American Transmission Company (ATC) on Oct. 15 said that its 10-year plan to address the need for electric grid improvements calls for expenditures of $1.8bn in asset maintenance and $0.2bn in regional Multi-Value Projects (MVPs).
The plan also calls for expenditures of $0.4bn in network projects, as well as between $0.5bn and $1.1bn in other capital expenditures, the company said.
In the assessment, the company provided an update on its major projects, including the:
- Mackinac – McGulpin 138-kV – Straits Cable Replacement Project, which involves ATC replacing the 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 was developed for such reasons as two 138-kV submarine circuits being damaged by an anchor strike in April 2018. The project is estimated to be in service in 2021
- Bayport – Pioneer and Pioneer – Crivitz project, which involves the rebuild of a 69-kV transmission line in northeastern Wisconsin, along with associated substation work, that was approved by the Public Service Commission of Wisconsin in the spring at a cost of $51.7m. About 22 miles of line on 1910s-vintage lattice towers running between the Bayport substation and Pioneer substation will be rebuilt, with the line serving three distribution substations in Brown County and Oconto County. The project will be complete in late 2022
- Arcadian Substation – Asset Renewal project, which consists of 138-kV and 345-kV asset renewals of early 1970s vintage equipment and the reconfiguration of the 345-kV bus from a straight bus to a breaker-and-a-half. The cost of the project is estimated to be $45m. An application will be filed with the Wisconsin commission in November, the company said, adding that construction is scheduled to begin in late 2022, with the project scheduled to be in service by June 2024
- Juneautown Distribution Interconnection Project, which is a 138-kV transmission to distribution interconnection needed to meet We Energies’ growing reliability and economic needs in downtown Milwaukee. The cost of the project is estimated to be $33.8m and includes a new Juneautown 138/13.2-kV gas-insulated substation. The Wisconsin commission approved a certificate of authority for the project in August. Construction began in summer 2019, and the project is scheduled to be in service in December
Andy Dolan, ATC vice president of system planning, said in the statement that the company’s long-term planning efforts require flexibility to support an evolving and sustainable energy future.
Dolan said that ATC has seen more than 2,200 MW of fossil-fueled generation retire in the company’s footprint since the beginning of 2018, adding that ATC is studying proposals from the Midcontinent ISO (MISO) to connect more than 8,200 MW of solar generation and nearly 1,500 MW of wind generation.
Jim Vespalec, director of asset planning and engineering with ATC, said in the statement: “Our asset maintenance projects are driven by the need to address aging infrastructure initially installed decades ago. Overall, project expenditures in the 2020 plan reflect the measures necessary to maintain and reinforce the system and upgrade its resiliency.”
As noted in the plan, common needs that drive system improvements include renewable energy mandates and pending air quality regulations that affect how the transmission system will be built and used, as well as new technologies, such as synchronized phasor measurements, demand-side management, and distributed energy resources, that affect how the grid is planned and operated to maintain reliability.
Among other things, the plan discussed transmission system limitations and electricity usage by zones. For instance, in Zone 5, or Southeast Wisconsin, ATC said that a significant transmission system performance challenge involves heavy energy market flows through the zone, resulting in potential high post-contingency line loadings. Electric load is forecast to grow about 0.3% annually through 2031. ATC also said that Zone 5 planned projects include the partial rebuild of the St. Lawrence-Barton-Auburn 138-kV lines (8032/9752), which is scheduled to be in service in 2022.