As much as I hate to admit it, the article is basically correct. The part about the .22 rifle may be stretching it somewhat although the bushings on the transformers may be vulnerable to damage from a .22 at close range. The real danger is from .50 BMG AP rounds. 50 cal rifles are readily available to the public and 50 BMG rounds can be had for $3.50 each. A .50 BMG will puncture the casing on a station transformer from a fair distance. And as the article mentions, high capacity substation transformers are custome made to order and have very long lead times.
My guess is that most electrical service to California could be interrupted by taking out 5 or 6 key high voltage substation transformers.
I wouldn’t think it would require a .50. All you need to do is punch a hole in it so the oil starts leaking out and wait for it to overheat.
There are lots of rifles that can do it at calibers much more common than .50 BMG.
There are many ways it can be done with homemade items.
Rifles are not the problem. There is a study that was done under President Bush (W) that said we needed ways to replace these custom built transformers quickly. It is about a two year wait to have one built now, and they are built overseas.
A design was developed for a three part modular transformer that could replace 95% of the large custom jobs. Each module could be transported in a standard container by semi-truck and train.
I do not know if they ever built a prototype.
If we were wasting money on the stimulus, some of it should have gone for 20 of these systems. They would likely cost less than 20 million, total, but I guess Solyndra was considered far more important than insuring that we could get the power grid up quickly after a massive solar flare, EMP attack, or physical attack such as the one described.