Abstract
Minerals Management Service (MMS) and Cape Wind Associates LLC (CWA) have requested an analysis of the probability that an oil spill might occur at the Cape Wind Energy Project in Nantucket Sound, Massachusetts. This analysis has been prepared as part of an Environmental Impact Study (EIS) of the Cape Wind Energy Project.
The worst-case discharge would be an instantaneous and simultaneous release of 40,000 gallons of electric insulating oil1,2 and 2,000 gallons of diesel and other oils from the ESP and up to 200 gallons of turbine and other lubricating oils from the gearboxes of each of the 130 wind turbine generators (WTG) for a total release of 68,000 gallons of oil in the entire complex – an extremely unlikely scenario. Such a worst-case discharge event would only occur if something damaged the ESP and all 130 of the WTGs to the extent that the entire contents of all four electrical transformer insulating oil tanks, as well as the oil in each of the WTGs, would be released almost instantaneously. There is the possibility of spillage of some lesser portion of the oil from one or more components of the Cape Wind complex. Additional potential sources of oil spillage for the Cape Wind Energy Project would include the 500 maintenance vessel trips that would occur annually3, as well as vessels that transit the area and may impact one of the structures. Unlike many other electricity-transmitting cables, there is no oil in the cables that connect the turbines and ESP, and ESP and the land-based facility. There is no chance of a spill from these cables.