Attacks on two DTEK solar farms last spring is a good example. They destroyed many solar panels and some of the transformers, which step up voltage for long distances or step it down for use in homes. Replacing the transformers and swapping out destroyed panels allowed the farms, which generate 400 megawatts, to be back up in seven days.

Timchenko said an attack on a thermal generating station, which experienced a similar amount of damage, took three to four months to rebuild.