The Connecticut Light and Power Co. has announced that construction of the 45-mile overhead section of the Middletown-Norwalk transmission upgrade is complete. One of the largest electric infrastructure upgrades in the United States, the overall project is 96 percent complete and ahead of schedule.
This final section of the new 345-kV overhead line has been energized and, with the previously energized northern section, is significantly improving the reliability of service along this corridor from Middletown to Milford, Connecticut. This span includes the new Beseck Switching Station in Wallingford and the new East Devon Substation in Milford.
Construction of the Middletown-Norwalk project is currently expected to be completed in the first quarter of 2009. The entire 69-mile, 345-kV transmission line goes through 18 towns and is a joint project with United Illuminating. The project will reduce electric congestion and associated costs for Connecticut customers and add much-needed capacity to the existing southwest Connecticut system.
“The Middletown-Norwalk project has been under development and construction for the past seven years, and, when complete, will benefit all Connecticut electric customers and the reliability of the regional power grid,” said Charles W. Shivery, Northeast Utilities chairman, president and chief executive officer. “As electricity demand continues to grow, a strong, reliable transmission system is critical to meeting our customers’ needs and the region’s economic health.”
Construction on the Middletown-Norwalk project began in the spring of 2006. “We want to thank all of our customers and neighbors as well as state and local officials for their continuing cooperation and patience during the construction of this very important project,” Shivery said. He also noted that the project has an excellent safety record. An estimated 1,000 people have worked more than 2.4 million hours without any major safety incidents.
The project’s 24-mile underground section construction activities should be largely completed later this year. This section is expected to be energized and placed in service in early 2009 after testing is completed. This project used many innovative engineering and construction technologies, including solid-core underground cables that require no oil so they are more environmentally friendly. In addition, much of the project’s overhead portion was constructed using helicopters to string power lines from tower to tower, reducing construction time and lessening environmental impacts on nearby lands.
The Middletown-Norwalk project is one of four major initiatives in southwest Connecticut that will resolve long-standing reliability challenges and will make the regional transmission grid more secure and efficient. The company energized its 21-mile Bethel-Norwalk 345-kV line ahead of schedule and under budget in October 2006. In July 2008, CL&P and the Long Island Power Authority energized 11 miles of undersea 138-kV electric cables between Connecticut and New York, ahead of schedule and on budget. Glenbrook Cables, the remaining southwest Connecticut transmission project between Norwalk and Stamford, is now 95 percent complete and is expected to be in service by the end of 2008, further extending the benefits of the 345-kV bulk power system in Connecticut.