Refer to Table ZS-3 and Figure ZS-15

Summary of key findings

• Load growth in the northern Brown County will drive the need for system reinforcements.
• Additional reinforcements are needed due to load growth in the Oshkosh, Manitowoc and eastern Calumet County areas.

A provisional project to rebuild and convert the Bayport-Pioneer 69-kV line to 138-kV operation is tentatively scheduled for 2016. This project would provide network service to the currently radially-served Bayport, Suamico and Sobieski and address potential low voltages and thermal overloads under single-contingency conditions.

Several capacitor bank projects have been deferred and are now scheduled for the 2015-2018 timeframe. Additional adjustment of the in-service dates may be needed upon further analysis. Those projects are:

• Install 2-16.3 MVAR capacitor banks at the Mears Corners 138-kV Substation (2015) - This provisional project is to address the potential low voltage issues in the Woodenshoe, Mears Corners, and Sunset Point areas under single contingency conditions until additional reinforcements are implemented in the area. The provisional project has been deferred from 2011 to 2015 primarily due to an updated load model in the area.
• Install 2-16.3 MVAR capacitor banks at the Rosiere 138-kV Substation (2015) - This provisional project is to address the potential low voltage issue in the Ontario, Dyckesville, and Rosiere areas under single contingency conditions until additional reinforcements are implemented in the area. Due to the uncertainty of load demand in the area, a detailed study needs to be done for an accurate in-service date. The provisional project has been deferred from 2011 to 2015 primarily due to an updated load model in the area.
• Install 1-28.8 MVAR capacitor bank at the Butternut 138-kV Substation (2016) –This provisional project is to address potential low voltages at the Butternut, Forward Energy Center and Hickory 138-kV substations under single contingency conditions. The project has been deferred from 2015 to 2016 due to an updated load model in the area.
• Install 2-16.3 MVAR capacitor banks at the Aviation 138-kV Substation (2018) – This provisional project is to address the potential low voltage issues at the Progress and Ellinwood Substations under single contingency conditions. The project has been deferred from 2015 to 2018 due to updated load model in the area.

A new 138-kV line project is proposed to address potential heavy flows on the Shoto-Mirro-Northeast-Revere 69-kV line or the Shoto 138/69-kV transformer under single- contingency conditions during non-peak periods under certain generation patterns. The project includes constructing a new Shoto to Custer 138-kV line and installing a new 138/69-kV transformer at Custer Substation. This project has been deferred from 2014 to 2016 based upon updated generator information. In addition, the in-service date may need to be adjusted after a more detailed study is completed (such as economic benefit analysis).

A provisional project for replacing the two existing Glenview 138/69-kV transformers is scheduled for 2014. It would address the potential overload of the transformers under single contingency conditions. The transformer overloads are primarily due to higher load demand at Brillion Iron Works (BIW). This project may be able to be deferred several years by swapping the loads on the Glenview 69-kV and 138-kV buses.

In the 2018 summer peak timeframe, the two 138/69-kV transformers at the Sunset Point Substation would be overloaded under single contingency conditions. To address these overload issues, replacing the two existing transformers with larger transformers is proposed for 2018. The project has been deferred from 2015 to 2018 due to an updated load model in the area. In addition, the in-service date may need to be adjusted further depending on the analysis performed in the 2009 10-Year Assessment.

Replacing the 1200A breaker at the Edgewater T22 345/138-kV transformer is proposed for 2018 to address potential transformer overloads under single contingency conditions. The project has been deferred from 2014 to 2018 due to an updated load model in the area. The in-service date may need to be adjusted further depending on the analysis performed in the 2009 10-Year Assessment.

Uprating the Melissa-Tayco 138-kV line (0.16 miles) is scheduled for 2016 to address the line overload under single contingency conditions and certain generation patterns. The project has been deferred from 2014 to 2016 based on updated generation dispatch information. The in-service date may need to be adjusted further depending on the results of an economic benefit analysis and system studies performed in the 2009 10-Year Assessment.

Due to generation retirements and/or updated load forecast information, several projects have been cancelled. Those projects are:

• replacing the existing 138/69-kV transformer at South Sheboygan Falls with a 100 MVA transformer,
• reconductoring Pulliam-Danz-Henry Street and Pulliam-Van Buren 69-kV lines, and
• constructing the Northside-City Limits 138-kV line.