Central Maine Power has submitted to the Maine Public Utilities Commission plans for a $1.4 billion expansion of its power transmission system that involves upgrading 485 miles of transmission lines and substations from Orrington, Maine, to Newington, N.H. The new line will pass through already existing power line corridors in 80 communities, including Eliot and South Berwick.
CMP and Maine Public Service Co., which services northern Maine, have also announced a separate, joint project to connect a proposed 1,000-megawatt wind generation project in northern Maine to the CMP power grid and other parts of the New England grid to the south.
The plan for the new power lines grew out of study undertaken by CMP, which looked at overall reliability of the electric power transmission system. It found that without significant changes in demand patterns, transmission capacity or new supply, serious problems would emerge as early as 2012.
This project should not be confused with CMP’s separate application to rebuild a 9.4-mile section of 115-kilovolt line that runs from the Quaker Hill substation in North Berwick through South Berwick and ends at the Three Rivers substation in Eliot. This project has been subject to a formal compliant to the Maine Public Utilities Commission by local residents.
CMP prepared the major expansion project in conjunction with neighboring utilities in Maine and New Hampshire with oversight by ISO New England, the organization responsible for managing electricity supply and transmission for the New England states, according to CMP President Sara Burns.
“That is a major upgrade to our existing power system,” said CMP spokesman John Carroll. “The 345-kilovolt is the bulk power system …; that is the I-95 or the I-295 in our power system. It moves power in and out of Maine from generation plants long distances away.”
The existing systems “were all built in the late ’60s in response to the ‘blackout’ of ’66 so it’s been operating since ’71 without any significant changes or enhancements. Our system is old but obviously very functional, but it’s become obsolete,” he said.
CMP also sees the new line creating economic opportunities and jobs.
“On its own, the construction will create nearly 6,000 new jobs in Maine, and having a strong, reliable grid will mean brighter prospects for existing business and emerging renewable energy industries,” Burns said.
Natural Resources Council of Maine staff member Dylan Voorhees said he has mixed reaction to the proposed system.
“This is an enormously complicated and expensive project,” he said. “We want to see the minimum transmission lines possible needed to meet our energy demand.”
He said the council is also concerned that transmission lines be placed in appropriate sites, which is less of a concern in this project since it uses existing right-of-ways.
“We also have a strong interest in facilitating the development and utilization of a very significant renewable resource in Northern Maine that is a thousand or more megawatts of wind power,” he said, referring to the wind farm proposal. “We’re just beginning to assess how well the partners are doing in balancing all these considerations.”
Carroll said the PUC has six months to render a decision on the CMP application.
“Realistically, we hope we’re through this in a year. In a parallel process we’ll be meeting with 80 communities through which the lines run beginning in the fall or early winter,” he said.
Carroll said the new 345-kilovolt lines will go down the same corridor as the existing 115-kilovolt line CMP plans on rebuilding. A corridor is a cleared swath of land that is maintained for high voltage power lines.
Building the new 345-kilovolt line will not make the 115-kilovolt line unnecessary or redundant, he said.
“It’s important to recognize they are completely separate systems,” Carroll said. “If the 345-kilovolt line is the I-95, then the 115-kilovolt line is the local Route 201. Both are needed. The 115 that we’re rebuilding is part of a grid, a second tier that we have throughout the state. None of the need changes at all for that as we build the 345.”
The rebuilt 115-kilovolt line is being moved closer to the edge of the existing corridor, which CMP maintains will reduce the amount of down time for the power line during the rebuilding process rather than simply rebuilding it in its current location.
In addition, moving the rebuilt line clears a path in the center of the corridor for the new 345-kilovolt line, Carroll said.
The Eliot Board of Selectmen and the South Berwick Town Council voted on July 10 and July 14 respectively to become interveners in the application to the PUC regarding the 115-kilivolt line. Becoming an intervener gives the towns standing to participate more fully in the PUC review process, including the authority to make comments on the application said town officials.
By David Ramsay
23 July 2008