"Even during civil wars, militias will spare the other side's power because they want to use it when they conquer the other side's territory."

Yes & no -- the US military has used graphite bombs[0] to disrupt power systems, however in a relatively non-destructive manner.

[0] http://www.globalsecurity.org/military/systems/munitions/blu...

The US military also has floating nuclear power plants capable of powering entire cities in an emergency. They used one in Banda Aceh after the tsunami. Other combatants prefer not to mess with the lights.

From the 8 year old knowledge I was told by someone in said industry that worked on government nuclear projects..

These mobile nuclear power plants are transportable via classic steel rail way. The reactor is about the size of a normal train car. (Although I'd guess there are many accompanying components too.) The fuel is typically enriched nuclear matter in ceramic like pellets.

A single car of unspent fuel can power NY City for a month.

Big populations impacted that depend on electricity for food, water, and waste will receive these before rural populations.

I'd be interested in the restrictions to the public in such circumstances. Rationed EV charging, no home A/C usage, community cooking centers.

The US is a bad example in this case because it hasn't really fought wars with equal powers except for total war during WWI/II. Even the Civil War was largely an asymmetric conflict. General Sherman could destroy rail and other industrial infrastructure because the Union had industrialized so much that they could restore anything they needed relatively quickly with parts and equipment brought in from the North. During the World Wars, retreating German troops would often go scorched earth on their own infrastructure to prevent the advance of the Allies as a last ditch attempt to slow their losses and come to a more favorable conclusion that total defeat.

In the case of wars in the last 30 years, the US military has operated on a shock and awe strategy followed by nation building. The former encouraged destroying (or crippling) power generation to cause chaos and the latter is very lucrative to American companies that come in to build the power generation afterwards. Since the US military has absurd resources, bringing in portable generators by the thousands (along with the fuel) is also easier than having to deal with existing infrastructure that was already decaying and incapable of properly supporting their logistics. During the wars in Iraq and Afghanistan, many of the power stations rebuilt by the US were never used, even for the military, and sit idle to this day.

To be fair, we didn't have an electricity grid when we had our civil war. ;-)

"Getting bits diddled remotely by bad actors is not something they've had to think about as long."

They should never have to worry about this.

Power plant equipment, etc., should not have networking capability. Not just no Internet, but no networking.

You might be surprised to learn that all power plants have some sort of primitive "networking" capability, albeit something that looks more like a direct point-to-point phone line between plants and the grid operator (see DNP3.) As you can imagine these are relatively expensive to install, but part of the bring-up of a new power plant.

All of these plants also have some sort of SCADA system internally and turbine fields need the same (the turbines need to be connected to each other, and the operator needs to be able to control the turbines in some way: e.g. turning them off when there is an excess of power, reading power output, faults, etc.) So one way or another, communication needs to occur whether it's over an IP network or a dedicated PTP line.

If someone gets physical access it's mostly game-over unless you've got builtin hardware-level encryption between all of the internal components of the facility. If there wasn't an ethernet port in the server cabinet the hacker could just connect an RS-485 line and start sending MODBUS commands or whatever protocol the SCADA system is using.

But the article does a good job pointing out that the assumption that "the facility/network is secure" does not hold as well in distributed generation as it did for traditional power generation.

Edit: see also https://en.wikipedia.org/wiki/DNP3

This is how it was done in the old days. Companies want to cut costs (employ less Substation Technicians), so they upgraded their equipment and systems to allow for remote operation. You used to have to call a SubTech locally at each substation if you wanted breakers, disconnects, or switches operated. Now, system operators will be able to do most of that remotely and only have to call a SubTech during emergencies when manual operation is required. Without networking you also have a lot less RELIABILITY (something grid operators and the DOE care greatly about). You can't have protective tripping and relaying without networking and comms, especially on the transmission lines that connect major metro areas that are hundreds of miles away from each other.

TLDR: Its a business decision.

When a major storm hits, and linemen swarm a region, the lack of remote-control and monitoring on distribution substations and unmanned windfarms makes things much worse.

And storms hit far more often.

Wind farms can cover hundreds of square miles. I don't think that's a reasonable limit to set.