January 2012 Capital Investment - National Grid

Exhibit ___ (EIOP-19)Page 104 of 684Indoor SubstationsThe purpose of this strategy is to replace, retrofit, or retire the twenty-four remainingindoor distribution substations. The indoor substations were built in the 1920s throughthe 1940s. These substations have inherent safety risks due to design and equipmentcondition. Sixteen of these indoor substations remain to be rebuilt in the City of Buffaloand five are in Niagara Falls. The remaining three substations are located in Syracuse,Gloversville and Troy. In addition to future work, the Plan includes three indoorsubstations under construction (Buffalo Stations #29, #43, and #52). Details of the assetcondition issues and key drivers are outlined in the asset condition report. 8Drivers:These indoor substations are obsolete. Their outmoded design does not meet currentlyaccepted safety practices, equipment and protection schemes are becoming unreliablein their function of interrupting faults, and in general the condition of equipment showssigns of deterioration.Customer Benefits:Under normal conditions, failure of obsolete indoor substation equipment could result insustained customer interruptions until some type of replacement is installed. Equipmentoutages can result in increased operation and loading on parallel equipment. Indoorsubstations typically supply urban environments, including critical loads such as police,fire and hospitals. This program mitigates the risk for a long-term, sustained, customerinterruptions occurring in these urban areas.2011 to 2012 Variance:The projected program investment is shown in the table below. The spending has beenmodified based on lessons learned regarding scheduling, the availability of resourcesand further development of the plan for each substation.Table IV-21Indoor SubstationsProgram Variance ($millions)CIP FY12 FY13 FY14 FY15 FY16 FY17 Total2011 7.2 15.5 16.1 15.8 19.3 - 73.82012 - 9.3 5.1 8.0 3.6 5.8 31.8Three on-going indoor substation projects are expected to exceed $1 million in any fiscalyear: Buffalo Stations #29, #43 and #52. Four, proposed indoor substation projects areexpected to exceed $1 million in any fiscal year: Buffalo Stations #27, #37 and #59, andBrighton substation. Other substations will be initiated during the plan. Buffalosubstation work is retrofit. Brighton substation is expected to be retired after the load isconverted and transferred onto the Rock Cut #286 substation, which will be expandedwith a second transformer and metal-clad switchgear.Sub-transmission system line work related to this strategy is included in Chapter 3.8 Report on the Condition of Physical Elements of Transmission and Distribution Systems, Case06-M-0878, October 1, 2011, pg. II-109.IV-28 28105