Yeah, the EMP thing caused me to do a little web research myself. I'm still suspicious about how big a trouble and how bad it really would be. I'm also not sure anyone really knows for sure, and if they do, I'm sure the air force has their reports classified. The results from the starfish test (last space-burst over the pacific) pegged their instrumentation, blew out a couple of strings of series connected street lights in Hawaii, and shut down HF radio for a while.
One guess (from
http://blackmagic.com/ses/bruceg/EMC/EMP-Light.html) has the initial field strength at about 3kV/m (spread across the entire RF spectrum), or about twice as much bang as a typical nearby lightning strike.
That being said, most if not all of our electronics these days are pretty solidly shielded to keep their own internally generated RF noise inside the box (FCC part 15 compliance among others). The auto manufacturer's factory standards for emissions make part 15 look wimpy, especially around the broadcast and CB bands. That shielding works both ways.
The line conducted stuff coming in through the wires is where it gets vulnerable. I’m talking about a power surge that will last several seconds, and be monumental. If we are lucky, every surge protector in the house will kick in and conduct enough of it to trip the main breaker before everything plugged in (and turned on) dies. In other words, your cell phone itself just might survive, while the rest of the network goes down.
Does anyone know if a direct lightning strike will fry a car's electronic systems? (either turned on or off) I'm betting that 10,000 amps flowing over the surface of the car body would make a decent simulated EMP source. They may not be the same thing, but I don't think they're
that different.
The power distribution grid is vulnerable. It goes down on its own when everyone turns on their AC at the same time. That colossal power surge the EMP will generate will damage it and initially cause widespread blackouts. I don't think it will get totally screwed however. It isn't going to blow up every substation and pole pig in the network. Lightning ACTUALLY HITS power lines every now and then and the gear designed to die first and “take one for the team” does so, saving everything else. (I.e. high voltage fuses) If an EMP does manage to fry everything else, our lives will probably end in that same white flash. I expect that the network will go down, and every last lineman on the payroll will be doing overtime checking/replacing every last fuse in the network. The big question is will they get to our streets before they run out of replacements.
The power plants will be pretty resilient. I once scored a hardhat tour of the Sesquehanna power storage facility in upstate NY and got an up close look at their generators and systems. The primary controllers on top of the turbines, regulating the speed (keeping it in phase with the grid)
were 100% mechanical. You can't make it more EMP proof than that. They also run emergency drills where their operators go down into the bowels of the plant and drive the systems directly off the big control cabinets. (no computers, just big switches, meters, etc.) Remember, the owners will also count of hundreds if not thousands of dollars of lost revenue for each
second of downtime. No plant manager in their right mind is going to let some cheap little circuit get in the way of their operation. They will have at least one or two spares at all times on site along with those backup protocols and emergency drills. Coal plants also keep a month or two of fuel onsite in case of supply disruptions like railroad strikes, etc.