The Montana Public Service Commission has determined that NorthWestern Energy’s power plan is deficient and ordered the utility to revise it within 30 days, with the possibility of a brief extension.

The PSC identified five areas where the plan lacked necessary information, including the absence of mathematical analysis or scenario testing. The commission also found the plan inadequately addressed demand-response programs designed to help customers reduce energy consumption.

During public comment on the filing, stakeholders raised concerns about NorthWestern’s emphasis on data center development, a shift away from renewable energy investments, and the potential for rising consumer electricity bills. NorthWestern, which maintains headquarters in Butte, countered that its plan would serve Montana’s energy needs “reliably, safely and affordably,” according to the utility’s public statements on the matter.

The revision deadline marks a significant checkpoint in NorthWestern’s resource planning process as Montana continues to balance growing electricity demand with the state’s energy policy objectives. The utility’s next steps will determine whether it can address the commission’s concerns or face further regulatory scrutiny.