January 10, 2020

Combined Locks Substation

The substation on Janssen Street in Combined Locks serves more than 5,000 customers in Combined Locks, Little Chute, and Kaukauna, and it is one of three interconnect substations to the transmission grid. The existing substation, approximately 100’ away from the proposed new location, is about 50 years old and is causing increasing maintenance expense and may become unreliable soon.

Substation Rebuild

This substation is almost 50 years old. Maintenance costs keep going up and availability of components are decreasing. Kaukauna Utilities needs to consider accessibility and operational issues for staff to safely work at this substation. With the rebuild, KU can modernize technologies for future use.

Design Criteria

The following criteria was considered with each design option – safety, operational impacts, accessibility, neighbors’ concerns, sound engineering, and financial impact.

Evaluated Designs

  1. If KU rebuilt the substation in its current place, we would lack accessibility to the substation, have limited space, and encounter poor engineering and operational design.
  2. Expanding to the south or east would require the 138 kV substation to be replaced; this would add another $2,000,000 to the project. Midwest Paper Group would be required to take extended outages during construction. This option would also require land acquisition from Midwest Paper Group.
  3. Re-routing State Street to the South of the substation was also considered. This would add an estimated $1,000,000 for roadwork (if grade were flat). Midwest Paper Group would lose a large portion of their parking.
  4. One option was to expand the substation to the southwest. This option provided sound engineering for the substation, but when looking at operational and financial impacts, this option was ruled out. Operationally, accessibility for large equipment, bus routing, and the increased complexity of feeder exits became issues of concern. The financial impacts of this option would be an additional $1,000,000 – $1,400,000 for excavation, a retaining wall, and feeder routing.
  5. If the substation were expanded west, no zoning changes would be required (special exception permit needed). Most of the rebuilt substation would be on unoccupied property and without disruption to the existing substation. This option would improve accessibility and would not alter the existing 138 kV substation, resulting in approximately $2,000,000 in savings.

Final Design

As submitted to PSC

  • Design would require acquisition of 521 Janssen St., the parcel around it, and vacation of Locks Ave
  • 138 kV operational impacts are avoided
  • Convert westward outgoing 12 kV circuits to underground

Changes to PSC proposal

  • Straightened bus to allow for 25 foot setback
  • Moved control house back
  • Changed from vinyl slatted chain link fence to masonry walls on north and west sides

As a result of the town hall meeting, Kaukauna Utilities modified the design:

  • Shift South – add small retaining wall to the hill, shift some equipment south
    • More than 70 foot setback from property line
    • Increased natural screening and green space; including the frontage of the existing substation
    • Project cost increase of $100,000

Click here to view renderings of the final substation.

Benefits to a New Substation

The three major benefits to a new substation increase reliability, safety, and functionality.

Reliability: A new substation means that you will be assured of continued power quality and reliability as your area continues to grow and the demand for electricity increases. Aged substations have a higher frequency of failure, and under peak conditions, power quality issues such as blinks and brown-outs can occur.

Safety: The substation will provide additional clearances to allow KU’s employees access to all switching equipment and allow them to reconfigure the system with lower risk of incidental contact.

Functionality: By adding modern technology to the new substation, KU’s systems operations center will receive more information from the substation to aid in decision making when switching loads. This technology will also provide the ability for the equipment in the substation to communicate with other devices in the field to make smarter decisions during electrical faults.


How long will construction take?

Construction is beginning early 2020 and should be completed by the end of summer 2020.

What happens if the substation is not rebuilt?

Customers will experience more outages due to deterioration of equipment. As much of the equipment has become obsolete, it is an issue obtaining parts. This will cause outage duration to increase as well.

How is KU paying for this?

This project was budgeted in KU’s 2017 5-Year Capital Improvement Plan. Bond proceeds were issued in 2017 to fund this project.

Will the substation be loud, an eyesore, or a disturbance to surrounding residential areas?

The new transformers are designed to meet national standards that will result in reduced sound levels compared to the existing transformers. A typical new substation transformer will produce approximately 65 dB of noise measured at 2.0 meters from the transformer.  This is about the loudness of a newer standard residential outdoor air conditioning unit.  The sound level diminishes the further away from the sound producing source. To further reduce the sound, the visual barrier wall contains sound absorbing properties. This wall, along with some landscaping will help the substation blend into the surrounding area.

Substation yard lights for safety and security will be on dusk to dawn sensors and will be positioned in a direction to minimize light pollution to neighboring residents. There will be additional lights that can be switched on if work needs to be completed at the site.