January 2012 Capital Investment - National Grid

Exhibit ___ (EIOP-19)Page 32 of 684• Installing a 27 MVAR capacitor bank at Batavia to boost area voltage (C31478) -$3.6m.Drivers:Studies of the 115kV and 230kV transmission systems were conducted for the Frontier,Southwest and Genesee regions of western New York, to determine compliance withapplicable reliability standards. Studies which were initially performed in 2007 and thenreconfirmed in 2008 and 2010 evaluated the system for existing load levels up to a 15year forecasted load level. Included within each of these evaluations was testing of bothN-1 and N-1-1 design criteria, ensuring compliance with NERC TPL Standards, NPCCDirectory #1, NYSRC Reliability Rules and the Company’s Transmission Planning Guide(TGP 28). These standards require the entire transmission system to meet N-0 and N-1voltage, thermal and stability criteria as well as the bulk power system and long leadtime items to meet the same criteria for N-1-1 conditions. Several reliability criteriaissues for the area were discovered under various study conditions. Issues includedvoltage problems around Homer Hill and Dunkirk (N-0, N-1, N-1-1), and voltageproblems around Batavia, Brockport and Golah (N-1).In the Southwest Region, multiple reinforcement projects are required to correct all N-1conditions. In addition to the problems in the Homer Hill area, bus faults at Dunkirk willcreate low voltage problems on the circuits between Dunkirk and Falconer. For theGenesee Region, several voltage related problems were found in the Batavia and Golahareas. For bus faults at Lockport, voltage problems develop in the Batavia area.Thermal concerns were also present on one of the circuits between Lockport andBatavia. At Golah, an outage of the circuit between Mortimer and Golah (N-1) wouldresult in Golah being fed radially from Batavia. This in turn would cause low voltagelevels at Golah (below 80 percent). This contingency can also be caused by bus faults atMortimer and Golah.Timing of the work planned for this area, and the remainder of the service area, can beaffected by closure of generation supply due to environmental or other regulatory issues.Customer Benefits:Customers will benefit from this program in several ways, including:• Exposure to service interruptions, including load shedding, in the event thatcertain key contingencies which may occur would be reduced significantly.Generation that currently must be run at times to ensure voltage support andstability will no longer be required for these purposes, avoiding future costs ofdispatching the generation out of NYISO merit order.• Circuits that are normally open, which provide a backup source to loads in theHomer Hill area will be operated normally closed, reducing the frequency andlength of outages for certain contingencies.• Some capability to accommodate new or expanding load will be added to thesystem.II-1533