American Transmission Company (ATC) on Oct. 8 said that its 10-year plan for electric grid improvements calls for expenditures of $1.5bn in asset maintenance, $0.3bn in regional Multi-Value Projects, $0.5bn in network projects, as well as between $0.5bn and $1.1bn in other capital expenditures.
According to the plan, common needs that drive system improvements include new or retiring generation; public policy; asset renewal; and new technologies.
ATC noted that for planning purposes, its service area is divided into five zones representing distinct geographic or usage areas. Discussing “Zone 5 – Southeast Wisconsin,” for instance, ATC said that electric load in that zone – which includes such counties as Milwaukee and Kenosha – is forecast to grow about 0.7% annually through 2028. Transmission system performance issues in Zone 5 include heavy market flows to and from the south, resulting in high 345-kV and 138-kV line loadings and the need to monitor potential multiple contingency conditions, ATC said.
Notable projects in that zone include the Mount Pleasant Tech Interconnection Project; Spring Valley-North Lake Geneva 138-kV line construction; and the “Juneautown substation, new T-D interconnection” project, ATC said.
The plan included an update on major projects, including the 180-mile, 345-kV Badger Coulee transmission line, which ATC expects to energize this fall. A portion of that Midcontinent ISO (MISO) Multi-Value Project – from the Cardinal substation to the North Madison substation – was placed in service in fall 2017. ATC added in its plan that the line, developed jointly with Xcel Energy (NYSE:XEL), will, for instance, offset the need for about $190m in lower-voltage upgrades in western Wisconsin, as well as establish another pathway for renewable energy into Wisconsin with a connection to key load centers.
According to ATC’s website, the Badger Coulee project is estimated to cost about $580m.
Another project included in the plan was the Bay Lake Project, which is a package of proposals that address the shifting balance between generation, load, and transmission in the northern portion of ATC’s service area. ATC added that the North Appleton-Morgan project, for instance, was placed in service in September, and includes 345-kV, as well as 138-kV, lines from ATC’s North Appleton substation in Outagamie County to the Morgan substation in Oconto County, Wis.
ATC said that both substations have been expanded and additional work was required at 11 other substations. A new substation – the Benson Lake substation in Marinette County – which was placed into service in July 2017, includes a large voltage-control device. ATC added that the North Appleton-Morgan project was approved by Wisconsin regulators in May 2015, with an authorized cost of $328m.
Construction is underway on another project, the $71m Spring Valley-North Lake Geneva Project, which was approved by Wisconsin regulators in spring 2016, and is needed to meet an increase in electric demand in Walworth and Kenosha counties in Wisconsin.
ATC added that the project involves power line modifications as well as construction of a new:
- 138-kV transmission line of about 23 miles, stretching from the North Lake Geneva substation in southern Walworth County to the Spring Valley substation in western Kenosha County
- 138-kV and 69-kV substation on an ATC-owned parcel along Highway 50 in the Town of Wheatland
- 69-kV transmission line to connect the new substation to the existing Twin Lakes substation in Twin Lakes
The project is expected to be placed in service in 2019, ATC said.
The Mount Pleasant Tech Interconnection project is expected to have all electrical infrastructure in service by late 2019. Construction is underway on that project, which is designed to support Foxconn, ATC added, noting that upon completion, Foxconn will be one of the largest manufacturing facilities in the country with a campus build-out anticipated to be about 22 million square feet. The initial projected electric usage would be 200 MW at that manufacturing facility, with an additional 30 MW of expected economic growth in the surrounding area, ATC said.
The Mount Pleasant project is estimated to cost about $117m, and includes:
- Building the new 345/138-kV Mount Pleasant substation
- Looping the Racine-Pleasant Prairie 345-kV line into the new substation
- Stringing a new Racine-Pleasant Prairie 345-kV circuit in the vacant position on existing structures and looping that new circuit into the new substation
- Reconfiguring the Racine substation 345-kV bus
- Rerouting the Pleasant Prairie and Bain 345-kV line
- Uprating the Elm Road-Racine 345-kV line
- Building four new 138-kV underground lines – about 400 feet – from the Mount Pleasant substation to serve a customer-owned substation
Wisconsin regulators approved the project in July, ATC added.
The company also noted that construction on the estimated $34.1m, 138-kV, distribution-transmission Juneautown Interconnection Project – which is needed to meet We Energies’ growing reliability and economic needs – is scheduled to begin in fall 2019. The facilities are scheduled to be in service about 12 months after construction begins, ATC said, adding that the project includes:
- A new Juneautown 138/13.2-kV gas-insulated substation
- Looping the 138-kV line between the Haymarket and Harbor substations to feed the new substation
- Routing the new line segments through new underground corridors
An application for a certificate of authority that was filed in January with the Public Service Commission of Wisconsin was approved in August, ATC said.
Another project that the company discussed is the Finger Road-Canal project, which ATC said is a rebuild of a 69-kV line in northeastern Wisconsin, along with associated substation work. Wisconsin regulators approved the project in spring 2017 at a cost of $60.7m. ATC added that about 55 miles of line on 1950s-vintage wood poles between the Finger Road substation and Canal substation will be rebuilt. The line serves seven distribution substations in northern Kewaunee County and Door County. ATC added that the project includes:
- Replacing 834 wood pole structures
- Replacing line conductor and adding a fiber optic shield wire
- Updating at terminal-end substations of jumpers, selective bus conductor, and disconnect switches
ATC said that construction is scheduled to be complete in January 2021.
Another project that is estimated to be in service in 2021 is the Mackinac-McGulpin 138-kV Submarine Cable Replacement project, which involves replacing two four-mile, 138-kV submarine transmission lines connecting the Upper Peninsula of Michigan to lower Michigan, at an estimated cost of $105m.
The project, which was submitted for MISO review in the MTEP18 planning cycle – was developed because, for instance, two 138-kV submarine circuits were damaged by an anchor strike on April 1, 2018; three working cables have been reconfigured to form one 138-kV circuit; and the remaining cables contain a mineral-oil based dielectric fluid. A submarine cable failure could result in a fluid leak into Lake Michigan and Lake Huron, the company said.
ATC also said that the Bayport-Pioneer project is scheduled to be in service in December 2021. That $51.7m project – which involves the rebuild of a 69-kV transmission line in northeastern Wisconsin, along with associated substation work – will be submitted to the commission next spring, ATC said. About 22 miles of line on 1910s-vintage wood poles running between the Bayport substation and Pioneer substation would be rebuilt, the company said, adding that the line would serve three distribution substations in Brown County and Oconto County.
ATC said that the Bayport-Pioneer asset renewal project includes:
- Stringing both Bayport-Pioneer lines, combining, and operating as one line at 138 kV
- Converting the Suamico and Sobieski substations to 138 kV operation
- De-energizing the Pulliam-Bayport 69-kV section of line
ATC also noted that if approved by Wisconsin and Iowa regulators, the Cardinal-Hickory Creek project is estimated to be in service in 2023. ATC said that it, ITC Midwest LLC, and Dairyland Power Cooperative in April filed an application with Wisconsin regulators for a 102- to 120-mile, 345-kV transmission line connecting Dubuque County, Iowa to Dane County, Wis. That project is another MISO Multi-Value Project, ATC said, adding that studies indicate that the project would deliver benefits to local communities and the Midwest region by, for instance, connecting to other 345-kV transmission lines in the Upper Midwest and helping to enable 25 GW of cost-effective renewable energy to be delivered to communities in the region.