If you want to lose sleep, check out the work of the Secure the Grid Coalition. Scary stuff!, Here are just a few quotes from its website.
The grid can be seriously disrupted for prolonged periods by a number of man-caused events, like physical assaults, power surges, cyber warfare against the grid, or high-altitude electromagnetic pulse (EMP) caused by the detonation of a nuclear weapon outside the atmosphere above the United States.Such events could disable or destroy outright key parts of the power grid, prompting the cascading collapse of every one of the other critical infrastructures that assure the availability of water, food, medicine, finance, transportation, telecommunications, etc., possibly for years.
America’s electric grid, data centers, telecommunications networks, and other critical infrastructure can be damaged or destroyed in several different ways: a nuclear weapon that generates an EMP (Electro-Magnetic Pulse) effect; a geo-magnetic storm from the sun that also can generate an EMP effect; a smaller, localized EMP that can be created with everyday equipment from Radio Shack; cyber warfare; and direct physical attacks.
A nuclear EMP is a very real threat, given what we know about the Iranian and North Korean nuclear weapons and ballistic missile programs. Both countries have demonstrated advanced capabilities to create a functioning nuclear warhead as well as to build and test the ballistic missiles that might be used as delivery vehicles for such weapons.
Devices capable of subjecting transformers and other critical infrastructure to localized, but destructive, levels of EMP can be built from readily available equipment. While the damage would not be anywhere near as devastating or widespread as a nuclear EMP device might cause, the ease of acquiring and assembling parts obtainable from a local electronics shop means that terrorists have a relatively easy way to cause significant damage to local communities.
The Secure the Grid Coalition is an ad hoc group of policy, energy, and national security experts, legislators, and industry insiders who are dedicated to strengthening America’s electrical grid. The Coalition aims to raise awareness to the national and international threat of EMP as well as pass legislation to strengthen the grid.