NorthWestern Energy (NWMT)

Interconnection Information


NorthWestern Energy (NorthWestern) is providing this web page in accordance with Federal Energy Regulatory Commission (FERC) Order Nos. 2003 and 2006 and in response to requests for potential generation and transmission line interconnections to its electric system.


NorthWestern uses the generator interconnection process FERC has developed in its Order Nos. 2003 and 2006 when dealing with generation interconnection requests. NorthWestern also applies many aspects of the generator interconnection process to requests for transmission line interconnections. The applicant must submit a completed interconnection request (forms can be found below) to start the formal interconnection process. When the completed request (with the Initial Processing Fee) is received, NorthWestern Energy will establish the applicant's priority in the corresponding interconnection queue. Questions pertaining to interconnection may be directed to Autumn Mueller at, by telephone (406) 497-3174, or at the address given below. A completed request and applicable fee should be submitted to:

NorthWestern Energy
Attn: Autumn Mueller
         Generation and Transmission Interconnection
11 E. Park Street
Butte, MT  59701


Interconnection Queue (includes the generator interconnection information as required by FERC Order No. 2003, as well as interconnection information for load and transmission interconnection requests).


Large Generator Interconnection Request Form (Greater than 20 MW)


Small Generator Interconnection Request Form (No Larger than 20 MW)


Pre-application Request Form


The official FERC documents pertaining to Large and Small Generator Interconnection Agreements and Procedures may be found at 


In addition to the Interconnection Request Form, please completely fill out the Required Information Sheet for your particular type of generator.


Battery Storage Required Information


Induction or Synchronous Generation Required Information


Solar Generation Required Information


Wind Generation Required Information


For any project with a Battery addition, please fill out both the specific type of generation (wind, solar, etc.) sheet and the Battery Required Information Sheet.




Transmission Line Interconnection Request Form


NorthWestern Energy has modeled the process for interconnection of Transmission Lines after the Large Generator Interconnection Procedures and Agreements as possible. 


Base Case Request


NorthWestern Base Case information is posted in accordance with FERC Order 845. 



It should be noted that the submittal of an interconnection request does not constitute a request for transmission service. It is also the case that any study results, system expansions, etc. at the expense of the applicant, do not imply the applicant will receive any transmission required to deliver the generation output to load. The applicant must follow the procedures described in NorthWestern Energy�s FERC Open Access Transmission Tariff to request and/or reserve transmission service.