Attachment K Business Practice –NorthWestern Energy
NWE Local Transmission Planning
Attachment K Business Practice
If there is any difference between this Business Practice and the Tariff, the Tariff is correct.
Don Bauer
Transmission Eng. – Planning & Capacity West Manager
Don.bauer@northwestern.com
Phone: (406) 497-3542
Effective Date: After FERC approval
From: FERC Order 1000 – October 2012 Filing
FERC Order 1000 – September 16, 2013 Compliance Filing
To:
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Attachment K Business Practice –NorthWestern Energy
Table of Contents
Preamble ......................................................................................................................................... 5
Introduction ................................................................................................................................. 6
Principle 1 – Coordination .......................................................................................................... 8
FERC Order Requirement Summary ...................................................................................... 8
Coordination, Generally.......................................................................................................... 8
NWE Stakeholder Coordination ............................................................................................. 8
NWE OASIS Website ............................................................................................................. 8
Stakeholder Involvement Simplified ...................................................................................... 8
NWE Contact Information ...................................................................................................... 9
Comparable Stakeholder Involvement .................................................................................... 9
Types of Planning Meetings ................................................................................................... 9
Meeting Information ............................................................................................................. 10
Announcements and Communications: ................................................................................ 11
Coordination of Study Results From Local Transmission Plan, Interconnection Studies,
Transmission Service and Economic Congestion Studies .................................................... 11
Regional/Interconnection wide Coordination ....................................................................... 12
Principle 2 – Openness.............................................................................................................. 13
FERC Order Requirement Summary .................................................................................... 13
NWE’s Open Planning Process ............................................................................................ 13
Public Meetings .................................................................................................................... 13
Standards of Conduct and Critical Energy Information ....................................................... 13
Confidentiality ...................................................................................................................... 13
Regional and Interconnection wide Planning ....................................................................... 14
Principle 3 – Transparency ....................................................................................................... 15
FERC Order Requirement Summary .................................................................................... 15
Technical Analyses Transparency ........................................................................................ 15
Consistent Application .......................................................................................................... 16
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Data Access ........................................................................................................................... 16
Opportunity For Review and Comment ................................................................................ 16
Replication of Planning Studies ............................................................................................ 17
Regional/Interconnection wide Transparency ...................................................................... 17
Principle 4 - Information Exchange .......................................................................................... 18
FERC Order Requirement Summary .................................................................................... 18
Information Request.............................................................................................................. 18
Schedule ................................................................................................................................ 19
Procedure For Data Submission............................................................................................ 19
Data Use In Planning Process ............................................................................................... 20
Confidentiality ...................................................................................................................... 20
Customer Responsibility ....................................................................................................... 20
Principle 5 – Comparability ...................................................................................................... 21
FERC Order Requirement Summary .................................................................................... 21
Ensuring Comparability ........................................................................................................ 21
Principle 6 - Dispute Resolution ............................................................................................... 22
FERC Order Requirement Summary .................................................................................... 22
NWE Dispute Resolution...................................................................................................... 22
Regional and Interconnection wide Dispute Resolution ....................................................... 22
Principle 7 – Regional Participation ......................................................................................... 23
FERC Order Requirement Summary .................................................................................... 23
Regional Participation ........................................................................................................... 23
Regional Plan and Data Coordination................................................................................... 24
Interconnection wide Participation ....................................................................................... 24
NWE and Regional Planning Process Differences ............................................................... 24
Simultaneous Plan Feasibility ............................................................................................... 25
Principle 8 - Economic Congestion Studies.............................................................................. 26
FERC Order Requirement Summary .................................................................................... 26
High-Priority Study Requests ............................................................................................... 27
Requesting A High-Priority Local Economic Congestion Study ......................................... 27
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Attachment K Business Practice –NorthWestern Energy
Valid NWE Request .............................................................................................................. 27
Economic Congestion Study Classification .......................................................................... 27
Number of NWE High-Priority Studies ................................................................................ 28
Prioritizing NWE Local Economic Study Requests ............................................................. 28
Clustering Study Requests .................................................................................................... 28
NWE Local Economic Congestion Study............................................................................. 29
Customer’s Obligation To Share Data .................................................................................. 30
NWE Obligation ................................................................................................................... 30
Cost to Conduct NWE’s Two High Priority Local Economic Congestion Studies .............. 30
NWE Local Economic Congestion Study Timeline and Process ......................................... 31
Additional Local Economic Congestion Studies .................................................................. 32
Process for Additional Economic Congestion Studies ......................................................... 32
Regional Economic Congestion Study Coordination ........................................................... 33
Economic Congestion Study Posting .................................................................................... 33
Principle 9 - Cost Allocation for New Projects ........................................................................ 34
FERC Order Requirement Summary .................................................................................... 34
Projects Not Covered Under Existing Cost Allocation Rules .............................................. 34
NWE Cost Allocation Methodology Projects Outside the OATT ........................................ 35
Regional and Interregional Cost Allocation ......................................................................... 36
Recovery of Planning Costs .................................................................................................. 36
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Attachment K Business Practice –NorthWestern Energy
Preamble
The Federal Energy Regulatory Commission (FERC) issued its Order No. 890 on February 16,
2007 (Order). The Order provided amendments to the regulations and the pro forma Open
Access Transmission Tariff (OATT) adopted in Orders 888 and 889. The Order became
effective May 14, 2007, which is 60 days following the date the Order was published in the
Federal Register. One objective of the Order is to limit undue discrimination in planning the
transmission system by requiring coordinated, open, and transparent transmission planning on
both a local and interconnection wide level and by involving stakeholders in the early stages of
transmission planning. FERC outlined the need for reform in transmission planning through
Order No. 890.
Accordingly, each public utility transmission provider is required to submit, as part of a
compliance filing, a proposal for a planning process that complies with the planning principles
and other requirements in the Order. The Order requires a more inclusive transmission planning
process incorporating the following nine principles: (1) Coordination, (2) Openness, (3)
Transparency, (4) Information exchange, (5) Comparability, (6) Dispute resolution, (7) Regional
participation, (8) Economic planning studies, and (9) Cost allocation for new projects. This
Business Practice provides a discussion on these 9 principles.
In 2011, FERC issued Order 1000 amending their Order 890 regional planning requirements
requiring each transmission provider participate in a regional transmission planning process that
produces a Regional Transmission Plan by complying with Order No. 890 transmission planning
principles of coordination, openness, transparency, information exchange, comparability, dispute
resolution and economic planning. This Order also requires each public utility transmission
provider to consider transmission needs driven by public policy requirements established by state
or federal laws or regulations in its local and regional transmission planning processes and
evaluate potential solutions to meet those needs. The order does not prohibit including additional
public policy requirements that go beyond state or federal laws or regulations. FERC declined to
specify which public policy requirements must be considered or included in the plan. The
planning process must provide stakeholders with an opportunity to provide input on needs driven
by public policy requirements.
The URL address to access NWE’s Attachment K and the various documents and business
practices discussed in this document are identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
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Attachment K Business Practice –NorthWestern Energy
Introduction
NorthWestern Energy (“NWE”), with input from stakeholders, developed the nine principles of
NWE’s Attachment K Business Practice (“Business Practice”). This Business Practice and its
supporting documents and business practices can be obtained on NWE’s OASIS website by
following the URL address identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
The NWE local transmission system provides regulated electric transmission services to
approximately 295,000 electric customers. Figure 1, below, provides a graphical overview of
NWE’s transmission system. NWE’s electric transmission system consists of over 7,000 miles
of transmission lines and associated terminal facilities. This system, with voltage levels ranging
from 50,000 to 500,000 volts, serves an area of 97,540 square miles, which is equivalent to twothirds of Montana. The system has interconnections to five major transmission systems1 located
in the Western Electricity Coordinating Council (WECC) area and Mid-Continent Area Power
Pool (MAPP) region through WAPA’s DC interconnection. NWE is registered as a Balancing
Authority, Planning Authority and Transmission Planner. NWE does not currently own
generation used to serve retail customer load.
The URL address to the various documents and business practices discussed in this document
and in NWE Attachment K are identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
1
The five interconnected systems are Idaho Power Company, Avista Corporation, Bonneville Power
Administration, WAPA and PacifiCorp.
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Attachment K Business Practice –NorthWestern Energy
Figure 1: NWE Local Transmission System
Peace
River
British
Alberta
Columbia
Canada
Seattle
Washington
Portland
Area
Montana
Celilo
Pacific
Ocean
Colstrip
Oregon
Idaho
Malin
Midpoint
Round
Mountain
Nevada
San Francisco
Area
Denver
Area
Utah
Four
Corners
Market
Colorado
New
Place
Los
Angeles
Area
Jim
Laramie
Bridger River
Salt Lake
City Area
Las
Vegas
Area
California
Wyoming
Borah
Mexico
Phoenix
Area
Arizona
San Diego
Mexico
Tucson
Area
Albuquerque
El Paso
The following Attachment K Business Practice was developed in collaboration with interested
stakeholders in an open, transparent forum.
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Attachment K Business Practice –NorthWestern Energy
Principle 1 – Coordination
FERC Order Requirement Summary
The Commission Determination is found within paragraphs 451 – 454 of the Order. The
Coordination principle requires appropriate lines of communications among transmission
providers, transmission-providing neighbors, State authorities, customers, and other
stakeholders. Transmission providers are allowed to craft coordination requirements that work
for those providers, their customers and stakeholders.
Coordination, Generally
NWE’s Local Transmission Plan (or LTP), also referred to as Local Transmission System Plan
(LTSP), will be coordinated in two ways. First, during the development stage of the Local
Transmission Plan NWE will have an open public process to allow two-way communication
with stakeholders and interested parties. Second, NWE’s Local Transmission Plan will be
coordinated with its regional planning entity - the Northern Tier Transmission Group’s
(“NTTG”), other regional planning entities and the Western Electricity Coordinating Council’s
(“WECC”) interconnection wide planning entity. See the URL address for the NTTG
“Transmission Planning Guidance Document” and other documents and business practices
identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
NWE Stakeholder Coordination
NWE’s local transmission plan planning coordination is an open public process that allows and
promotes customers, interconnected neighbors, regulatory and state bodies and other stakeholder
participation in a coordinated nondiscriminatory process for local transmission plan
development. To accomplish this coordination, NWE will have an open meeting policy and a
transparent process that will afford stakeholders an opportunity to regularly meet with NWE and
to provide input on content, methodology, process and other elements used in the development of
NWE’s transmission plan. Furthermore, NWE has a permanent planning committee called the
Transmission Advisory Committee (“TRANSAC”) that will be involved in developing the local
transmission plan.
NWE OASIS Website
NWE’s OASIS website can be accessed through the URL address identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Stakeholder Involvement Simplified
To simplify stakeholder involvement and understanding of NWE’s planning process, NWE has
an area on NWE’s OASIS website dedicated to transmission planning. The URL addresses for
this website area can be found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
On this website, stakeholders can learn about NWE planning activities including:

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Attachment K Business Practice –NorthWestern Energy

Future meeting announcements,

Review NWE calendar of events and the study cycle,

Review reports and meeting material, and

Obtain NWE contact information.
A list of Frequently Asked Questions is also posted on NWE OASIS website to simplify
stakeholder understanding of NWE’s local area planning process. NWE’s OASIS website can
be accessed through the URL address identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
NWE Contact Information
Interested parties can provide comment or contact NWE directly by following the directions
provided in the “How To Contact Transmission Planning” folder on NWE’s OASIS website.
NWE’s OASIS website can be accessed through the URL address identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Comparable Stakeholder Involvement
NWE will make its stakeholder meetings open to the public, except when Standards of Conduct
(SOC) concerns require portions of the meeting to be closed to some participants. NWE’s open
process will allow participation by stakeholders, including, but not limited to, the Montana
Public Service Commission, the Montana Consumer Council, transmission customers (network
and point-to-point), existing generator owners, new project developers, cooperatives,
interconnecting utilities, the Governor’s Office, transmission-providing neighbors and other
stakeholders.
Types of Planning Meetings
NWE will have two types of planning meetings to involve stakeholders in the planning process
and to facilitate and coordinate stakeholder input and involvement in NWE local transmission
plan planning. These planning meetings are the Transmission Advisory Committee
(“TRANSAC”) meetings and Open Public meetings.
TRANSAC Meeting: TRANSAC will be engaged in the various stages of developing NWE’s
local transmission plan. Access to TRANSAC Charter can be achieved through the URL address
identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
The purpose of this advisory committee will be to provide input to NWE on its local
transmission plan. TRANSAC will not make decisions or implement the plan. The ultimate
responsibility for the transmission plan will remain with NWE.
TRANSAC membership is open to anyone and will be established through self-nomination. If
the membership is either too small or too large, NWE will work with the committee to determine
whether adjusting the size is appropriate and, if so, what mechanism should be used to
accomplish the adjustment. NWE will encourage membership from neighboring transmission
providers, affected state authorities, regulators, customers and other stakeholders.
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Attachment K Business Practice –NorthWestern Energy
All TRANSAC meetings will be open to the public and will allow open and transparent dialogue
on all aspects of the transmission plan to the maximum extent allowed without violating
Standards of Conduct (“SOC”) information and Critical Energy Infrastructure Information
(“CEII”). Members on this committee will be encouraged to be involved in each meeting and to
be actively engaged in the process.
TRANSAC is a stand-alone committee that will provide input only into NWE’s transmission
plan. TRANSAC may determine that it needs to form a sub-committee to address a specific
issue or task. Participation on this sub-committee will be open to anyone. The responsibilities of
the sub-committee and its structure will be determined by TRANSAC. If a sub-committee is to
be formed, NWE will consult with TRANSAC before formation and an announcement of the
formation of the sub-committee, its responsibilities and who to contact for more information or
to join will be posted on the Transmission Planning portion of NWE’s OASIS website.
Open Public Meeting: NWE will hold open public meetings to allow a two-way communication
on NWE’s transmission plan. Open public meetings will be scheduled by TRANSAC.
Meeting Information
The number of meetings, scope, notice requirements, and the format for these two types of
meetings is described below.
Number of Meetings:
TRANSAC: TRANSAC will meet regularly in an open forum. NWE will encourage TRANSAC
to meet as often as needed to provide meaningful input into NWE’s transmission plan
development. NWE would anticipate that TRANSAC will meet at least quarterly.
Open Public Meeting: NWE will work with TRANSAC to schedule and hold open public
meetings that will be designed to communicate information about its transmission plan and to
receive input on its transmission plan. TRANSAC may adjust the number of public meetings as
needed, but NWE anticipates one or two meetings per year.
Scope of Meetings:
The meetings will be open to discuss non-confidential aspects of transmission planning activities
including, but not limited to methodology, study inputs, criteria, and study process and results.
The intent is to provide a forum that allows stakeholders to have meaningful input into NWE’s
transmission plan development. Dissemination of market sensitive information or critical
infrastructure information must follow FERC Standards Of Conduct (SOC) requirements and
CEII requirements.
Notice:
TRANSAC: There will be two forms of meeting notice: (1) A list of participants (name,
organization, phone and email) will be maintained and notice for each meeting will be provided
to prior participants by email; (2) Notice of a TRANSAC meeting will be posted on NWE’s
OASIS website no later than fourteen (14) calendar days prior to the meeting and the available
meeting material will be distributed at least two (2) business days prior to the meeting. Any
additional meeting material presented during the TRANSAC meeting will be posted on NWE’s
OASIS website. The Transmission Planning section of NWE’s OASIS website will include a
calendar of events and study cycle” (“Calendar”) document. Access to this calendar can be
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Attachment K Business Practice –NorthWestern Energy
achieved through the URL address identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Open Public Meeting: NWE will use, as appropriate, three forms of meeting notice: (1) A list of
participants (name, organization, phone and email) from prior open public meetings will be
maintained and meeting notices will be provided to prior participants by email or by mail if
email is not available; (2) Local media (radio, newspaper, etc) may be used as appropriate to
announce the open public meetings; (3) Notice of an open public meeting will be posted on
NWE’s OASIS website at least thirty (30) calendar days prior to the meeting.
Format:
NWE will retain a neutral moderator to help plan and moderate the meetings. These meetings
will be designed to provide opportunities for information exchange about NWE’s transmission
plans, methodology and processes. Notes taken at the meetings and other information from the
meetings will be posted on NWE’s OASIS website.
TRANSAC: TRANSAC meetings will be held either face-to-face or by conference call. The
face-to-face meetings will also include a phone connection and a web conference service for
those who cannot attend in person.
Open Public Meeting: The Open Public Meeting will be a face-to-face meeting between NWE
and the public.
Announcements and Communications:
Announcements and communications will be posted under the Transmission Planning folders on
NWE’s OASIS website. Information regarding NWE public meetings will be posted and
emailed to interested parties as described under the Notice discussion above.
Coordination of Study Results From Local Transmission Plan, Interconnection
Studies, Transmission Service and Economic Congestion Studies
The Local Transmission Plan study (for retail load service), Interconnection study, Transmission
Service study and the Economic Congestion study (for customer economic congestion study
request described below) are distinct and separate studies. They examine the transmission
system for different purposes and from different perspectives (reliability evaluation vs. economic
dispatch evaluation). Even though these studies are distinct and separate, the applicable study
results from each study will be made available to the other study for consideration See Figure 2:
Sharing System and Economic Congestion Study Results.
Sharing Study Result
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Q5 Data Collect
Decision
Reporting
Year 2
Prior Cycle Results
Data Collect, Goal & Scenario
Base Case Develop
Q3-6 Technical Study
Economic Planning Study
Year 1
Local Transmission Plan
Sys Planning Cycle
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
Interconnect & TSR
Study Results
Trans Svc &
Interconnect
Prior Year Results
Receive Requests
Prioritize & Begin Study
Study
Finish Study & Report
Receive Requests
Prioritize & Begin Study
Study
Finish Study & Report
Attachment K Business Practice –NorthWestern Energy
Figure 2: Sharing System and Economic Congestion Study Results
NWE, in consultation with TRANSAC, will determine the proposed new projects to evaluate or
re-evaluate in the development of the LTP.
Any project included in the prior LTP will be subject to reevaluation in NWE’s planning process
if construction contracts have not been awarded prior to the beginning of the biennial planning
cycle.
Proposed new interconnection (i.e., generation resource, transmission project, or new large load)
or request for transmission service may be coordinated into the Local Transmission Plan during
Q1 and Q5 if 1) there is a signed agreement in place, or 2) it is included in the WECC base case,
or 3) TRANSAC requests including it in the Local Transmission Plan.
Regional/Interconnection wide Coordination
NWE is a member and actively engaged in the Northern Tier Transmission Group (“NTTG”),
which is a permanent planning committee. NWE will coordinate its biannual transmission plan
with NTTG and with other planning entities as required. NTTG has participation of state
commissions, including the Montana PSC. NTTG will coordinate its planning proposals with
WECC and other regional planning entities (e.g., ColumbiaGrid, WestConnect, CAISO.). NTTG
is an open stakeholder process that has formal stakeholder meetings. Addition information can
be found on the NTTG website at http://nttg.biz or on NWE’s OASIS website through the URL
address identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
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Attachment K Business Practice –NorthWestern Energy
Principle 2 – Openness
FERC Order Requirement Summary
The Commission Determination is found within paragraph 460 of the Order. The Openness
principle requires that Transmission planning meetings are open to all affected parties, including
all transmission and interconnection customers, state commissions and other stakeholders. If
subgroups are used, the overall transmission plan and planning process must remain open.
NWE’s local transmission plan will be open to all stakeholders and interested individuals to
provide comments and input in the development of NWE’s transmission plan. These principles
are described below.
Figure 3: Planning Process
NWE’s Open Planning Process
NWE’s local transmission planning
process will be open to all stakeholders.
Stakeholders will have the opportunity
through TRANSAC to review and
comment on NWE’s local transmission
plan throughout the development of the
plan. See Figure 3: Planning Process to
the right. This process is also described
in Principle 3 of this document.
Overview
Local Transmission System Planning Process
1. Goal & Scenario
2. Technical Study
3. Decision
NWE
Transmission
Advisory
Committee
Input to Plan
NWE shall have an open planning
4. Reporting
process that provides all stakeholders the
opportunity to provide input into the transmission needs driven by public policy requirements for
consideration in the development of the LTP.
Public Meetings
NWE’s TRANSAC and the Open Public Meetings will be open to public participation and input.
These meetings will be designed to foster an open transparent two-way communication between
NWE and its stakeholders and affected parties
Standards of Conduct and Critical Energy Information
Protection of Critical Energy Infrastructure Information (CEII) and market sensitive information
covered by FERC Standards of Conduct (SOC) will be observed. NWE’s Anti Trust and SOC
documents are posted on NWE’s OASIS website.
Confidentiality
Access to confidential data by a stakeholder will require a confidentiality agreement. There are
two confidentiality agreements that apply – NWE confidentiality agreement for NWE
confidential data and a WECC confidentiality agreement for confidential WECC base case data.
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Attachment K Business Practice –NorthWestern Energy

Access to NWE confidential data will require signing NWE’s confidentiality
agreement. A copy of NWE’s confidentiality agreement has been developed and
posted on NWE’s OASIS website as identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practic
e_Links.doc. Stakeholders shall have an opportunity to submit comments on the
form of confidentiality agreement. Confidential information shall be provided
only to those participants in the planning process that require such information
and that execute the confidentiality agreement; provided, however, any such
information may be supplied to (i) federal, state or local regulatory authorities that
request such information and protect such information subject to non-disclosure
regulations, or (ii) upon order of a court of competent jurisdiction.

Access to WECC load and resource data and WECC base case data will require
signing a WECC confidentiality agreement. A confidentiality agreement is not
required for WECC members to obtain access to base case data. A copy of the
WECC non-member confidentiality agreement is posted in NWE’s OASIS
website. A copy of WECC’s confidentiality agreement is available through the
ULR found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practic
e_Links.doc.
NWE will apply equal protection to NWE confidential information and to confidential
information received from customers. In the event that a party claims that their planning-related
information is confidential, any party seeking access to such information must agree to adhere to
the terms of a confidentiality agreement.
It is recognized that certain data may not be available to certain participants, even though a
confidentiality agreement is signed, due to their relationship to the market.
Disclosure of confidential data to state commissions, FERC and other regulatory bodies will be
governed by the appropriate protective order. Before confidential data is released to regulating
bodies, NWE will seek protection of that data through a protective order.
Regional and Interconnection wide Planning
With respect to regional and interconnection wide planning entity openness, NWE will
coordinate and provide NTTG, WECC and other planning entities with NWE’s local
transmission plan, associated assumptions and other information as requested. Confidential data
will be protected through NWE confidentially requirements and/or the confidentiality
requirements of the regional and interconnection wide entities. Information regarding NTTG
regional and interregional planning can be found on the NTTG website at http://nttg.biz.
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Attachment K Business Practice –NorthWestern Energy
Principle 3 – Transparency
FERC Order Requirement Summary
The Commission Determination is found within paragraphs 471-479 of the Order. The
Transparency principle requires disclosure of basic methodology, criteria, assumptions, process
and data that underlie transmission plans. Methodologies, criteria and processes must be
published and consistently applied. The SOC compliance to the release of certain information is
critical.
NWE will disclose its basic methodology, criteria, process and data used to develop its local
transmission plan. NWE’s written document, ETP Method Criteria and Process Business
Practice is posted on NWE’s website. Access to this document is available through the ULR
found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Also see Principle 7 in this document for additional discussion. A discussion document on the
interconnection wide, regional and local plan and data coordination is located under the
“Transmission Planning Guidance Document” section in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc. .
NWE’s local transmission plan will cover a fifteen (15) year time period and will be completed
every two years.
To keep NWE process transparent, NWE has developed and will update as needed a list of
frequently asked questions. See the list of Frequently Asked Questions that is posted on NWE
OASIS website at the URL address identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Technical Analyses Transparency
NWE’s local transmission plan2 technical analyses will use different engineering studies to
evaluate the system performance. Transparency of the technical analysis is important and will be
achieved through communications with TRANSAC. The technical studies are designed to use
different engineering perspectives to ensure system reliability is maintained. These methods will
include, but are not limited to, the following types of analyses.

Steady-State Powerflow Analyses

Post Transient Steady-State Powerflow Analyses (or Steady-State Post Fault Analyses)

Transient Stability Analyses (or Dynamic Analyses)

Short Circuit Fault Duty Analyses

Reactive Margin Analyses
These studies are for expansion planning within NWE’s balancing area. For regional or interconnection wide
congestion studies, See Sections 3 and 4 of NWE’s Attachment K.
2
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Attachment K Business Practice –NorthWestern Energy
Consistent Application
The Transparency Principle requires a discussion as to “how they treat retail native loads, in
order to ensure that standards are consistently applied.” The openness and transparency of
NWE’s planning process will ensure consistent application of the NWE’s methodology, criteria,
and process to all balancing area customers’ data (i.e., retail, network and point-to-point). All
customers will be treated on an equal and comparable basis using the local transmission planning
process, methodology and criteria described herein. All valid customer data will be included in
the planning analysis without regard to their classification.
The evaluation process and selection criteria for inclusion of transmission needs driven by Public
Policy Requirements and Considerations into the LTP will be the same as those used for any
other local transmission and non transmission project evaluated in the LTP process. The
technical analysis will require transmission needs driven by Public Policy Requirements and
Considerations to be evaluated jointly with other local projects in the context of different base
and uncertainty scenario cases, rather than considering transmission needs driven by Public
Policy Requirements and Considerations separately from other transmission needs.
Data Access
Interested persons can obtain access to NWE’s data used in the transmission planning process by
contacting NWE directly if this data is not available on NWE OASIS site. NWE’s contact
information is provided in the “How To Contact Transmission Planning” folder on NWE’s
OASIS website identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Access to confidential information will follow the process described in Principle 2, Openness.
It is recognized that certain data may not be available to certain participants, even though a
confidentiality agreement is signed, due to their relationship to the market.
Opportunity For Review and Comment
Stakeholders, through the TRANSAC meetings, will have opportunity to review, discuss and
comment on NWE’s methodology, criteria, and assumptions and to propose public policy
requirements and transmission driven by public policy requirement and alternative mitigation for
upgrades that are proposed by NWE.
In addition to the written documentation, NWE will use its planning meetings (i.e., TRANSAC
meetings and the Open Public meetings) to communicate basic information and to receive
comments that may improve the methodology, criteria and process.
Changes or updates to database assumptions used in the local transmission plan development
will be presented to TRANSAC and posted on NWE’s OASIS website. Interested parties can
comment on these changes or updates by participating in TRANSAC or Open Public Meeting or
by contacting NWE directly by email or by letter.
Study results will be presented in a manner that is clear to stakeholders. The local transmission
planning report will be designed to provide a clear understanding to stakeholders. NWE will
obtain input from TRANSAC in writing the report.
NWE will take necessary precautions to protect CEII and SOC information using appropriate
mechanisms. See Principle 2 – Openness for additional discussion.
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Attachment K Business Practice –NorthWestern Energy
Replication of Planning Studies
Using appropriate base case data and the PTI PSS/E software, will enable customers,
stakeholders or independent third parties to replicate the results of NWE power-flow planning
studies and associated economic planning studies. Replication of NWE’s transient stability
studies is possible, but will require NWE’s non-proprietary software that must be used with the
PTI PSS/E model. A confidentiality agreement will be required for stakeholders who are not
members of WECC to obtain WECC base cases. WECC members can obtain the base case
powerflow data directly from WECC.
Regional/Interconnection wide Transparency
In the region, NWE will participate in and rely on transparency of the NTTG and WECC for
regional and interconnection wide planning process. The URL addresses for NTTG and WECC
documents can be found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc or
http://www.nttg.biz for regional and interregional planning or http://www.wecc.biz/ for
interconnection wide planning.
.
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Attachment K Business Practice –NorthWestern Energy
Principle 4 - Information Exchange
FERC Order Requirement Summary
The Commission Determination is found within paragraphs 486-488 of the Order. The
Information Exchange principle requires transmission customers to submit information on
projected load and resources. Network, native load and point-to-point customer’s information is
to be supplied on a comparable basis. Transmission providers must develop guidelines and a
schedule for load data submittals from network and point-to-point customers. The information
collected by transmission providers to provide transmission service to their native load customers
must be transparent, and equivalent information must be provided by transmission customers to
ensure effective planning and comparability.
FERC Order 1000 requires that the Transmission Provider receive from all stakeholders
proposed public policy requirements and transmission needs driven by public policy
requirements for potential consideration in the LTP.
NWE's guideline and schedule for the exchange of information is as follows.
Information Request
NWE will determine the load and generation information needed from customers that will be
used to meet its transmission planning requirements and to meet NWE’s requirements of FERC
Standards, FERC Order 890 and Order 1000 requirements and NWE’s Open Access
Transmission Tariff. NWE will tailor its request for information from Load Serving Entities
(“LSE”) and/or customers (e.g., network and point-to-point) after the annual WECC Loads and
Resources data request and the WECC Power Supply Assessment data request. NWE will
augment the WECC data requests with requests for other transmission planning data as necessary
to study the local transmission system. NWE will gather the following types of data.

Historical Data: NWE's request will ask for one year of monthly historical energy and peak
data for the last calendar year.

Load Forecast Data: NWE will request fifteen (15) years of monthly energy and peak load
forecast data from network and point-to-point transmission customers.

Generation Forecast Data: NWE will request fifteen (15) years of data from generators.
Generators will be asked to provide technical engineering data for their generator and
interconnection facilities. Data reporting requirements (e.g., monthly energy, peak
capability, fuel type, etc.) will follow the WECC Loads and Resource Data Request and
WECC Power Supply Assessment data requirements.

Other Supply Sources: Transmission Customer shall provide fifteen (15) years of monthly
energy and peak data for electrical supply sources not from generators including, but not
limited to, point of receipt and point of delivery

Demand Resource: NWE will ask for demand response resource savings, conservation
savings, and other customer load reduction alternatives that would reduce or alter their load
forecast.
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Attachment K Business Practice –NorthWestern Energy

From all stakeholders NWE will receive public policy requirements and transmission needs
driven by public policy requirements.

Interruptible and Other: Customers who are on an interruptible load tariff will be asked to
supply a peak load forecast with and without the interruptible portion of the forecast data
applied.

Number of Years of Data: NWE will request fifteen (15) years of data.

Type of Peak Load Data: The monthly peak load forecast should be based on an average
(i.e., 1-in-2 or 50% probability of being exceeded) temperature assumption.

Peak Load Forecast Temperature Adjustment: NWE will request the temperature adjustment
methodology to adjust the 1-in-2 winter and summer peak load forecasts to an alternative
probability assumption (e.g., a 1-in-10 and 1-in-20 temperature probability). The alternative
to providing this methodology, the MW peak forecast for a 1-in-10 and 1-in-20 methodology
can be provided.

Narrative Requirements: NWE may request other information such as:
1.
Discussion of reasons for significant increases or decreases in load or generation
forecast;
2.
Source and vintage of load forecast and generation resource information;
3.
Weather station assumptions associated with load forecast

Comparability: The same type of data request for generator forecast data and load forecast
data will be sent to generators and customers within NWE’s balancing area.

Use and Confidentiality: The data received will be used to develop NWE’s transmission plan
and for reporting purposes. Market sensitive and customer specific data will be confidential.
Confidential data will be administered according to SOC and CEII requirements.
Schedule
NWE will request forecast data annually during the fall time period (Sep-Dec). This annual
schedule will be coordinated with NWE and NTTG’s biannual transmission planning cycle. The
data collection timeline is linked to the annual WECC Load and Resource Data Request
submission and may be adjusted if WECC changes its data request response time frames. NWE
will provide as much advance notice as possible for changes. The URL address for the “LTP
Study Cycle” can be found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Procedure For Data Submission
NWE will provide an Excel workbook and instructions to the responsible party for the data
collection. This workbook will be sent by email to all of the responsible parties. The URL
address to access an example of the “L&R Data Request” can be found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
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Attachment K Business Practice –NorthWestern Energy
Data Use In Planning Process
All appropriate customer forecast data will be used in NWE’s database.
Confidentiality
NWE will keep all customer specific data confidential. Critical Energy Infrastructure
Information and WECC base case data are confidential, but can be obtained by signing the
appropriate confidentiality agreement. However, some confidential data may not be available to
marketing entities/individuals because of the market sensitive nature of the information (e.g.,
generator or line maintenance outages). For additional information also see Principle 2,
Confidentiality section.
Customer Responsibility
Customers will be asked to provide NWE with generation, load forecast, and demand response
resources to the maximum extent practical and consistent with protection of proprietary
information. Customers should also provide timely written (email) notice of material changes to
information previously provided relating to its load, its resources, or other aspects of its facility
or operations affecting NWE’s ability to provide service.
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Attachment K Business Practice –NorthWestern Energy
Principle 5 – Comparability
FERC Order Requirement Summary
The Commission determination is found within paragraphs 494-495 of the Order. The
Comparability principle requires the Transmission Provider to develop a transmission plan, after
considering the data and comments supplied by customers and other stakeholders, that: 1) meets
the specific service requests of its transmission customers; and 2) provides comparable treatment
to similarly situated customers (network and retail native load). Customer demand resources
should be considered on a comparable basis to the service provided by comparable generation
resources.
NWE’s local transmission plan will be developed after considering and including appropriate
comments on the data, process and methodology received from stakeholders. The customer and
generator data will augment and replace, if appropriate, NWE data used to develop the
transmission plan.
Ensuring Comparability
Comparability will be achieved in NWE’s local transmission plan in developing NWE’s local
transmission by including valid data that is received from generators and customers, as is
appropriate and to the extent necessary, in the database used in the reliability assessment.
All stakeholder submissions, including public policy requirements and transmission needs driven
by public policy requirements, will be evaluated on a basis comparable to data and submissions
required for planning the transmission system for both retail and wholesale customers, and
solutions will be evaluated based on a comparison of their relative economics and ability to meet
reliability criteria.
Combining the forecast load and generation information received from the customers with
NWE’s transmission line and equipment data for the desired year to be studied develops the base
case used in a technical reliability assessment. The load forecast and/or generation dispatch
patterns are varied independently, within appropriate ranges, to depict a specific operating
condition such as the summer peak period. Varying the load and generation patterns in this
manner causes the flows across the transmission lines to vary. Because this assessment is
reliability3 based which is focused on identifying load and generation dispatch patterns that stress
the system, there is no discrimination to customer type or generation dispatch pattern analyzed.
By following this process the resulting plan will have treated similarly situated customers in a
comparable manner.
3
Reliability includes adequacy and security considerations. Adequacy evaluates whether or not there is sufficient
transmission capacity to serve the load without violating criteria. Security evaluates whether or not the transmission
system response will meet appropriate criteria (voltage, thermal, frequency, reactive margin, etc.) after a
transmission element(s) becomes unavailable for service (e.g., a forced outage of a transmission line).
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Attachment K Business Practice –NorthWestern Energy
Principle 6 - Dispute Resolution
FERC Order Requirement Summary
The Commission Determination is found within paragraphs 501-503 of the Order. The Dispute
Resolution principle requires an Alternate Dispute Resolution (ADR) process be available to
manage disputes that arise from the planning process. ADR must address both substantive and
procedural planning disputes. Three steps should be included in the ADR process: 1)
Negotiation, 2) Mediation, and 3) Arbitration. Existing ADR procedures can be used.
Several dispute resolution processes exist – NWE's process dispute, regional and interconnection
wide dispute.
NWE Dispute Resolution
NWE’s dispute resolution process is provided in the OATT, Attachment K, Section 2.8. The
URL addresses to access NWE’s Attachment K and to other documents and business practices
are identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Regional and Interconnection wide Dispute Resolution
NWE will follow the NTTG regional dispute resolution or the WECC interconnection wide
dispute resolution process for regional and interconnection wide planning disputes, respectively.
NTTG and WECC dispute resolution processes are provided in NWE’s OATT, Attachment K,
Section 3.5 and 4.5, respectively. The URL addresses to access NWE’s Attachment K and to
other documents and business practices are identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
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Attachment K Business Practice –NorthWestern Energy
Principle 7 – Regional Participation
FERC Order Requirement Summary
The Commission Determination is found within paragraphs 523-528 of FERC Order 890 and
within FERC Order 1000 requirements that focused on participation in regional and interregional
planning. The Regional Participation principle requires Transmission Providers to coordinate
with interconnected systems to: 1) share system plans to ensure they are simultaneously feasible
and otherwise use consistent assumptions and data, and 2) identify system enhancements that
could relieve congestion or integrate new resources. The existing regional processes may be
used if they are open and inclusive, address both reliability and economic considerations, and
coordinate these issues across the region. Regions must have adequate scope and coordination.
In 2011, FERC issued Order 1000 amending their Order 890 regional planning requirements
requiring each transmission provider participate in a regional transmission planning process that
produces a Regional Transmission Plan by complying with Order No. 890 transmission planning
principles of coordination, openness, transparency, information exchange, comparability, dispute
resolution and economic planning.
NWE’s participation in interconnection wide4 and regional5 planning activities will range from
providing data to providing NWE's local transmission plan to participating in regional and
interconnection wide studies and committees. NWE’s electric transmission system data,
assumptions and plan will be shared with interconnected transmission systems, regions and
interconnection wide entities as required or requested. NWE’s base case data and NWE local
transmission plan will be provided when appropriate and with the confidential data protected.
Regional Participation
The URL addresses to access various NTTG regional documents can be found on the NTTG
website at http://nttg.biz or in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
In the regional context, NWE is an active member of the Northern Tier Transmission Group
(“NTTG”). NTTG will develop a coordinated Regional Transmission Plan and will respond to
requests for Economic Planning Studies.
NWE is a member of NTTG, and uses the NTTG process for regional, interregional planning,
and coordination with adjacent regional groups.
The NTTG Planning Agreement and the NTTG Planning Charter govern the relationship
between NWE local transmission planning and the NTTG regional transmission planning. These
documents are available on the NTTG website at http://nttg.biz or on NWE’s OASIS website.
The FERC 890 and 1000 principle obligations are met by NTTG providing an open forum to
4
See Section 4 Interconnection wide Planning Process of Attachment K Transmission Planning Process. The
URL can be found in Section A. of the Attachment K Business Practice Links document:
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
5
See Section 3 Regional Planning Process of Attachment K Transmission Planning Process. The URL can be
found in Section A. of the Attachment K Business Practice Links Document:
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
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Attachment K Business Practice –NorthWestern Energy
coordinate transmission plans of its members with those of other regional transmission groups
within the Region. NTTG has a cost allocation committee that will determine cost allocations
for qualifying system additions where agreement on cost allocation has not been reached.
NWE will participate in the NTTG planning process to ensure data and assumptions are
consistent and represented in the NTTG regional plan. The NTTG regional plan will be
coordinated by NTTG with interregional planning entities (i.e., ColumbiaGrid, WestConnect and
CAISO). Once the NTTG’s regional plan is developed, it will be shared with WECC and other
regional entities. The Regional Planning Process is outlined in Section 3 of NWE’s OATT
Attachment K6.
Regional Plan and Data Coordination
NWE will coordinate and submit its data, assumptions and local transmission plan to NTTG for
inclusion in the NTTG regional transmission plan. Data and plan information will be
coordinated between the local planning process and the NTTG regional planning process5.
NTTG will coordinate with other regional planning process within the West.
Customers can be directly involved in NWE’s local planning through participation in NWE’s
TRANSAC, and be involved in NTTG regional planning.
Interconnection wide Participation
NWE will participate in interconnection wide transmission reliability planning studies as
appropriate to ensure data and assumptions are coordinated. The footprint of the study and how
NWE is affected by the request will guide NWE’s participation in the study.
Customers can be directly involved in NWE’s planning, which will discuss the interconnection
wide planning efforts by participating in NWE’s TRANSAC. Customers can also be directly
involved in the WECC interconnection wide planning.
NWE will continue providing its local transmission plan, data and assumptions to WECC
interconnection wide committees that are responsible for building databases. Interconnection
wide committees use these data for database development, load and resource assessments,
operating studies and planning studies.
NWE and Regional Planning Process Differences
The processes used by NWE and NTTG to develop its local and regional plans are different.
NTTG’s regional plan is an informational plan whereas NWE’s LPT is a construction plan.
NWE’s process will focus on developing a transmission plan to service its balancing area needs
whereas the objective of the NTTG regional plan will is to develop a Regional Transmission
Plan that meets the regional transmission needs more efficiently and cost effectively than the
initial regional transmission plan by using a “bottom up” approach to develop an initial regional
transmission plan based on a combination of the previously approved NTTG Regional
Transmission Plan and a roll up of the transmission providers’ local transmission plans. Using a
regional perspective, then NTTG considers those projects together with merchant developer
6
See Section 3 Regional Planning Process of Attachment K Transmission Planning Process. The URL can be
found in Section A. of the Attachment K Business Practice Links Document:
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
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Attachment K Business Practice –NorthWestern Energy
projects, non-transmission projects, regional transmission solutions for public policy
requirements and projects generated through the analysis to produce an optimized regional plan.
Regional planning will be done by the NTTG membership with oversight by the NTTG Planning
Committee.
Through the development of the NTTG’s regional plan, NWE and other stakeholders will have
opportunity for input into the regional plan development by participating in the open NTTG
Planning meetings.
The NTTG Steering Committee will approve the NTTG regional transmission plan that is
developed by the NTTG Planning Committee. The NTTG regional plan will be forwarded to
WECC TEPPC, other regional planning entities and appropriate regulatory bodies.
Simultaneous Plan Feasibility
The simultaneous feasibility of local, regional and interconnection wide plans will be achieved in
two ways. First, NWE’s plan will be coordinated with the NTTG regional plan. The NTTG
regional plan will be coordinated with neighboring regional plans through interregional
coordination required by FERC Order 1000. Because these plans are vertically and horizontally
coordinated, simultaneous feasibility will be known.
Second, WECC also requires new project(s) or upgrades to existing paths with potential regional
or interconnection wide impacts to follow the WECC Regional Planning Process and the WECC
Path Rating Process requirements. The WECC processes may proceed after the NTTG/WECC
planning process or be coincident to the NTTG/WECC processes. Proceeding through the
WECC processes requires that the feasible project(s) have a sponsor.
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Attachment K Business Practice –NorthWestern Energy
Principle 8 - Economic Congestion Studies
FERC Order Requirement Summary
The Commission Determination is found within paragraphs 542-551 of the Order. The
Economic Congestion Studies (or Economic Studies) are studies provided to all parties with
information on future transmission needs. These studies are separate from those performed for
requests for transmission service and generation interconnection. This Economic Congestion
Studies principle requires planning to address both reliability and economic considerations.
Stakeholders are given the right to request a defined number of high priority studies annually to
address congestion or integration of new resources or load. The rule does not obligate
Transmission Providers to fund economic planning projects and it does not “assign cost
responsibility for those investments or otherwise determine whether they should be
implemented”. The rule also requires customers, stakeholders and merchants to provide
economic data.
This principle embraces two types of studies – a study of significant and recurring congestion
and a study to consider whether transmission upgrades or other investment can reduce the overall
costs of serving native load. Collectively, these studies are called Economic Congestion Studies.
The Order allows customers to choose the studies that are of greatest value to them.
An Economic Congestion Study differs from an Interconnection Study, Transmission Service
Request Study and Local Transmission Planning study in several ways.

Economic Congestion Study: An Economic Congestion Study means an assessment to
determine whether transmission upgrades can reduce the overall cost of reliably serving the
forecasted needs of the Transmission Provider and its Transmission Customers taking service
under the Tariff. An Economic Congestion Study is a transmission production cost or power
flow study, which is not a system impact study or facilities study for interconnection or
transmission service. The study will result in (i) an overall non-binding high-level estimate
of the estimated cost to increase transmission capacity for a request, and (ii) a value
associated with this capacity based upon anticipated resource production cost savings to the
extent that the requestor supplies adequate information to do so. The output of each
completed study will be posted on NWE’s OASIS, and will not assign cost responsibility for
those investments or otherwise determine whether they should be implemented in any
transmission plan.

Interconnection Study: An Interconnection Study is a reliability study, which shall mean any
of the following studies: the Interconnection Feasibility Study, the Interconnection System
Impact Study, and the Interconnection Facilities Study. The purpose of an Interconnection
Study is to study the transmission system with the proposed facility to identify the
transmission fixes, if any, that are required to maintain acceptable transmission system
reliability performance with all lines in service and with one or more lines forced out of
service. An interconnection Study is initiated when an interconnection request is received for
proposed generation, transmission or large load interconnection from a project sponsor.
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Attachment K Business Practice –NorthWestern Energy

Transmission Service Request: A Transmission Service Request study is similar to an
Interconnection Study, but it focuses on moving the requested amount of MW from a Pointof-Receipt to a Point-of-Delivery. It is initiated when a request for Transmission Service is
received from a customer.

Local Transmission Plan Study: A Local Transmission Plan planning study will evaluate the
local transmission need for native load service. It is the responsibility of the Transmission
Provider to plan for and maintain a reliable transmission system for its native load customers.
NWE’s Attachment K Section 2.7 also addresses economic congestion studies. The URL to
access NWE’s Attachment K can be found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
High-Priority Study Requests
Stakeholders will have the right to submit a request in writing to NWE asking NWE to conduct a
high-priority Local Economic Congestion Study. Stakeholders should make their requests for a
regional or interconnection wide Economic Congestion Study directly to NTTG or WECC
TEPPC.
Requesting A High-Priority Local Economic Congestion Study
A request for a high-priority Local Economic Congestion Study can be made by completing,
signing and returning to NWE the “Economic Congestion Study Request Form”. This economic
congestion study request form is identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Processing requests will follow the procedure described in the “NWE Economic Congestion
Study Timeline and Process” section below. Stakeholders should make their requests for a
regional or interconnection wide Economic Congestion Study directly to NTTG or WECC
TEPPC.
NWE reserves the right to request additional information, information that is in addition to the
required information provided in the original request form, if that information is needed to
complete the study.
Valid NWE Request
A valid request will be a request that supplies all the data in NWE’s Economic Congestion Study
Request Form (i.e., Required Data). Requests that are not valid will follow the procedure
described in the “NWE Economic Congestion Study Timeline and Process” section below.
Economic Congestion Study Classification
Valid requests will be classified as a local study (i.e., NWE Local Economic Congestion Study
request), a NTTG Regional Economic Congestion Study request or an Interconnection wide
Economic Congestion Study request. Regional or Interconnection wide Economic Congestion
Studies that are received by NWE will be forwarded to NTTG or WECC TEPPC, respectively,
for study.
A study request that is confined to NWE’s transmission will be classified as an NWE Local
Economic Congestion Study. To be considered as a NWE Local Economic Congestion Study,
the study request must (1) contain Point of Receipt and Point of Delivery within NWE’s
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Attachment K Business Practice –NorthWestern Energy
scheduling footprint, or (2) be reasonably determined by NWE to be geographically located
within NWE’s scheduling footprint. All other economic congestion study requests will be
classified as a Regional or Interconnection wide Economic Congestion Study and will be
forwarded to NTTG for disposition.
Number of NWE High-Priority Studies
NWE will study up to two high-priority NWE Local Economic Congestion Studies annually to
address congestion or the integration of new resources or loads. As described below, additional
studies may be studied, but the customer making the request will fund these Additional Studies.
Prioritizing NWE Local Economic Study Requests
If more than two valid NWE Local Economic Congestion Study requests are received, and if
after clustering the requests (described below) more than two distinct studies remain, then NWE
will prioritize the studies identifying the two highest priority studies based on Section 2.7.6 of
NWE’s OATT Attachment K. The URL to access NWE’s Attachment K can be found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
The studies in excess of the two highest priority studies will be called Additional Studies. A
stakeholder shall request an Additional Study within (10) business days of receiving notice from
the Transmission Provider by email that their request was not classified as one of the two high
priority Local Economic Congestion Studies. NWE will coordinate the prioritization with its
advisory committee, TRANSAC. Sponsors of the Local Economic Congestion Study Request
are invited to participate in the open TRANSAC meeting. The prioritization methodology will
focus on the spirit of economic congestion study as stated by FERC. That is, “any such studies
conducted pursuant to this principle … would be for the purposes of planning for the alleviation
of congestion through integration of new supply and demand resource into the interconnection
wide transmission grid or expand the interconnection wide transmission grid in a manner that can
benefit large numbers of customers, such as by evaluating transmission upgrades necessary to
connect major new areas of generation resource (such as areas that support substantial wind
generation). Specific requests for service would continue to be studied pursuant to existing pro
forma OATT processes.”8 Request that do not meet the spirit of this statement may not be
studied.
Clustering Study Requests
If the Transmission Provider receives more than two Local Economic Study Requests per year, it
will prioritize the requests, including requests that are clustered, and determine which Local
Economic Study Request(s) will be performed based on an evaluation of the following:

NWE will consult with TRANSAC in making clustering decisions.

No request is exempt from being included in a cluster study if appropriate.

The most significant opportunities to reduce overall costs of the Local Transmission Plan are
through the integration of new supply and Demand Resources into the local transmission
grid, or expanding the local transmission system in a manner that can benefit large numbers
8
Paragraph 549, FERC Order 890, OATT Reform.
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Attachment K Business Practice –NorthWestern Energy
of customers, such as evaluating transmission upgrades necessary to connect major new areas
of generation resource and/or load, while reliably serving the load growth needs being
studied in the Local Transmission Plan, with input from stakeholders.

All information and data resulting from the study will be provided to NTTG and other
interconnection wide entities.
If a request is to move power into NWE’s Balancing Area (i.e., the Point-of-Delivery) or the
request originates within NWE’s Balancing area (i.e., Point-of-Receipt) and moves power out of
NWE’s balancing area, then the request will be classified as a Regional or Interconnection wide
Economic Congestion Study and will be forwarded to NTTG or WECC TEPPC for disposition.

A Regional/Interconnection wide Study may require a study of NWE’s local transmission
system to accommodate the request. For example, a request to move power from Montana to
Idaho may require NWE’s local transmission system to be enhanced to move the power from
the source in Montana to the northern terminal of the MT-ID line congestion.
NWE Local Economic Congestion Study
Once a valid request is received and clustered, if appropriate, NWE will proceed with the NWE
Local Economic Congestion Study. NWE’s Local Economic Congestion Study will be
conducted, including appropriate sensitivity analysis, in a manner that is open and coordinated
with TRANSAC.
With respect to a NWE Economic Congestion Study, NWE will analyze and report on some or
all of the following elements as directed by the requestor.
Location and Magnitude of Congestion: The location(s) of the congestion will be made known
through examination of historical path performance, past studies or through limited powerflow
and transient stability study. To the extent hourly data is available and applicable to the request,
NWE will evaluate historical records to assess the historical duration and magnitude of
congestion across the congested path. Several years of data will be analyzed if it is available to
make this assessment. Once NWE’s studies identify the location of a future congestion, NWE
will obtain that path’s historical hourly flows and extrapolate the flow data to the year when
congestion occurs. Additional factors such as load growth need, potential future generation, and
transmission service requests needs are examples of adjustments that may be added to historical
flows to make this assessment. This extrapolated data may provide an example of the congestion
hourly profile. Extrapolation of the hourly data will be completed for pre-defined assumptions
about the relevant adjustments. It should be noted that information developed in this manner
may or may not provide a valid example of future congestion across a path, unless the path is
“radial” interface between two areas, because flows across the path may not be linear (i.e., onefor-one) due to other network transmission paths offloading and generation or load growth
patterns.
Possible Remedies: NWE will define the transmission mitigation options that could relieve the
congestion in whole or in part. NWE transmission planning will likely need input from NWE’s
Default Supply and/or the customers making the request to define the non-transmission
mitigation measures that could relieve the congestion in whole or in part. The robustness of the
possible remedies may be affected by failure of customers to provide information. A plan will
be considered acceptable only if it meets all reliability criteria.
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Attachment K Business Practice –NorthWestern Energy
Associated Cost of Congestion: The cost of congestion will be the most difficult for NWE to
evaluate since NWE is primarily a transmission company with limited knowledge of generation
dispatch costs, unless the customer making the request provides the information. If NWE does
not obtain this data from the customers making the request, NWE will not be able to complete
this portion of the Local Economic Congestion Study. NWE’s Default Supply will be required
to submit relevant data as appropriate. Confidential information and CEII data will be protected
as appropriate. NWE will not be able to complete this portion of the Local Economic
Congestion Study internally because the study requires an economic dispatch model such as
PROMOD. NWE will likely consult this portion of the study request to NTTG, WECC or to a
consultant.
Cost to Relieving Congestion: Once the mitigation measures are identified, NWE will use best
efforts to estimate the cost to relieve the congestion. NWE will be able to define the costs for
transmission mitigation measures, but may need help from the customers making the request or
NWE’s Default Supply to define the costs of the non-transmission solutions.
Customer’s Obligation To Share Data
The customers’ obligation to share information is critical to completing a Local Economic
Congestion Study. NWE cannot be obligated to study the cost of congestion if it does not have
the information to do so. Any customer requesting a Local Economic Congestion Study must
supply all relevant information that it has in its possession for the study. If critical study
information is missing, NWE will work with the customer to determine how the data can be
obtained or estimated. If critical data cannot be obtained or estimated, the study cannot be
completed. All confidential data will be protected by SOC and CEII concerns.
NWE Obligation
This Principle does not require a Local Economic Congestion Study to be completed by NWE
unless requested by customers. The Principle does not obligate NWE to fund economic projects
or to assign cost responsibility for investments or to determine whether the investment should be
implemented.
Cost to Conduct NWE’s Two High Priority Local Economic Congestion Studies
The cost to conduct the two high priority NWE’s Local Economic Congestion Studies will be
tracked and included in NWE’s next FERC filing for recovery as part of the overall pro forma
OATT cost of service.
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Attachment K Business Practice –NorthWestern Energy
NWE Local Economic Congestion Study Timeline and Process
Figure 4: NWE Local Economic
Congestion Study
NWE will follow the process shown in Figure 4:
NWE Local Economic Congestion Study. The
following process steps will be used.
1
Requests Received: Economic congestion
study requests will be received from
customers during a predetermined 60calendar day Request Window.
1.1
Customers must complete and return
the Economic Congestion Study
Request form and all relevant data
within the Request Window.
NWE Economic Planning Study
Mth *
1
2
3
4
5
6
7
8
9
10
11
12
Activity
Receive Requests
Cluster & Prioritize
Study
1.2
The start and close of the Request
Window will be January 1st through
the end of February of each year.
1.3
frames.
Requests that are not valid will be
returned to customer for revision.
Revised requests that are not returned to NWE within 15 calendar days will be
deemed withdrawn.
Report
Results Meeting
* NWE will use reasonable efforts to meet these time
2
3
Cluster and Prioritize: The studies will be clustered, if appropriate, and prioritized during
the next 30 calendar days.
2.1
Studies will be classified as either a NWE Local, Regional or Interconnection wide
Economic Congestion Study.
2.2
Regional and Interconnection wide Economic Congestion Studies will be forwarded
to NTTG.
2.3
Customers will be notified of their study request classification.
Study: NWE will use reasonable efforts to complete the study between March 1st and
September 30th each year.
3.1
NWE will establish a pre-study conference call with the customer(s) to discuss the
details of the study.
3.2
The progress of all NWE Local Economic Congestion Studies will be discussed at
TRANSAC. The customer(s) will be informed of these TRANSAC meetings and
are encouraged to participate in these meetings.
3.3
If the study will not be completed within the specified study time, NWE will inform
the customer in writing of the delay, the reason for the delay and an estimated time
for completion.
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Attachment K Business Practice –NorthWestern Energy
4
Report: NWE will furnish the customer with a study report within 30 days of completion
of the study.
5
Study Results Meeting: NWE will schedule a study results meeting, which may be
coordinated with the next scheduled TRANSAC meeting.
6
Posting: The report will be posted on NWE’s OASIS website under the Transmission
Planning Tab.
7
The Local Economic Congestion Study result will be available for reference and
appropriate consideration into NWE’s local transmission plan planning study and will be
forwarded to NTTG.
Additional Local Economic Congestion Studies
Local economic congestion study requests that are not prioritized as one of the two highest
priority studies will be called Additional Studies. A stakeholder shall request an Additional
Study within (10) business days of receiving notice from the Transmission Provider by email that
their request was not classified a one of the two high priority local Economic Congestion
Studies. Sponsors of Additional Study requests will be given the option to pay for consulting
services to complete the study or to withdraw the study. The sponsor may re-submit the
economic congestion study request for study consideration in the next economic congestion
study cycle. The process that will be followed for Additional Studies is discussed below.
If NWE’s Local Economic Congestion Study will not be completed by the end of the study
period, NWE will inform the requestor(s) before the end of the study period of the study delay,
the reasons for the delay and an estimated completion date. NWE will make reasonable efforts
to complete the two high priority studies within the allotted study time.
Process for Additional Economic Congestion Studies
The following process will be used for conducting an Additional Economic Congestion Study.
1. Once the customer’s economic study request has been determined to not be one of the two
high-priority studies describe above, NWE will notify the customer within 15 calendar days
of that determination. An Additional Economic Congestion Study Agreement will
accompany the notification.
2. Upon receipt of the Additional Economic Congestion Study Agreement, the customer must
sign and return the Agreement with a study deposit within 10 business days of receipt of the
Additional Economic Congestion Study Agreement.

The study deposit is $75,000.

If NWE does not receive the signed study agreement and deposit within 10 business
days, the Economic Congestion Study request will be deemed withdrawn.

Withdrawn study requests may be re-submitted by the customer for consideration
during the next NWE Economic Congestion Study cycle.
3. Customer will be responsible for all actual costs to complete the economic congestion study.

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Attachment K Business Practice –NorthWestern Energy

The customer will be invoiced monthly for actual study costs greater than the $75,000
study deposit.

The customer must pay the invoiced amount within 30-calendar days of receipt.
4. Once NWE receives the signed study agreement and deposit, NWE will follow the NWE
Economic Congestion Study Process starting with step 3.
Regional Economic Congestion Study Coordination
Interconnection wide and Regional Economic Congestion Studies that are received by NWE will
be forwarded to NTTG for disposition. Additional information on NTTG economic congestion
study process can be found through the “NTTG Info & Documents” URL address in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Economic Congestion Study Posting
NWE will post a listing of all Economic Congestion Study requests received by NWE. This list
will include the following information.









Date received
Study Request Name
Brief discussion of study request
Whether or not the request is valid
Type of study (NWE high-priority study, additional study, regional study)
Cluster status (none or cluster group number)
Request status (received, in study, study complete, withdrawn)
Date the study request forwarded to the sub-region, if appropriate
Expected completion date
This listing will be posted on NWE’s OASIS website under the Transmission Planning tab.
Interested persons can contact NWE for copies of the completed economic congestion study
reports shown on this listed posting. The URL address for the “Economic Congestion Study
Request Listing & Meeting Info” is identified in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
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Attachment K Business Practice –NorthWestern Energy
Principle 9 - Cost Allocation for New Projects
FERC Order Requirement Summary
The Commission Determination is found within paragraphs 557-561 of the Order. The Cost
Allocation for New Projects principle requires the planning process to address cost allocation for
joint projects, economic projects, and projects that do not fit into existing OATT cost allocation
principles. Examples of new projects requiring a cost allocation principle are projects involving
several transmission owners or economic projects that are identified through the study process
described in Principle 8 – Economic Congestion Studies. The rule does not specify a particular
allocation method, but the method should provide for fair allocation to beneficiaries, adequate
incentives to construct transmission, and should have the support of state authorities and regionwide participants.
Principle 9 states that “t[T]he proposal should identify the types of new projects that are not
covered under existing cost allocation rules and, therefore, would be affected by this cost
allocation principle. … We will not impose a particular allocation method for such projects, but
rather will permit transmission providers and stakeholders to determine their own specific
criteria which best fit their own experiences and interconnection wide needs.”
Projects Not Covered Under Existing Cost Allocation Rules
The following are examples of projects not covered under existing cost allocation rules and
would be affected by the cost allocation principle.

A new project confined to NWE balancing area not for load service. For example, this
project could move power across a future internal transmission constraint and be the result of
a NWE Economic Congestion Study. This project may have little or no interconnection wide
impact, but would be a proactive look to relieve future transmission congestion. WECC
Regional Planning Process and Path Rating Process may be required, but regional
coordination would be required.

A new project extending beyond NWE’s balancing area. A project from an interconnection
wide economic congestion study could be a major transmission line that has regional or
interconnection wide consequences. An example would be a new transmission line starting
in Montana and terminating in Phoenix. This study would traverse a large geographic area
and would impact the transmission systems of at least one other utility. This project would
have regional impacts and would require regional coordination through NTTG. The WECC
Interconnection wide Planning Process and the Path Rating Process would also be required.

A new project involving several transmission owners. An example of this would be a new
transmission line, sponsored by several entities, built to move power out of NWE’s balancing
area to the Northwest. This project could have regional and interconnection wide impacts
and would require regional coordination through NTTG. The WECC Regional Planning
Process and the Path Rating Process would also be required.
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Attachment K Business Practice –NorthWestern Energy

A new project resulting from an Open Season Solicitation. This type of project could be a
major transmission line that has regional or interconnection wide consequences. An example
would be a new transmission line starting in Montana and terminating in Idaho. This study
would traverse a large geographic area and would impact the transmission systems of at least
one other utility. A joint study would be required and would be facilitated by NTTG. This
project could have regional and interconnection wide impacts and would require regional
coordination through NTTG. The WECC Regional Planning Process and the Path Rating
Process would also be required.
NWE Cost Allocation Methodology Projects Outside the OATT
The URL address to access NWE’s “Local Cost Allocation Methodology Outside of OATT”
business practice is found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
NWE’s cost allocation methodology is described in Section 2.6 of NWE Attachment K. The
URL address for this document can be found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
For new local projects that do not fit into NWE OATT cost allocation principles, NWE will
follow the “NWE Local Cost Allocation Methodology Projects Outside OATT” that is posted on
NWE’s website unless a mutually agreeable cost allocation method can be reached between
NWE and the project participants or sponsors. In developing alternative cost allocation methods,
NWE will seek input from its stakeholders, through TRANSAC, if appropriate. Cost allocation
will be discussed and agreed to on a case-by-case basis with project participants or sponsors. It
is possible that the cost allocation principles for economic congestion projects will be different
from the cost allocation methods for projects involving multiple owners.
The cost allocation developed from this methodology for a Project falling outside NWE’s OATT
are not binding and are intended to represent an example of the cost allocation that could be
agreed to by the sponsors of the study request. The actual cost allocation for a project will be
determined once the project is committed to and the cost allocation is negotiated and agreed to
by the committed project sponsors, which may be different than the sponsors making the study
request. The actual cost allocation will be specified in the contract between the committed
project sponsors.
There are various methods to assign costs for new projects within NWE's balancing area that do
not have a interconnection wide impact and do not fall under NWE’s tariff. One methodology is
the principle based on cost-causation as shown in “NWE Local Cost Allocation Methodology
Projects Outside OATT”. The costs that are allocated to customers are all appropriate costs for
the system mitigation (i.e., upgrades, enhancements, etc.) that eliminate the unacceptable system
performance. Through this principle, the customer whose request caused the problems is the
customer that benefits most through the elimination of the problem and the quantification is
based on the relative contribution to the problem being eliminated. Other methods that could be
used for cost allocation include, but are not limited to, the following.

An open season to determine ownership share;

Open season for allocation of capacity without ownership; and

Share prorated on MW use.
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Attachment K Business Practice –NorthWestern Energy

Any of these methods may be the appropriate method for a particular situation.
Regional and Interregional Cost Allocation
The NTTG cost allocation principles are posted on the NTTG web page and on NWE’s OASIS
website. The URL address to access additional information for NTTG cost allocation can be
found on the NTTG website at http://nttg.biz or under the “NTTG Info & Documents” section
found in
http://www.oasis.oati.com/NWMT/NWMTdocs/Attachment_K_Business_Practice_Links.doc.
Recovery of Planning Costs
NWE does not have a specific mechanism under the OATT or other funding sources for the
recovery of the planning-related costs. NWE will capture the planning costs for NWE OATT
using traditional test period requirements in the next FERC tariff filing. No specific allocation to
specific customers is contemplated.
TRANSAC will be NWE’s vehicle to discuss if any other entities are in need of cost recovery for
planning related activities.
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