The current transmission system serving southwest Connecticut remains the only part of the state not currently served by a 345-kV transmission system, nor does it meet national electric reliability standards. But, Connecticut Light & Power (CL&P; Hartford, Connecticut, U.S.) and United Illuminating Co. (UI; New Haven, Connecticut) plan to change that with their proposed 345-kV line between the Middletown and Norwalk substations in Virginia’s densely populated Fairfield County.

However, the upgrade has met stiff opposition and debate regarding public safety issues and the environmental impact of the line. In December 2004, after months of hearings and town meetings, the state’s Reliability & Operability Committee (ROC) recommended underground placement of the 38.6-km (24-mile) section of the proposed 111-km (69-mile) line to the Connecticut Siting Council (CSC). This is expected to clear up most of the environmental and public safety concerns raised thus far by municipalities and residences along the proposed route.

Several consulting and engineer firms, including KEMA Consulting (Burlington, Massachusetts, U.S.), EnerNex Corp. (Knoxville, Tennessee, U.S.), and POWER Engineers Inc. (Hailey, Idaho, U.S.), have conducted studies of route selection, variant load scenarios and system configuration. The design now calls for reinforcement of existing 345-kV lines between Haddam and Middletown and replacement of above-ground 115-kV lines with new 345-kV overhead lines beginning at Middletown.

The route will run along the existing right of way to a proposed new substation in Milford. New structures for the overhead portion will either be monopoles or H-frames, depending on the width of the right of way. The underground sections begin at the proposed Milford Substation and travel predominantly under the Boston Post Road into Norwalk using cross-linked polyethylene insulated cable (XLPE).

Facts and Figures

The cost of the project (which is being split 20% UI and 80% CP&L) has risen an estimated 80% since the original proposal two years ago. Initial estimates were around US$600 million, but the general rise in costs for steel, labor and other equipment, coupled with higher-than-expected costs for the underground section, are expected to boost the final price tag. In addition, there may also be additional expenses associated with reducing exposure to magnetic fields. New cost projections indicate the project may top $1 billion. Nevertheless, citizens and regulators agree the line is a necessity.

Moving Ahead

The ROC, which was formed in June 2004 to address questions and concerns primarily about the proposed underground portion of the Middletown/Norwalk Project, will continue to hold regular meetings as needed with a final ruling expected by April 7. The CSC, which makes the final determination, is expected to follow the ROC’s recommendation.

The two utilities also are planning to invest in upgrading substations and additional off-ramps along the route at Milford, Bridgeport and New Haven. Existing and planned generation facilities will also be connected to the new line. The new line also will give utilities the ability to sell electricity to neighboring New York City and Westchester County. l