This is indeed most concerning, a SINGLE attack such as the one reported is unlikely to have severe consequences, but a concerted attack at a number of sites over a large geograpahical area could result in severe disruption.

Substations are inherently vulnerable, they are large, in the open air, and no matter how secure fencing is made, still vulnerable to rifle fire from a considerable distance.

Large transformers are normally equiped with safety devices that monitor the oil level and take the transformer off line if the oil is lost. This would still interupt supply in the case of a large scale attack, but should save the transformer. It can be restored to use after mending the hole and re filling with oil.

It is my view that the government should subsidise the manufacture of perhaps a few dozen spare very large transformers, these are readily available in modest numbers from several suppliers. A sudden need for say 50 under emergency conditions would be problematic, but ordering perhaps 10 a year whilst times are normal and keeping these at strageic locations could help a lot. Spare transformers could be hidden or well gaurded, perhaps on military bases that are already secure.

For the individual, this should be another reason for preps in general, off grid electricity, food, fuel, water etc, as widely disscussed on these forums.

For essiential industries and services, this should be another reason to keep standby generating plant in good order, and to keep plenty of fuel.