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.
Attacks on centralized hydro and coal power plants are effective, but expensive since requiring several large ballistic rockets with 300-500 kg high explosive payloads.
In contrast to that you can take out a large PV module field for about 30 k$ with a mass produced item like a Geran-2 with a cluster munitions payload. This can’t be cost-effectively protected against, so rebuilding the plant doesn’t help. Attacks taking out vulnerable centralized parts like speciality high voltage transformers which are difficult to source are synergistic, since causing grid partitioning events and potential cascading failures due to overload.