American Transmission Company (ATC) on Oct. 4 said that it issued its 2017 10-Year Transmission System Assessment, calling for expenditures of $1.4bn in asset maintenance, $0.48bn in regional Multi-Value Projects, between $0.7bn and $1bn in network projects, and between $0.3bn and $0.8bn in other capital expenditures.
According to the assessment, ATC’s current planning studies show a reduced need for new projects due to slowing load growth and other factors. As a result, there is a reduction in ATC’s capital plan, the company said.
The assessment calls for a lower capital expenditure than in recent years, from $2.8bn to $3.6bn in system improvements.
ATC also noted that over the past 10 years, it has upgraded more than 875 miles of transmission line; improved 98 electric substations; built 24 new transmission lines (436 miles); connected 2,700 MW of new generation at 16 sites; increased import and export capability; and improved transmission reliability.
Common needs that drive system improvements include:
- New or retiring generation – changes the generation impact on transmission
- Economics – greater access to the wholesale energy marketplace provides economic opportunities to utility customers
- Enhanced NERC reliability standards – require a greater degree of redundancy and analysis to assure reliable operation
- Public policy – renewable energy mandates and pending air quality regulations will affect how the transmission system will be built and used
- Asset renewal – maintaining the system in good operating condition extends its life and improves safety and performance
The assessment included an update on major projects. For instance, ATC said that construction is underway on the Badger Coulee transmission line, which is one of the Midcontinent ISO’s (MISO) 17 Multi-Value Projects (MVPs). The line was approved by the Public Service Commission of Wisconsin in spring 2015, ATC said, adding that a portion of the project from the Cardinal substation to the North Madison substation will be placed in service this fall.
The entire Badger Coulee project is expected to be in service in late 2018, ATC said, noting that the 180-mile, 345-kV line between the La Crosse and Dane County areas will deliver reliability, economic, and public policy benefits. Developed jointly with Xcel Energy (NYSE:XEL), the line will, among other things, offset the need for about $190m in lower-voltage upgrades in western Wisconsin, ATC said.
Of the Bay Lake Project, the company noted that it is a package of projects that address the shifting balance between generation, load, and transmission in the northern portion of ATC’s service area.
The Holmes-Old Mead Road portion of the project, a $120m, 58-mile, 138-kV line from the Holmes substation in Menominee County to the Old Mead Road substation in Escanaba, Mich., was placed into service on time and under budget last year, ATC said.
As part of the North Appleton-Morgan project, a new substation, Benson Lake in Marinette County, was placed into service in July, ATC said, adding that the substation includes a large voltage-control device.
Construction of the 345-kV and 138-kV lines from the North Appleton substation in Outagamie County to the Morgan substation in Oconto County, Wis., is underway, ATC said, noting that both substations will be expanded.
Additional work will be required at 11 other substations, the company said. The project was approved by Wisconsin regulators in May 2015, ATC said, adding that construction of the $328m project began last year, and it has an in-service date of late 2018.
Discussing the Cardinal-Hickory Creek Project, ATC said that it, ITC Midwest LLC, and Dairyland Power Cooperative have plans for the 125-mile, 345-kV transmission line connecting Dubuque County, Iowa, to Dane County, Wis.
The project is another of MISO’s MVPs, the company said, adding that studies indicate that the project will deliver benefits to local communities and the Midwest region by, for instance, expanding infrastructure to support public policy for greater use of renewables.
If approved by Wisconsin and Iowa regulators, the project is estimated to be in service in 2023, ATC said.
Discussing the Northern Area Reliability Assessment, ATC said that it initiated an effort in 2014 to engage stakeholders and identify potential reinforcements due to generation uncertainties in the northern portion of the ATC system. The 10-year project list includes these preliminary projects:
- Plains-National 138-kV line
- Plains-Arnold 138-kV line uprate
- Increased Plains 345/138-kV transformer capacity
- Morgan-Thunder-Crivitz 138-kV project
ATC added that it had collaborated with MISO to include those projects in the MISO Transmission Expansion Plan 2015 (MTEP15), and that ATC is assisting with the evaluation of generation proposals in that area of Michigan. The need for some of the transmission projects may be eliminated if generation is appropriately located in that area, ATC said.
ATC also discussed the Wisconsin-Illinois Reliability Project, noting that it has proposed the reinforcement project to address reliability concerns associated with the high-voltage transmission system in southeastern Wisconsin.
The reliability concerns are impacted by system load and generation profiles, ATC said, adding that to enable more efficient power flow, the project reconfigures two existing 345-kV lines in Wisconsin and Illinois, linking them with about three to miles of new double-circuit, 345-kV transmission line and a new substation.
The proposed reliability project has been approved in the MISO regional planning process and by the Illinois Commerce Commission, ATC said. The project, which also requires approval from Wisconsin regulators, is targeted for completion in 2021, ATC said.
The company also noted that construction is underway on 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.
The project is expected to be placed into service in 2019, and involves:
- Construction of a new, approximately 23-mile, 138-kV transmission line, stretching from the North Lake Geneva substation in southern Walworth County to the Spring Valley substation in western Kenosha County
- Construction of a new 138-kV and 69-kV substation on an ATC-owned parcel along Highway 50 in the Town of Wheatland
- Construction of a new 69-kV transmission line to connect the new substation to the existing Twin Lakes substation in Twin Lakes
- Other power line modifications
ATC also addressed the Finger Road-Canal project, noting that the $60.7m rebuild of the 69-kV line in northeastern Wisconsin, along with associated substation work, was approved by Wisconsin regulators last spring. About 55 miles of 1950s-vintage wood poles running 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.
The project – of which construction is scheduled to be complete in January 2021 – includes the replacement of:
- 834 wood pole structures
- Line conductor, as well as the addition of a fiber optic shield wire
- Some associated substation equipment
ATC also discussed different zones, including “Zone 2.” There are a number of transmission system performance issues in Michigan’s Upper Peninsula and northern Wisconsin, or Zone 2, including limited ability to import or export power, generator instability, overloaded lines and equipment, low and high system voltages, and chronic limitations to transmission service, ATC said. The company noted that the most notable planned, proposed, and provisional network projects and asset renewal projects in Zone 2 include the planned Munising-Blaney Park 69-kV partial rebuild project, which is driven by condition and performance issues, and has an in-service date of 2019.