NorthWestern Energy’s 20-year electricity plan doesn’t cut it — not according to the Montanans who packed two Helena hearings last week to tell state regulators the utility is favoring data centers and fossil fuels over the ratepayers who’ll foot the bill.
NorthWestern Energy, a regulated monopoly and Montana’s largest utility, is required every three years to file a 20-year blueprint for how it plans to generate and deliver electricity to the more than 413,000 electric customers it currently counts across the state. And the Public Service Commission solicits public feedback on the document — called an Integrated Resource Plan, or IRP — before signing off on it.
At a time when anxiety is running high over energy-gulping data centers and utility bills that keep climbing, a total of more than 40 people showed up at the PSC’s two public hearings on July 21 and 23 — down from the usual five hearings — ahead of the comment period closing on Tuesday, July 28.
Fueling that anxiety are the three data centers with which NorthWestern has signed letters of intent over the past two years — new energy demand that the utility doesn’t count as a given in its long-term forecast, choosing instead to model it only as a hypothetical add-on. Even without them, NorthWestern acknowledges a capacity shortfall is coming as soon as the winter of 2027-28 — one that could grow to nearly 200 megawatts once an existing supply contract expires — and the company has yet to say how, exactly, it will close that gap.
“We don’t have a choice in who provides our power, so at the very least, NorthWestern needs to be transparent and provide that information to the public.”
Others pointed to a broader pattern of opacity. The terms of NorthWestern’s data center agreements remain hidden from public view, and the IRP itself contains redacted sections — confidentiality the PSC granted at the utility’s request, over objections from environmental and consumer groups.
“We don’t have a choice in who provides our power, so at the very least, NorthWestern needs to be transparent and provide that information to the public,” said Colette Berg of Montanans Against Data Centers Action Team, or MADCAT.
But we know more than the redacted contracts show. NorthWestern has named two of the three data center developers itself — Atlas Power Group and Quantica Infrastructure — while the third, Sabey Data Centers, was identified only through separate reporting. What remains hidden in all three cases isn’t who’s involved, but what they’ve actually agreed to:
- Atlas Power Group (Butte) — a cryptocurrency mining operation, the Missoulian reported, already a NorthWestern customer since 2019. NorthWestern announced the deal in December 2024, projecting 75 megawatts of service beginning this year, with growth of up to another 75 megawatts over the following three to five years.
- Sabey Data Centers — planned two data centers near Butte, pitched as a $1 billion project, after agreeing to buy 606 acres of land, as the Montana Standard reported — collapsed in June before closing.
- Quantica Infrastructure (Yellowstone County) — an AI-focused data center, the largest of the three. Signed on for up to 1,000 megawatts — enough, Montana Free Press reported, to require nearly all the electricity NorthWestern’s power plants currently generate.
The IRP, filed in May, describes all three letters of intent as active. But the ground has already shifted: In June, Sabey terminated its buy-sell agreement for the 606 acres near Butte — where it had planned two 500,000-square-foot data centers — after an existing occupant exercised a right of first refusal on the land. Sabey says it’s still interested in building somewhere in southwest Montana.
Combined, the three had signaled they could eventually draw up to 1,400 megawatts — roughly double NorthWestern’s entire current Montana customer load — though Sabey’s piece of that is now uncertain after its Butte deal fell apart.
None of the three is the data center project near Bonner. That proposal, unaffiliated with NorthWestern, died in July after the property owner withdrew support amid public pressure — separate from Missoula County’s one-year data-center moratorium, which wouldn’t have applied to the Bonner proposal anyway.
Montana is attractive for data centers, according to the plan, because of its position along a long-haul fiber corridor, relatively low land and energy costs, and a cool climate suited to passive cooling.
Data centers weren’t commenters’ only concern. The 385-page IRP gives climate change only a passing mention, they noted, while it projects the coal-fired Colstrip plant will continue running into the 2040s.
Public health was another flashpoint. Robert Merchant, a pulmonary surgeon from Billings who testified virtually, criticized the IRP for failing to quantify the health costs of fossil fuel generation, pointing to research from the Rocky Mountain Institute estimating that emissions from Colstrip alone account for $2.1 billion in health costs and 151 premature deaths.
“You don’t work for Northwestern Energy, you work for us,” said Jen Milner, who tuned in virtually from Bozeman and directed her comment at PSC President Jeff Welborn.
The PSC can’t approve or reject the plan outright, but it can find it deficient and require NorthWestern to address specific shortcomings. Commissioners are expected to weigh in at a work session in mid-August, after written public comment closes July 28. Montanans can comment through the PSC’s online portal at reddi.mt.gov (Docket 2026.04.026) or by emailing [email protected].
