Letter Re: Question on generators and EMP

HJL,

We have been considering having a whole house generator installed at our house, since we occasionally lose power in our neighborhood for days at a time. Additionally, the threat of an EMP pulse damaging the grid and our being without power for a lengthy period of time is an even greater concern.

My question is: is a whole house natural gas powered generator, like a Generac 22kv unit (along with the associated auto switching panel), susceptible to EMP? If so, what would be the best way to protect it? When I ask the electrical contractors bidding on the job, they just look at me like I’m from another planet!

Further, how vulnerable is the country’s natural gas supply? The generator will do no good if the gas is out. Thanks for any guidance you can provide. Bill in PA

HJL Responds: Anything attached to the power grid will be highly susceptible in the event of an EMP event, whether it is nuclear or solar in scope. The electrical charge builds up on long stretches of wire, which act like an antenna, and the power grid represents the majority of above-ground conductive wires. While the grid is fairly well protected against slower events, like lightning, the sheer size of a large solar event or the high speed of a nuclear event would easily bypass or overwhelm most of the protective structures. The wires themselves may or may not be affected, but it is difficult to protect sensitive electronics attached to the power grid from the resulting energy spikes. If your system is isolated from the grid system, wired properly, and well grounded, it should be able to survive such an event. However, if the system is attached through an auto-transfer type switch, your vulnerability increases. The only sure protection is isolation and a decent Faraday cage, connecting the system and powering it up only after the danger has passed.

If you are depending on a natural gas distribution, you are at the mercy of the supply chain. If any part of the chain breaks down, you have no fuel until the chain is reconstructed or an alternative found. For immediate use, an LP generator is probably the best bet, but you have to store the LP in sufficient quantity yourself. Lacking that ability, living in a gas-producing area is the next best bet. JWR’s books profile several situations that would work well.