Jump to Header Jump to Main Content Jump to Footer


The concept of electricity transmission first took shape in the late 1800s as early innovators sought to move power over long distances. Over the next century, rapid industrialization would spur the growth of vast networks of generation, transmission and distribution systems to power the economy.

Today, we are seeing another leap for the grid: more renewable energy, the retirement of traditional fossil fuel generation, and an accelerating use of advanced technology. As we think about how we invest today in the grid to come, we need to envision tying regions together with stronger infrastructure to connect remote renewable and other resources, enhance reliability, and ensure adequate energy resources are available in real time to satisfy customer needs.

We and other transmission system operators maintain that smart and timely investment in backbone transmission infrastructure is the best means for delivering customer benefits — by efficiently facilitating the integration of evolving technologies and new fuel sources.

Examining Generation Import Capacity

Against this backdrop, ITC undertook a study to examine Michigan’s Capacity Import Limit, or basically, how much generation capacity can be imported into the Lower Peninsula through our transmission connections with Ohio and Indiana. Through the study process, we determined that in order to import more power into Michigan, voltage issues must be addressed. That is, we currently have enough wire in the system to maintain imports, but imports are limited by low voltage constraints and can become severely impaired considering the recent generation retirement announcements for Michigan.

To address this, our company proposed a modern solution based on proven technology — Static Var Compensators (SVC) — that will not only allow for additional capacity to be imported, but also provide an operational tool to ensure voltage stability for a diverse set of system conditions. This means that more power can be reliably transmitted through the system over existing lines from a variety of generation sources.

Ensuring Voltage Stability

What does that mean for our system performance? Well, for facilities that have a critical voltage target — say the electricity that comes and goes from a power plant — the SVC constantly monitors the critical facility, holding the voltage constant within the target range. If there’s a system disturbance, the SVC can immediately react to it and instantly inject voltage-ampere reactive (VARs) into the system to maintain the desired voltage.

ITC’s Toll Road Project is one recent example of how the company is implementing modern technology in order to help ensure reliability at a substation that supplies power to the 1170 MW-Enrico Fermi II Generating Station — a nuclear power plant on the shores of Lake Erie near Monroe, Michigan.

We began considering an SVC for this area in the early 2010s. The project was approved by MISO in 2013, and many years of planning, designing, engineering, and construction followed.

We completed the first step in the process in 2018 — the construction of the new 120-kV Toll Road Station, which includes (11) 120-kV breakers and a termination of the Fermi to Swan Creek circuit at the new station. Later that year, ITC and its construction partners installed a new 150 MVAR SVC at Toll Road Station, improving the voltage stability in southeast Michigan. Just this February, the Fermi to Vital 120-kV line was cut into the station in February following the SVC installation.

The SVC installation not only strengthens the region’s grid stability but provides operational flexibly for maintenance activities. There are six 120-kV lines coming out of our Toll Road station. Without the SVC, taking any single element out of service could risk compromising system reliability in the region. With the SVCs in place, standard repairs on ITC’s facilities can be performed on schedule — thus enhancing grid reliability — and during these planned maintenance activities the integrity of the grid is preserved, and system flows are not interrupted.

While this is a single aspect of one of many projects at our company, the SVC initiative represents the long-term, forward-looking vison required when considering the development timeline of a transmission project. It is this approach and foresight that is necessary when anticipating our future energy needs and planning the system accordingly.

Investing in Infrastructure

Today’s transmission planners, regulators, and RTOs are facing unique and complex challenges to manage reliability and capacity issues, while also thinking about how to design the grid of the future. Transmission infrastructure requires immense foresight and careful planning, and in order to keep pace with changes in generation and distribution — especially as it relates to clean energy technology — it’s vital that we start preparing now for the future grid.

The private investor-owned utility industry historically has funded investments in the power grid — as ITC did with the Toll Road Project — and we stand ready to make needed improvements going forward, provided the regulatory and planning environment is conducive to investment.

The good news is that transmission investment offers a multitude of benefits — enabling access to lower-cost, greener resources reliably and efficiently. We’ve come a long way since the early days of transmission, and clearly there is much more to do today to meet long-term needs by modernizing our country’s grid infrastructure.

Simon Whitelocke
July 31, 2019