,440,000 a year.

Now the cost side. Say the utility built $400 million of generation and shared transmission to serve the full 300 MW. Utilities recover capital through an annual revenue requirement covering return, depreciation, taxes and operations. Assume 12 percent a year: $400,000,000 x 0.12 = $48,000,000 a year.

How much of that does the customer cover? Only the demand charge goes toward fixed costs in this sketch. At the minimum: $3,060,000 x 12 = $36,720,000 a year. Gap: $48,000,000 minus $36,720,000 = $11,280,000 a year that falls on other customers unless the contract has more protection: a higher minimum, an exit fee, collateral, or a facilities charge.

And if the developer goes bankrupt, the minimum bill is only as good as the collateral behind it. That is why staff in the Brisbie case asked for parent guarantees.

Real filings are more complex: energy charges, demand ratchets, time-of-use periods. But the logic holds. A minimum bill protects against a customer that underperforms while it stays solvent and stays put. Exit fees and collateral protect against one that leaves. Neither one fixes a cost allocation method that puts too little of the shared system on the new class to begin with, which is why IPC-E-26-07 matters.

Common mix-ups

  • Claim: The county can require the data center to protect ratepayers. What the evidence shows: Rates are set by the PUC. A county or city can intervene in the PUC case, as the City of Boise did in IPC-E-26-07, but a land-use condition cannot set a utility rate.
  • Claim: If the customer pays for its substation, others are protected. What the evidence shows: That covers the first bucket. Shared transmission and new generation are the larger costs and are divided by cost-of-service methods.
  • Claim: A utility's no-harm study settles the question. What the evidence shows: In the Brisbie case, staff found Idaho Power's study insufficient because it used a single set of assumptions. Look for sensitivity cases where the load arrives late, smaller or not at all.

Reporting angle

  • Bookmark the PUC case search and check the utility's code weekly. New cases appear as applications before any press release.
  • In any special contract, find: contracted MW, minimum demand percentage, term, exit fee, collateral, and who pays for each cost bucket.
  • Read staff comments first, then intervenor testimony. Ask each intervenor what number they think the utility got wrong.
  • Ask what is filed as confidential and why. Ask whether a redacted version exists.
  • Note comment deadlines and publish them, so readers who want to file comments can.

Research angle

Check yourself

1. As of its October 7, 2026 update, what was the status of Idaho PUC case IPC-E-26-07 on cost of service for new large-load customers?

2. A data center contracts for 300 MW with an 85 percent minimum demand. It actually uses 120 MW. At an assumed $12 per kW-month demand charge, what is the monthly minimum demand bill?

3. In Order No. 35777 (May 2023) on the Brisbie LLC data center contract, what did the commission say about Idaho Power's projected $17.8 million no-harm benefit?

4. Which cost is hardest to fence off onto a single large customer?

5. Who can take part in an Idaho PUC case like IPC-E-26-07?

Terms in this lesson

Cost of service study
A utility analysis that divides the cost of running the system among customer classes, which then shapes each class's rates.
Intervenor
A person or organization granted formal party status in a utility commission case, with the right to file testimony and question witnesses.
Minimum bill (minimum demand charge)
A contract term requiring a customer to pay for a set share of contracted capacity even if it uses less.
Contribution in aid of construction
Money a customer pays up front toward facilities built to serve it, so other customers don't carry that cost.
No-harm analysis
A utility study meant to show that serving a new customer will not raise costs for existing customers.

Full glossary

Sources