Maine Power Reliability Project

The Maine Power Reliability Program (www.mainepower.com) includes a proposal to build a new, 345-kilovolt (kV) transmission line from Orrington, Maine (15 miles south of Bangor), to Newington, New Hampshire. The line will follow existing transmission corridors through nearly 80 Maine towns, including Detroit, Benton, Windsor, Lewiston, Yarmouth, Gorham, and Eliot. The program includes investments in new substations, upgrades to existing substations, and improvements to the 115-kilovolt (kV) electric system in central Maine.

The Maine Power Reliability Program began in January of 2007 with a study to project the region's future needs for electricity service. The first phase of the study, which was completed last summer, found that serious problems would emerge as early as 2012 without significant changes in demand patterns, transmission capacity, or new supply. The proposal includes transmission investments and recommendations to encourage alternatives to transmission, such as new generation, or programs to manage the growth in peak electricity demand.

CMP prepared its plan in conjunction with neighboring utilities in Maine and New Hampshire with oversight by ISO New England (www.iso-ne.com), the organization responsible for managing electricity supply and transmission for the New England states.

The preferred route calls for the construction of an additional 345kV transmission line following existing transmission corridors from Orrington to the Maine-New Hampshire interconnect in Eliot (Orrington-Detroit-Benton-Windsor-Lewiston-Gorham-Eliot-Newington, NH). CMP is also planning to build several new 115kV lines and upgrade others on existing corridors.

This project is using the Program Management approach. Central Maine Power (http://www.cmpco.com/) has very limited staff and has selected Burns & McDonnell as the successful Program Manager.

I. Progress Energy Florida’s Baseload Project

Progress Energy Florida (www.progress-energy.com) is considering adding about 200 miles of transmission lines across nine counties to maintain reliability and to move energy efficiently to customers throughout the region and state. The lines would be 230 and 500 kilovolts (kV).

Transmission lines are planned in three main segments: from Levy County south to Hernando County, from Pinellas County east to Kathleen in Polk County, and from Levy County east to the Wildwood/Leesburg area. These proposed transmission lines could affect the counties of Citrus, Hernando, Hillsborough, Lake, Levy, Marion, Pinellas, Polk, and Sumter.

The transmission lines are expected to be built on two types of structures. Typically, the single steel poles are between 90 and 165 feet tall; the H-frame (two-pole)

structures about 120 feet tall. The structures would be spaced 700 to 1,300 feet apart, depending on the structure and terrain.

This project is using the EPC and Program Management approach. Progress has hired Patrick Engineering as an Owner’s Engineer to prepare 500-kV standards and EPC bid packages. In addition, Progress plans to hire a Program Manager to handle construction management, inspection, budgeting, scheduling, public relations and more. The current plan is to allow the future Program Manager the opportunity to bid on the EPC work.

345 kV High Ampacity OH/UG Project

1Dana R. Crissey

1Oncor Electric Delivery, LLC, Transmission Line Engineering Department, P.O.

Box 970, Ft. Worth, TX 76101-0970; (817) 215-6266; [email protected] ABSTRACT

When TXU Electric Delivery (now known as Oncor Electric Delivery) filed a CCN application with the Public Utility Commission of Texas (PUCT) in 2006 it planned to construct a new 345 kV line approximately 6.5 miles long on single pole structures. During the PUCT’s review of the application the City of Dallas intervened in the process and requested that a portion of the line be constructed using UG technology.

The new line was necessary to provide additional capacity and reliability to the Dallas Central Business District. The circuit needed to be rated at 3400 Amperes.

After much deliberation, the PUCT ruled that Oncor should construct a 0.7 mile segment of the line underground.

Thus began the first 345 kV underground project on the Oncor system. There are a number of 345 kV underground projects in service throughout the United States but none with a dynamic rating capability near the 3400 Ampere range required for this project. Selecting the correct technology and materials and developing a design to properly implement them has presented engineering (and political) challenges that Oncor will not soon forget.

The line is currently under design and will be constructed Spring through Fall of 2009.

Background

In March, 2006 Oncor Electric Delivery filed an application for a Certificate of Convenience and Necessity (CCN) with the Public Utility Commission of Texas (PUCT) to construct the W. Levee-Norwood 345 kV line. The line would consist of two 345 kV circuits, with one circuit installed initially and the second as system needs dictated. The line would connect two existing major switching stations and was necessary to provide additional capacity and reliability to the area near downtown Dallas. As required in the filing Oncor had selected preferred and 10 alternate routes between the two existing stations.

During the PUCT review of Oncor’s application a number of parties exercised their right to intervene and become a part of the regulatory process, including the City of Dallas. The City desired to modify the route of the line and also requested the PUCT to direct Oncor to construct a portion of the line using underground technology instead of overhead. The City contended that an underground line in the area near downtown would be more aesthetically pleasing and that a portion of the route was

subject to near term development plans due to the City’s proposed Trinity River Project which had been approved by voters in a May 1998 bond election. The City of Dallas also offered to reimburse Oncor for 25% of the difference between cost of the installed underground line and what the overhead alternative would have cost.

The PUCT agreed with the City’s proposal and directed Oncor by a 2-1 vote to construct a 0.7 mile section of the line underground. The remainder of the line would be constructed utilizing over methods but a large portion of the line would be built within the median of Irving Blvd., a major arterial street.

Thus began a process that is currently entering the construction phase and is scheduled to be complete by December 2009.

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West Levee Norwood Transmission Line –