A few months ago, I stumbled upon one of the most extraordinary articles I've ever read. In testimony before a congressional committee, it was stated that a prolonged collapse of this country's power grid due to hunger, disease, and social collapse could result in the death of up to 90% of the American population. According to the document, the network could be destroyed by solar storms or electromagnetic pulse (EMP) attacks. Serious storms, such as the Carrington event of 1859, are expected to occur approximately once every 150 years.
High-voltage transformers are the weak link in the system, and the Federal Energy Regulatory Commission (FERC) has identified 30 of them as critical. The simultaneous loss of just 9, in various combinations, could paralyze the network and cause a cascading failure, leading to a “coast to coast blackout”. If HV transformers are irreparably damaged, they may not be replaced for 1 to 2 years from now, which would be devastating. The vast majority of these units are custom made. To answer these questions, I did some research.
I read congressional testimonies, technical reports from expert groups, a book, academic articles, insurance company evaluations, several industry technical reports, and several reports in the specialized media. What I found was sometimes contradictory. Somewhat worryingly, both sides of the issue accused each other of bias due to financial incentives. Overall, my view is that, while some of the risk of EMP and solar storms is overrated, it is still a serious problem and one of the main secondary risks for which we should prepare. I summarize my conclusions in the form of a dialogue.
Overall, the combination of human intervention and automatic network self-protection makes me feel that long-term catastrophic collapse caused by a solar storm is unlikely but possible. We must take the preparation very seriously. Should we move to EMP attacks? However, in their voltage injection tests, they discovered that with sufficient tension, the inputs of the DPRs could be permanently damaged. Some devices required voltages of up to 80 kV to be damaged. Others required voltages as low as 5 kV. But what's even more interesting is that the induced voltage also depends on the polarization of the field, the angle of incidence (psi), and the azimuthal angle (phi).
Depending on where the input power line is located and how it is oriented, the actual induced voltage can be much lower than what you would expect under peak conditions. Based on the known locations of the substations in the U. S., and assuming random orientations, the authors were able to estimate the distribution of voltages induced in these substations assuming a very strong nuclear attack. In most cases, the induced voltages would be lower than 10 kV but some would be even higher. A malfunction of relays during an EMP attack would likely result in failure of other power grid systems leading to large-scale cascading blackouts and widespread equipment damage.
In particular, E1 effects on protection relays are likely to interrupt substation's self-protection processes necessary to interrupt flow of current E3 through transformers. EMPs are by no means one of main national security challenges nor most pressing concern for security of our electrical grid. A careful and reasoned plan presented like one we saw last week at White House makes sense. Other people especially those who have worked on EMP Commission are much more concerned about these risks. They point out that hundreds of network components have not been thoroughly tested and that problems in one part of network can cascade to other parts in unpredictable ways. Sometimes media have portrayed these people in negative light. In an article that seemed irresponsible to me Slate described EMP's concern as “a right-wing concern and conservative fixation” while Wired says that EMPs field is full of “exaggerations” and “alarmism”.Scott Aaronson senior director of national security policy at Edison Electrical Institute says that an EMP attack will most likely occur on local scale which means that grid is likely to work well overall.
They concluded that while an EMP attack could cause some damage to some states there was no risk of prolonged collapse throughout country. According to reasonably careful report from EPRI general view is that impact of even major EMP attack will likely be short-term and regional rather than long-term and domestic. And if country were planning to use large nuclear weapon it would make more sense according to morbid logic of war to launch it conventionally on city than launch an EMP attack that at best would cause brief power outages in some states. The report concluded that one year after large-scale EMP or CME nine out ten Americans would die from various causes derived from attack. EMPs are associated with intentional attacks that use high-altitude nuclear detonations specialized conventional munitions or directed non-nuclear energy devices. Several government agencies were concerned that attack was general rehearsal for larger-scale attack.