The continuing shift from coal generation to renewables and other cleaner sources of energy is changing the nature of power delivery throughout the country. Utilities need more versatility and flexibility in traditional generation and transmission to accommodate the evolving intermittent nature of renewables.
For one of our transmission partners, Michigan-based Wolverine Power Cooperative, this changing landscape fostered the need for a new energy source to serve its member distribution cooperatives in the western and northern parts of Michigan’s Lower Peninsula.
Wolverine’s load is about 850 MW, which the company meets with a combination of power purchase agreements, fractional baseload ownership and owned peaking turbines totaling 1,000 MW. Its portfolio is strong in renewables, supplying its members with 20 percent renewable energy. The company’s projected future energy requirements for the 280,000 rural customers its members serve—combined with some expiring supply agreements—revealed the need for an additional 400 MW of capacity, which must be able to respond quickly to changes in load and the variability of renewable generation.
“We spent three years studying our options before firming up a plan for a 440 MW, two-unit natural gas peaking plant to be located west of Gaylord. The location we picked in Elmira Township is right on top of two natural gas lines and near the transmission needed to move the power onto the grid,” said Wolverine President and CEO Eric Baker. “The technology meets our key strategic issues of flexibility and a clean environmental footprint and gives us the option of converting to combined cycle down the road,” Baker said.
Once the final decision was made to proceed, work began in earnest in January 2015. Wolverine faced a tight 18-month timeline to get the plant built and in service. In addition to quickly securing long lead-time equipment such as turbines and transformers, the company needed a number of transmission upgrades to strengthen the 138 kV portion of the grid in northern Michigan.
At this point, Wolverine approached Michigan-based ITC—the largest independent transmission company in the U.S.—to aid in connecting Wolverine’s new gas-fired Alpine Power Plant to the high-voltage transmission grid in northern Michigan.
Finding the Right Partner
ITC and Wolverine have worked together since ITC’s inception in 2003 and therefore understand each other very well.
The transmission side of the project for ITC included the expansion and reconfiguration of ITC’s Livingston substation, and the expansion and upgrade of 2.8 miles of ITC transmission line to double-circuit, 138 kV constructed to 230 kV specifications. This upgrade was done to be compatible with recent upgrades of other ITC transmission lines in northern Michigan to 230 kV standards.
Most notably, the transmission work had to be completed on a 12-month schedule beginning in May 2015, putting considerable pressure on the combined Wolverine and ITC project teams.
“Our engineering and supply chain groups were really proactive in anticipating the needs of these updated, bigger conductors and bigger towers. We reached out to our vendors early in the process to make sure that we had the required equipment in time to meet our expedited construction schedule,” said David Mindham, an ITC Planning Engineer at the time. “What really helped us was reaching out early to the stakeholders and making sure that all the parties were really in tune with the plan from the very beginning. I think it speaks volumes to ITC’s expertise in the transmission field that we can come up with such an expedited plan and really execute on that plan to meet the needs of customers and serve the state.”
While the need for new baseload generation was clear, the related transmission solution to meeting that need was less so. There were a number of unique challenges in northern Michigan, and ITC and its construction partners looked at a number of technologies and locations.
Placing a large synchronous generator in a remote part of the system lacking sufficient high voltage transmission required engineers to overcome issues with transient stability and thermal overloads. All parties were working quickly to overcome the issues, but until they did, ITC could not begin construction. A problem like this could typically delay a project by months or years, which pressed ITC and Wolverine engineers to solve the issue while maintaining an aggressive timeline and adhering to the requirements of an RTO interconnection process.
The construction delays caused by the reliability issues were not the only challenge. Ordering specialized materials on a faster timeline was also a major endeavor, as crucial parts such as insulators, arrived at the eleventh hour. Ultimately, ingenuity and close collaboration between ITC, Wolverine and construction partners won the day.
There’s an inherent risk in any project that involves transmission upgrades, but both companies’ extensive experiences in grid planning mitigated that risk entirely.
“In Wolverine, we have a partner, customer and collaborator that shared our high standards,” said Jason Sutton, Manager, Capital Projects for ITC. “We have our way of doing things, and this aligns well with Wolverine. Communication between groups was efficient—project managers often remarked that we never had to wait for Wolverine to respond, and vice versa.”
Powering Northern Michigan
Historically, one key electricity infrastructure problem in rural Northern Michigan is that by the time generation is transported there, at least a hundred miles of line have been used. There are two main transmission lines in the area, and when one undertakes maintenance on one line, they are relying solely on the other. In these situations, there are serious consequences for customers—especially to the city-run power systems in the region.
“The location Wolverine selected is perfect for generation in northern Michigan,” said John Andree, Manager of Planning for ITC. “And our partner Wolverine is a serious generator owner that understands the transmission system because we’ve worked with them for years. It was the ideal spot for a good, large utility-scale generator system like this.”
The Wolverine plant and related transmission infrastructure went into service in June 2016, right on time. The plant has since proven vital to the Northern Michigan grid in terms of system reliability and cost efficiency to Wolverine’s members. Today it serves as the largest and most efficient generator in the northern half of Michigan. As the state continues to pursue its energy goals, it will be increasingly important for northern Michigan to have such robust and modern energy infrastructure.
About the author: Jessica Miller is Director, Capital Projects, for ITC Holdings Corp. She is responsible for ITC project management, field supervision, and project controls staff for all ITC business units. Miller has 19 years of utility experience in engineering and leadership in the areas of transmission substation design, transmission line design, operations, project management, field supervisions, and project controls. She joined ITC in 2007. Miller holds a Bachelor of Science in Electrical Engineering from Kettering University, a nationally recognized and ABET-accredited engineering program. She also holds a Master’s in Business Administration from University of Michigan-Flint.