[Merrill]

The standard approach, as was used in Iraq, is to dispense foil streamers or other conductive chaff over the substations. The US used airplanes, but these days drones could do the job. Or you could use a drone to tow a copper wire across one of the high-voltage distribution power lines. If done on enough lines at the same time the sudden decrease in load may cause the generators to overspeed.

[Merrill]

The Weapon that Disabled Iraq’s Power Grid

https://cyberarms.wordpress.com/2010/04/28/the-weapon-that-d...