January 2012 Capital Investment - National Grid

Exhibit ___ (EIOP-19)Page 129 of 684Area SummaryThe drivers behind the transmission capacity related projects in the Syracuse OswegoCortland (SOC) study area are:• Area load has, over time, reached levels that result in potential post-contingencyoverloading of one of the Clay 345-115kV autotransformers, as well as three 115kVcircuits in the Syracuse area.• Fault current levels have been identified in excess of the interrupting capability ofbreakers at six different substations in the area.•Key sub-transmission and distribution drivers include the following:• Load growth in the Syracuse University and the North Syracuse areas are majordrivers of distribution capacity work.• The condition of the Ash St. substation is an asset condition driver.Area DescriptionThe SOC study area includes the 345kV and 115kV transmission facilities in the CentralRegion and all of the 115kV and above transmission facilities around the Oswego Complexarea, including the 345kV Scriba and Volney stations.The SOC area is bordered by Elbridge substation in the West, Cortland substation in theSouth, Oneida substation in the East, and Clay substation in the North. The majorsubstations in the area includeThis areaalso includes some of the assets stretching between Mortimer and Elbridge.Within the SOC study area, there are eight distribution study areas: Cazenovia, Cortland,East Syracuse, Manilus-Fayetteville, North Syracuse, Syracuse, Volney and West Syracuse.The Cazenovia study area serves approximately 6,500 customers. The study area is a veryrural region, with the Village of Cazenovia and the Cazenovia Industrial Park being the onlylarge loads. The distribution system consists of one 34.5-13.2kV, and four 34.5-4.8kVsubstations. The only physical constraint is Cazenovia Lake and the residential load whichis spread around the Cazenovia Lake.The Cortland study area serves approximately 32,800 customers. The study area is definedby the region that includes the City of Cortland and the surrounding towns and villages. It islocated in central New York between Syracuse and Binghamton. The primary distributionsystem voltages in Cortland are 13.2kV and 4.8kV. Most of the area is fed from a 34.5kVsub-transmission system supplied out of the Cortland and Labrador substations.The East Syracuse study area serves approximately 16,000 customers. The study area isan industrial suburb of the City of Syracuse. The distribution system consists of one 115-34.5kV, three 115-13.2kV and three 34.5-4.8kV substations. The transmission supply isadequate and the only physical barriers are Interstate 690 and Interstate 481 going throughV - 15130