January 2012 Capital Investment - National Grid

Exhibit ___ (EIOP-19)Page 140 of 684Area SummaryThe principal drivers for transmission projects in this area, from a capacity and assetcondition perspective, are:• Low post-contingency voltages at Huntley and Gardenville.• .• High post-contingency autotransformer loadings on the 230-115kV banks atGardenville.• High post-contingency 115kV line loadings on lines extending south and east fromNiagara, Packard, and Gardenville.• The proposed rebuild of Old Gardenville Station to address station configurationissues as well as asset condition issues and the replacement of obsolete relays. Theproject is currently in preliminary engineering with major construction anticipated tocommence in FY14.Key sub-transmission and distribution drivers include the following:• Reliability issues and load growth in the Amherst area. There is approximately10MVA of new load identified in the area. The new Frankhauser Substation willalleviate these issues.• Load growth of 5 - 10MW associated with the new Buffalo Niagara Medical Campuswill be served by Elm Street substation.• Area loading requiring the upgrade of multiple Buffalo area substations, includingBuffalo Station 56 and Buffalo Station 214.• Indoor substations are an asset condition issue and there are several replacementprojects in progress.Area DescriptionThe Frontier transmission study area includes assets within NYISO Zone A. The areaincludes assets as far east as Lockport, the Niagara and Buffalo areas and the systemstretching south to Gardenville.Within the Frontier study area there are ten distribution study areas: Amherst, Cheektowaga,Elm, Grand Island, Kensington, Niagara, Niagara Falls, Sawyer, Seneca and Tonawanda.V - 26141