CEP of Kalibr: 3 m
Proof of Kalibr hitting pinpoint targets: it destroyed a single barracks in Lviv which is much smaller than a substation.
The most important substations - transmission substations - aren't located in suburbs. Here's what a transmission substation looks like, note how its in the middle of nowhere. There's not many of these.
There's also only 1 step up substation per power plant. It is located a small distance away from the main power plant. Without it, electricity generated cannot be transmitted. Here's what one looks like, it's the one for Hoover Dam.
Also note it's in the middle of nowhere.
Dude, do you know how many missile fired at the barrack in Lviv : 4
And yes, it is smaller than a single substation, so you would expect more missile is needed to completely destroy the target that is bigger than that Barrack. Now you are talking about 1 barrack, but how many substation is in Lviv? Care to venture a guess?
3 Meters CEP does not mean you can hit anything within that 3 meters, 3 meters CEP means you have a theoretically 3 meters error of probability, CEP means half of the missile would land within 3 meters of each other, and the other half outside, because of the arc and tangent, the further away the target it, it multiple the error distant. It's like a tank gun, if a target is 500 meters away, and my CEP is 1 meters, let's say the shot felt 10 meters behind. If that target is 1500 meters away, and if my CEP is 1 meter, then the distant I missed is not 10 meters but 30 meters. And in this case, for a Kalibr missile, it will not be 30 meters, but 90 meters. That is why one of those missile ended up 5 miles away as reported to the barrack attack
And finally, sure, some substation is standalone in the country side, but if you are talking about inside a big city like Kyiv or Lviv, it would not be most of the case, in side a city center, you would expect to have majority of those substation that are going to be in the local area.
Let's say even if you can target all the substation within a certain area and disable the power grid, the amount of resource you are going to spend on is going to be huge, and for what? To stop electricity supplying in one city? You may as well use your missile or bomb on other target that would make a difference.
That's why nobody in any military will attack power grid infrastructure to interrupt power supply, for a few hours yes, say if you want a few hours of darkness to take the town, but not as a continue arrangement. We don't do it in the State even we have better Air Force and better missile. I mean, sure, you can go waste 300-400 missile on 50 or so substation that wouldn't change anything in the battlefield.
You either bomb their power plant, which is the most efficient way to do, or you don't do it at all and move on.