A man-made EMP poses a greater threat. If one goes off in your neighborhood, there's a significant risk that the concentrated pulse will induce extra voltage in the circuit-board components, frying them for good. The best bet for protecting your electronics is to store them in a Faraday cage: a cube of interweaving metals, preferably copper and quarter-inch-thick steel, which together can act as an electromagnetic shield. Like in a lightning rod, the copper attracts electricity while the steel absorbs magnetic pulses. A cage big enough to hold all your favorite gadgets—your cellphone, TV, computer, and so on—runs in the neighborhood of $15,000. An EMP could also crash the power grid, so you might want to spring for an extra cage to protect your generator too.