January 2012 Capital Investment - National Grid

Exhibit ___ (EIOP-19)Page 48 of 684bushing potential devices which have been another source of failure. Ongoingmaintenance of the breakers is addressing the oil leaks.Given the number of transmission lines at the Lockport Station and the deterioratedconditions of the structures and controls that support them, a station rebuild is proposedto prevent future outages caused by equipment failures.Further work at the Lockport Station has been deferred in order to manage and reducecapital investment. However, delaying the rebuild maintains current risks associatedwith the asset condition issues noted above.Huntley (C11496) $0National Grid has started the process to investigate Huntley substation asset conditionneeds. Among the needs are: permanent capacitor banks at the Huntley 115 kV bus toreplace the mobile banks currently there; improved grounding in the switchyard; removalof all National Grid controls, batteries and communications equipment from inside theHuntley Generating Station to a control house in the yard (both 115kV & 230kV); addinga second station service supply; refurbishing the existing oil circuit breakers; replacingthe potential transformers; installing new CCVTs for 115 kV and 230 kV relaying; andrefurbishing the 230 kV cable pumping plant.While conceptual engineering was completed in 2011, no further work is planned atHuntley in the Plan period in order to reduce and manage short-term capital investment.However, delaying rebuild of the Huntley station maintains the current risks associatedwith having National Grid assets located in separately owned control rooms, such asmisoperation, inconsistent maintenance and uncontrolled conditions and access.Lighthouse Hill (C31662) $1.5mThis facility is a significant switching station with two 115kV buses and seventransmission lines connecting to the station, allowing power to flow from the Oswegogenerating complex to the Watertown area in the north and Clay Station in Syracuse.Seven OCBs are located 200 feet from the Salmon River located about 70 feet belowthe yard elevation. The station is located a mile up-stream of the New York StateWildlife Fish Hatchery. Although the risk is low, any significant oil spill in the stationwould have a detrimental environmental impact. Even at 70 feet above the river levelthere is also the risk of a flooding event at the station given its proximity to the river. Inaddition, the disconnect switches are in a very poor condition.Another significant issue at Lighthouse Hill is that the land is owned by Brookfield Powerand operated as a shared facility under a contractual agreement. The lack of directaccess to Brookfield’s control room at Lighthouse Hill is not ideal as it limits theCompany’s control over the housing conditions for the battery and relay systems. TheCompany has controls on the first floor of the control house which is immediatelyadjacent and downstream of Brookfield’s hydroelectric dam. An uncontrolled releasefrom the dam could flood the control room area. Flooding in the area occurred asrecently as October 1, 2010 due to a rain event.II-3149