WHITEFIELD — As aging fossil fuel and nuclear power plants are phased out in New England, the region is turning to clean energy sources. But Coos County’s ability to host additional clean or renewable energy facilities is blocked by the limitations of the so-called Coos Loop transmission line.
In a recent briefing to the Coos County delegation, Bill Quinlan, president of Eversource New Hampshire Operations, said the industry is undergoing transformational change. He said traditional power plants that have been the backbone of New England’s power grid are closing, and individual states are moving the region toward sources of clean energy.
Ten years ago, Quinlan said there were nine nuclear plants in New England. There are now two — Seabrook in New Hampshire and Millstone in Connecticut. The coal-fired Merrimack station in Bow produces a fraction of the power it did because it cannot compete with power generated by natural gas or renewable sources.
Quinlan said while the North Country has always had an interest in being part of the solution, upgrading its aging infrastructure is critical to moving power.
Specifically the 73-mile 115kV transmission line that runs between Groveton, Whitefield and Berlin has significant thermal, voltage and stability limitations and is considered at capacity. There are times when North Country generators are forced to shut down to avoid overloading sections of the loop.
Quinlan explained that the Coos Loop was designed during the 1950s and '60s to move power generated by plants on the loop to the paper mills that existed then. The power generated in Coos County, mostly from hydroelectric facilities, was consumed locally.
“Today that picture has changed,” Quinlan said.
All but one of the mills has closed, and he said there has not been new demand for that power on the loop. Instead the power generated in Coos has to be moved to other regions where there is a need for it. The problem, Quinlan said, is the Coos Loop was not designed to move the power to other regions.
At the same time, he said clean energy developers have added new renewable generation with the 65-megawatt Burgess BioPower plant and the 99-megawatt Granite Reliable Power wind farm.
Part of the Northern Pass project would have upgraded the Coos Loop. At the time, Northern Pass said it would increase the size of the conductor cable on the western and northern section of the loop.
Eversource regularly inspects its electric infrastructure across the state and Quinlan said much of the infrastructure in Coos County is in need of critical work. The old wooden infrastructure does not meet today’s standards and is being replaced with steel. He suggested taking a systemic approach to looking at issues with the infrastructure and loop.
Quinlan said he did not have an estimate for what it would cost to upgrade the Coos Loop but said the work proposed as part of Northern Pass was in the $50 million to $70 million range. A 2011 legislative committee that was charged with studying the issue recommended building a new line that could handle an additional 400 megawatts of capacity at a cost of $150 million.
The question has always been how to pay for the upgrade. Traditionally it has been up to the power producer to cover the cost of upgrading the system. Local officials have argued the cost is more than a generator could afford.
Quinlan said the question is whether regulators would allow the cost of upgrading the loop to be shared by all of Eversource’s 3 million customers on the argument that the power will largely benefit customers south of Coos County.