Now that’s interesting information.
I may have understated the problem.
From p.49 of the
Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack (2008):
“Recovery from transmission system damage and power plant damage will be impeded primarily by the manufacture and delivery of long lead-time components. Delivery time for a single, large transformer today is typically one to two years and some very large special transformers, critical to the system, are even longer. There are roughly 2,000 transformers in use in the transmission system today at 345 kV and above with many more at lesser voltages that are only slightly less critical. No transformers above 100 kV are produced in the United States any longer. The current U.S. replacement rate for the 345 kV and higher voltage units is 10 per year; worldwide production capacity of these units is less than 100 per year. Spare transformers are available in some areas and systems, but because of the unique requirements of each transformer, there are no standard spares. The spares also are owned by individual utilities and not generally available to others due to the risk over the long lead time if they are being used. Transformers that will cover several options are very expensive and are both large and hard to move. NERC keeps a record of all spare transformers.”
http://www.empcommission.org/docs/A2473-EMP_Commission-7MB.pdf