Economic planning

ATC utilizes three methods to determine which projects have the potential for economic benefits:

  1. Stakeholder Input and Analyses
  2. Reliability Project Screening
  3. Congestion Severity Index

These methods are described below.

Stakeholder Input and Analyses

In March 2008, Federal Energy Regulatory Commission (FERC) Order 890-A took effect. As part of this order, FERC requires a coordinated, open, and transparent transmission planning process on both a local and regional level. To comply with these requirements, ATC submitted a compliance filing on Order 890-A that provides a timeline of actions to ensure that the economic planning process is both coordinated and open.  ATC has also submitted a compliance filing on Order 1000 that incorporates public policy requirement needs into its economic planning analysis

Annually, ATC will use a process with consistent timelines that combines stakeholder input, historical data, future line flow forecasts, and updated information on the electric system to identify transmission upgrades for economic evaluation.

Each year:

  • During February, we hold an initial stakeholder meeting to review the market congestion summary and potential fixes and to discuss economic study scenarios, drivers, ranges, and assumptions.
  • By March 1, we work with stakeholders to request and prioritize new/other economic studies and recommend study assumptions.
  • By April 15 – we identify preliminary areas of economic study, study assumptions and models and solicit further comments from stakeholders, including soliciting stakeholders for public policy requirements that drive transmission needs.
  • By May 15 – we finalize areas of economic study, study assumptions and models to be used in analysis, including a determination as to why or why not public policy requirements were included in the assumptions.
  • By November 15 – we provide a summary of the results of the economic analyses to our stakeholders.

ATC conducts analyses of the projects identified for study over several months’ time and posts the key results, including the extent to which these savings offset project costs. When the expected benefits of a studied project are high enough to justify its costs, the process of developing it as a formal proposal is begun.

As a result of the 2015 ATC/stakeholder collaborative process, we are performing economic analyses on the following ATC facilities:

Economic Planning Study Areas
  • Janesville/Beloit 138 kV Project
  • Green Bay Area 138 kV Project

Studies will be performed and results shared with stakeholders over the course of the year. In addition, customers and stakeholders who would like to request specific economic studies can do so if they are willing to pay for the studies and are willing to have the results posted publicly.

Reliability Project Screening

Economic analyses were performed on 15 projects from the 2014 10-Year Assessment project list to determine whether those projects were candidates for acceleration or deferral based on economic considerations. Please refer Table EP-1 for the list of projects screened. The list of 15 projects was based primarily on the availability of redispatch and capital costs of the projects; however, lower cost projects specifically identified by the ATC planning department were also included in the study. Generation interconnection and distribution interconnection projects were not eligible for inclusion in this list. Further, capacitor bank projects were not considered since the voltage benefits provided were not captured by the PROMOD software analysis. Finally, projects with in-service dates prior to 2019 were not considered since development of those projects was too far underway to make scheduling changes. As a result of this screening, two projects showed economic savings to ATC customers. Both the Arcadian to Waukesha 138 kV rebuilds and the Spring Green 2nd transformer both had savings that helped offset costs, but could not cover them completely. They will continue to be studied further for acceleration.

A similar analysis will be performed in the 2016 10-Year Assessment based upon the 2015 Assessment project list.

Table EP-1

 System AdditionsPlanning Zone
1Presque Isle - Tilden 138 kV line loop into National and uprate National - Tilden 138 kV line2
2Winona - Atlantic 69-kV line reconductor2
3Lakota Road - Winona 69-kV line conversion to 138-kV2
4Plains - National 138-kV line2
5Plains second 345/138-kV transformer2
6Plains - Arnold 138-kV line upgrade2
7Spring Green 2nd 138/69 kV Transformer3
8West Middleton - Blount 138-kV line3
9West Middleton- Pheasant Branch 69 kV double circuit3
10Colley Road second 138/69-kV transformer3
11Portage - Columbia 69-kV line conversion to 138-kV3
12Shoto-Custer 138kV line and 138/69-kV transformer at Custer4
13Highway V - Tower Drive 138-kV line reconductor4
14Depere - Glory Road 138-kV line uprate4
15Arcadian - Waukesha 138-kV line reconductors5
Economically Screened Projects from 2014 TYA Project List

Congestion Severity Index

ATC developed a Congestion Severity Index for use as the screening indicator to track locations on the transmission system where constraints to the delivery of economic energy exist. The Congestion Severity Index combines the financial impact of constraints with the frequency of constraints. The financial impact during an hour is the calculated theoretical maximum number of dollars that could be paid into the market due to congestion on the constraint in question. The sum of the total financial impacts for each hour during which the constraint occurs forms the basis of the Congestion Severity Index. This information is used as a starting point in determining areas of the system where potential upgrades may be cost-effective. This data is combined with stakeholder input and ATC planning recommendations to identify a group of projects to study. A list of the most severe market constraints in the Day Ahead and Real Time markets for 2014 is given in Tables ZS-5 and ZS-6, respectively. Maps depicting the geographic locations of the most severe market constraints in the Day Ahead and Real Time markets for 2014 are shown in Figure ZS-27 and Figure ZS-28, respectively.

Table ZS-5

Severity IndexHoursConstraintPotential Solution
100.527,353Total for All ATC Day Ahead Constraints - 2014
43.08822Minnesota to Wisconsin Exports Interface (MWEX)Monroe County - Council Creek 161 kV line (In-service 2015)
Badger - Coulee 345 kV line (Proposed 2018)
14.33546Blackhawk - Colley Road 138 kVTransmission status may have contributed to this constraint
9.331,093Highway V - Preble 138 kVBay Lake Project: North Appleton - Morgan 345 & 138 kV lines (Proposed 2019)
Highway V - Preble 138 kV rebuild (Provisional 2020)
Transmission status may have contributed to this constraint
4.59104Forest Junction - Lake Park 138 kVTransmission status may have contributed to this constraint
2.71227Presque Isle - Tilden 138 kVPresque Isle - Tilden 138 kV loop into National (Provisional 2019)
Transmission status may have contributed to this constraint
2.36207Bluemound - Butler 138 kV (5061)Transmission status may have contributed to this constraint
1.98230Paddock - Town Line Road 138 kVPaddock - Town Line Road 138 kV rebuild (In-service 2014)
Generation and transmission status may have contributed to this constraint
1.73509McMillan - Wildwood 115 kVBadger - Coulee 345 kV line (Proposed 2018)
1.6098Forest Junction - Kaukauna Central 138 kVTransmission status may have contributed to this constraint
1.3358Pleasant Prairie - Zion Energy Center 345 kVSE Wisconsin - NE Illinois 345 kV transmission reinforcement (Provisional 2020)
ATC Day Ahead Market Most Limiting Elements - 2014

Table ZS-6

Severity IndexHoursConstraintPotential Solution
59.211,073.2Total for All ATC Real Time Constraints - 2014
13.72185.9Highway V - Preble 138 kVBay Lake Project: North Appleton - Morgan 345 & 138 kV lines (Proposed 2019)
Highway V - Preble 138 kV rebuild (Provisional 2020)
Transmission status may have contributed to this constraint
6.1261.2Pleasant Prairie - Zion Energy Center 345 kVSE Wisconsin - NE Illinois 345 kV transmission reinforcement (Provisional 2020)
4.6898.7Blackhawk - Colley Road 138 kVTransmission status may have contributed to this constraint
4.1691.3McMillan - Wildwood 115 kVBadger - Coulee 345 kV line (Proposed 2018)
3.4748.8Presque Isle - Tilden 138 kVPresque Isle - Tilden 138 kV loop into National (Provisional 2019)
Transmission status may have contributed to this constraint
3.0543.3Paddock - Town Line Road 138 kVPaddock - Town Line Road 138 kV rebuild (In-service 2014)
Generation and transmission status may have contributed to this constraint
1.9231.8Bluemound - Butler 138 kV (5061)Transmission status may have contributed to this constraint
1.7714.9Forest Junction - Kaukauna Central 138 kVTransmission status may have contributed to this constraint
1.469.6Forest Junction - Lake Park 138 kVTransmission status may have contributed to this constraint
1.437.7City Limits - Lake Park 138 kVTransmission status may have contributed to this constraint
ATC Real Time Market Most Limiting Elements - 2014

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